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Publisher: John Wiley and Sons   (Total: 1589 journals)

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Showing 1 - 200 of 1589 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 65, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 47, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 52, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 164, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 6, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 4)
Addiction     Hybrid Journal   (Followers: 35, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 14, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 27, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 267, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 10)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 148, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 92, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 34, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 16, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 4, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 6, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 37, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 278, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 17, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 138, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 9, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 18)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 219)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 222, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 7, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 47, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 1, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 8, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 13)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 25, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 89, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 49, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 70, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 207, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 49, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 36, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 27, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 15, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 3, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 5)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 246, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 52, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 320, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1, SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 8, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 4, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 4, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 6, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 47, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 7, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 5, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 14, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 18, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 408, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 5, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 72, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 21, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 36, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 11, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 4, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 41, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 37, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 44, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 141, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 6, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 243, SJR: 2.083, h-index: 125)

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Journal Cover Advanced Science
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  This is an Open Access Journal Open Access journal
   ISSN (Online) 2198-3844
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Recent Progress on MOF-Derived Heteroatom-Doped Carbon-Based
           Electrocatalysts for Oxygen Reduction Reaction

    • Authors: Qian Ren; Hui Wang, Xue-Feng Lu, Ye-Xiang Tong, Gao-Ren Li
      Abstract: The oxygen reduction reaction (ORR) is the core reaction of numerous sustainable energy-conversion technologies such as fuel cells and metal–air batteries. It is crucial to develop a cost-effective, highly active, and durable electrocatalysts for ORR to overcome the sluggish kinetics of four electrons pathway. In recent years, the carbon-based electrocatalysts derived from metal–organic frameworks (MOFs) have attracted tremendous attention and have been shown to exhibit superior catalytic activity and excellent intrinsic properties such as large surface area, large pore volume, uniform pore distribution, and tunable chemical structure. Here in this review, the development of MOF-derived heteroatom-doped carbon-based electrocatalysts, including non-metal (such as N, S, B, and P) and metal (such as Fe and Co) doped carbon materials, is summarized. It furthermore, it is demonstrated that the enhancement of ORR performance is associated with favorably well-designed porous structure, large surface area, and high-tensity active sites. Finally, the future perspectives of carbon-based electrocatalysts for ORR are provided with an emphasis on the development of a clear mechanism of MOF-derived non-metal-doped electrocatalysts and certain metal-doped electrocatalysts.Molecular organic framework-derived heteroatom-doped carbon-based electrocatalysts, including nonmetal (such as N, S, B, and P) and metal (such as Fe and Co) doped carbon materials, have attracted tremendous attention and some of them exhibit superior electrocatalytic performance for oxygen reduction reaction. Significant progress has been achieved and more innovations for carbon-based electrocatalysts will be realized in the future.
      PubDate: 2017-12-05T06:06:55.78564-05:0
      DOI: 10.1002/advs.201700515
       
  • Increasing Photovoltaic Performance of an Organic Cationic Chromophore by
           Anion Exchange

    • Authors: Donatas Gesevičius; Antonia Neels, Sandra Jenatsch, Erwin Hack, Lucas Viani, Stavros Athanasopoulos, Frank Nüesch, Jakob Heier
      Abstract: A symmetrical cyanine dye chromophore is modified with different counteranions to study the effect on crystal packing, polarizability, thermal stability, optical properties, light absorbing layer morphology, and organic photovoltaic (OPV) device parameters. Four sulfonate-based anions and the bulky bistriflylimide anion are introduced to the 2-[5-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3-pentadien-1-yl]-1,3,3-trimethyl-3H-indolium chromophore using an Amberlyst A26 (OH− form) anion exchanger. Anionic charge distribution clearly correlates with device performance, whereby an average efficiency of 2% was reached in a standard bilayer organic solar. Evidence is given that the negative charge of the anion distributed over a large number of atoms is significantly more important than the size of the organic moieties of the sulfonate charge carrying group. This provides a clear strategy for future design of more efficient cyanine dyes for OPV applications.A facile route for introducing various organic sulfonates and the bistriflylimide to a cationic cyanine chromophore using an Amberlyst A26 (OH− form) anion exchanger is demonstrated. The impact of these anions on crystal packing, thin-film morphology, optical properties, and organic photovoltaic device performance is investigated. It can be concluded that the negative charge distribution of the anion is a critical factor in cyanine salt design.
      PubDate: 2017-12-05T06:05:48.110685-05:
      DOI: 10.1002/advs.201700496
       
  • Radiation-Sensitive Dendrimer-Based Drug Delivery System

    • Authors: Szu-Yuan Wu; Hsiao-Ying Chou, Chiou-Hwa Yuh, Shewaye Lakew Mekuria, Yu-Chih Kao, Hsieh-Chih Tsai
      Abstract: Combination of chemotherapy and radiotherapy is used to enhance local drug delivery while reducing off-target tissue effects. Anticancer drug doxorubicin (DOX) is loaded into l-cysteine modified G4.5 dendrimer (GC/DOX) and released at different pH values in the presence and absence of γ-radiation. Presence of γ-radiation significantly improves DOX release from the GC/DOX under acidic pH conditions, suggesting that GC dendrimer is a radiation-sensitive drug delivery system. GC/DOX is further evaluated by determining cytotoxicity in uterine cervical carcinoma HeLa cells. GC/DOX shows high affinity for cancer cells and effective drug release following an external stimulus (radiation exposure), whereas an in vivo zebrafish study confirms that l-cysteine acts as a radiosensitizer. GC/DOX treatment combined with radiotherapy synergistically and successfully inhibits cancer cell growth.Radiation sensitive dendrimeric nanoparticles are constructed from carboxyl-terminate polyamidoamine dendrimers generation 4.5 conjugated with cysteine (GC). Doxorubicin (DOX)-loaded GC nanoparticle can be taken up by HeLa cells and drug can be released from GC nanoparticles in the presence of radiation and an acidic environment. The DOX-loaded GC nanoparticles exhibit promising radiation therapeutic results in a zebrafish cancer model.
      PubDate: 2017-12-05T06:02:05.351332-05:
      DOI: 10.1002/advs.201700339
       
  • Asymmetric Hybrid Polymer–Lipid Giant Vesicles as Cell Membrane
           Mimics

    • Authors: Ariane Peyret; Emmanuel Ibarboure, Jean-François Le Meins, Sebastien Lecommandoux
      Abstract: Lipid membrane asymmetry plays an important role in cell function and activity, being for instance a relevant signal of its integrity. The development of artificial asymmetric membranes thus represents a key challenge. In this context, an emulsion-centrifugation method is developed to prepare giant vesicles with an asymmetric membrane composed of an inner monolayer of poly(butadiene)-b-poly(ethylene oxide) (PBut-b-PEO) and outer monolayer of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The formation of a complete membrane asymmetry is demonstrated and its stability with time is followed by measuring lipid transverse diffusion. From fluorescence spectroscopy measurements, the lipid half-life is estimated to be 7.5 h. Using fluorescence recovery after photobleaching technique, the diffusion coefficient of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (DOPE-rhod, inserted into the POPC leaflet) is determined to be about D = 1.8 ± 0.50 μm2 s−1 at 25 °C and D = 2.3 ± 0.7 μm2 s−1 at 37 °C, between the characteristic values of pure POPC and pure polymer giant vesicles and in good agreement with the diffusion of lipids in a variety of biological membranes. These results demonstrate the ability to prepare a cell-like model system that displays an asymmetric membrane with transverse and translational diffusion properties similar to that of biological cells.Cell-sized biomimetic vesicles with an asymmetric lipid/polymer membrane are generated from an emulsion/centrifugation method. Lipid transverse and lateral diffusion kinetics as studied via fluorescence quenching assays and confocal microscopy reveals consistent similarity to cells.
      PubDate: 2017-12-05T06:01:12.53418-05:0
      DOI: 10.1002/advs.201700453
       
  • In Vivo Photoacoustic Imaging of Brain Injury and Rehabilitation by
           High-Efficient Near-Infrared Dye Labeled Mesenchymal Stem Cells with
           Enhanced Brain Barrier Permeability

    • Authors: Weitao Li; Ronghe Chen, Jing Lv, Hongke Wang, Yu Liu, Ya Peng, Zhiyu Qian, Guo Fu, Liming Nie
      Abstract: Stem cell migration and interaction with pathology are critical to understand the complexity and status of disease recovery progress. However, the dynamic visualization still remains a great challenge due to imaging technical limitation, cell labeling difficulty, or blood–brain barrier (BBB). Herein, fast photoacoustic tomography (PAT) with optical molecular probes is applied to noninvasively monitor traumatic brain injury (TBI) and its rehabilitation. The vascular distribution and TBI hemorrhage are clearly imaged, longitudinally monitored, and quantified. Bone mesenchymal stem cells (BMSCs) labeled with modified Prussian blue particles (PBPs), excellent near-infrared dyes and photoacoustic contrasts, are intravenously injected to the mice for improved observation and efficient therapy. BMSCs are demonstrated to be capable of overcoming BBB with enhanced delivery of PBPs to the brain parenchyma. Notably, the versatile BMSCs are observed by PAT to home to the damage region and repair the ruptured vasculature. Moreover, the wound treated by BMSCs exhibits much faster recovery speed than that without treatment. These findings can potentially provide a new noninvasive and high-resolution approach to image TBI, monitor recovery process, and especially trace BMSCs. This study will stimulate extensive researches on brain diseases and provide promising strategies of dye labeled BMSCs in regenerative medicine.Photoacoustic tomography (PAT) with optical molecular probes is applied to noninvasively monitor on-the-spot traumatic brain injury (TBI) and its recovery process with bone mesenchymal stem cell (BMSC) therapy. TBI hemorrhage is clearly imaged and BMSCs labeled with modified Prussian blue particles are successfully visualized in vivo by PAT. Significantly, stem cell therapy contributes to the rehabilitation of brain injury.
      PubDate: 2017-12-05T00:06:53.522866-05:
      DOI: 10.1002/advs.201700277
       
  • Graphene-Based MicroRNA Transfection Blocks Preosteoclast Fusion to
           Increase Bone Formation and Vascularization

    • Authors: Ce Dou; Ning Ding, Fei Luo, Tianyong Hou, Zhen Cao, Yun Bai, Chuan Liu, Jianzhong Xu, Shiwu Dong
      Abstract: The objective of this study is to design a graphene-based miRNA transfection drug delivery system for antiresorptive therapy. An efficient nonviral gene delivery system is developed using polyethylenimine (PEI) functionalized graphene oxide (GO) complex loaded with miR-7b overexpression plasmid. GO-PEI complex exhibits excellent transfection efficiency within the acceptable range of cytotoxicity. The overexpression of miR-7b after GO-PEI-miR-7b transfection significantly abrogates osteoclast (OC) fusion and bone resorption activity by hampering the expression of an essential fusogenic molecule dendritic cell-specific transmembrane protein. However, osteoclastogenesis occurs without cell–cell fusion and preosteoclast (POC) is preserved. Through preservation of POC, GO-PEI-miR-7b transfection promotes mesenchymal stem cell osteogenesis and endothelial progenitor cells angiogenesis in the coculture system. Platelet-derived growth factor-BB secreted by POC is increased by GO-PEI-miR-7b both in vitro and in vivo. In treating osteoporotic ovariectomized mice, GO-PEI-miR-7b significantly enhances bone mineral density, bone volume as well as bone vascularization through increasing CD31hiEmcnhi cell number. This study provides a cell–cell fusion targeted miRNA transfection drug delivery strategy in treating bone disorders with excessive osteoclastic bone resorption.A graphene based miRNA transfection system is developed using graphene oxide (GO)-PEI loaded with miR-7b plasmid. GO-PEI-miR-7b efficiently delivers miR-7b plasmid into bone marrow macrophages and reduces the expression of target protein dendritic cell-specific transmembrane protein (DC-STAMP) thus blocking cell-cell fusion to preserve pre-osteoclasts for better osteogenesis and angiogenesis.
      PubDate: 2017-12-04T09:26:25.358086-05:
      DOI: 10.1002/advs.201700578
       
  • Dopant-Free and Carrier-Selective Heterocontacts for Silicon Solar Cells:
           Recent Advances and Perspectives

    • Authors: Pingqi Gao; Zhenhai Yang, Jian He, Jing Yu, Peipei Liu, Juye Zhu, Ziyi Ge, Jichun Ye
      Abstract: By combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c-Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p+- and n+-HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier-selective contacts (CSCs) can be formed directly with c-Si substrates, and thereafter form IBC cells, via a dopant-free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant-free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant-free hole-selective CSCs, i.e., poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole-selective materials modification, interfacial passivation, contact resistivity, light-trapping structure and device architecture design, etc. By analyzing the structure–property relationships of hole-selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high-performance SCs have been highlighted.Carrier-selective dopant-free contacts with Si are of great interest to both fundamental researchers and the photovoltaic industry due to the extreme simplifications in device structure and manufacturing procedure. Here, recent advances and open challenges in two typical hole-selective designs of organic poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and transition metal oxides are reported, examining the topic from both the materials and device engineering.
      PubDate: 2017-12-04T02:17:39.819918-05:
      DOI: 10.1002/advs.201700547
       
  • Magnetic Sponge with Neutral–Ionic Phase Transitions

    • Authors: Wataru Kosaka; Yusuke Takahashi, Masaki Nishio, Keisuke Narushima, Hiroki Fukunaga, Hitoshi Miyasaka
      Abstract: Phase transitions caused by the charge instability between the neutral and ionic phases of compounds, i.e., N–I phase transitions, provide avenues for switching the intrinsic properties of compounds related to electron/spin correlation and dipole generation as well as charge distribution. However, it is extremely difficult to control the transition temperature (Tc) for the N–I phase transition, and only chemical modification based on the original material have been investigated. Here, a design overview of the tuning of N–I phase transition by interstitial guest molecules is presented. This study reports a new chain coordination-polymer [Ru2(3,4-Cl2PhCO2)4TCNQ(EtO)2]∙DCE (1-DCE; 3,4-Cl2PhCO2− = 3,4-dichlorobenzoate; TCNQ(EtO)2 2,5-diethoxy-7,7,8,8-tetracyanoquinodimethane; and DCE = 1,2-dichloroethane) that exhibits a one-step N–I transition at 230 K (= Tc) with the N- and I-states possessing a simple paramagnetic state and a ferrimagnetically correlated state for the high- and low-temperature phases, respectively. The Tc continuously decreases depending on the content of DCE, which eventually disappears with the complete evacuation of DCE, affording solvent-free compound 1 with the N-state in the entire temperature range (this behavior is reversible). This is an example of tuning the in situ Tc for the N–I phase transition via the control of the interstitial guest molecules.A chain coordination polymer, exhibiting a one-step neutral–ionic (N–I) transition is reported. The transition temperature decreases with the gradual evacuation of the crystallization solvent and eventually vanishes. Desolvated compound is neutral in the entire temperature range. The transition behavior is completely recovered by solvent adsorption and therefore the N–I transition synergistically occurs by linking with the degree of solvation.
      PubDate: 2017-12-04T02:11:54.741378-05:
      DOI: 10.1002/advs.201700526
       
  • Nickel Hydr(oxy)oxide Nanoparticles on Metallic MoS2 Nanosheets: A
           Synergistic Electrocatalyst for Hydrogen Evolution Reaction

    • Authors: Xing Zhang; Yongye Liang
      Abstract: Molybdenum disulfide (MoS2)-based materials have been recently identified as promising electrocatalysts for hydrogen evolution reaction (HER). However, little work has been done to improve the catalytic performance of MoS2 toward HER in alkaline electrolytes, which is more suitable for water splitting in large-scale applications. Here, it is reported that the hybridization of 0D nickel hydr(oxy)oxide nanoparticles with 2D metallic MoS2 nanosheets can significantly enhance the HER activities in alkaline and neutral electrolytes. Impressively, the optimized hybrid catalyst can drive a cathodic current density of 10 mA cm−2 at an overpotential of ≈73 mV for HER in 1 m KOH, about 185 mV smaller than the original MoS2. The improved HER activity is attributed to a bifunctional mechanism adopted in these hybrid catalysts, in which nickel hydr(oxy)oxide promotes the water adsorption and dissociation to supply protons for subsequent reactions occurred on MoS2 to generate H2.1T-MoS2 nanosheets hybridized with nickel hydr(oxy)oxide nanoparticles can synergistically facilitate the hydrogen evolution reaction (HER) in alkaline and neutral electrolytes through a bifunctional mechanism. The optimized hybrid catalyst can drive a cathodic current density of 10 mA cm−2 at an overpotential of ≈73 mV for HER in 1 m KOH, about 185 mV smaller than the original MoS2.
      PubDate: 2017-12-04T02:10:43.872772-05:
      DOI: 10.1002/advs.201700644
       
  • Nanogap-Engineerable Electromechanical System for Ultralow Power Memory

    • Authors: Jian Zhang; Ya Deng, Xiao Hu, Jean Pierre Nshimiyimana, Siyu Liu, Xiannian Chi, Pei Wu, Fengliang Dong, Peipei Chen, Weiguo Chu, Haiqing Zhou, Lianfeng Sun
      Abstract: Nanogap engineering of low-dimensional nanomaterials has received considerable interest in a variety of fields, ranging from molecular electronics to memories. Creating nanogaps at a certain position is of vital importance for the repeatable fabrication of the devices. Here, a rational design of nonvolatile memories based on sub-5 nm nanogaped single-walled carbon nanotubes (SWNTs) via the electromechanical motion is reported. The nanogaps are readily realized by electroburning in a partially suspended SWNT device with nanoscale region. The SWNT memory devices are applicable for both metallic and semiconducting SWNTs, resolving the challenge of separation of semiconducting SWNTs from metallic ones. Meanwhile, the memory devices exhibit excellent performance: ultralow writing energy (4.1 × 10−19 J bit−1), ON/OFF ratio of 105, stable switching ON operations, and over 30 h retention time in ambient conditions.A novel design of nonvolatile memory device based on sub-5 nm nanogaped single-walled carbon nanotubes (SWNTs) via the electromechanical motion is demonstrated. The nanogaps are readily realized by electroburning in a partially suspended SWNT device with a nanoscale region. The memory devices have ultralow power consumption and exhibit excellent performance in ambient conditions.
      PubDate: 2017-12-03T00:05:46.804855-05:
      DOI: 10.1002/advs.201700588
       
  • Electrochemically Synthesis of Nickel Cobalt Sulfide for High-Performance
           Flexible Asymmetric Supercapacitors

    • Authors: Chunyan Zhang; Xiaoyi Cai, Yao Qian, Haifeng Jiang, Lijun Zhou, Baosheng Li, Linfei Lai, Zexiang Shen, Wei Huang
      Abstract: A lightweight, flexible, and highly efficient energy management strategy is highly desirable for flexible electronic devices to meet a rapidly growing demand. Herein, Ni–Co–S nanosheet array is successfully deposited on graphene foam (Ni–Co–S/GF) by a one-step electrochemical method. The Ni–Co–S/GF composed of Ni–Co–S nanosheet array which is vertically aligned to GF and provides a large interfacial area for redox reactions with optimum interstitials facilitates the ions diffusion. The Ni–Co–S/GF electrodes have high specific capacitance values of 2918 and 2364 F g−1 at current densities of 1 and 20 A g−1, respectively. Using such hierarchical Ni–Co–S/GF as the cathode, a flexible asymmetric supercapacitor (ASC) is further fabricated with polypyrrple(PPy)/GF as the anode. The flexible asymmetric supercapacitors have maximum operation potential window of 1.65 V, and energy densities of 79.3 and 37.7 Wh kg−1 when the power densities are 825.0 and 16100 W kg−1, respectively. It's worth nothing that the ASC cells have robust flexibility with performance well maintained when the devices were bent to different angles from 180° to 15° at a duration of 5 min. The efficient electrochemical deposition method of Ni–Co–S with a preferred orientation of nanosheet arrays is applicable for the flexible energy storage devices.The Ni–Co–S nanosheet arrays have been successfully deposited on 3D porous graphene by electrochemical method, which presents excellent electrochemical performance. Flexible, robust supercapacitor devices with Ni–Co–S/graphene foam cathode and polypyrrole/graphene foam anode have been demonstrated with their electrochemical performance systematically evaluated.
      PubDate: 2017-12-02T00:06:37.175453-05:
      DOI: 10.1002/advs.201700375
       
  • Tuning Transpiration by Interfacial Solar Absorber-Leaf Engineering

    • Authors: Shendong Zhuang; Lin Zhou, Weichao Xu, Ning Xu, Xiaozhen Hu, Xiuqiang Li, Guangxin Lv, Qinghui Zheng, Shining Zhu, Zhenlin Wang, Jia Zhu
      Abstract: Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber–water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber–leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber-leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle.Tunable transpiration: Inspired by interfacial solar-driven water evaporation, the concept of tunable transpiration based on interfacial solar absorber-leaf engineering is proposed. The plant transpiration efficiency, as well as relative humidity and temperature of the air nearby could be tuned by solar absorption of membranes in direct contact with the leaf surface.
      PubDate: 2017-12-02T00:05:53.824251-05:
      DOI: 10.1002/advs.201700497
       
  • Stimuli-Directed Dynamic Reconfiguration in Self-Organized Helical
           Superstructures Enabled by Chemical Kinetics of Chiral Molecular Motors

    • Authors: Jian Sun; Ruochen Lan, Yanzi Gao, Meng Wang, Wanshu Zhang, Ling Wang, Lanying Zhang, Zhou Yang, Huai Yang
      Abstract: Dynamic controllability of self-organized helical superstructures in spatial dimensions is a key step to promote bottom-up artificial nanoarchitectures and functional devices for diverse applications in a variety of areas. Here, a light-driven chiral overcrowded alkene molecular motor with rod-like substituent is designed and synthesized, and its thermal isomerization reaction exhibits an increasing structural entropy effect on chemical kinetic analysis in anisotropic achiral liquid crystal host than that in isotropic organic liquid. Interestingly, the stimuli-directed angular orientation motion of helical axes in the self-organized helical superstructures doped with the chiral motors enables the dynamic reconfiguration between the planar (thermostationary) and focal conic (photostationary) states. The reversible micromorphology deformation processes are compatible with the free energy fluctuation of self-organized helical superstructures and the chemical kinetics of chiral motors under different conditions. Furthermore, stimuli-directed reversible nonmechanical beam steering is achieved in dynamic hidden periodic photopatterns with reconfigurable attributes prerecorded with a corresponding photomask and photoinduced polymerization.Stimuli-directed dynamic controllability of reconfiguration between planar and focal conic states is demonstrated in self-organized helical superstructures doped with chiral molecular motors. The reversible reconfiguration is compatible with the chemical kinetics of chiral molecular motors under different conditions, thus functioning in the temporal evolution of nonmechanical 1D diffraction prerecorded with photomask and photoinduced polymerization.
      PubDate: 2017-12-01T05:52:20.277711-05:
      DOI: 10.1002/advs.201700613
       
  • Electroplex as a New Concept of Universal Host for Improved Efficiency and
           Lifetime in Red, Yellow, Green, and Blue Phosphorescent Organic
           Light-Emitting Diodes

    • Authors: Wook Song; Jun Yeob Lee, Yong Joo Cho, Hyeonghwa Yu, Hany Aziz, Kang Mun Lee
      Abstract: A new concept of host, electroplex host, is developed for high efficiency and long lifetime phosphorescent organic light-emitting diodes by mixing two host materials generating an electroplex under an electric field. A carbazole-type host and a triazine-type host are selected as the host materials to form the electroplex host. The electroplex host is found to induce light emission through an energy transfer process rather than charge trapping, and universally improves the lifetime of red, yellow, green, and blue phosphorescent organic light-emitting diodes by more than four times. Furthermore, the electroplex host shows much longer lifetime than a common exciplex host. This is the first demonstration of using the electroplex as the host of high efficiency and long lifetime phosphorescent organic light-emitting diodes.A new concept of host, electroplex host, is developed for high efficiency and long lifetime phosphorescent organic light-emitting diodes. The electroplex host is found to induce light emission through an energy transfer process and universally improves the lifetime of red, yellow, green, and blue phosphorescent organic light-emitting diodes by more than four times.
      PubDate: 2017-12-01T05:51:30.948287-05:
      DOI: 10.1002/advs.201700608
       
  • Swimming Back and Forth Using Planar Flagellar Propulsion at Low Reynolds
           Numbers

    • Authors: Islam S. M. Khalil; Ahmet Fatih Tabak, Youssef Hamed, Mohamed E. Mitwally, Mohamed Tawakol, Anke Klingner, Metin Sitti
      Abstract: Peritrichously flagellated Escherichia coli swim back and forth by wrapping their flagella together in a helical bundle. However, other monotrichous bacteria cannot swim back and forth with a single flagellum and planar wave propagation. Quantifying this observation, a magnetically driven soft two-tailed microrobot capable of reversing its swimming direction without making a U-turn trajectory or actively modifying the direction of wave propagation is designed and developed. The microrobot contains magnetic microparticles within the polymer matrix of its head and consists of two collinear, unequal, and opposite ultrathin tails. It is driven and steered using a uniform magnetic field along the direction of motion with a sinusoidally varying orthogonal component. Distinct reversal frequencies that enable selective and independent excitation of the first or the second tail of the microrobot based on their tail length ratio are found. While the first tail provides a propulsive force below one of the reversal frequencies, the second is almost passive, and the net propulsive force achieves flagellated motion along one direction. On the other hand, the second tail achieves flagellated propulsion along the opposite direction above the reversal frequency.Soft two-tailed microrobots are designed, fabricated, and controlled using periodic magnetic fields. The feasibility of swimming back and forth using planar flagellar propulsion without a U-Turn trajectory is demonstrated experimentally. One-tailed microrobots have to undergo U-turn trajectories with relatively large curvature to swim along opposite direction.
      PubDate: 2017-12-01T02:36:24.777954-05:
      DOI: 10.1002/advs.201700461
       
  • Titania-Coated Gold Nano-Bipyramids for Blocking Autophagy Flux and
           Sensitizing Cancer Cells to Proteasome Inhibitor-Induced Death

    • Authors: Hong-Ye Wan; Jian-Li Chen, Xingzhong Zhu, Liang Liu, Jianfang Wang, Xiao-Ming Zhu
      Abstract: Targeting protein degradation is recognized as a valid approach to cancer therapy. The ubiquitin–proteasome system (UPS) and the autophagy–lysosome pathway are two major pathways for intracellular protein degradation. Proteasome inhibitors such as bortezomib are clinically approved for treating malignancies, but to date, they are still unsatisfactory for cancer therapy. This study identifies titania-coated gold nano-bipyramid (NBP/TiO2) nanostructures as an autophagic flux inhibitor, as the smallest NBP/TiO2 nanostructures induce significant autophagosome accumulation in human glioblastoma U-87 MG cells via blocking the autophagosome–lysosome fusion process and inhibiting lysosomal degradation. Further study indicates that NBP/TiO2 nanostructures reduce the intracellular level of mature cathepsin B and directly inhibit the proteolytic activity of cathepsin B, thereby further inhibiting trypsin-like proteolytic activity, which is a potential cotarget for UPS inhibition. NBP/TiO2 nanostructures interact synergistically with bortezomib to suppress the viability of U-87 MG cells, as the combined treatment synergistically induces the intracellular accumulation of ubiquitinated protein and endoplasmic reticulum stress. In addition, photothermal therapy further synergistically reduces the cell viability. In summary, this study suggests that NBP/TiO2 nanostructures function as a promising anticancer agent in combination with proteasome inhibitors.Titania-coated gold nano-bipyramid (NBP/TiO2) nanostructures act as an autophagic flux inhibitor. They block the autophagosome–lysosome fusion process and impair the lysosomal degradation capacity by inhibiting mature cathepsin B. NBP/TiO2 nanostructures synergistically block intracellular protein degradation and enhance the anticancer effect of the proteasome inhibitor bortezomib.
      PubDate: 2017-12-01T02:31:10.871523-05:
      DOI: 10.1002/advs.201700585
       
  • Ultrahigh, Ultrafast, and Self-Powered Visible-Near-Infrared Optical
           Position-Sensitive Detector Based on a CVD-Prepared Vertically Standing
           Few-Layer MoS2/Si Heterojunction

    • Authors: Ridong Cong; Shuang Qiao, Jihong Liu, Jiansong Mi, Wei Yu, Baolai Liang, Guangsheng Fu, Caofeng Pan, Shufang Wang
      Abstract: MoS2, as a typical transition metal dichalcogenide, has attracted great interest because of its distinctive electronic, optical, and catalytic properties. However, its advantages of strong light absorption and fast intralayer mobility cannot be well developed in the usual reported monolayer/few-layer structures, which make the performances of MoS2-based devices undesirable. Here, large-area, high-quality, and vertically oriented few-layer MoS2 (V-MoS2) nanosheets are prepared by chemical vapor deposition and successfully transferred onto an Si substrate to form the V-MoS2/Si heterojunction. Because of the strong light absorption and the fast carrier transport speed of the V-MoS2 nanosheets, as well as the strong built-in electric field at the interface of V-MoS2 and Si, lateral photovoltaic effect (LPE) measurements suggest that the V-MoS2/Si heterojunction is a self-powered, high-performance position sensitive detector (PSD). The PSD demonstrates ultrahigh position sensitivity over a wide spectrum, ranging from 350 to 1100 nm, with position sensitivity up to 401.1 mV mm−1, and shows an ultrafast response speed of 16 ns with excellent stability and reproducibility. Moreover, considering the special carrier transport process in LPE, for the first time, the intralayer and the interlayer transport times in V-MoS2 are obtained experimentally as 5 and 11 ns, respectively.Large-area, high-quality, and vertically oriented few-layer MoS2 (V-MoS2) nanosheets are prepared by chemical vapor deposition and successfully transferred onto an Si substrate to form the V-MoS2/Si heterojunction. Lateral photovoltaic effect and optoelectronic response measurements demonstrate that the V-MoS2/Si heterojunction is an ultrahigh-sensitivity, ultrafast response speed, and self-powered visible-near-infrared position-sensitive detector.
      PubDate: 2017-12-01T02:26:07.631052-05:
      DOI: 10.1002/advs.201700502
       
  • A Pickering Emulsion Route to Swimming Active Janus Colloids

    • Authors: Richard J. Archer; Andrew J. Parnell, Andrew I. Campbell, Jonathan R. Howse, Stephen J. Ebbens
      Abstract: The field of active colloids is attracting significant interest to both enable applications and allow investigations of new collective colloidal phenomena. One convenient active colloidal system that has been much studied is spherical Janus particles, where a hemispherical coating of platinum decomposes hydrogen peroxide to produce rapid motion. However, at present producing these active colloids relies on a physical vapor deposition (PVD) process, which is difficult to scale and requires access to expensive equipment. In this work, it is demonstrated that Pickering emulsion masking combined with solution phase metallization can produce self-motile catalytic Janus particles. Comparison of the motion and catalytic activity with PVD colloids reveals a higher catalytic activity for a given thickness of platinum due to the particulate nature of the deposited coating. This Pickering emulsion based method will assist in producing active colloids for future applications and aid experimental research into a wide range of active colloid phenomena.A Pickering emulsion synthesis of micrometer-scale self-motile catalytic Janus colloids is demonstrated. Compared to current production techniques involving metal evaporation, this new approach provides a low energy, scalable solution based synthesis. This method consequently enhances the viability of deploying motile colloids for real-world applications, as well as facilitating lab-scale investigation of collective active colloids behavior.
      PubDate: 2017-12-01T02:16:27.953845-05:
      DOI: 10.1002/advs.201700528
       
  • Photoinduced Rapid Transformation from Au Nanoagglomerates to
           Drug-Conjugated Au Nanovesicles

    • Authors: Bijay Kumar Poudel; Jong Oh Kim, Jeong Hoon Byeon
      Abstract: Gold (Au) agglomerates (AGs) are reassembled using Triton X-100 (T) and doxorubicin (D) dissolved in ethanol under 185 nm photoirradiation to form TAuD nanovesicles (NVs) under ambient gas flow conditions. The positively charged Au particles are then electrostatically conjugated with the anionic chains of TD components via a flowing drop (FD) reaction. Photoirradiation of the droplets in a tubular reactor continues the photophysicochemical reactions, resulting in the reassembly of Au AGs and TD into TAuD NVs. The fabricated NVs are electrostatically collected onto a polished aluminum rod in a single-pass configuration. The dispersion of NVs is employed for bioassays to confirm uptake by cells and accumulation in tumors. The chemo-photothermal activity is determined both in vitro and in vivo. Different combinations of components are also used to fabricate NVs using the FD reaction, and these NVs are suitable for gene delivery as well. This newly designed gaseous single-pass process results in the reassembly of Au AGs for incorporation with TD without the need of batch wet chemical reactions, modifications, separations, or purifications. Thus, this process offers an efficient platform for preparing biofunctional Au nanostructures that requires neither complex physicochemical steps nor special storage techniques.Ultrafast reassembly of agglomerated gold nanoparticles demonstrates the gas-phase photochemistry between gold and bioactive molecules in a single-pass configuration via a flowing drop reaction under 185 nm irradiation. The materials produced materials are used for chemo-photothermal therapy and gene delivery.
      PubDate: 2017-12-01T02:15:59.0302-05:00
      DOI: 10.1002/advs.201700563
       
  • Self-Assembled Graphene-Based Architectures and Their Applications

    • Authors: Zhongke Yuan; Xiaofen Xiao, Jing Li, Zhe Zhao, Dingshan Yu, Quan Li
      Abstract: Due to unique planar structures and remarkable thermal, electronic, and mechanical properties, chemically modified graphenes (CMGs) such as graphene oxides, reduced graphene oxides, and the related derivatives are recognized as the attractive building blocks for “bottom-up” nanotechnology, while self-assembly of CMGs has emerged as one of the most promising approaches to construct advanced functional materials/systems based on graphene. By virtue of a variety of noncovalent forces like hydrogen bonding, van der Waals interaction, metal-to-ligand bonds, electrostatic attraction, hydrophobic–hydrophilic interactions, and π–π interactions, the CMGs bearing various functional groups are highly desirable for the assemblies with themselves and a variety of organic and/or inorganic species which can yield various hierarchical nanostructures and macroscopic composites endowed with unique structures, properties, and functions for widespread technological applications such as electronics, optoelectronics, electrocatalysis/photocatalysis, environment, and energy storage and conversion. In this review, significant recent advances concerning the self-assembly of CMGs are summarized, and the broad applications of self-assembled graphene-based materials as well as some future opportunities and challenges in this vibrant area are elucidated.Self-assembly of chemically modified graphenes allows the fabrication of a variety of hierarchical architectures and macroscopic composites endowed with unique properties and functions for a wide range of technological applications. State-of-the-art self-assembly strategies, self-assembled graphene-based architectures, and their applications are comprehensively reviewed.
      PubDate: 2017-11-30T00:06:44.682163-05:
      DOI: 10.1002/advs.201700626
       
  • 3D-Bioprinted Osteoblast-Laden Nanocomposite Hydrogel Constructs with
           Induced Microenvironments Promote Cell Viability, Differentiation, and
           Osteogenesis both In Vitro and In Vivo

    • Authors: Xinyun Zhai; Changshun Ruan, Yufei Ma, Delin Cheng, Mingming Wu, Wenguang Liu, Xiaoli Zhao, Haobo Pan, William Weijia Lu
      Abstract: An osteoblast-laden nanocomposite hydrogel construct, based on polyethylene glycol diacrylate (PEGDA)/laponite XLG nanoclay ([Mg5.34Li0.66Si8O20(OH)4]Na0.66, clay)/hyaluronic acid sodium salt (HA) bio-inks, is developed by a two-channel 3D bioprinting method. The novel biodegradable bio-ink A, comprised of a poly(ethylene glycol) (PEG)–clay nanocomposite crosslinked hydrogel, is used to facilitate 3D-bioprinting and enables the efficient delivery of oxygen and nutrients to growing cells. HA with encapsulated primary rat osteoblasts (ROBs) is applied as bio-ink B with a view to improving cell viability, distribution uniformity, and deposition efficiency. The cell-laden PEG–clay constructs not only encapsulated osteoblasts with more than 95% viability in the short term but also exhibited excellent osteogenic ability in the long term, due to the release of bioactive ions (magnesium ions, Mg2+ and silicon ions, Si4+), which induces the suitable microenvironment to promote the differentiation of the loaded exogenous ROBs, both in vitro and in vivo. This 3D-bioprinting method holds much promise for bone tissue regeneration in terms of cell engraftment, survival, and ultimately long-term function.An osteoblast-laden nanocomposite hydrogel construct is developed using a two-channel 3D-bioprinting method for bone regeneration. The cell-laden scaffold reveals high cell viability (>95%) in the short term after 3D-bioprinting and exhibits excellent osteogenic capability both in vitro and in vivo in the long term due to the bioactive ions that are gradually released.
      PubDate: 2017-11-24T09:26:09.501061-05:
      DOI: 10.1002/advs.201700550
       
  • High Thermoelectric Power Factor of High-Mobility 2D Electron Gas

    • Authors: Hiromichi Ohta; Sung Wng Kim, Shota Kaneki, Atsushi Yamamoto, Tamotsu Hashizume
      Abstract: Thermoelectric conversion is an energy harvesting technology that directly converts waste heat from various sources into electricity by the Seebeck effect of thermoelectric materials with a large thermopower (S), high electrical conductivity (σ), and low thermal conductivity (κ). State-of-the-art nanostructuring techniques that significantly reduce κ have realized high-performance thermoelectric materials with a figure of merit (ZT = S2∙σ∙T∙κ−1) between 1.5 and 2. Although the power factor (PF = S2∙σ) must also be enhanced to further improve ZT, the maximum PF remains near 1.5–4 mW m−1 K−2 due to the well-known trade-off relationship between S and σ. At a maximized PF, σ is much lower than the ideal value since impurity doping suppresses the carrier mobility. A metal-oxide-semiconductor high electron mobility transistor (MOS-HEMT) structure on an AlGaN/GaN heterostructure is prepared. Applying a gate electric field to the MOS-HEMT simultaneously modulates S and σ of the high-mobility electron gas from −490 µV K−1 and ≈10−1 S cm−1 to −90 µV K−1 and ≈104 S cm−1, while maintaining a high carrier mobility (≈1500 cm2 V−1 s−1). The maximized PF of the high-mobility electron gas is ≈9 mW m−1 K−2, which is a two- to sixfold increase compared to state-of-the-art practical thermoelectric materials.High-mobility 2D electron gas induced at an AlGaN/GaN heterointerface exhibits a high thermoelectric power factor of ≈9 mW m−1 K−2 at room temperature, which is an order magnitude greater than that of doped GaN bulk and a factor of 2–6 compared to those of state-of-the-art practical thermoelectric materials (1.5–4 mW m−1 K−2).
      PubDate: 2017-11-24T05:23:05.183095-05:
      DOI: 10.1002/advs.201700696
       
  • Carbon Nanodots: Dual-Color-Emitting Carbon Nanodots for Multicolor
           Bioimaging and Optogenetic Control of Ion Channels (Adv. Sci. 11/2017)

    • Authors: Hyemin Kim; Yoonsang Park, Songeun Beack, Seulgi Han, Dooyup Jung, Hyung Joon Cha, Woosung Kwon, Sei Kwang Hahn
      Abstract: Carbon nanodots (CNDs) have been widely investigated for theranostic applications including fluorescence imaging, photoacoustic imaging, photothermal therapy, and photodynamic therapy. In article number 1700325, Sei Kwang Hahn, Woosung Kwon, and co-workers develop dual-color-emitting CNDs uniquely designed by the electronic structure engineering for both futuristic multi-color bioimaging and optogenetic control of ion channels.
      PubDate: 2017-11-23T06:57:57.882509-05:
      DOI: 10.1002/advs.201770054
       
  • Biosensing: Enhanced Charge Collection in MOF-525–PEDOT Nanotube
           Composites Enable Highly Sensitive Biosensing (Adv. Sci. 11/2017)

    • Authors: Tzu-Yen Huang; Chung-Wei Kung, Yu-Te Liao, Sheng-Yuan Kao, Mingshan Cheng, Ting-Hsiang Chang, Joel Henzie, Hatem R. Alamri, Zeid A. Alothman, Yusuke Yamauchi, Kuo-Chuan Ho, Kevin C.-W. Wu
      Abstract: In article number 1700261, the Wu group presents poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) conformally coated with porphyrin-based metal–organic framework nanocrystals (MOF-525), where MOF-525 serve as an electrocatalytic surface and PEDOT NTs act as a charge collector to rapidly transport the electron from MOF nanocrystals. The innovative composites establish a new generation of porous electrodes for highly efficient electrochemical biosensing.
      PubDate: 2017-11-23T06:57:57.512437-05:
      DOI: 10.1002/advs.201770053
       
  • Contents: (Adv. Sci. 11/2017)

    • PubDate: 2017-11-23T06:57:56.371868-05:
      DOI: 10.1002/advs.201770055
       
  • Masthead: (Adv. Sci. 11/2017)

    • PubDate: 2017-11-23T06:57:52.71437-05:0
      DOI: 10.1002/advs.201770056
       
  • Cell Imaging: In Situ Ligation of High- and Low-Affinity Ligands to Cell
           Surface Receptors Enables Highly Selective Recognition (Adv. Sci. 11/2017)
           

    • Authors: Misako Taichi; Shogo Nomura, Ikuhiko Nakase, Rie Imamaki, Yasuhiko Kizuka, Fumi Ota, Naoshi Dohmae, Shinobu Kitazume, Naoyuki Taniguchi, Katsunori Tanaka
      Abstract: An entirely unexplored concept of simultaneously recognizing two receptors using high- and low-affinity ligands is developed in article number 1700147 by Katsunori Tanaka and co-workers. Ligating them in situ on the target cell surface offers a new paradigm for visualizing target cells with a high imaging contrast.
      PubDate: 2017-11-23T06:57:52.659011-05:
      DOI: 10.1002/advs.201770057
       
  • Lead-Free Hybrid Perovskite Absorbers for Viable Application: Can We Eat
           the Cake and Have It too'

    • Authors: Lusheng Liang; Peng Gao
      Abstract: Many years since the booming of research on perovskite solar cells (PSCs), the hybrid perovskite materials developed for photovoltaic application form three main categories since 2009: (i) high-performance unstable lead-containing perovskites, (ii) low-performance lead-free perovskites, and (iii) moderate performance and stable lead-containing perovskites. The search for alternative materials to replace lead leads to the second group of perovskite materials. To date, a number of these compounds have been synthesized and applied in photovoltaic devices. Here, lead-free hybrid light absorbers used in PV devices are focused and their recent developments in related solar cell applications are reviewed comprehensively. In the first part, group 14 metals (Sn and Ge)-based perovskites are introduced with more emphasis on the optimization of Sn-based PSCs. Then concerns on halide hybrids of group 15 metals (Bi and Sb) are raised, which are mainly perovskite derivatives. At the same time, transition metal Cu-based perovskites are also referred. In the end, an outlook is given on the design strategy of lead-free halide hybrid absorbers for photovoltaic applications. It is believed that this timely review can represent our unique view of the field and shed some light on the direction of development of such promising materials.Real clean energy means the whole process of its generation has low environmental and health impact. Recent progress of five types of hybrid halide absorbers against the thorny problem of lead toxicity is introduced based on the state-of-the-art perovskite solar cells (PSCs). Can we make high-efficiency PSCs without being poisoned'
      PubDate: 2017-11-20T05:58:22.744229-05:
      DOI: 10.1002/advs.201700331
       
  • Modified Back Contact Interface of CZTSe Thin Film Solar Cells:
           Elimination of Double Layer Distribution in Absorber Layer

    • Authors: Zhaojing Zhang; Liyong Yao, Yi Zhang, Jianping Ao, Jinlian Bi, Shoushuai Gao, Qing Gao, Ming-Jer Jeng, Guozhong Sun, Zhiqiang Zhou, Qing He, Yun Sun
      Abstract: Double layer distribution exists in Cu2SnZnSe4 (CZTSe) thin films prepared by selenizing the metallic precursors, which will degrade the back contact of Mo substrate to absorber layer and thus suppressing the performance of solar cell. In this work, the double-layer distribution of CZTSe film is eliminated entirely and the formation of MoSe2 interfacial layer is inhibited successfully. CZTSe film is prepared by selenizing the precursor deposited by electrodeposition method under Se and SnSex mixed atmosphere. It is found that the insufficient reaction between ZnSe and Cu-Sn-Se phases in the bottom of the film is the reason why the double layer distribution of CZTSe film is formed. By increasing Sn content in the metallic precursor, thus making up the loss of Sn because of the decomposition of CZTSe and facilitate the diffusion of liquid Cu2Se, the double layer distribution is eliminated entirely. The crystallization of the formed thin film is dense and the grains go through the entire film without voids. And there is no obvious MoSe2 layer formed between CZTSe and Mo. As a consequence, the series resistance of the solar cell reduces significantly to 0.14 Ω cm2 and a CZTSe solar cell with efficiency of 7.2% is fabricated.The double layer distribution in Cu2ZnSnSe4 (CZTSe) solar cells can be eliminated entirely by increasing Sn content of the metallic precursor, and thus modifying the back contact of CZTSe solar cells and thus reducing the series resistance to a low level. The efficiency of CZTSe solar cell is improved from 5.07% with double layer distribution to 7.2% without double layer distribution.
      PubDate: 2017-11-20T05:55:57.609676-05:
      DOI: 10.1002/advs.201700645
       
  • Hydrothermal Cation Exchange Enabled Gradual Evolution of Au@ZnS–AgAuS
           Yolk–Shell Nanocrystals and Their Visible Light Photocatalytic
           Applications

    • Authors: Jingwen Feng; Jia Liu, Xiaoyan Cheng, Jiajia Liu, Meng Xu, Jiatao Zhang
      Abstract: Yolk–shell hybrid nanoparticles with noble metal core and programmed semiconductor shell composition may exhibit synergistic effects and tunable catalytic properties. In this work, the hydrothermal cation exchange synthesis of Au@ZnS–AgAuS yolk–shell nanocrystals (Y–S NCs) with well-fabricated void size, grain-boundary-architectured ZnS–AgAuS shell and in situ generated Au cocatalyst are demonstrated. Starting from the novel cavity-free Au@AgAuS core-shell NCs, via aqueous cation exchange reaction with Zn2+, the gradual evolution with produced Au@ZnS–AgAuS Y–S NCs can be achieved successfully. This unprecedented evolution can be reasonably explained by cation exchange initialized chemical etching of Au core, followed by the diffusion through the shell to be AgAuS and then ZnS. By hydrothermal treatment provided optimal redox environment, Au ions in shell were partially reduced to be Au NCs on the surface. The UV–vis absorption spectra evolution and visible light photocatalytic performances, including improved photodegradation behavior and photocatalytic hydrogen evolution activity, have demonstrated their potential applications. This new one-pot way to get diverse heterointerfaces for better photoinduced electron/hole separation synergistically can be anticipated for more kinds of photocatalytic organic synthesis.In this work, the hydrothermal cation exchange synthesis of Au@ZnS–AgAuS yolk–shell nanocrystals (Y–S NCs) with well-fabricated void size, ZnS–AgAuS shell and in situ generated Au cocatalyst are demonstrated. The concept of this strategy can be useful for the synthesis of other noble metal and semiconductor hybrid composites with tunable Y–S structures and new applications.
      PubDate: 2017-11-20T02:40:47.457973-05:
      DOI: 10.1002/advs.201700376
       
  • Size-Controlled Graphene Nanodot Arrays/ZnO Hybrids for High-Performance
           UV Photodetectors

    • Authors: Ruidie Tang; Sancan Han, Feng Teng, Kai Hu, Zhiming Zhang, Mingxiang Hu, Xiaosheng Fang
      Abstract: Graphene nanodots (GNDs) are one of the most attractive graphene nanostructures due to their tunable optoelectronic properties. Fabricated by polystyrene-nanosphere lithography, uniformly sized graphene nanodots array (GNDA) is constructed as an ultraviolet photodetector (PD) with ZnO nanofilm spin coated on it. The size of GNDA can be well controlled from 45 to 20 nm varying the etching time. It is revealed in the study that the photoelectric properties of ZnO/GNDA PD are highly GNDA size-dependent. The highest responsivity (R) and external quantum efficiency of ZnO/GNDA (20 nm) PD are 22.55 mA W−1 and 9.32%, almost twofold of that of ZnO PD. Both ZnO/GNDA (20 nm) PD and ZnO/GNDA (30 nm) PD exhibit much faster response speed under on/off switching light and have shorter rise/decay time compared with ZnO PD. However, as the size of GNDA increase to 45 nm, the PD appears poor performance. The size-dependent phenomenon can be explained by the energy band alignments in ZnO/GNDA hybrids. These efforts reveal the enhancement of GNDs on traditional photodetectors with tunable optoelectronic properties and hold great potential to pave a new way to explore the various remarkable photodetection performances by controlling the size of the nanostructures.Graphene nanodots are one of the most attractive graphene nanostructures due to their tunable optoelectronic properties. Uniformly sized graphene nanodots array (GNDA) fabricated by lithography is constructed as a ultraviolet photodetector (PD) with ZnO nanofilm. The photoelectric properties of ZnO/GNDA PD are highly GNDA size-dependent, which can be explained by different energy band alignments in ZnO/GNDA hybrids with different GNDA sizes.
      PubDate: 2017-11-17T00:07:42.792257-05:
      DOI: 10.1002/advs.201700334
       
  • Zigzag-Elongated Fused π-Electronic Core: A Molecular Design Strategy to
           Maximize Charge-Carrier Mobility

    • Authors: Akito Yamamoto; Yoshinori Murata, Chikahiko Mitsui, Hiroyuki Ishii, Masakazu Yamagishi, Masafumi Yano, Hiroyasu Sato, Akihito Yamano, Jun Takeya, Toshihiro Okamoto
      Abstract: Printed and flexible electronics requires solution-processable organic semiconductors with a carrier mobility (μ) of ≈10 cm2 V−1 s−1 as well as high chemical and thermal durability. In this study, chryseno[2,1-b:8,7-b′]dithiophene (ChDT) and its derivatives, which have a zigzag-elongated fused π-electronic core (π-core) and a peculiar highest occupied molecular orbital (HOMO) configuration, are reported as materials with conceptually new semiconducting π-cores. ChDT and its derivatives are prepared by a versatile synthetic procedure. A comprehensive investigation reveals that the ChDT π-core exhibits increasing structural stability in the bulk crystal phase, and that it is unaffected by a variation of the transfer integral, induced by the perpetual molecular motion of organic materials owing to the combination of its molecular shape and its particular HOMO configuration. Notably, ChDT derivatives exhibit excellent chemical and thermal stability, high charge-carrier mobility under ambient conditions (μ ≤ 10 cm2 V−1 s−1), and a crystal phase that is highly stable, even at temperatures above 250 °C.Chryseno[2,1-b:8,7-b′]dithiophene (ChDT) derivatives, which have a peculiar highest occupied molecular orbital (HOMO) configuration are newly designed and developed. This HOMO configuration is insusceptible to the change rate of the transfer integral from the molecular displacement in an aggregated structure induced by molecular motion. Notably, the synthesized ChDT derivatives exhibit a high mobility up to 10 cm2 V−1 s−1.
      PubDate: 2017-11-15T01:05:03.0765-05:00
      DOI: 10.1002/advs.201700317
       
  • Advanced Energy Storage Devices: Basic Principles, Analytical Methods, and
           Rational Materials Design

    • Authors: Jilei Liu; Jin Wang, Chaohe Xu, Hao Jiang, Chunzhong Li, Lili Zhang, Jianyi Lin, Ze Xiang Shen
      Abstract: Tremendous efforts have been dedicated into the development of high-performance energy storage devices with nanoscale design and hybrid approaches. The boundary between the electrochemical capacitors and batteries becomes less distinctive. The same material may display capacitive or battery-like behavior depending on the electrode design and the charge storage guest ions. Therefore, the underlying mechanisms and the electrochemical processes occurring upon charge storage may be confusing for researchers who are new to the field as well as some of the chemists and material scientists already in the field. This review provides fundamentals of the similarities and differences between electrochemical capacitors and batteries from kinetic and material point of view. Basic techniques and analysis methods to distinguish the capacitive and battery-like behavior are discussed. Furthermore, guidelines for material selection, the state-of-the-art materials, and the electrode design rules to advanced electrode are proposed.Fundamentals of the similarities and differences between electrochemical capacitors and batteries from kinetic and material point of view are provided in this review. Basic techniques and analysis methods to distinguish the capacitive and battery-like behavior are discussed. Furthermore, guidelines for material selection, the state-of-the-art materials, and the electrode design rules to advanced electrode are proposed.
      PubDate: 2017-11-15T00:42:57.901823-05:
      DOI: 10.1002/advs.201700322
       
  • Recent Progress in Single-Crystalline Perovskite Research Including
           Crystal Preparation, Property Evaluation, and Applications

    • Authors: Yucheng Liu; Zhou Yang, Shengzhong (Frank) Liu
      Abstract: Organic–inorganic lead halide perovskites are promising optoelectronic materials resulting from their significant light absorption properties and unique long carrier dynamics, such as a long carrier lifetime, carrier diffusion length, and high carrier mobility. These advantageous properties have allowed for the utilization of lead halide perovskite materials in solar cells, LEDs, photodetectors, lasers, etc. To further explore their potential, intrinsic properties should be thoroughly investigated. Single crystals with few defects are the best candidates to disclose a variety of interesting and important properties of these materials, ultimately, showing the increased importance of single-crystalline perovskite research. In this review, recent progress on the crystallization, investigation, and primary device applications of single-crystalline perovskites are summarized and analyzed. Further improvements in device design and preparation are also discussed.Single-crystalline perovskites show better and more intrinsic optoelectronic properties, which are critical for devices design and performance prediction. In this review, the crystal growth, property investigations as well as device application of single crystals are summarized and discussed. At the end, the strategies for improving the performances of single-crystalline devices are outlooked.
      PubDate: 2017-11-10T10:18:12.151801-05:
      DOI: 10.1002/advs.201700471
       
  • Verifying the Rechargeability of Li-CO2 Batteries on Working Cathodes of
           Ni Nanoparticles Highly Dispersed on N-Doped Graphene

    • Authors: Zhang Zhang; Xin-Gai Wang, Xu Zhang, Zhaojun Xie, Ya-Nan Chen, Lipo Ma, Zhangquan Peng, Zhen Zhou
      Abstract: Li-CO2 batteries could skillfully combine the reduction of “greenhouse effect” with energy storage systems. However, Li-CO2 batteries still suffer from unsatisfactory electrochemical performances and their rechargeability is challenged. Here, it is reported that a composite of Ni nanoparticles highly dispersed on N-doped graphene (Ni-NG) with 3D porous structure, exhibits a superior discharge capacity of 17 625 mA h g−1, as the air cathode for Li-CO2 batteries. The batteries with these highly efficient cathodes could sustain 100 cycles at a cutoff capacity of 1000 mA h g−1 with low overpotentials at the current density of 100 mA g−1. Particularly, the Ni-NG cathodes allow to observe the appearance/disappearance of agglomerated Li2CO3 particles and carbon thin films directly upon discharge/charge processes. In addition, the recycle of CO2 is detected through in situ differential electrochemical mass spectrometry. This is a critical step to verify the electrochemical rechargeability of Li-CO2 batteries. Also, first-principles computations further prove that Ni nanoparticles are active sites for the reaction of Li and CO2, which could guide to design more advantageous catalysts for rechargeable Li-CO2 batteries.A composite of Ni nanoparticles highly dispersed on N-doped graphene is prepared as the air cathode for Li-CO2 batteries, with high discharge capacity and excellent cyclic stability. The cathode allows to observe the morphological evolution of discharge products directly and reversible consumption and evolution of CO2, and then the reversibility of electrochemical reactions could well be understood in Li-CO2 batteries.
      PubDate: 2017-11-10T06:06:23.084513-05:
      DOI: 10.1002/advs.201700567
       
  • Aqueous-Containing Precursor Solutions for Efficient Perovskite Solar
           Cells

    • Authors: Dianyi Liu; Christopher J. Traverse, Pei Chen, Mark Elinski, Chenchen Yang, Lili Wang, Margaret Young, Richard R. Lunt
      Abstract: Perovskite semiconductors have emerged as competitive candidates for photovoltaic applications due to their exceptional optoelectronic properties. However, the impact of moisture instability on perovskite films is still a key challenge for perovskite devices. While substantial effort is focused on preventing moisture interaction during the fabrication process, it is demonstrated that low moisture sensitivity, enhanced crystallization, and high performance can actually be achieved by exposure to high water content (up to 25 vol%) during fabrication with an aqueous-containing perovskite precursor. The perovskite solar cells fabricated by this aqueous method show good reproducibility of high efficiency with average power conversion efficiency (PCE) of 18.7% and champion PCE of 20.1% under solar simulation. This study shows that water–perovskite interactions do not necessarily negatively impact the perovskite film preparation process even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.Perovskite solar cells fabricated by an aqueous-containing precursor method show good reproducibility with a high average power conversion efficiency (PCE) of 18.7% and a champion PCE of 20.1%. The study shows that water–perovskite interactions do not necessarily negatively impact perovskites even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.
      PubDate: 2017-11-10T06:05:56.195979-05:
      DOI: 10.1002/advs.201700484
       
  • Nanomicelle-Assisted Targeted Ocular Delivery with Enhanced
           Antiinflammatory Efficacy In Vivo

    • Authors: Yu-Hua Weng; Xiao-Wei Ma, Jing Che, Chan Li, Juan Liu, Shi-Zhu Chen, Yu-Qin Wang, Ya-Ling Gan, Hao Chen, Zhong-Bo Hu, Kai-Hui Nan, Xing-Jie Liang
      Abstract: Ocular inflammations are common diseases that may lead to serious vision-threatening obstacles. Eye drops for antiinflammation therapy need to be administered multiple times daily at a high dosage due to the rapid precorneal removal and low bioavailability of drugs. To overcome these problems, a cRGD-functionalized DSPE-PEG2000 nanomicelle (DSPE-PEG2000-cRGD) encapsulated with flurbiprofen is proposed. The tailored nanomicelles trigger specific binding to integrin receptors on the ocular surface, which leads to rapid and robust mucoadhesion, superior ocular surface retention, and transcorneal penetration behaviors of nanomicelles. Due to the enhanced drug delivery on ocular surface and in aqueous humor, the functionalized nanoformulation significantly improves ocular antiinflammation efficacy at a low dosage by blocking the synthesis of inflammatory mediators and cytokines. The present study demonstrates a promising strategy that uses a functional peptide combined with nanomicelles for targeted delivery to the eye in ophthalmologic applications.This study proposed as functionalized flurbiprofen-encapsulated DSPE-PEG2000-cRGD nanomicelles that can trigger specific binding to the ocular surface, leading to rapid and robust mucoadhesion, superior ocular surface retention, and transcorneal penetration behaviors of nanomicelles. The functionalized nanoformulation significantly improves ocular antiinflammation efficacy at a low dosage.
      PubDate: 2017-11-10T04:47:25.981222-05:
      DOI: 10.1002/advs.201700455
       
  • Electrocatalysts for Hydrogen Evolution in Alkaline Electrolytes:
           Mechanisms, Challenges, and Prospective Solutions

    • Authors: Nasir Mahmood; Yunduo Yao, Jing-Wen Zhang, Lun Pan, Xiangwen Zhang, Ji-Jun Zou
      Abstract: Hydrogen evolution reaction (HER) in alkaline medium is currently a point of focus for sustainable development of hydrogen as an alternative clean fuel for various energy systems, but suffers from sluggish reaction kinetics due to additional water dissociation step. So, the state-of-the-art catalysts performing well in acidic media lose considerable catalytic performance in alkaline media. This review summarizes the recent developments to overcome the kinetics issues of alkaline HER, synthesis of materials with modified morphologies, and electronic structures to tune the active sites and their applications as efficient catalysts for HER. It first explains the fundamentals and electrochemistry of HER and then outlines the requirements for an efficient and stable catalyst in alkaline medium. The challenges with alkaline HER and limitation with the electrocatalysts along with prospective solutions are then highlighted. It further describes the synthesis methods of advanced nanostructures based on carbon, noble, and inexpensive metals and their heterogeneous structures. These heterogeneous structures provide some ideal systems for analyzing the role of structure and synergy on alkaline HER catalysis. At the end, it provides the concluding remarks and future perspectives that can be helpful for tuning the catalysts active-sites with improved electrochemical efficiencies in future.In this review, recent progress and solutions to the challenges associated with electrocatalysts for hydrogen evolution reaction (HER) in alkaline electrolytes are systematically explained. It further describes the reaction controlling factors and ambiguity of the alkaline HER process and outlines the possible ways to enhance the catalyst efficiency and stability. By modifying the electronic structure of catalysts through developing their heterostructures can overcome the water dissociation barrier to realize alkaline HER.
      PubDate: 2017-11-10T04:37:02.805231-05:
      DOI: 10.1002/advs.201700464
       
  • Multidrug Resistance in Cancer Circumvented Using a Cytosolic Drug
           Reservoir

    • Authors: Li Fan; Silu Zhang, Chunyuan Zhang, Chun Yin, Zhiqin Chu, Chaojun Song, Ge Lin, Quan Li
      Abstract: It is discovered that sustained cytosolic drug release at a sufficient concentration is an effective mechanism to circumvent multidrug resistance and consequently enhance antitumor drug efficacy. It is showed that a simple way to enable this mechanism is to reach an intracellular kinetic balance of the drug movement between the drug released from the carrier into the cytosol and the one removed from the cell interior. By adopting nanoparticle (NP) as the drug carrier, a reservoir of drug can be maintained inside the cells upon effective cellular uptake of these NPs via endocytosis. This study shows that gradual release of the drug from the NP carrier provides a feasible scheme for sustained drug release in cells, resulting in relatively stable cytosolic drug concentration level, particularly in the drug resistant case. By implementing an “optical switch” with light irradiation on photosensitizer in the same nanoparticle carrier, cytosolic drug release is further promoted, which increases cytosolic drug concentration with good concentration retention. Enhanced drug efficacy in drug sensitive as well as resistant models is demonstrated both in vitro and in vivo. Such a mechanism is shown to efficiently circumvent multidrug resistance, and at the same time largely reduce the systemic toxicity of the anticancer drug.It is discovered that sustained cytosolic drug release at a sufficient concentration is an effective mechanism to circumvent multidrug resistance for cancer therapy. This study shows that a simple way to enable this mechanism is to reach an intracellular kinetic balance of the drug movement between the drug released from the carrier into the cytosol and the one removed from the cell interior.
      PubDate: 2017-11-09T00:07:29.501209-05:
      DOI: 10.1002/advs.201700289
       
  • Turning the Old Adjuvant from Gel to Nanoparticles to Amplify CD8+ T Cell
           Responses

    • Authors: Hao Jiang; Qin Wang, Lin Li, Qin Zeng, Hanmei Li, Tao Gong, Zhirong Zhang, Xun Sun
      Abstract: Due to its safety and efficacy, aluminum hydroxide is used as an immune adjuvant in human vaccines for over 80 years. Being a Th2 stimulator, the classical gel-like adjuvant, however, fails to generate CD8+ T cell responses, which are important for cancer vaccines. Here, aluminum hydroxide is turned from gel into nano-sized vaccine carriers AlO(OH)-polymer nanoparticles (APNs) to promote their lymphatic migration. After actively uptaken via scavenger receptor-A by antigen-presenting cells (APCs) resident in lymph nodes (LNs), APNs destabilize lysosomes resulting in efficient cytosolic delivery and cross-presentation of antigens. It is demonstrated that administration of APNs loaded with ovalbumin (OVA) and CpG led to the codelivery of both cargos into APCs in LNs, leading to their activation and subsequent adaptive immunity. A prime-boost strategy with low doses of OVA (1.5 µg) and CpG (0.45 µg) induces potent CD8+ T cell responses and dramatically prolongs the survival of B16-OVA tumor-bearing mice. More impressively, when using B16F10 lysates instead of OVA as antigen, substantial antitumor effects on B16F10 tumor model are observed by using APN-CpG. These results suggest the great potential of APNs as vaccine carriers that activate CD8+ T cell responses and the bright prospect of aluminum adjuvant in a nanoparticle formulation.Aluminum hydroxide is turned from gel into nanoparticles (APNs) to promote their lymphatic migration. Footpad injection of APNs leads to the codelivery of ovalbumin and CpG into antigen presenting cells (APCs) in lymph nodes, leading to APC activation and subsequent adaptive immunity. More impressively, when using B16F10 lysates as antigen, substantial antitumor effects on B16F10 tumor model are observed by using APN-CpG.
      PubDate: 2017-11-09T00:06:15.502418-05:
      DOI: 10.1002/advs.201700426
       
  • Environment-Adaptive Coassembly/Self-Sorting and Stimulus-Responsiveness
           Transfer Based on Cholesterol Building Blocks

    • Authors: Pengyao Xing; Huijun Phoebe Tham, Peizhou Li, Hongzhong Chen, Huijing Xiang, Yanli Zhao
      Abstract: Manipulating the property transfer in nanosystems is a challenging task since it requires switchable molecular packing such as separate aggregation (self-sorting) or synergistic aggregation (coassembly). Herein, a unique manipulation of self-sorting/coassembly aggregation and the observation of switchable stimulus-responsiveness transfer in a two component self-assembly system are reported. Two building blocks bearing the same cholesterol group give versatile topological structures in polar and nonpolar solvents. One building block (cholesterol conjugated cynanostilbene, CCS) consists of cholesterol conjugated with a cynanostilbene unit, and the other one (C10CN) is comprised of cholesterol connected with a naphthalimide group having a flexible long alkyl chain. Their assemblies including gel, crystalline plates, and vesicles are obtained. In gel and crystalline plate phases, the self-sorting behavior dominates, while synergistic coassembly occurs in vesicle phase. Since CCS having the cyanostilbene group can respond to the light irradiation, it undergoes light-induced chiral amplification. C10CN is thermally responsive, whereby its supramolecular chirality is inversed upon heating. In coassembled vesicles, it is interestingly observed that their responsiveness can be transferred by each other, i.e., the C10CN segment is sensitive to the light irradiation, while CCS is thermoresponsive. This unprecedented behavior of the property transfer may shine a light to the precise fabrication of smart materials.Adaptive organic building blocks bearing cyanostilbene and naphthalimide groups enable the occurrence of selective coassembly/self-sorting behavior, allowing for controllable stimuli-responsiveness transfer between different components.
      PubDate: 2017-11-08T06:51:27.364728-05:
      DOI: 10.1002/advs.201700552
       
  • Toward Aerogel Electrodes of Superior Rate Performance in Supercapacitors
           through Engineered Hollow Nanoparticles of NiCo2O4

    • Authors: Jianjiang Li; Shuai Chen, Xiaoyi Zhu, Xilin She, Tongchao Liu, Huawei Zhang, Sridhar Komarneni, Dongjiang Yang, Xiangdong Yao
      Abstract: A biomass-templated pathway is developed for scalable synthesis of NiCo2O4@carbon aerogel electrodes for supercapacitors, where NiCo2O4 hollow nanoparticles with an average outer diameter of 30–40 nm are conjoined by graphitic carbon forming a 3D aerogel structure. This kind of NiCo2O4 aerogel structure shows large specific surface area (167.8 m2 g−1), high specific capacitance (903.2 F g−1 at a current density of 1 A g−1), outstanding rate performance (96.2% capacity retention from 1 to 10 A g−1), and excellent cycling stability (nearly without capacitance loss after 3000 cycles at 10 A g−1). The unique structure of the 3D hollow aerogel synergistically contributes to the high performance. For instance, the 3D interconnected porous structure of the aerogel is beneficial for electrolyte ion diffusion and for shortening the electron transport pathways, and thus can improve the rate performance. The conductive carbon joint greatly enhances the specific capacity, and the hollow structure prohibits the volume changes during the charge–discharge process to significantly improve the cycling stability. This work represents a giant step toward the preparation of high-performance commercial supercapacitors.Hollow NiCo2O4@carbon aerogel is synthesized by a biomass-template approach utilizing the ion-exchange process between metal ion and sodium alginate solution. This kind of NiCo2O4@carbon aerogel shows large specific surface area, high specific capacitance, outstanding rate performance, and excellent cycling stability for the supercapacitor.
      PubDate: 2017-11-08T00:07:26.358777-05:
      DOI: 10.1002/advs.201700345
       
  • Through-Bond Energy Transfer Cassette with Dual-Stokes Shifts for
           “Double Checked” Cell Imaging

    • Authors: Xiangdong Xue; Shubin Jin, Zhipeng Li, Chunqiu Zhang, Weisheng Guo, Liming Hu, Paul C. Wang, Jinchao Zhang, Xing-Jie Liang
      Abstract: Organic dyes generally suffer from small Stokes shift that usually leads to self-quenching and -gaining errors during the fluorescent imaging process. Here, a through-bond energy transfer (TBET) cassette is developed with large Stokes shift to pursue precise cell imaging. The TBET is constructed by covalently conjugated tetraphenylethene (acts as donor) and rhodamine (acceptor) through an acetylene bond. The constructed TBET cassette distinctly behaves as dual-Stokes shifts, including a large pseudo-Stokes shift caused by energy transfer, from donor's absorption to acceptor's emission (up to 260 nm) and a smaller Stokes shift of acceptor molecules itself. Due to the intrinsic dual-Stokes shifts, TBET cassette exhibits specific “dual distinct absorbances, single shared emission” properties, which can be excitated under two different laser channels. By colocalization of the imaging readouts of these two channels, the precisely “double checked” fluorescent imaging is achieved in living cells.Through-bond energy transfer (TBET) cassette is constructed with intrinsically “dual distinct absorbances, single shared emission” properties and realized precisely, “double checked” fluorescent imaging in living cells.
      PubDate: 2017-10-27T23:06:52.675929-05:
      DOI: 10.1002/advs.201700229
       
  • Identifying the Cause of Rupture of Li-Ion Batteries during Thermal
           Runaway

    • Authors: Donal P. Finegan; Eric Darcy, Matthew Keyser, Bernhard Tjaden, Thomas M. M. Heenan, Rhodri Jervis, Josh J. Bailey, Nghia T. Vo, Oxana V. Magdysyuk, Michael Drakopoulos, Marco Di Michiel, Alexander Rack, Gareth Hinds, Dan J. L. Brett, Paul R. Shearing
      Abstract: As the energy density of lithium-ion cells and batteries increases, controlling the outcomes of thermal runaway becomes more challenging. If the high rate of gas generation during thermal runaway is not adequately vented, commercial cell designs can rupture and explode, presenting serious safety concerns. Here, ultra-high-speed synchrotron X-ray imaging is used at>20 000 frames per second to characterize the venting processes of six different 18650 cell designs undergoing thermal runaway. For the first time, the mechanisms that lead to the most catastrophic type of cell failure, rupture, and explosion are identified and elucidated in detail. The practical application of the technique is highlighted by evaluating a novel 18650 cell design with a second vent at the base, which is shown to avoid the critical stages that lead to rupture. The insights yielded in this study shed new light on battery failure and are expected to guide the development of safer commercial cell designs.Thermal runaway of 18650 lithium-ion cells can result in a wide range of failure mechanisms, from controlled release of gases to catastrophic bursting and generation of projectiles. Here, the structural dynamics associated with venting and rupture of five different commercial 18650 cell designs are captured and explored using high-speed X-ray imaging at up to 20 272 frames per second.
      PubDate: 2017-10-27T06:21:15.239281-05:
      DOI: 10.1002/advs.201700369
       
  • Enhanced Proton Conductivity in Y-Doped BaZrO3 via Strain Engineering

    • Authors: Aline Fluri; Aris Marcolongo, Vladimir Roddatis, Alexander Wokaun, Daniele Pergolesi, Nicola Marzari, Thomas Lippert
      Abstract: The effects of stress-induced lattice distortions (strain) on the conductivity of Y-doped BaZrO3, a high-temperature proton conductor with key technological applications for sustainable electrochemical energy conversion, are studied. Highly ordered epitaxial thin films are grown in different strain states while monitoring the stress generation and evolution in situ. Enhanced proton conductivity due to lower activation energies is discovered under controlled conditions of tensile strain. In particular, a twofold increased conductivity is measured at 200 °C along a 0.7% tensile strained lattice. This is at variance with conclusions coming from force-field simulations or the static calculations of diffusion barriers. Here, extensive first-principles molecular dynamic simulations of proton diffusivity in the proton-trapping regime are therefore performed and found to agree with the experiments. The simulations highlight that compressive strain confines protons in planes parallel to the substrate, while tensile strain boosts diffusivity in the perpendicular direction, with the net result that the overall conductivity is enhanced. It is indeed the presence of the dopant and the proton-trapping effect that makes tensile strain favorable for proton conduction.Tensile lattice strain is shown for the first time to enhance the proton conduction in the grain interior, which is in contradiction to previous theoretical simulations. Through the synergy of experiment and theory, a new approach to the theoretical modeling of the proton conduction mechanism is developed, which is capable of explaining the experimental results.
      PubDate: 2017-10-27T06:16:51.712744-05:
      DOI: 10.1002/advs.201700467
       
  • Overcoming the Limitations of Sputtered Nickel Oxide for High-Efficiency
           and Large-Area Perovskite Solar Cells

    • Authors: Guijun Li; Yibin Jiang, Sunbin Deng, Alwin Tam, Ping Xu, Man Wong, Hoi-Sing Kwok
      Abstract: Perovskite solar cells (PSCs) are one of the promising photovoltaic technologies for solar electricity generation. NiOx is an inorganic p-type semiconductor widely used to address the stability issue of PSCs. Although high efficiency is obtained for the devices employing NiOx as the hole transport layer, the fabrication methods have yet to be demonstrated for industrially relevant manufacturing of large-area and high-performance devices. Here, it is shown that these requirements can be satisfied by using the magnetron sputtering, which is well established in the industry. The limitations of low fill factor and short-circuit current commonly observed in sputtered NiOx-derived PSCs can be overcome through magnesium doping and low oxygen partial pressure deposition. The fabricated PSCs show a high power conversion efficiency of up to 18.5%, along with negligible hysteresis, improved ambient stability, and high reproducibility. In addition, good uniformity is also demonstrated over an area of 100 cm2. The simple and well-established approach constitutes a reliable and scale method paving the way for the commercialization of PSCs.An industrially relevant manufacturing of perovskite solar cells is demonstrated with the magnetron sputtered NiMgOx, and the limitations of low fill factor and short-circuit current commonly observed in sputtered NiOx-derived devices can be overcome through magnesium doping and low oxygen partial pressure deposition. The as fabricated devices show a high efficiency of up to 18.5%, along with good uniformity over a large-area of 100 cm2.
      PubDate: 2017-10-26T03:56:03.945905-05:
      DOI: 10.1002/advs.201700463
       
  • 3D Printing of Lotus Root-Like Biomimetic Materials for Cell Delivery and
           Tissue Regeneration

    • Authors: Chun Feng; Wenjie Zhang, Cuijun Deng, Guanglong Li, Jiang Chang, Zhiyuan Zhang, Xinquan Jiang, Chengtie Wu
      Abstract: Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root-like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.Inspired by the microstructure of lotus root, lotus root-like biomimetic materials are successfully prepared via a modified 3D printing strategy with different kinds of materials, channel numbers, shapes, porosity, surface area, and mechanical properties. The biomimetic materials significantly improve in vitro cell attachment and proliferation as well as in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.
      PubDate: 2017-10-26T02:01:35.809572-05:
      DOI: 10.1002/advs.201700401
       
  • An Aqueous Ca-Ion Battery

    • Authors: Saman Gheytani; Yanliang Liang, Feilong Wu, Yan Jing, Hui Dong, Karun K. Rao, Xiaowei Chi, Fang Fang, Yan Yao
      Abstract: Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anode and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.An aqueous Ca-ion battery is demonstrated using two low-cost materials as the electrodes. The battery shows specific energy of 54 Wh kg−1, high-rate capability, and stable cycling performance with high coulombic efficiency and is a promising energy storage system for large-scale applications.
      PubDate: 2017-10-26T02:00:42.480278-05:
      DOI: 10.1002/advs.201700465
       
  • Nonlocal Response in Infrared Detector with Semiconducting Carbon
           Nanotubes and Graphdiyne

    • Authors: Zhe Zheng; Hehai Fang, Dan Liu, Zhenjun Tan, Xin Gao, Weida Hu, Hailin Peng, Lianming Tong, Wenping Hu, Jin Zhang
      Abstract: Semiconducting single-walled carbon nanotubes (s-SWNTs) are regarded as an important candidate for infrared (IR) optical detection due to their excellent intrinsic properties. However, the strong binding energy of excitons in s-SWNTs seriously impedes the development of s-SWNTs IR photodetector. This Communication reports an IR photodetector with highly pure s-SWNTs and γ-graphdiyne. The heterojunctions between the two materials can efficiently separate the photogenerated excitons. In comparison to device fabricated only with s-SWNTs, this IR detector shows a uniform response in the whole channel of the device. The response time is demonstrated to be below 1 ms. The optimal responsivity and detectivity approximately reach 0.4 mA W−1 and 5 × 106 cmHz1/2 W−1, respectively.The uniform response is gotten through the combination of semiconducting single-walled carbon nanotubes and γ-graphdiyne without decrease of electrical transport property of the device. The signal can be collected in the whole channel area and the responsivity and detectivity approximately reach 0.4 mA W−1 and 5 × 106 cmHz1/2 W−1, respectively. The response time is below 1 ms.
      PubDate: 2017-10-25T23:07:33.168083-05:
      DOI: 10.1002/advs.201700472
       
  • Pursuing Polymer Dielectric Interfacial Effect in Organic Transistors for
           Photosensing Performance Optimization

    • Authors: Xiaohan Wu; Yingli Chu, Rui Liu, Howard E. Katz, Jia Huang
      Abstract: Polymer dielectrics in organic field-effect transistors (OFETs) are essential to provide the devices with overall flexibility, stretchability, and printability and simultaneously introduce charge interaction on the interface with organic semiconductors (OSCs). The interfacial effect between various polymer dielectrics and OSCs significantly and intricately influences device performance. However, understanding of this effect is limited because the interface is buried and the interfacial charge interaction is difficult to stimulate and characterize. Here, this challenge is overcome by utilizing illumination to stimulate the interfacial effect in various OFETs and to characterize the responses of the effect by measuring photoinduced changes of the OFETs performances. This systemic investigation reveals the mechanism of the intricate interfacial effect in detail, and mathematically explains how the photosensitive OFETs characteristics are determined by parameters including polar group of the polymer dielectric and the OSC side chain. By utilizing this mechanism, performance of organic electronics can be precisely controlled and optimized. OFETs with strong interfacial effect can also show a signal additivity caused by repeated light pulses, which is applicable for photostimulated synapse emulator. Therefore, this work enlightens a detailed understanding on the interface effect and provides novel strategies for optimizing OFET photosensory performances.The significant and intricate semiconductor/dielectric interfacial effect in flexbile organic transistors is systematically investigated, giving a mechanism that mathematically explains how the photosensitive device characteristics are determined by parameters including polar group of the polymer dielectrics and side chain of the organic semiconductors. By utilizing the mechanism, performance of the organic electronics can be optimized, and photostimulated synapse emulators are obtained.
      PubDate: 2017-10-16T01:31:44.717918-05:
      DOI: 10.1002/advs.201700442
       
  • Earth-Abundant Tin Sulfide-Based Photocathodes for Solar Hydrogen
           Production

    • Authors: Wei Cheng; Nirala Singh, Will Elliott, Joun Lee, Alan Rassoolkhani, Xuejun Jin, Eric W. McFarland, Syed Mubeen
      Abstract: Tin-based chalcogenide semiconductors, though attractive materials for photovoltaics, have to date exhibited poor performance and stability for photoelectrochemical applications. Here, a novel strategy is reported to improve performance and stability of tin monosulfide (SnS) nanoplatelet thin films for H2 production in acidic media without any use of sacrificial reagent. P-type SnS nanoplatelet films are coated with the n-CdS buffer layer and the TiO2 passivation layer to form type II heterojunction photocathodes. These photocathodes with subsequent deposition of Pt nanoparticles generate a photovoltage of 300 mV and a photocurrent density of 2.4 mA cm−2 at 0 V versus reversible hydrogen electrode (RHE) for water splitting under simulated visible-light illumination (λ> 500 nm, Pin = 80 mW cm−2). The incident photon-to-current efficiency at 0 V versus RHE for H2 production reach a maximum of 12.7% at 575 nm with internal quantum efficiency of 13.8%. The faradaic efficiency for hydrogen evolution remains close to unity after 6000 s of illumination, confirming the robustness of the heterojunction for solar H2 production.A novel strategy is reported to improve performance and stability of tin monosulfide (SnS) nanoplatelet thin films for H2 production in acidic media without any use of sacrificial reagent. This is achieved by fabricating p-SnS/n-CdS/TiO2 type II heterojunction photocathodes which generate a photovoltage of 300 mV and a hydrogen production photocurrent density of 2.4 mA cm−2 under visible-light illumination.
      PubDate: 2017-10-16T01:31:04.127952-05:
      DOI: 10.1002/advs.201700362
       
  • Electroionic Antagonistic Muscles Based on Nitrogen-Doped Carbons Derived
           from Poly(Triazine-Triptycene)

    • Authors: Sandipan Roy; Jaehwan Kim, Moumita Kotal, Kwang Jin Kim, Il-Kwon Oh
      Abstract: Electroactive soft actuators and bioinspired artificial muscles have received burgeoning interest as essential components in future electronic devices such as soft haptic-feedback systems, human-friendly wearable electronics, and active biomedical devices. However, important challenging issues including fast response time, ultralow input power, robust operation in harsh environments, high-resolution controllability, and cost-effectiveness remain to be resolved for more practical applications. Here, an electroionic antagonistic artificial muscle is reported based on hierarchically porous nitrogen-doped carbon (HPNC) electrodes derived from a microporous poly(triazine-triptycene) organic framework (PtztpOF). The HPNC, which exhibits hierarchically micro- and mesoporous structures, high specific capacitance of 330 F g−1 in aqueous solution, large specific surface area of 830.46 m2 g−1, and graphitic nitrogen doping, offers high electrical conductivity of 0.073 MS m−1 and outstanding volumetric capacitance of 10.4 MF m−3. Furthermore, it is demonstrated that a novel electroionic antagonistic muscle based on HPNC electrodes successfully displays extremely reliable and large bending deformations and long-term durability under ultralow input voltages. Therefore, microporous polymer or covalent organic frameworks can be applied to provide significant improvements in electroactive artificial muscles, which can play key roles as technological advances toward bioinspired actuating devices required for next-generation soft and wearable electronics.Ultrasensitive bioinspired ionic actuators are newly developed using hierarchically porous nitrogen-doped carbon electrodes derived from poly(triazine-triptycene) organic framework. Owing to remarkable electro-chemomechanical properties of the electrodes such as high specific capacitance and electrical conductivity, and large surface area with hierarchical porosity, the bioinspired actuators exhibit large bending actuation and long-term durability under ultralow input voltages.
      PubDate: 2017-10-11T10:50:59.143801-05:
      DOI: 10.1002/advs.201700410
       
  • Electronic and Optoelectronic Applications Based on 2D Novel Anisotropic
           Transition Metal Dichalcogenides

    • Authors: Chuanhui Gong; Yuxi Zhang, Wei Chen, Junwei Chu, Tianyu Lei, Junru Pu, Liping Dai, Chunyang Wu, Yuhua Cheng, Tianyou Zhai, Liang Li, Jie Xiong
      Abstract: With the continuous exploration of 2D transition metal dichalcogenides (TMDs), novel high-performance devices based on the remarkable electronic and optoelectronic natures of 2D TMDs are increasingly emerging. As fresh blood of 2D TMD family, anisotropic MTe2 and ReX2 (M = Mo, W, and X = S, Se) have drawn increasing attention owing to their low-symmetry structures and charming properties of mechanics, electronics, and optoelectronics, which are suitable for the applications of field-effect transistors (FETs), photodetectors, thermoelectric and piezoelectric applications, especially catering to anisotropic devices. Herein, a comprehensive review is introduced, concentrating on their recent progresses and various applications in recent years. First, the crystalline structure and the origin of the strong anisotropy characterized by various techniques are discussed. Specifically, the preparation of these 2D materials is presented and various growth methods are summarized. Then, high-performance applications of these anisotropic TMDs, including FETs, photodetectors, and thermoelectric and piezoelectric applications are discussed. Finally, the conclusion and outlook of these applications are proposed.The recent research progresses of low-symmetry MTe2 (M = Mo, W) and ReX2 (X = S, Se) are presented with an emphasis on the crystalline structure, preparation methods, and novel electronic and optoelectronic applications.
      PubDate: 2017-10-06T08:46:24.291743-05:
      DOI: 10.1002/advs.201700231
       
  • Remarkable Enhancement of the Hole Mobility in Several Organic
           Small-Molecules, Polymers, and Small-Molecule:Polymer Blend Transistors by
           Simple Admixing of the Lewis Acid p-Dopant B(C6F5)3

    • Authors: Julianna Panidi; Alexandra F. Paterson, Dongyoon Khim, Zhuping Fei, Yang Han, Leonidas Tsetseris, George Vourlias, Panos A. Patsalas, Martin Heeney, Thomas D. Anthopoulos
      Abstract: Improving the charge carrier mobility of solution-processable organic semiconductors is critical for the development of advanced organic thin-film transistors and their application in the emerging sector of printed electronics. Here, a simple method is reported for enhancing the hole mobility in a wide range of organic semiconductors, including small-molecules, polymers, and small-molecule:polymer blends, with the latter systems exhibiting the highest mobility. The method is simple and relies on admixing of the molecular Lewis acid B(C6F5)3 in the semiconductor formulation prior to solution deposition. Two prototypical semiconductors where B(C6F5)3 is shown to have a remarkable impact are the blends of 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene:poly(triarylamine) (diF-TESADT:PTAA) and 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene:poly(indacenodithiophene-co-benzothiadiazole) (C8-BTBT:C16-IDTBT), for which hole mobilities of 8 and 11 cm2 V−1 s−1, respectively, are obtained. Doping of the 6,13-bis(triisopropylsilylethynyl)pentacene:PTAA blend with B(C6F5)3 is also shown to increase the maximum hole mobility to 3.7 cm2 V−1 s−1. Analysis of the single and multicomponent materials reveals that B(C6F5)3 plays a dual role, first acting as an efficient p-dopant, and secondly as a microstructure modifier. Semiconductors that undergo simultaneous p-doping and dopant-induced long-range crystallization are found to consistently outperform transistors based on the pristine materials. Our work underscores Lewis acid doping as a generic strategy towards high performance printed organic microelectronics.Admixing the Lewis acid B(C6F5)3 with various organic conjugated small-molecules, polymers, and small-molecule:polymer blends leads to a remarkable increase in their field-effect hole mobility. In the case of small-molecule:polymer blends, the effect is shown to be due to the synergistic processes of p-doping and dopant-induced long-range crystallinity in the composite layer yielding transistor with hole mobility of up to 11 cm2 V−1 s−1.
      PubDate: 2017-10-05T01:11:09.966955-05:
      DOI: 10.1002/advs.201700290
       
  • Photogating in Low Dimensional Photodetectors

    • Authors: Hehai Fang; Weida Hu
      Abstract: Low dimensional materials including quantum dots, nanowires, 2D materials, and so forth have attracted increasing research interests for electronic and optoelectronic devices in recent years. Photogating, which is usually observed in photodetectors based on low dimensional materials and their hybrid structures, is demonstrated to play an important role. Photogating is considered as a way of conductance modulation through photoinduced gate voltage instead of simply and totally attributing it to trap states. This review first focuses on the gain of photogating and reveals the distinction from conventional photoconductive effect. The trap- and hybrid-induced photogating including their origins, formations, and characteristics are subsequently discussed. Then, the recent progress on trap- and hybrid-induced photogating in low dimensional photodetectors is elaborated. Though a high gain bandwidth product as high as 109 Hz is reported in several cases, a trade-off between gain and bandwidth has to be made for this type of photogating. The general photogating is put forward according to another three reported studies very recently. General photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high-performance photodetectors.Photogating is considered as a way of conductance modulation through photoinduced voltage. The origins, formations, and characteristics of the trap- and hybrid-induced photogating are discussed. This type of photogating enables a trade-off between gain and bandwidth. However, general photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high-performance photodetectors.
      PubDate: 2017-10-04T04:37:03.159617-05:
      DOI: 10.1002/advs.201700323
       
  • Dual-Color-Emitting Carbon Nanodots for Multicolor Bioimaging and
           Optogenetic Control of Ion Channels

    • Authors: Hyemin Kim; Yoonsang Park, Songeun Beack, Seulgi Han, Dooyup Jung, Hyung Joon Cha, Woosung Kwon, Sei Kwang Hahn
      Abstract: The development of intrinsically multicolor-emitting carbon nanodots (CNDs) has been one of the great challenges for their various fields of applications. Here, the controlled electronic structure engineering of CNDs is performed to emit two distinct colors via the facile surface modification with 4-octyloxyaniline. The so-called dual-color-emitting CNDs (DC-CNDs) can be stably encapsulated within poly(styrene-co-maleic anhydride) (PSMA). The prepared water-soluble DC-CNDs@PSMA can be successfully applied to in vitro and in vivo dual-color bioimaging and optogenetics. In vivo optical imaging can visualize the biodistribution of intravenously injected DC-CNDs@PSMA. In addition, the light-triggered activation of ion channel, channelrhodopsin-2, for optogenetic applications is demonstrated. As a new type of fluorophore, DC-CNDs offer a big insight into the design of charge-transfer complexes for various optical and biomedical applications.A dual-color-emitting carbon nanodot (DC-CND) is successfully developed by the facile surface modification with 4-octyloxyaniline to emit two distinct colors according to the excitation wavelength. The biocompatible DC-CNDs show the great potential for multicolor bioimaging and the optogenetic control of channelrhodopsin-2.
      PubDate: 2017-10-03T23:07:43.959407-05:
      DOI: 10.1002/advs.201700325
       
  • Simultaneous Optimization of Carrier Concentration and Alloy Scattering
           for Ultrahigh Performance GeTe Thermoelectrics

    • Authors: Juan Li; Zhiwei Chen, Xinyue Zhang, Hulei Yu, Zihua Wu, Huaqing Xie, Yue Chen, Yanzhong Pei
      Abstract: In order to locate the optimal carrier concentrations for peaking the thermoelectric performance in p-type group IV monotellurides, existing efforts focus on aliovalent doping, either to increase (in PbTe) or to decrease (in SnTe and GeTe) the hole concentration. The limited solubility of aliovalent dopants usually introduces insufficient phonon scattering for thermoelectric performance maximization. With a decrease in the size of cation, the concentration of holes, induced by cation vacancies in intrinsic compounds, increases rapidly from ≈1018 cm−3 in PbTe to ≈1020 cm−3 in SnTe and then to ≈1021 cm−3 in GeTe. This motivates a strategy here for reducing the carrier concentration in GeTe, by increasing the mean size of cations and vice-versa decreasing the average size of anions through isovalent substitutions for increased formation energy of cation vacancy. A combination of the simultaneously resulting strong phonon scattering due to the high solubility of isovalent impurities, an ultrahigh thermoelectric figure of merit, zT of 2.2 is achieved in GeTe–PbSe alloys. This corresponds to a 300% enhancement in average zT as compared to pristine GeTe. This work not only demonstrates GeTe as a promising thermoelectric material but also paves the way for enhancing the thermoelectric performance in similar materials.Apart from aliovalent doping, alloying GeTe with PbSe controls carrier concentration precisely through controlling the intrinsic cation vacancies. The isovalent point defects at cation and anion sites simultaneously decrease the lattice thermal conductivity to ≈0.5 W (m K)−1, and eventually thermoelectric figure of merit, zT ≈ 2.2 is achieved, which corresponds to a 300% improvement in the average zT compared to pristine GeTe.
      PubDate: 2017-09-30T23:06:28.193984-05:
      DOI: 10.1002/advs.201700341
       
  • Progress and Perspective of Electrocatalytic CO2 Reduction for Renewable
           Carbonaceous Fuels and Chemicals

    • Authors: Wenjun Zhang; Yi Hu, Lianbo Ma, Guoyin Zhu, Yanrong Wang, Xiaolan Xue, Renpeng Chen, Songyuan Yang, Zhong Jin
      Abstract: The worldwide unrestrained emission of carbon dioxide (CO2) has caused serious environmental pollution and climate change issues. For the sustainable development of human civilization, it is very desirable to convert CO2 to renewable fuels through clean and economical chemical processes. Recently, electrocatalytic CO2 conversion is regarded as a prospective pathway for the recycling of carbon resource and the generation of sustainable fuels. In this review, recent research advances in electrocatalytic CO2 reduction are summarized from both experimental and theoretical aspects. The referred electrocatalysts are divided into different classes, including metal–organic complexes, metals, metal alloys, inorganic metal compounds and carbon-based metal-free nanomaterials. Moreover, the selective formation processes of different reductive products, such as formic acid/formate (HCOOH/HCOO−), monoxide carbon (CO), formaldehyde (HCHO), methane (CH4), ethylene (C2H4), methanol (CH3OH), ethanol (CH3CH2OH), etc. are introduced in detail, respectively. Owing to the limited energy efficiency, unmanageable selectivity, low stability, and indeterminate mechanisms of electrocatalytic CO2 reduction, there are still many tough challenges need to be addressed. In view of this, the current research trends to overcome these obstacles in CO2 electroreduction field are summarized. We expect that this review will provide new insights into the further technique development and practical applications of CO2 electroreduction.The worldwide unrestrained emission of carbon dioxide (CO2) has caused serious environmental pollution and climate change issues. In this review, recent advances in electrocatalytic CO2 reduction are summarized from both experimental and theoretical aspects. It is expected that this review will provide new insights into the further technical development and practical applications of CO2 electroreduction.
      PubDate: 2017-09-29T12:17:28.818147-05:
      DOI: 10.1002/advs.201700275
       
  • Netrin-1 Promotes Inflammation Resolution to Achieve Endothelialization of
           Small-Diameter Tissue Engineering Blood Vessels by Improving Endothelial
           Progenitor Cells Function In Situ

    • Authors: Yanzhao Li; Simin Wan, Ge Liu, Wang Cai, Da Huo, Gang Li, Mingcan Yang, Yuxin Wang, Ge Guan, Ning Ding, Feila Liu, Wen Zeng, Chuhong Zhu
      Abstract: The transplant of small-diameter tissue engineering blood vessels (small-diameter TEBVs) (
      PubDate: 2017-09-28T11:29:15.168634-05:
      DOI: 10.1002/advs.201700278
       
  • Full-Color Emission Polymer Carbon Dots with Quench-Resistant Solid-State
           Fluorescence

    • Authors: Jieren Shao; Shoujun Zhu, Huiwen Liu, Yubin Song, Songyuan Tao, Bai Yang
      Abstract: Polymer carbon dots (PCDs) represent a new class of carbon dots (CDs) possessing sub-fluorophores and unique polymer-like structures. However, like small molecule dyes and traditional CDs, PCDs often suffer from self-quenching effect in solid state, limiting their potential applications. Moreover, it is hard to prepare PCDs that have the same chemical structure, exhibiting full-color emission under one fixed excitation wavelength by only modulating the concentration of the PCDs. Herein, self-quenching-resistant solid-state fluorescent polymer carbon dots (SSFPCDs) are prepared, which exhibit strong red SSF without any other additional solid matrices, while having a large production yield (≈89%) and a considerable quantum yield of 8.50%. When dispersed in water or solid matrices in gradient concentrations, they can exhibit yellow, green, and blue fluorescence, realizing the first SSFPCDs with the same chemical structure emitting in full-color range by changing the ratio of SSFPCDs to the solid matrices.A new type of polymer carbon dots (PCDs), possessing red quench-resistant solid state fluorescence, is developed, providing us a new way of achieving solid emission in the field of carbon dots. Moreover, these PCDs also exhibit full-color concentration-dependent emission, contributing to the realization of efficient full-color solid state fluorescence.
      PubDate: 2017-09-28T11:27:28.053202-05:
      DOI: 10.1002/advs.201700395
       
  • Field-Controlled Electrical Switch with Liquid Metal

    • Authors: James Wissman; Michael D. Dickey, Carmel Majidi
      Abstract: When immersed in an electrolyte, droplets of Ga-based liquid metal (LM) alloy can be manipulated in ways not possible with conventional electrocapillarity or electrowetting. This study demonstrates how LM electrochemistry can be exploited to coalesce and separate droplets under moderate voltages of ~1–10 V. This novel approach to droplet interaction can be explained with a theory that accounts for oxidation and reduction as well as fluidic instabilities. Based on simulations and experimental analysis, this study finds that droplet separation is governed by a unique limit-point instability that arises from gradients in bipolar electrochemical reactions that lead to gradients in interfacial tension. The LM coalescence and separation are used to create a field-programmable electrical switch. As with conventional relays or flip-flop latch circuits, the system can transition between bistable (separated or coalesced) states, making it useful for memory storage, logic, and shape-programmable circuitry using entirely liquids instead of solid-state materials.This study presents a fluidic electrical switch that reversibly changes states in response to moderate applied voltage (≈1–10 V). It comprises two liquid metal droplets anchored to copper pads and immersed in an electrolytic solution. This “liquid transistor” is the first soft-matter electrical switch that operates with voltages similar to that of conventional solid-state transistors.
      PubDate: 2017-09-26T23:07:06.137505-05:
      DOI: 10.1002/advs.201700169
       
  • Hematological Effects of Gold Nanorods on Erythrocytes: Hemolysis and
           Hemoglobin Conformational and Functional Changes

    • Authors: Xingchen Zhao; Dawei Lu, S. Qian Liu, Yiling Li, Rui Feng, Fang Hao, Guangbo Qu, Qunfang Zhou, Guibin Jiang
      Abstract: Gold nanorods (GNRs) are a unique class of metal nanostructures that have attractive potentials in biomedical applications, and the concern on their biological safety is concomitantly increasing. Hemocompatibility is extremely important as their contact with blood circulation is unavoidable during in vivo delivery. Herein, two kinds of GNRs coated with hexadecyltrimethylammonium bromide (C-GNRs) or poly(sodium-p-styrenesulfonate) are used to test their potential toxicological effects in blood. C-GNRs with positive surface charges efficiently induce hemolysis when encountering erythrocytes. Cellular internalization of C-GNRs is found, and they subsequently bind with hemoglobin, forming bioconjugates. The interaction between hemoglobin and C-GNR (stoichiometry 32.7:1) is regulated by electrostatic forces. Chromophores like tryptophan (Trp) are found to interact with C-GNRs, causing enhancement in fluorescence intensity. The conformation of protein is partially altered, evidenced by decrease in α-helical, increase in β-sheet and random coil of hemoglobin. Although C-GNRs do not essentially decrease oxygen binding capacity of hemoglobin, they hamper oxygen release from the protein. Heme, the oxygen binding unit, releases from hemoglobin upon C-GNR treatment, which could contribute to C-GNR-induced hemolysis. This study demonstrates the hematological effects of GNRs, revealing their potential risk in biomedical applications.The hematological effects are investigated for positively charged gold nanorods (C-GNRs) and negatively charged ones (P-GNRs). In contrast to P-GNRs, C-GNRs efficiently induce hemolysis when encountering erythrocytes. C-GNRs subsequently bind with hemoglobin after being encapsulated, inducing conformational and functional changes of the protein. The bound hemoglobin partially loses its function of oxygen release while retains the oxygen binding capacity.
      PubDate: 2017-09-25T11:10:59.116856-05:
      DOI: 10.1002/advs.201700296
       
  • Exploitation of the Large-Area Basal Plane of MoS2 and Preparation of
           Bifunctional Catalysts through On-Surface Self-Assembly

    • Authors: Yinghe Zhao; Qiang Li, Li Shi, Jinlan Wang
      Abstract: The development of nonprecious electrochemical catalysts for water splitting is a key step to achieve a sustainable energy supply for the future. Molybdenum disulfide (MoS2) has been extensively studied as a promising low-cost catalyst for hydrogen evolution reaction (HER), whereas HER is only catalyzed at the edge for pristine MoS2, leaving a large area of basal plane useless. Herein, on-surface self-assembly is demonstrated to be an effective, facile, and damage-free method to take full advantage of the large ratio surface of MoS2 for HER by using multiscale simulations. It is found that as supplement of edge sites of MoS2, on-MoS2 M(abt)2 (M = Ni, Co; abt = 2-aminobenzenethiolate) owns high HER activity, and the self-assembled M(abt)2 monolayers on MoS2 can be obtained through a simple liquid-deposition method. More importantly, on-surface self-assembly provides potential application for overall water splitting once the self-assembled systems prove to be of both HER and oxygen evolution reaction activities, for example, on-MoS2 Co(abt)2. This work opens up a new and promising avenue (on-surface self-assembly) toward the full exploitation of the basal plane of MoS2 for HER and the preparation of bifunctional catalysts for overall water splitting.On-surface self-assembly is demonstrated to be an effective, facile, and damage-free method to exploit the large-area basal plane of MoS2 for hydrogen evolution reaction (HER). Efficient exploitation for the basal plane of MoS2 is achieved based on significantly increased HER active sites by on-surface self-assembly. Moreover, on-surface self-assembly can serve for the preparation of bifunctional catalysts toward overall water splitting.
      PubDate: 2017-09-23T23:06:25.892835-05:
      DOI: 10.1002/advs.201700356
       
  • Enhanced Charge Collection in MOF-525–PEDOT Nanotube Composites Enable
           Highly Sensitive Biosensing

    • Authors: Tzu-Yen Huang; Chung-Wei Kung, Yu-Te Liao, Sheng-Yuan Kao, Mingshan Cheng, Ting-Hsiang Chang, Joel Henzie, Hatem R. Alamri, Zeid A. Alothman, Yusuke Yamauchi, Kuo-Chuan Ho, Kevin C.-W. Wu
      Abstract: With the aim of a reliable biosensing exhibiting enhanced sensitivity and selectivity, this study demonstrates a dopamine (DA) sensor composed of conductive poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) conformally coated with porphyrin-based metal–organic framework nanocrystals (MOF-525). The MOF-525 serves as an electrocatalytic surface, while the PEDOT NTs act as a charge collector to rapidly transport the electron from MOF nanocrystals. Bundles of these particles form a conductive interpenetrating network film that together: (i) improves charge transport pathways between the MOF-525 regions and (ii) increases the electrochemical active sites of the film. The electrocatalytic response is measured by cyclic voltammetry and differential pulse voltammetry techniques, where the linear concentration range of DA detection is estimated to be 2 × 10−6–270 × 10−6m and the detection limit is estimated to be 0.04 × 10−6m with high selectivity toward DA. Additionally, a real-time determination of DA released from living rat pheochromocytoma cells is realized. The combination of MOF5-25 and PEDOT NTs creates a new generation of porous electrodes for highly efficient electrochemical biosensing.A novel nanocomposite consists of poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) coated with porphyrin-based metal–organic framework nanocrystals (MOF-525) via in situ synthesis. The MOF-525 serves as an electrocatalytic surface and the PEDOT NTs act as a charge collector to rapidly transport the electron from MOF nanocrystals. The obtained nanocomposites establish a new generation of porous electrodes for highly efficient electrochemical biosensing.
      PubDate: 2017-09-22T23:07:27.320199-05:
      DOI: 10.1002/advs.201700261
       
  • Metallic Sn-Based Anode Materials: Application in High-Performance
           Lithium-Ion and Sodium-Ion Batteries

    • Authors: Hangjun Ying; Wei-Qiang Han
      Abstract: With the fast-growing demand for green and safe energy sources, rechargeable ion batteries have gradually occupied the major current market of energy storage devices due to their advantages of high capacities, long cycling life, superior rate ability, and so on. Metallic Sn-based anodes are perceived as one of the most promising alternatives to the conventional graphite anode and have attracted great attention due to the high theoretical capacities of Sn in both lithium-ion batteries (LIBs) (994 mA h g−1) and sodium-ion batteries (847 mA h g−1). Though Sony has used Sn–Co–C nanocomposites as its commercial LIB anodes, to develop even better batteries using metallic Sn-based anodes there are still two main obstacles that must be overcome: poor cycling stability and low coulombic efficiency. In this review, the latest and most outstanding developments in metallic Sn-based anodes for LIBs and SIBs are summarized. And it covers the modification strategies including size control, alloying, and structure design to effectually improve the electrochemical properties. The superiorities and limitations are analyzed and discussed, aiming to provide an in-depth understanding of the theoretical works and practical developments of metallic Sn-based anode materials.To overcome the main obstacles of poor cycling stability and low coulombic efficiency faced by metallic Sn-based anodes, a lot of modification methods have been developed, including size control, alloying, and structure design. In this review, the state-of-the-art works of metallic Sn-based anodes are summarized and classified, and the superiorities and limitations are analyzed and discussed.
      PubDate: 2017-09-22T01:56:26.910629-05:
      DOI: 10.1002/advs.201700298
       
  • Steering Photoelectrons Excited in Carbon Dots into Platinum Cluster
           Catalyst for Solar-Driven Hydrogen Production

    • Authors: Xiaoyong Xu; Wenshuai Tang, Yiting Zhou, Zhijia Bao, Yuanchang Su, Jingguo Hu, Haibo Zeng
      Abstract: In composite photosynthetic systems, one most primary promise is to pursue the effect coupling among light harvesting, charge transfer, and catalytic kinetics. Herein, this study designs the reduced carbon dots (r-CDs) as both photon harvesters and photoelectron donors in combination with the platinum (Pt) clusters and fabricated the function-integrated r-CD/Pt photocatalyst through a photochemical route to control the anchoring of Pt clusters on r-CDs' surface for solar-driven hydrogen (H2) generation. In the obtained r-CD/Pt composite, the r-CDs absorb solar photons and transform them into energetic electrons, which transfer to the Pt clusters with favorable charge separation for H2 evolution reaction (HER). As a result, the efficient coupling of respective natures from r-CDs in photon harvesting and Pt in proton reduction is achieved through well-steered photoelectron transfer in the r-CD/Pt system to cultivate a remarkable and stable photocatalytic H2 evolution activity with an average rate of 681 µmol g−1 h−1. This work integrates two functional components into an effective HER photocatalyst and gains deep insights into the regulation of the function coupling in composite photosynthetic systems.This study reports an effective r-CD/Pt composite photocatalyst based on the combination of two superior function components for solar H2 production. The efficient coupling of respective natures from r-CDs in photon harvesting and Pt in proton reduction is achieved to cultivate a remarkable and stable photocatalytic H2 evolution activity.
      PubDate: 2017-09-21T04:01:06.920851-05:
      DOI: 10.1002/advs.201700273
       
  • Rational Design of a Water-Storable Hierarchical Architecture Decorated
           with Amorphous Barium Oxide and Nickel Nanoparticles as a Solid Oxide Fuel
           Cell Anode with Excellent Sulfur Tolerance

    • Authors: Yufei Song; Wei Wang, Lei Ge, Xiaomin Xu, Zhenbao Zhang, Paulo Sérgio Barros Julião, Wei Zhou, Zongping Shao
      Abstract: Solid oxide fuel cells (SOFCs), which can directly convert chemical energy stored in fuels into electric power, represent a useful technology for a more sustainable future. They are particularly attractive given that they can be easily integrated into the currently available fossil fuel infrastructure to realize an ideal clean energy system. However, the widespread use of the SOFC technology is hindered by sulfur poisoning at the anode caused by the sulfur impurities in fossil fuels. Therefore, improving the sulfur tolerance of the anode is critical for developing SOFCs for use with fossil fuels. Herein, a novel, highly active, sulfur-tolerant anode for intermediate-temperature SOFCs is prepared via a facile impregnation and limited reaction protocol. During synthesis, Ni nanoparticles, water-storable BaZr0.4Ce0.4Y0.2O3−δ (BZCY) perovskite, and amorphous BaO are formed in situ and deposited on the surface of a Sm0.2Ce0.8O1.9 (SDC) scaffold. More specifically, a porous SDC scaffold is impregnated with a well-designed proton-conducting perovskite oxide liquid precursor with the nominal composition of Ba(Zr0.4Ce0.4Y0.2)0.8Ni0.2O3−δ (BZCYN), calcined and reduced in hydrogen. The as-synthesized hierarchical architecture exhibits high H2 electro-oxidation activity, excellent operational stability, superior sulfur tolerance, and good thermal cyclability. This work demonstrates the potential of combining nanocatalysts and water-storable materials in advanced electrocatalysts for SOFCs.A novel, highly active, sulfur-tolerant anode composed of Ni nanoparticles, water-storable BaZr0.4Ce0.4Y0.2O3−δ perovskite, and amorphous BaO deposited on an Sm0.2Ce0.8O1.9 scaffold is prepared by a facile impregnation and limited reaction protocol providing excellent operational stability and outstanding thermal cyclability, making it a promising direction in solid oxide fuel cells.
      PubDate: 2017-09-15T23:16:56.202983-05:
      DOI: 10.1002/advs.201700337
       
  • Photodetectors Based on Organic–Inorganic Hybrid Lead Halide
           Perovskites

    • Authors: Jiachen Zhou; Jia Huang
      Abstract: Recent years have witnessed skyrocketing research achievements in organic–inorganic hybrid lead halide perovskites (OIHPs) in the photovoltaic field. In addition to photovoltaics, more and more studies have focused on OIHPs-based photodetectors in the past two years, due to the remarkable optoelectronic properties of OIHPs. This article summarizes the latest progress in this research field. To begin with, the factors influencing the performance of photodetectors are discussed, including both internal and external factors. In particular, the channel width and the incident power intensities should be taken into account to precisely and objectively evaluate and compare the output performance of different photodetectors. Next, photodetectors fabricated on single-component perovskites in terms of different micromorphologies are discussed, namely, 3D thin-film and single crystalline, 2D nanoplates, 1D nanowires, and 0D nanocrystals, respectively. Then, bilayer structured perovskite-based photodetectors incorporating inorganic and organic semiconductors are discussed to improve the optoelectronic performance of their pristine counterparts. Additionally, flexible OIHPs-based photodetectors are highlighted. Finally, a brief conclusion and outlook is given on the progress and challenges in the field of perovskites-based photodetectors.The latest progress in organic–inorganic hybrid lead halide perovskites (OIHPs)-based photodetectors (PDs) is summarized. The factors influencing their performance are discussed, including both internal (crystalline structure, micromorphology, and device architecture) and external factors. Single-component OIHPs-based PDs in terms of different micromorphologies and bilayer-structured OIHPs-based PDs incorporating semiconductors are discussed. In addition, flexible OIHPs-based PDs are highlighted.
      PubDate: 2017-09-15T13:11:52.263711-05:
      DOI: 10.1002/advs.201700256
       
  • Corrosion-Protected Hybrid Nanoparticles

    • Authors: Hyeon-Ho Jeong; Mariana Alarcón-Correa, Andrew G. Mark, Kwanghyo Son, Tung-Chun Lee, Peer Fischer
      Abstract: Nanoparticles composed of functional materials hold great promise for applications due to their unique electronic, optical, magnetic, and catalytic properties. However, a number of functional materials are not only difficult to fabricate at the nanoscale, but are also chemically unstable in solution. Hence, protecting nanoparticles from corrosion is a major challenge for those applications that require stability in aqueous solutions and biological fluids. Here, this study presents a generic scheme to grow hybrid 3D nanoparticles that are completely encapsulated by a nm thick protective shell. The method consists of vacuum-based growth and protection, and combines oblique physical vapor deposition with atomic layer deposition. It provides wide flexibility in the shape and composition of the nanoparticles, and the environments against which particles are protected. The work demonstrates the approach with multifunctional nanoparticles possessing ferromagnetic, plasmonic, and chiral properties. The present scheme allows nanocolloids, which immediately corrode without protection, to remain functional, at least for a week, in acidic solutions.A growth scheme is presented that enables the complete encapsulation of nanoparticles and nanostructures. Nanomaterials that are chemically unstable and prone to corrosion can be encapsulated with a nm thick shell and stabilized for days in corrosive environments.
      PubDate: 2017-09-15T13:11:04.284382-05:
      DOI: 10.1002/advs.201700234
       
  • CO2 Reduction: From the Electrochemical to Photochemical Approach

    • Authors: Jinghua Wu; Yang Huang, Wen Ye, Yanguang Li
      Abstract: Increasing CO2 concentration in the atmosphere is believed to have a profound impact on the global climate. To reverse the impact would necessitate not only curbing the reliance on fossil fuels but also developing effective strategies capture and utilize CO2 from the atmosphere. Among several available strategies, CO2 reduction via the electrochemical or photochemical approach is particularly attractive since the required energy input can be potentially supplied from renewable sources such as solar energy. In this Review, an overview on these two different but inherently connected approaches is provided and recent progress on the development, engineering, and understanding of CO2 reduction electrocatalysts and photocatalysts is summarized. First, the basic principles that govern electrocatalytic or photocatalytic CO2 reduction and their important performance metrics are discussed. Then, a detailed discussion on different CO2 reduction electrocatalysts and photocatalysts as well as their generally designing strategies is provided. At the end of this Review, perspectives on the opportunities and possible directions for future development of this field are presented.CO2 reduction to useful chemical fuels via the electrochemical or photochemical approach represents promising directions to convert and utilize this greenhouse gas molecule. The Review summarizes recent progress on the development, engineering, and understanding of CO2 reduction electrocatalysts and photocatalysts.
      PubDate: 2017-09-12T07:51:38.68804-05:0
      DOI: 10.1002/advs.201700194
       
  • Genome Editing for Cancer Therapy: Delivery of Cas9 Protein/sgRNA Plasmid
           via a Gold Nanocluster/Lipid Core–Shell Nanocarrier

    • Authors: Peng Wang; Lingmin Zhang, Yangzhouyun Xie, Nuoxin Wang, Rongbing Tang, Wenfu Zheng, Xingyu Jiang
      Abstract: The type II bacterial clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 (CRISPR-associated protein) system (CRISPR-Cas9) is a powerful toolbox for gene-editing, however, the nonviral delivery of CRISPR-Cas9 to cells or tissues remains a key challenge. This paper reports a strategy to deliver Cas9 protein and single guide RNA (sgRNA) plasmid by a nanocarrier with a core of gold nanoclusters (GNs) and a shell of lipids. By modifying the GNs with HIV-1-transactivator of transcription peptide, the cargo (Cas9/sgRNA) can be delivered into cell nuclei. This strategy is utilized to treat melanoma by designing sgRNA targeting Polo-like kinase-1 (Plk1) of the tumor. The nanoparticle (polyethylene glycol-lipid/GNs/Cas9 protein/sgPlk1 plasmid, LGCP) leads to>70% down-regulation of Plk1 protein expression of A375 cells in vitro. Moreover, the LGCP suppresses melanoma progress by 75% on mice. Thus, this strategy can deliver protein-nucleic acid hybrid agents for gene therapy.A strategy to deliver Cas9 protein and single guide RNA plasmid is reported by using a nanocarrier with a core of gold nanoclusters (GNs) and a shell of lipids. The nanoparticle (polyethylene glycol-lipid/GNs/Cas9 protein/sgPlk1 plasmid) can knockout Polo-like kinase-1 (Plk1) of target tumor and effectively suppress tumor progression in vitro and in vivo.
      PubDate: 2017-09-07T00:00:44.31243-05:0
      DOI: 10.1002/advs.201700175
       
  • Rod-Shaped Active Drug Particles Enable Efficient and Safe Gene Delivery

    • Authors: Xiaofei Xin; Xue Pei, Xin Yang, Yaqi Lv, Li Zhang, Wei He, Lifang Yin
      Abstract: Efficient microRNAs (miRNA) delivery into cells is a promising strategy for disease therapy, but is a major challenge because the available conventional nonviral vectors have significant drawbacks. In particular, after these vectors are entrapped in lysosomes, the escape efficiency of genes from lysosomes into the cytosol is less than 2%. Here, a novel approach for lethal-7a (let-7a) replacement therapy using rod-shaped active pure drug nanoparticles (≈130 nm in length, PNPs) with a dramatically high drug-loading of ≈300% as vectors is reported. Importantly, unlike other vectors, the developed PNPs/let-7a complexes (≈178 nm, CNPs) can enter cells and bypass the lysosomal route to localize to the cytosol, achieving efficient intracellular delivery of let-7a and a 50% reduction in expression of the target protein (KRAS). Also, CNPs prolong the t1/2 of blood circulation by ≈threefold and increase tumor accumulation by ≈1.5–2-fold, resulting in significantly improved antitumor efficacies. Additionally, no damage to normal organs is observed following systemic injection of CNPs. In conclusion, rod-shaped active PNPs enable efficient and safe delivery of miRNA with synergistic treatment for disease. This nanoplatform would also offer a viable strategy for the potent delivery of proteins and peptides in vitro and in vivo.An approach for microRNAs (let-7a) replacement therapy based on rod-shaped pure drug nanoparticles (PNPs) is reported. PNPs deliver let-7a to cancer cells bypassing the lysosomal route and enable twofold increase of let-7a and threefold decrease of target protein in tumor and ≈100% inhibition of tumor-growth and lung-metastasis. This work provides a valuable nanoplatform for efficient and safe gene delivery.
      PubDate: 2017-09-05T11:57:40.674143-05:
      DOI: 10.1002/advs.201700324
       
  • A New Electron Acceptor with meta-Alkoxyphenyl Side Chain for
           Fullerene-Free Polymer Solar Cells with 9.3% Efficiency

    • Authors: Zhenzhen Zhang; Liuliu Feng, Shutao Xu, Ye Liu, Hongjian Peng, Zhi-Guo Zhang, Yongfang Li, Yingping Zou
      Abstract: A new small molecule acceptor, m-ITIC-OR, based on indacenodithieno[3,2-b]thiophene core with meta-alkoxyphenyl side chains, is designed and synthesized. The m-ITIC-OR film shows broader and redshift absorption compared to its solution and matched energy levels with a hexafluoroquinoxaline-based polymer donor-HFQx-T. Here, polymer solar cells (PSCs) by blending an HFQx-T donor and an m-ITIC-OR acceptor as an active layer deliver the power conversion efficiency (PCE) of 6.36% without any posttreatment. The investigations demonstrate that the HFQx-T:m-ITIC-OR blend films possess higher and more balanced charge mobility, negligible bimolecular recombination, and nanoscale interpenetrating morphology after thermal annealing (TA) treatment. Through a simple TA treatment at 150 °C for 5 min, an impressive PCE of 9.3% is obtained. This efficiency is among one of the highest PCEs for additive free PSCs. This is the first time alkoxyphenyl side chain is introduced into nonfullerene electron acceptor; more interestingly, the new electron acceptor (m-ITIC-OR) in this work shows a great potential for highly efficient photovoltaic properties.A new electron acceptor (m-ITIC-OR) with meta-alkoxyphenyl side chains is designed and synthesized. A power conversion efficiency of 9.3% is achieved in nonfullerene polymer solar cells, demonstrating that the meta-alkoxyphenyl side chain is promising for constructing a high-performance electron acceptor due to its simplicity and low cost. m-ITIC-OR shows a great potential for photovoltaic applications.
      PubDate: 2017-08-17T23:07:25.478657-05:
      DOI: 10.1002/advs.201700152
       
  • Nanoporous PbSe–SiO2 Thermoelectric Composites

    • Authors: Chao-Feng Wu; Tian-Ran Wei, Fu-Hua Sun, Jing-Feng Li
      Abstract: Nanoporous architecture has long been predicted theoretically for its proficiency in suppressing thermal conduction, but less concerned as a practical approach for better thermoelectric materials hitherto probably due to its technical challenges. This article demonstrates a study on nanoporous PbSe–SiO2 composites fabricated by a facile method of mechanical alloying assisted by subsequent wet-milling and then spark plasma sintering. Owing to the formation of random nanopores and additional interface scattering, the lattice thermal conductivity is limited to a value as low as 0.56 W m−1 K−1 at above 600 K, almost the same low level achieved by introducing nanoscale precipitates. Besides, the room-temperature electrical transport is found to be dominated by the grain-boundary potential barrier scattering, whose effect fades away with increasing temperatures. Consequently, a maximum ZT of 1.15 at 823 K is achieved in the PbSe + 0.7 vol% SiO2 composition with>20% increase in average ZT, indicating the great potential of nanoporous structuring toward high thermoelectric conversion efficiency.Nanoporous thermoelectric composites are fabricated by a facile milling method, where nanosized SiO2 particles help to create randomly distributed nanopores throughout PbSe matrix. The existence of nanoporous structure significantly lowers the thermal conductivity with a low plateau above 600 K, eventually benefiting the thermoelectric efficiency of PbSe at moderate temperatures.
      PubDate: 2017-08-11T23:08:37.723383-05:
      DOI: 10.1002/advs.201700199
       
  • Self-Tuning n-Type Bi2(Te,Se)3/SiC Thermoelectric Nanocomposites to
           Realize High Performances up to 300 °C

    • Authors: Yu Pan; Umut Aydemir, Fu-Hua Sun, Chao-Feng Wu, Thomas C. Chasapis, G. Jeffrey Snyder, Jing-Feng Li
      Abstract: Bi2Te3 thermoelectric materials are utilized for refrigeration for decades, while their application of energy harvesting requires stable thermoelectric and mechanical performances at elevated temperatures. This work reveals that a steady zT of ≈0.85 at 200 to 300 °C can be achieved by doping small amounts of copper iodide (CuI) in Bi2Te2.2Se0.8–silicon carbide (SiC) composites, where SiC nanodispersion enhances the flexural strength. It is found that CuI plays two important roles with atomic Cu/I dopants and CuI precipitates. The Cu/I dopants show a self-tuning behavior due to increasing solubility with increasing temperatures. The increased doping concentration increases electrical conductivity at high temperatures and effectively suppresses the intrinsic excitation. In addition, a large reduction of lattice thermal conductivity is achieved due to the “in situ” CuI nanoprecipitates acting as phonon-scattering centers. Over 60% reduction of bipolar thermal conductivity is achieved, raising the maximum useful temperature of Bi2Te3 for substantially higher efficiency. For module applications, the reported materials are suitable for segmentation with a conventional ingot. This leads to high device ZT values of ≈0.9–1.0 and high efficiency up to 9.2% from 300 to 573 K, which can be of great significance for power generation from waste heat.High device ZT and efficiency can be achieved by segmenting a Bi2Te2.79Se0.21 ingot and a Cu/I-doped Bi2Te2.2Se0.8 sample. By extending the use of Bi2Te3 to higher temperatures, the overall efficiency is increased to 9.2%, which rivals that of mid temperature materials (hot side temperature ≈675–900 K), making Bi2Te3 competitive for waste-heat power generation applications.
      PubDate: 2017-08-11T23:07:51.502048-05:
      DOI: 10.1002/advs.201700259
       
  • Sequentially Programmable and Cellularly Selective Assembly of Fluorescent
           Polymerized Vesicles for Monitoring Cell Apoptosis

    • Authors: Shu Peng; Yu-Chen Pan, Yaling Wang, Zhe Xu, Chao Chen, Dan Ding, Yongjian Wang, Dong-Sheng Guo
      Abstract: The introduction of controlled self-assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme-activated examples reported before, controlled self-assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self-assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof-of-principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis-inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal-to-noise ratio.Thermochromic fluorescent polymerized vesicles are successfully constructed in living cells by implementing a sequentially programmable self-assembling strategy, which may find use in various biomedical applications, as herein demonstrated by a proof-of-principle example for monitoring the cell apoptosis process involved in the overexpression of cholinesterase.
      PubDate: 2017-08-10T01:40:41.294949-05:
      DOI: 10.1002/advs.201700310
       
  • Anchoring CoFe2O4 Nanoparticles on N-Doped Carbon Nanofibers for
           High-Performance Oxygen Evolution Reaction

    • Authors: Tongfei Li; Yinjie Lv, Jiahui Su, Yi Wang, Qian Yang, Yiwei Zhang, Jiancheng Zhou, Lin Xu, Dongmei Sun, Yawen Tang
      Abstract: The exploration of earth-abundant and high-efficiency electrocatalysts for the oxygen evolution reaction (OER) is of great significant for sustainable energy conversion and storage applications. Although spinel-type binary transition metal oxides (AB2O4, A, B = metal) represent a class of promising candidates for water oxidation catalysis, their intrinsically inferior electrical conductivity exert remarkably negative impacts on their electrochemical performances. Herein, we demonstrates a feasible electrospinning approach to concurrently synthesize CoFe2O4 nanoparticles homogeneously embedded in 1D N-doped carbon nanofibers (denoted as CoFe2O4@N-CNFs). By integrating the catalytically active CoFe2O4 nanoparticles with the N-doped carbon nanofibers, the as-synthesized CoFe2O4@N-CNF nanohybrid manifests superior OER performance with a low overpotential, a large current density, a small Tafel slope, and long-term durability in alkaline solution, outperforming the single component counterparts (pure CoFe2O4 and N-doped carbon nanofibers) and the commercial RuO2 catalyst. Impressively, the overpotential of CoFe2O4@N-CNFs at the current density of 30.0 mA cm−2 negatively shifts 186 mV as compared with the commercial RuO2 catalyst and the current density of the CoFe2O4@N-CNFs at 1.8 V is almost 3.4 times of that on RuO2 benchmark. The present work would open a new avenue for the exploration of cost-effective and efficient OER electrocatalysts to substitute noble metals for various renewable energy conversion/storage applications.A simple and scalable electrospinning strategy is developed for the concurrent synthesis of CoFe2O4 nanoparticles homogeneously embedded in N-doped carbon nanofibers (denoted as CoFe2O4@N-CNFs). The synthesized CoFe2O4@N-CNFs are demonstrated superior oxygen evolution reaction performance with a low overpotential, a large current density, a small Tafel slope, and long-term durability in alkaline solution.
      PubDate: 2017-08-07T01:26:49.999977-05:
      DOI: 10.1002/advs.201700226
       
  • High Performance Solid Polymer Electrolytes for Rechargeable Batteries: A
           Self-Catalyzed Strategy toward Facile Synthesis

    • Authors: Yanyan Cui; Xinmiao Liang, Jingchao Chai, Zili Cui, Qinglei Wang, Weisheng He, Xiaochen Liu, Zhihong Liu, Guanglei Cui, Jiwen Feng
      Abstract: It is urgent to seek high performance solid polymer electrolytes (SPEs) via a facile chemistry and simple process. The lithium salts are composed of complex anions that are stabilized by a Lewis acid agent. This Lewis acid can initiate the ring opening polymerization. Herein, a self-catalyzed strategy toward facile synthesis of crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte (C-PEGDE) is presented. It is manifested that the poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte possesses a superior electrochemical stability window up to 4.5 V versus Li/Li+ and considerable ionic conductivity of 8.9 × 10−5 S cm−1 at ambient temperature. Moreover, the LiFePO4/C-PEGDE/Li batteries deliver stable charge/discharge profiles and considerable rate capability. It is demonstrated that this self-catalyzed strategy can be a very effective approach for high performance solid polymer electrolytes.A self-catalyzed strategy is used to synthesize crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte in which lithium salts are used as a facile cationic polymerization catalyst. This crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte presents excellent conductivity and assembled LiFePO4/Li battery using this electrolyte displays stable charge/discharge profiles, considerable C-rate capability, and cycling performance.
      PubDate: 2017-08-02T23:06:28.546992-05:
      DOI: 10.1002/advs.201700174
       
  • Thermal Release Transfer Printing for Stretchable Conformal Bioelectronics

    • Authors: Zhuocheng Yan; Taisong Pan, Miaomiao Xue, Changyong Chen, Yan Cui, Guang Yao, Long Huang, Feiyi Liao, Wei Jing, Hulin Zhang, Min Gao, Daqing Guo, Yang Xia, Yuan Lin
      Abstract: Soft neural electrode arrays that are mechanically matched between neural tissues and electrodes offer valuable opportunities for the development of disease diagnose and brain computer interface systems. Here, a thermal release transfer printing method for fabrication of stretchable bioelectronics, such as soft neural electrode arrays, is presented. Due to the large, switchable and irreversible change in adhesion strength of thermal release tape, a low-cost, easy-to-operate, and temperature-controlled transfer printing process can be achieved. The mechanism of this method is analyzed by experiments and fracture-mechanics models. Using the thermal release transfer printing method, a stretchable neural electrode array is fabricated by a sacrificial-layer-free process. The ability of the as-fabricated electrode array to conform different curvilinear surfaces is confirmed by experimental and theoretical studies. High-quality electrocorticography signals of anesthetized rat are collected with the as-fabricated electrode array, which proves good conformal interface between the electrodes and dura mater. The application of the as-fabricated electrode array on detecting the steady-state visual evoked potentials research is also demonstrated by in vivo experiments and the results are compared with those detected by stainless-steel screw electrodes.A low-cost, easy-to-operate, and temperature-controlled thermal release transfer printing method is successfully realized to form stretchable bioelectronics for medical systems. Using this method, a stretchable neural electrode array with metal/polyimide structure is fabricated by a sacrificial-layer-free process and is successfully used for detecting high-fidelity electrocorticography signals from the dura mater of anesthetized rat.
      PubDate: 2017-07-31T06:07:10.832718-05:
      DOI: 10.1002/advs.201700251
       
  • Aluminum-Doped Cesium Lead Bromide Perovskite Nanocrystals with Stable
           Blue Photoluminescence Used for Display Backlight

    • Authors: Ming Liu; Guohua Zhong, Yongming Yin, Jingsheng Miao, Ke Li, Chengqun Wang, Xiuru Xu, Clifton Shen, Hong Meng
      Abstract: Bright and stable blue emitters with narrow full-width at half-maxima are particularly desirable for applications in television displays and related technologies. Here, this study shows that doping aluminum (Al3+) ion into CsPbBr3 nanocrystals (NCs) using AlBr3 can afford lead-halide perovskites NCs with stable blue photoluminescence. First, theoretical and experimental analyses reveal that the extended band gap and quantum confinement effect of elongated shape give rise to the desirable blueshifted emission. Second, the aluminum ion incorporation path is rationalized qualitatively by invoking fundamental considerations about binding relations in AlBr3 and its dimer. Finally, the absence of anion-exchange effect is corroborated when green CsPbBr3 and blue Al:CsPbBr3 NCs are mixed. Combinations of the above two NCs with red-emitting CdSe@ZnS NCs result in UV-pumped white light-emitting diodes (LED) with an National Television System Committee (NTSC) value of 116% and ITU-R Recommendation B.T. 2020 (Rec. 2020) of 87%. The color coordinates of the white LED are optimized at (0.32, 0.34) in CIE 1931. The results suggest that low-cost, earth-abundant, solution-processable Al-doped perovskite NCs can be promising candidate materials for blue down-conversion layer in backlit displays.Doping aluminum (Al3+) ion into CsPbBr3 nanocrystals (NCs) can afford lead-halide perovskite NCs with stable blue photoluminescence. Cation compositional engineering of perovskite NCs provides an additional way to rationally tune the photophysical property. By this way, emission spectra broadening and chromaticity drifting issues caused by fast anion exchange in different halide perovskite NCs based conversion layers can be avoid.
      PubDate: 2017-07-31T06:06:26.589817-05:
      DOI: 10.1002/advs.201700335
       
  • In Situ Ligation of High- and Low-Affinity Ligands to Cell Surface
           Receptors Enables Highly Selective Recognition

    • Authors: Misako Taichi; Shogo Nomura, Ikuhiko Nakase, Rie Imamaki, Yasuhiko Kizuka, Fumi Ota, Naoshi Dohmae, Shinobu Kitazume, Naoyuki Taniguchi, Katsunori Tanaka
      Abstract: This paper reports an entirely unexplored concept of simultaneously recognizing two receptors using high- and low-affinity ligands through ligating them in situ on the target cell surface. This de novo approach is inspired by the pretargeting strategy frequently applied in molecular imaging, and has now evolved as the basis of a new paradigm for visualizing target cells with a high imaging contrast. A distinct advantage of using a labeled low-affinity ligand such as glycan is that the excess labeled ligand can be washed away from the cells, whereas the ligand bound to the cell, even at the milli molar affinity level, can be anchored by a bioorthogonal reaction with a pretargeted high-affinity ligand on the surface. Consequently, nonspecific background is minimized, leading to improved imaging contrast. Importantly, despite previously unexplored for molecular imaging, a notoriously weak glycan/lectin interaction can now be utilized as a highly selective ligand to the targets.An entirely unexplored concept of simultaneously recognizing two receptors using high- and low-affinity ligands through ligating them on the target cell surface is reported. This de novo approach is inspired by the pretargeting strategy frequently applied in molecular imaging, and has now evolved as the basis of a new paradigm for visualizing target cells with a high imaging contrast.
      PubDate: 2017-07-28T01:00:02.38928-05:0
      DOI: 10.1002/advs.201700147
       
  • Toward Bioelectronic Medicine—Neuromodulation of Small Peripheral Nerves
           Using Flexible Neural Clip

    • Authors: Sanghoon Lee; Wendy Yen Xian Peh, Jiahui Wang, Fengyuan Yang, John S. Ho, Nitish V. Thakor, Shih-Cheng Yen, Chengkuo Lee
      Abstract: Neural modulation technology and the capability to affect organ function have spawned the new field of bioelectronic medicine. Therapeutic interventions depend on wireless bioelectronic neural interfaces that can conformally and easily attach to small (few hundred micrometers) nerves located deep in the body without neural damage. Besides size, factors like flexibility and compliance to attach and adapt to visceral nerves associated moving organs are of paramount importance and have not been previously addressed. This study proposes a novel flexible neural clip (FNC) that can be used to interface with a variety of different peripheral nerves. To illustrate the flexibility of the design, this study stimulates the pelvic nerve, the vagus nerve, and branches of the sciatic nerve and evaluates the feasibility of the design in modulating the function of each of these nerves. It is found that this FNC allows fine-tuning of physiological processes such as micturition, heart rate, and muscle contractions. Furthermore, this study also tests the ability of wirelessly powered FNC to enable remote modulation of visceral pelvic nerves located deep in the body. These results show that the FNC can be used with a range of different nerves, providing one of the critical pieces in the field of bioelectronics medicines.The proposed novel flexible neural clip (FNC) enables easy and conformal implantation on a variety of the peripheral nerves, allowing fine-tuning of physiological processes such as micturition, heart rate, and muscle contractions. Furthermore, the wireless FNC remotes modulation of visceral pelvic nerves located deep in the body. This FNC would pave a way of wireless neural modulation for bioelectronic medicine in the future.
      PubDate: 2017-07-26T23:07:59.407608-05:
      DOI: 10.1002/advs.201700149
       
  • A 3D Printed Implantable Device for Voiding the Bladder Using Shape Memory
           Alloy (SMA) Actuators

    • Authors: Faezeh Arab Hassani; Wendy Yen Xian Peh, Gil Gerald Lasam Gammad, Roshini Priya Mogan, Tze Kiat Ng, Tricia Li Chuen Kuo, Lay Guat Ng, Percy Luu, Shih-Cheng Yen, Chengkuo Lee
      Abstract: Underactive bladder or detrusor underactivity (DU) is defined as a reduction of contraction strength or duration of the bladder wall. Despite the serious healthcare implications of DU, there are limited solutions for affected individuals. A flexible 3D printed implantable device driven by shape memory alloys (SMA) actuators is presented here for the first time to physically contract the bladder to restore voluntary control of the bladder for individuals suffering from DU. This approach is used initially in benchtop experiments with a rubber balloon acting as a model for the rat bladder to verify its potential for voiding, and that the operating temperatures are safe for the eventual implantation of the device in a rat. The device is then implanted and tested on an anesthetized rat, and a voiding volume of more than 8% is successfully achieved for the SMA-based device without any surgical intervention or drug injection to relax the external sphincter.A novel flexible actuating device driven by shape memory alloy wires is developed and tested in a benchtop setup to study its potential in physically contracting a rubber replica of a bladder. The device is then implanted successfully in an anesthetized animal. This device can potentially help affected individuals with detrusor muscle atrophy to achieve facilitated micturition.
      PubDate: 2017-07-26T23:07:28.243884-05:
      DOI: 10.1002/advs.201700143
       
  • Single Nucleotide Polymorphism Genotyping in Single-Molecule Electronic
           Circuits

    • Authors: Gen He; Jie Li, Chuanmin Qi, Xuefeng Guo
      Abstract: Establishing low-cost, high-throughput, simple, and accurate single nucleotide polymorphism (SNP) genotyping techniques is beneficial for understanding the intrinsic relationship between individual genetic variations and their biological functions on a genomic scale. Here, a straightforward and reliable single-molecule approach is demonstrated for precise SNP authentication by directly measuring the fluctuations in electrical signals in an electronic circuit, which is fabricated from a high-gain field-effect silicon nanowire decorated with a single hairpin DNA, in the presence of different target DNAs. By simply comparing the proportion difference of a probe-target duplex structure throughout the process, this study implements allele-specific and accurate SNP detection. These results are supported by the statistical analyses of different dynamic parameters such as the mean lifetime and the unwinding probability of the duplex conformation. In comparison with conventional polymerase chain reaction and optical methods, this convenient and label-free method is complementary to existing optical methods and also shows several advantages, such as simple operation and no requirement for fluorescent labeling, thus promising a futuristic route toward the next-generation genotyping technique.A straightforward and reliable single-molecule approach for precise single nucleotide polymorphism detection is developed through directly measuring the fluctuation of electrical signals in an electronic circuit, which is fabricated from a high-gain field-effect silicon nanowire decorated by a single hairpin DNA, in the presence of different target DNAs, promising a futuristic route toward the next-generation genotyping technique.
      PubDate: 2017-07-26T06:21:09.799987-05:
      DOI: 10.1002/advs.201700158
       
  • Realizing the Embedded Growth of Large Li2O2 Aggregations by Matching
           Different Metal Oxides for High-Capacity and High-Rate Lithium Oxygen
           Batteries

    • Authors: Peng Zhang; Shoufeng Zhang, Mu He, Junwei Lang, Aimin Ren, Shan Xu, Xingbin Yan
      Abstract: Large Li2O2 aggregations can produce high-capacity of lithium oxygen (Li-O2) batteries, but the larger ones usually lead to less-efficient contact between Li2O2 and electrode materials. Herein, a hierarchical cathode architecture based on different discharge characteristics of α-MnO2 and Co3O4 is constructed, which can enable the embedded growth of large Li2O2 aggregations to solve this problem. Through experimental observations and first-principle calculations, it is found that α-MnO2 nanorod tends to form uniform Li2O2 particles due to its preferential Li+ adsorption and similar LiO2 adsorption energies of different crystal faces, whereas Co3O4 nanosheet tends to simultaneously generate Li2O2 film and Li2O2 nanosheets due to its preferential O2 adsorption and different LiO2 adsorption energies of varied crystal faces. Thus, the composite cathode architecture in which Co3O4 nanosheets are grown on α-MnO2 nanorods can exhibit extraordinary synergetic effects, i.e., α-MnO2 nanorods provide the initial nucleation sites for Li2O2 deposition while Co3O4 nanosheets provide dissolved LiO2 to promote the subsequent growth of Li2O2. Consequently, the composite cathode achieves the embedded growth of large Li2O2 aggregations and thus exhibits significantly improved specific capacity, rate capability, and cyclic stability compared with the single metal oxide electrode.Embedded growth of Li2O2 is realized through a scientific fabrication of α-MnO2/Co3O4 cathode architecture, of which α-MnO2 plays the role of initially nucleation sites for Li2O2 while Co3O4 produces plenty of dissolved LiO2, inducing the formation of large Li2O2 aggregations with embedded structure, and thus showing remarkably improved electrochemical performance of Li-O2 battery.
      PubDate: 2017-07-20T00:21:51.146652-05:
      DOI: 10.1002/advs.201700172
       
  • Mixed-Organic-Cation Tin Iodide for Lead-Free Perovskite Solar Cells with
           an Efficiency of 8.12%

    • Authors: Ziran Zhao; Feidan Gu, Yunlong Li, Weihai Sun, Senyun Ye, Haixia Rao, Zhiwei Liu, Zuqiang Bian, Chunhui Huang
      Abstract: In this work, a fully tin-based, mixed-organic-cation perovskite absorber (FA)x(MA)1−xSnI3 (FA = NH2CH = NH2+, MA = CH3NH3+) for lead-free perovskite solar cells (PSCs) with inverted structure is presented. By optimizing the ratio of FA and MA cations, a maximum power conversion efficiency of 8.12% is achieved for the (FA)0.75(MA)0.25SnI3-based device along with a high open-circuit voltage of 0.61 V, which originates from improved perovskite film morphology and inhibits recombination process in the device. The cation-mixing approach proves to be a facile method for the efficiency enhancement of tin-based PSCs.For the first time, an efficiency of over 8% is achieved for tin-based perovskite solar cells along with a high open-circuit voltage of 0.61 V by utilizing (FA)0.75(MA)0.25SnI3 as the absorber. The cation-mixing method is proven to effectively improve the morphology of tin-based perovskite films and reduce recombination process in the devices.
      PubDate: 2017-07-14T05:11:02.081234-05:
      DOI: 10.1002/advs.201700204
       
  • Culture-Free Detection of Crop Pathogens at the Single-Cell Level by
           Micro-Raman Spectroscopy

    • Authors: Qinhua Gan; Xuetao Wang, Yun Wang, Zhenyu Xie, Yang Tian, Yandu Lu
      Abstract: The rapid and sensitive identification of invasive plant pathogens has important applications in biotechnology, plant quarantine, and food security. Current methods are far too time-consuming and need a pre-enrichment period ranging from hours to days. Here, a micro-Raman spectroscopy-based bioassay for culture-free pathogen quarantine inspection at the single cell level within 40 min is presented. The application of this approach can readily and specifically detect plant pathogens Burkholderia gladioli pv. alliicola and Erwinia chrysanthemi that are closely related pathogenically. Furthermore, the single-bacterium detection was able to discriminate them from a reference Raman spectral library including multiple quarantine-relevant pathogens with broad host ranges and an array of pathogenic variants. To show the usefulness of this assay, Burkholderia gladioli pv. alliicola and Erwinia chrysanthemi are detected at single-bacterium level in plant tissue lesions without pre-enrichment. The results are confirmed by the plate-counting method and a genetic molecular approach, which display comparable recognition ratios to the Raman spectroscopy-based bioassay. The results represent a critical step toward the use of micro-Raman spectroscopy in rapid and culture-free discrimination of quarantine relevant plant pathogens.A micro-Raman spectroscopy-based bioassay enables fast and noninvasive discrimination of plant pathogens, and accurate culture-free single-bacterium detection in plant tissue lesions with an identification ratio comparable to those of genetic molecular approaches.
      PubDate: 2017-07-10T10:45:32.301021-05:
      DOI: 10.1002/advs.201700127
       
  • A Facile Surface Reconstruction Mechanism toward Better Electrochemical
           Performance of Li4Ti5O12 in Lithium-Ion Battery

    • Authors: Kun Qian; Linkai Tang, Marnix Wagemaker, Yan-Bing He, Dongqing Liu, Hai Li, Ruiying Shi, Baohua Li, Feiyu Kang
      Abstract: Through a facile sodium sulfide (Na2S)-assisted hydrothermal treatment, clean and nondefective surfaces are constructed on micrometer-sized Li4Ti5O12 particles. The remarkable improvement of surface quality shows a higher first cycle Coulombic efficiency (≈95%), a significantly enhanced cycling performance, and a better rate capability in electrochemical measurements. A combined study of Raman spectroscopy and inductive coupled plasma emission spectroscopy reveals that the evolution of Li4Ti5O12 surface in a water-based hydrothermal environment is a hydrolysis–recrystallization process, which can introduce a new phase of anatase-TiO2. While, with a small amount of Na2S (0.004 mol L−1 at least), the spinel-Li4Ti5O12 phase is maintained without a second phase. During this process, the alkaline environment created by Na2S and the surface adsorption of the sulfur-containing group (HS− or S2−) can suppress the recrystallization of anatase-TiO2 and renew the particle surfaces. This finding gives a better understanding of the surface–property relationship on Li4Ti5O12 and guidance on preparation and modification of electrode material other than coating or doping.Clean and nondefective surfaces are constructed on Li4Ti5O12 particles through a facile sodium sulfide (Na2S) assisted hydrothermal treatment. By improving the surface quality, a higher first cycle Coulombic efficiency (≈95%), a significantly enhanced cycling performance, and rate capability are realized, which highlight the newly discovered surface reconstruction mechanism and the surface–property relationship.
      PubDate: 2017-07-10T00:51:19.31229-05:0
      DOI: 10.1002/advs.201700205
       
  • Utilizing Co2+/Co3+ Redox Couple in P2-Layered Na0.66Co0.22Mn0.44Ti0.34O2
           Cathode for Sodium-Ion Batteries

    • Authors: Qin-Chao Wang; Enyuan Hu, Yang Pan, Na Xiao, Fan Hong, Zheng-Wen Fu, Xiao-Jing Wu, Seong-Min Bak, Xiao-Qing Yang, Yong-Ning Zhou
      Abstract: Developing sodium-ion batteries for large-scale energy storage applications is facing big challenges of the lack of high-performance cathode materials. Here, a series of new cathode materials Na0.66CoxMn0.66–xTi0.34O2 for sodium-ion batteries are designed and synthesized aiming to reduce transition metal-ion ordering, charge ordering, as well as Na+ and vacancy ordering. An interesting structure change of Na0.66CoxMn0.66–xTi0.34O2 from orthorhombic to hexagonal is revealed when Co content increases from x = 0 to 0.33. In particular, Na0.66Co0.22Mn0.44Ti0.34O2 with a P2-type layered structure delivers a reversible capacity of 120 mAh g−1 at 0.1 C. When the current density increases to 10 C, a reversible capacity of 63.2 mAh g−1 can still be obtained, indicating a promising rate capability. The low valence Co2+ substitution results in the formation of average Mn3.7+ valence state in Na0.66Co0.22Mn0.44Ti0.34O2, effectively suppressing the Mn3+-induced Jahn–Teller distortion, and in turn stabilizing the layered structure. X-ray absorption spectroscopy results suggest that the charge compensation of Na0.66Co0.22Mn0.44Ti0.34O2 during charge/discharge is contributed by Co2.2+/Co3+ and Mn3.3+/Mn4+ redox couples. This is the first time that the highly reversible Co2+/Co3+ redox couple is observed in P2-layered cathodes for sodium-ion batteries. This finding may open new approaches to design advanced intercalation-type cathode materials.Na0.66CoxMn0.66-xTi0.34O2 (0 ≤ x ≤ 0.33) for new cathode materials of sodium-ion batteries are designed and synthesized aiming to reduce transition metal ordering, charge ordering, as well as Na+ and vacancy ordering. The Co2+/Co3+ redox couple is revealed for the first time experimentally in the P2-layered cathodes, enabling a high rate capability with the help of Ti substitution.
      PubDate: 2017-07-06T10:52:15.013889-05:
      DOI: 10.1002/advs.201700219
       
  • Realization of Quasi-Omnidirectional Solar Cells with Superior Electrical
           Performance by All-Solution-Processed Si Nanopyramids

    • Authors: Sihua Zhong; Wenjie Wang, Miao Tan, Yufeng Zhuang, Wenzhong Shen
      Abstract: Large-scale (156 mm × 156 mm) quasi-omnidirectional solar cells are successfully realized and featured by keeping high cell performance over broad incident angles (θ), via employing Si nanopyramids (SiNPs) as surface texture. SiNPs are produced by the proposed metal-assisted alkaline etching method, which is an all-solution-processed method and highly simple together with cost-effective. Interestingly, compared to the conventional Si micropyramids (SiMPs)-textured solar cells, the SiNPs-textured solar cells possess lower carrier recombination and thus superior electrical performances, showing notable distinctions from other Si nanostructures-textured solar cells. Furthermore, SiNPs-textured solar cells have very little drop of quantum efficiency with increasing θ, demonstrating the quasi-omnidirectional characteristic. As an overall result, both the SiNPs-textured homojunction and heterojunction solar cells possess higher daily electric energy production with a maximum relative enhancement approaching 2.5%, when compared to their SiMPs-textured counterparts. The quasi-omnidirectional solar cell opens a new opportunity for photovoltaics to produce more electric energy with a low cost.Large-scale quasi-omnidirectional solar cells are successfully realized and featured by keeping high cell performance over broad incident angles, via employing Si nanopyramids as surface texture. Moreover, superior electrical performances are achieved in the Si nanopyramids-textured solar cells. As an overall result, higher daily/yearly electric energy can be produced compared to the conventional Si micropyramids-textured solar cells.
      PubDate: 2017-07-06T10:51:31.188843-05:
      DOI: 10.1002/advs.201700200
       
 
 
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