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  Subjects -> MATHEMATICS (Total: 909 journals)
    - APPLIED MATHEMATICS (75 journals)
    - GEOMETRY AND TOPOLOGY (20 journals)
    - MATHEMATICS (676 journals)
    - MATHEMATICS (GENERAL) (41 journals)
    - NUMERICAL ANALYSIS (19 journals)
    - PROBABILITIES AND MATH STATISTICS (78 journals)

MATHEMATICS (676 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 538 Journals sorted alphabetically
Abakós     Open Access   (Followers: 4)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 3)
Academic Voices : A Multidisciplinary Journal     Open Access   (Followers: 2)
Accounting Perspectives     Full-text available via subscription   (Followers: 7)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Mathematical Software (TOMS)     Hybrid Journal   (Followers: 6)
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 25)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1)
Acta Mathematica     Hybrid Journal   (Followers: 11)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 6)
Acta Mathematica Vietnamica     Hybrid Journal  
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal  
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Decision Sciences     Open Access   (Followers: 5)
Advances in Difference Equations     Open Access   (Followers: 2)
Advances in Fixed Point Theory     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 11)
Advances in Linear Algebra & Matrix Theory     Open Access   (Followers: 2)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Mathematical Physics     Open Access   (Followers: 5)
Advances in Mathematics     Full-text available via subscription   (Followers: 10)
Advances in Numerical Analysis     Open Access   (Followers: 4)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Pure and Applied Mathematics     Hybrid Journal   (Followers: 6)
Advances in Pure Mathematics     Open Access   (Followers: 4)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2)
African Journal of Educational Studies in Mathematics and Sciences     Full-text available via subscription   (Followers: 5)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Afrika Matematika     Hybrid Journal   (Followers: 1)
Air, Soil & Water Research     Open Access   (Followers: 9)
AKSIOMA Journal of Mathematics Education     Open Access   (Followers: 1)
Al-Jabar : Jurnal Pendidikan Matematika     Open Access  
Algebra and Logic     Hybrid Journal   (Followers: 4)
Algebra Colloquium     Hybrid Journal   (Followers: 4)
Algebra Universalis     Hybrid Journal   (Followers: 2)
Algorithmic Operations Research     Full-text available via subscription   (Followers: 5)
Algorithms     Open Access   (Followers: 11)
Algorithms Research     Open Access   (Followers: 1)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Mathematical Analysis     Open Access  
American Journal of Mathematics     Full-text available via subscription   (Followers: 7)
American Journal of Operations Research     Open Access   (Followers: 5)
American Mathematical Monthly     Full-text available via subscription   (Followers: 6)
An International Journal of Optimization and Control: Theories & Applications     Open Access   (Followers: 7)
Analele Universitatii Ovidius Constanta - Seria Matematica     Open Access   (Followers: 1)
Analysis     Hybrid Journal   (Followers: 2)
Analysis and Applications     Hybrid Journal   (Followers: 1)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 3)
Analysis Mathematica     Full-text available via subscription  
Annales Mathematicae Silesianae     Open Access  
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4)
Annales UMCS, Mathematica     Open Access   (Followers: 1)
Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica     Open Access  
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Discrete Mathematics     Full-text available via subscription   (Followers: 6)
Annals of Mathematics     Full-text available via subscription  
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 8)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of the Alexandru Ioan Cuza University - Mathematics     Open Access  
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1)
Annals of West University of Timisoara - Mathematics     Open Access  
Annuaire du Collège de France     Open Access   (Followers: 5)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applications of Mathematics     Hybrid Journal   (Followers: 1)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Mathematics     Open Access   (Followers: 3)
Applied Mathematics     Open Access   (Followers: 5)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 4)
Applied Mathematics - A Journal of Chinese Universities     Hybrid Journal  
Applied Mathematics Letters     Full-text available via subscription   (Followers: 1)
Applied Mathematics Research eXpress     Hybrid Journal   (Followers: 1)
Applied Network Science     Open Access   (Followers: 1)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Arab Journal of Mathematical Sciences     Open Access   (Followers: 3)
Arabian Journal of Mathematics     Open Access   (Followers: 2)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 1)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
Arnold Mathematical Journal     Hybrid Journal   (Followers: 1)
Artificial Satellites : The Journal of Space Research Centre of Polish Academy of Sciences     Open Access   (Followers: 21)
Asia-Pacific Journal of Operational Research     Hybrid Journal   (Followers: 3)
Asian Journal of Algebra     Open Access   (Followers: 1)
Asian Journal of Current Engineering & Maths     Open Access  
Asian-European Journal of Mathematics     Hybrid Journal   (Followers: 2)
Australian Mathematics Teacher, The     Full-text available via subscription   (Followers: 7)
Australian Primary Mathematics Classroom     Full-text available via subscription   (Followers: 3)
Australian Senior Mathematics Journal     Full-text available via subscription   (Followers: 1)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Axioms     Open Access   (Followers: 1)
Baltic International Yearbook of Cognition, Logic and Communication     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
BIBECHANA     Open Access   (Followers: 2)
BIT Numerical Mathematics     Hybrid Journal  
BoEM - Boletim online de Educação Matemática     Open Access  
Boletim Cearense de Educação e História da Matemática     Open Access  
Boletim de Educação Matemática     Open Access  
Boletín de la Sociedad Matemática Mexicana     Hybrid Journal  
Bollettino dell'Unione Matematica Italiana     Full-text available via subscription   (Followers: 1)
British Journal of Mathematical and Statistical Psychology     Full-text available via subscription   (Followers: 21)
Bruno Pini Mathematical Analysis Seminar     Open Access  
Buletinul Academiei de Stiinte a Republicii Moldova. Matematica     Open Access   (Followers: 11)
Bulletin des Sciences Mathamatiques     Full-text available via subscription   (Followers: 4)
Bulletin of Dnipropetrovsk University. Series : Communications in Mathematical Modeling and Differential Equations Theory     Open Access   (Followers: 1)
Bulletin of Mathematical Sciences     Open Access   (Followers: 1)
Bulletin of the Brazilian Mathematical Society, New Series     Hybrid Journal  
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 3)
Bulletin of the Malaysian Mathematical Sciences Society     Hybrid Journal  
Calculus of Variations and Partial Differential Equations     Hybrid Journal  
Canadian Journal of Science, Mathematics and Technology Education     Hybrid Journal   (Followers: 20)
Carpathian Mathematical Publications     Open Access   (Followers: 1)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 1)
CHANCE     Hybrid Journal   (Followers: 6)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
ChemSusChem     Hybrid Journal   (Followers: 7)
Chinese Annals of Mathematics, Series B     Hybrid Journal  
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Mathematics     Open Access  
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Cogent Mathematics     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Collectanea Mathematica     Hybrid Journal  
College Mathematics Journal     Full-text available via subscription   (Followers: 3)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Commentarii Mathematici Helvetici     Hybrid Journal   (Followers: 1)
Communications in Combinatorics and Optimization     Open Access  
Communications in Contemporary Mathematics     Hybrid Journal  
Communications in Mathematical Physics     Hybrid Journal   (Followers: 1)
Communications On Pure & Applied Mathematics     Hybrid Journal   (Followers: 3)
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Complex Variables and Elliptic Equations: An International Journal     Hybrid Journal  
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Comptes Rendus Mathematique     Full-text available via subscription   (Followers: 1)
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 6)
Concrete Operators     Open Access   (Followers: 4)
Confluentes Mathematici     Hybrid Journal  
Contributions to Game Theory and Management     Open Access  
COSMOS     Hybrid Journal  
Cryptography and Communications     Hybrid Journal   (Followers: 14)
Cuadernos de Investigación y Formación en Educación Matemática     Open Access  
Cubo. A Mathematical Journal     Open Access  
Current Research in Biostatistics     Open Access   (Followers: 9)
Czechoslovak Mathematical Journal     Hybrid Journal   (Followers: 1)
Demographic Research     Open Access   (Followers: 11)
Demonstratio Mathematica     Open Access  
Dependence Modeling     Open Access  
Design Journal : An International Journal for All Aspects of Design     Hybrid Journal   (Followers: 28)
Developments in Clay Science     Full-text available via subscription   (Followers: 1)
Developments in Mineral Processing     Full-text available via subscription   (Followers: 3)
Dhaka University Journal of Science     Open Access  
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 3)
Differentsial'nye Uravneniya     Open Access  
Discrete Mathematics     Hybrid Journal   (Followers: 8)
Discrete Mathematics & Theoretical Computer Science     Open Access  
Discrete Mathematics, Algorithms and Applications     Hybrid Journal   (Followers: 2)
Discussiones Mathematicae Graph Theory     Open Access   (Followers: 1)
Diskretnaya Matematika     Full-text available via subscription  
Dnipropetrovsk University Mathematics Bulletin     Open Access  
Doklady Akademii Nauk     Open Access  
Doklady Mathematics     Hybrid Journal  
Duke Mathematical Journal     Full-text available via subscription   (Followers: 1)
Eco Matemático     Open Access  
Edited Series on Advances in Nonlinear Science and Complexity     Full-text available via subscription  
Electronic Journal of Differential Equations     Open Access  
Electronic Journal of Graph Theory and Applications     Open Access   (Followers: 2)
Electronic Notes in Discrete Mathematics     Full-text available via subscription   (Followers: 2)
Elemente der Mathematik     Full-text available via subscription   (Followers: 4)
Energy for Sustainable Development     Hybrid Journal   (Followers: 9)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Ensino da Matemática em Debate     Open Access  
Entropy     Open Access   (Followers: 5)
ESAIM: Control Optimisation and Calculus of Variations     Full-text available via subscription   (Followers: 1)
European Journal of Combinatorics     Full-text available via subscription   (Followers: 5)
European Journal of Mathematics     Hybrid Journal   (Followers: 1)

        1 2 3 4 | Last

Journal Cover ChemSusChem
  [SJR: 2.649]   [H-I: 88]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1864-5631 - ISSN (Online) 1864-564X
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Carbon Molecular Sieve Membranes Derived from Tröger's Base-Based
           Microporous Polyimide for Gas Separation
    • Authors: Jian Jin; Zhenggong Wang, Huiting Ren, Shenxiang Zhang, Feng Zhang
      Abstract: Carbon molecular sieve (CMS) membrane based membrane attracts great attentions because of their outstanding gas separation performance. Polymer precursor is one of key points for preparation of high performance CMS. Tröger's base (TB) group is constructed by a bridged bicyclic amine. Such a bicyclic bridged stereo structure endows TB unit with highly contorted and great shape-persistent properties. In this work, a TB-based PIM-PI (TB-PI) is used as a polymer precursor to prepare CMS for the first time. By optimizing the thermal treatment condition, three CMS membranes treated under different soaking temperatures named TB-CMS-550, TB-CMS-650, and TB-CMS-800 were obtained. The TB-CMS membranes exhibit outstanding separation performance with comprehensive separation performances largely exceeding the 2008 updated Robeson upper bound for O2/N2, H2/CH4, H2/N2 and CO2/CH4 gas pairs, among which the permeability of H2 and CO2 up to 15000 barrer and simultaneously selectivity of H2/CH4 up to 200 and CO2/CH4 up to 110. This compresensive separation performance is superior to almost all of the CMS membranes derived from traditional polyimide precursors reported so far. Our work provides an effective strategy for fabricating high-performance CMS membranes through designing the stereo-structure of polymer precursor. The superior separation performance as compared to the stae-of-the-art conventional polyimides makes the TB-CMS membranes highly competitive for application.
      PubDate: 2018-01-19T03:30:56.574129-05:
      DOI: 10.1002/cssc.201702243
       
  • Deep Eutectic Solvent Aqueous Solutions as Efficient Media for the
           Solubilization of Hardwood Xylans
    • Authors: Eduarda S. Morais; Patrícia V. Mendonça, Jorge F. J. Coelho, Mara G. Freire, Carmen S. R. Freire, João A. P. Coutinho, Armando J. D. Silvestre
      Abstract: This work contributes to the development of integrated lignocellulosic-based biorefineries by the pioneering exploitation of hardwood xylans by solubilization and extraction in deep eutectic solvents (DES). DES formed by choline chloride and urea or acetic acid were initially evaluated as solvents for commercial xylan as a model compound. The effects of temperature, molar ratio, and concentration of the DES aqueous solutions were evaluated and optimized by using a response surface methodology. The results obtained demonstrated the potential of these solvents, with 328.23 g L−1 of xylan solubilization using 66.7 wt % DES in water at 80 °C. Furthermore, xylans could be recovered by precipitation from the DES aqueous media in yields above 90 %. The detailed characterization of the xylans recovered after solubilization in aqueous DES demonstrated that 4-O-methyl groups were eliminated from the 4-O-methylglucuronic acids moieties and uronic acids (15 %) were cleaved from the xylan backbone during this process. The similar Mw values of both pristine and recovered xylans confirmed the success of the reported procedure. DES recovery in four additional extraction cycles was also demonstrated. Finally, the successful extraction of xylans from Eucalyptus globulus wood by using aqueous solutions of DES was demonstrated.New media provides the solution: Deep eutectic solvents formed by choline chloride and urea in aqueous solutions display excellent ability to solubilize hardwood xylans and show great potential for the extraction of these polysaccharides from hardwoods in an integrated biorefinery context.
      PubDate: 2018-01-18T08:01:43.378652-05:
      DOI: 10.1002/cssc.201702007
       
  • N-modified NiO Surface for Superior Alkaline Hydrogen Evolution
    • Authors: Le Zhang; Peng Fei Liu, Yu Hang Li, Meng Yang Zu, Xu Li, Zheng Jiang, Yun Wang, Huijun Zhao, Huagui Yang
      Abstract: Boosting the sluggish kinetics of hydrogen evolution reaction in alkaline environments is the key for large application of water-alkali and chlor-alkali electrolysis. Herein, for the first time, we use nitrogen atoms to precisely modulate electrochemical active sites on the surface of nickel oxide with low coordinated oxygen atoms, to achieve enhanced kinetics of alkaline hydrogen evolution. Theoretical and experimental results demonstrate that the surface charge redistribution after modulation simultaneously facilitates the initial water dissociation step, as well as the subsequent recombination of Had from low coordinated oxygen sites and desorption of OH-ad from nickel sites, thus accelerating the overall hydrogen evolution process. The N-modulated nickel oxide enriched in low coordinated oxygen atoms exhibits significantly enhanced activity with a small overpotential of -100 mV at the current density of -10 mA cm-2 and a robust stability over 90 h for hydrogen evolution in 1.0 M KOH.
      PubDate: 2018-01-18T07:55:39.921625-05:
      DOI: 10.1002/cssc.201702371
       
  • Sustainable synthesis of oxalic (and succinic) acid via aerobic oxidation
           of C6 polyols by using M@CNT/NCNT (M=Fe, V) based catalysts in mild
           conditions
    • Authors: Angela Dibenedetto; Maria Ventura, David Williamson, Francesco Lobefaro, Matthew D. Jones, Davide Mattia, Francesco Nocito, Michele Aresta
      Abstract: Sustainable chemical industry encompasses the shift from fossil carbon to renewable carbon. The synthesis of chemicals from non-edible biomass (cellulosic or oily) represents one of the key steps for "greening" the chemical industry. In this paper we report the aerobic oxidation-cleavage of C6 polyols (5-HMF, glucose, fructose, sucrose) in water to oxalic acid-OA (and succinic acid-SA) under mild conditions using M@CNT/NCNT (M=Fe, V; CNT=carbon nanotubes; NCNT= N-doped CNT), which, under suitable conditions, are recoverable and reusable without any loss of efficiency. The influence of temperature, PO2, reaction time, stirring rate are discussed and the best reaction conditions are emphasized for an almost complete conversion of the starting material, with a good yield of OA equal to 48%. SA and formic acid are the only co-products. The former can be further converted into OA by oxidation in presence of formic acid allowing to reach an overall yield of OA>62%. This process is clean and does not produce organic waste nor gas emissions.
      PubDate: 2018-01-16T06:32:04.085088-05:
      DOI: 10.1002/cssc.201702347
       
  • Pyran-Bridged Indacenodithiophene as a Building Block for Constructing
           Efficient A–D–A-Type Nonfullerene Acceptors for Polymer Solar Cells
    • Authors: Shuguang Wen; Yao Wu, Yingying Wang, Yi Li, Ling Liu, Huanxiang Jiang, Zhitian Liu, Renqiang Yang
      Abstract: Invited for this month′s cover is the group of Renqiang Yang at the Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences. The image shows a new strategy of designing non-fullerene acceptors for polymer solar cells by introducing the oxygen atom into the conjugated backbone. The Full Paper itself is available at 10.1002/cssc.201701917.“These two materials should work together harmoniously…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201701917. View the Front Cover here: 10.1002/cssc.201800024.
      PubDate: 2018-01-15T10:56:04.489823-05:
      DOI: 10.1002/cssc.201800048
       
  • Polypropylene Nonwoven Fabric@Poly(ionic liquid)s for Switchable Oil/Water
           Separation, Dye Absorption and Antibacterial Applications
    • Authors: yongyuan ren; jiangna guo, dan xu, jing qin, qian lu, Feng Yan
      Abstract: Pollutants in wastewater include oils, dyes, and bacteria, making wastewater cleanup difficult. Here, we propose the preparation of multifunctional wastewater treatment media, poly(ionic liquid) grafted polypropylene (PP) nonwoven fabrics (PP@PIL), prepared via a simple and scalable surface grafting process. The fabricated PP@PIL fabrics exhibited superior switchable oil/water separation (η> 99%) and dye absorption performance (q = 410 mg/g), as well as high antibacterial properties. The oil/water separation could be easily switched via anion-exchanging of PIL segments. Moreover, the multiple functions (oil/water separation, dye absorption, and antibacterial properties) occurred at the same time, and did not interfere with each other. The multifunctional fibrous filter could be easily regenerated by washing with an acid solution, and the absorption capacity is maintained after many recycling tests. These promising features make PIL grafted PP nonwoven fabric a potential one-step treatment for multicomponent wastewater
      PubDate: 2018-01-15T05:54:12.831492-05:
      DOI: 10.1002/cssc.201702320
       
  • Photo-initiated Reduction of CO2 by H2 on Silica Surface
    • Authors: Chao Liu; Justin M. Notestein, Eric Weitz, Kimberly A. Gray
      Abstract: The reduction of CO2 is a promising route to produce valuable chemicals or fuels and create C-neutral resource cycles. Many different approaches to CO2 reduction have been investigated, but the ability of vacuum UV (VUV) irradiation to cleave C-O bonds has remained largely unexplored for use in processes that convert CO2 into useful products. Compared with other photo-driven CO2 conversion processes, here we demonstrate that VUV-initiated CO2 reduction can achieve much greater conversion under common photochemical reaction conditions when H2 and non-reducible oxides are present. Infrared spectroscopy provides evidence for a chain reaction initiated by VUV-induced CO2 splitting, which is enhanced in the presence of H2 and silica. When the reaction is carried out in the presence of silica or alumina surfaces, CO yields are increased and CH4 is formed as the only other detected product. CH4 production is not promoted by traditional photocatalysts such as TiO2 under these conditions. Assuming improvements in lamp and reactor efficiencies with scale up, or coupling with other available CO/CO2 hydrogenation techniques, these results reveal a potential, simple strategy by which CO2 could be valorized.
      PubDate: 2018-01-12T12:25:19.914081-05:
      DOI: 10.1002/cssc.201702341
       
  • Methanol-Water Aqueous Phase Reforming by the Assistant of Dehydrogenases
           at Near-Room Temperature
    • Authors: Yangbin Shen; Yulu Zhan, Shuping Li, Fandi Ning, Ying Du, Yunjie Huang, Ting He, Xiaochun Zhou
      Abstract: As an excellent hydrogen storage medium, methanol has many advantages, such as high hydrogen content (12.6 wt%), low-cost and availability from biomass or photocatalysis. However, conventional methanol-water reforming usually proceeds at high temperature. In this research, we successfully designed a new effective strategy to generate hydrogen from methanol at near-room temperature. The strategy involves two main procedures, which are CH3OHHCOOHH2 and NADHHCOOHH2. The first procedure (CH3OHHCOOHH2) is performed by alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and the Ir-catalyst. The second procedure (NADHHCOOHH2) is performed by formate dehydrogenase (FDH) and the Ir-catalyst. The Ir-catalyst is a reported polymer complex catalyst Cp*IrCl2(ppy), which owns high catalytic activity for formic acid decomposition at room temperature and compatibility to the enzymes, coenzyme and poisonous chemicals. This research reveals that the optimum hydrogen generation rate can reach up to 17.8 μmol h-1 g-1 under weak basic condition at 30 ℃. It will have high impact on hydrogen storage, production and applications, also provide a new inspiration for hydrogen generation from methanol.
      PubDate: 2018-01-11T21:55:44.42193-05:0
      DOI: 10.1002/cssc.201702359
       
  • Pyran-Bridged Indacenodithiophene as a Building Block for Constructing
           Efficient A–D–A-Type Nonfullerene Acceptors for Polymer Solar Cells
    • Authors: Shuguang Wen; Yao Wu, Yingying Wang, Yi Li, Ling Liu, Huanxiang Jiang, Zhitian Liu, Renqiang Yang
      Abstract: The Front Cover shows a representation of polymer solar cell with the energy from the sun. In their Full Paper, the authors use a ladder-type building block for constructing A–D–A nonfullerene acceptors through introduction of oxygen atoms into an indacenodithiophene unit, and used it in a polymer solar cell device. More information can be found in the Full Paper by Wen, Wu, et al.
      PubDate: 2018-01-11T09:12:29.23929-05:0
      DOI: 10.1002/cssc.201800024
       
  • Micelle-Assisted Electrodeposition of Mesoporous Fe–Pt Smooth Thin Films
           and their Electrocatalytic Activity towards the Hydrogen Evolution
           Reaction
    • Authors: Eloy Isarain-Chávez; Maria Dolors Baró, Carlos Alcantara, Salvador Pané, Jordi Sort, Eva Pellicer
      Abstract: The Cover Feature shows the water splitting reaction to produce hydrogen on a Fe-rich flat Fe–Pt mesoporous film fabricated through template-assisted electrodeposition onto various metallic substrates. The roughness and the amount of Fe incorporated in the films are influenced by the nature of the substrate. The films simultaneously exhibit ferromagnetic properties and electrocatalytic activity toward the hydrogen evolution reaction. More information can be found in the Full Paper by Isarain-Chávez et al.
      PubDate: 2018-01-11T09:12:19.836039-05:
      DOI: 10.1002/cssc.201800025
       
  • Encapsulating Co2P@C Core–Shell Nanoparticles in a Porous Carbon
           Sandwich as Dual-Doped Electrocatalyst for Hydrogen Evolution
    • Authors: Yuanyuan Yang; Xiongyi Liang, Feng Li, Shuwen Li, Xinzhe Li, Siu-Pang Ng, Chi-Man Lawrence Wu, Rong Li
      Abstract: The Cover Feature shows a 0-dimensional core–shell nanostructure of Co2P encapsulated into N,P-codoped porous carbon embedded into a N,P-codoped carbon network, which represents an appealing class of electrocatalysts for water-splitting catalysts in universal pH values. More information can be found in the Full Paper by Yang et al.
      PubDate: 2018-01-11T09:12:08.212309-05:
      DOI: 10.1002/cssc.201800026
       
  • Ultrathin Bismuth nanosheets as highly efficient electrocatalyst for CO2
           reduction
    • Authors: Panpan Su; Wenbin Xu, Yanling Qiu, Taotao Zhang, Xianfeng Li, Huamin Zhang
      Abstract: Electrochemical reducing CO2 to value-added products is an important and challenging reaction for sustainable energy study. In this study, bismuth nanosheets with thickness of ~10 nm were successfully prepared via electrochemical reduction of Bi3+. Ultrathin Bi nanosheets with numerous low-coordination sites can efficiently reduce CO2 to formate in aqueous solution. During the potential range of - 0.9 V to - 1.2 V vs RHE, the faradaic efficiency of formate is over 90%, which is one of the best reported Bi catalysts. At −0.7 V, the prepared Bi nanosheets exhibit much higher current for formate generation than that of bulk Bi, which is due to not only high surface area but also intrinsic electronic property change of ultrathin structure. Further, DFT calculation demonstrates that Bi nanosheets have the much higher electron state density around Fermi level than bulk counterpart, which favors the improvement of CO2 reduction on Bi nanosheets. At −1.0 V, Bi nanosheets exhibit high selectivity for formate and excellent stability during 5 hrs electrolysis measurement. The prepared Bi nanosheets with high activity and superior stability show great potential toward CO2 reduction area.
      PubDate: 2018-01-11T05:31:01.856408-05:
      DOI: 10.1002/cssc.201702229
       
  • Cellular Structure Fabricated on Ni Wire by a Simple and Cost-effective
           
    • Authors: Zhihong Wang; Fenhui Cao, Kongfa Chen, Yingming Yan, Yifu Chen, Yaohui Zhang, Xingbao Zhu, Bo Wei, Yueping Xiong, Zhe Lv
      Abstract: Cellular metals with the large surface-to-volume ratios and excellent electrical conductivity are widely applicable and have thus been studied extensively. It is highly desirable to develop a facile and cost-effective process for fabrication of porous metallic structures, more so for micron/nano pores. Herein, we propose a novel direct-flame strategy for in-situ fabrication of micron cellular architecture on Ni metal precursor. The flame provides required heat, but also serves as a fuel reformer providing a gas mixture of H2, CO and O2 for redox treatment of Ni metals. The redox processes at elevated temperatures allow a fast reconstruction of the metal, leading to cellular structure on Ni wire. This process is simple and clean, avoiding the use of sacrificial materials or templates. Further, nanocrystalline MnO2 is coated on the micron porous Ni wire (MPNW) to form a supercapacitor electrode. The MPNW-MnO2 electrode and the corresponding fiber-shaped supercapacitor exhibit high specific capacitance and excellent cycling stability. More importantly, this work provides a novel strategy for fabrication of cellular metals and alloys for a variety of applications, including catalysis, energy storage and conversion, and chemical sensing.
      PubDate: 2018-01-10T08:26:06.766362-05:
      DOI: 10.1002/cssc.201701886
       
  • Methylation of Polyols with Trimethylphosphate in the Presence of a Lewis
           or Brønsted Acid Catalyst
    • Authors: Marie-Christine Duclos; Aurélien Herbinski, Anne-Sophie Mora, Estelle Métay, Marc Lemaire
      Abstract: The alkylation of alcohols and polyols has been investigated with alkylphosphates in the presence of a Lewis or Brønsted acid catalyst. The permethylation of polyols was developed under solvent-free conditions at 100 °C with either iron triflate or Aquivion PW98, affording the isolated products in yields between 52 and 95 %. The methodology was also adjusted to carry out peralkylation with longer alkyl chains.A new polyol methylation process has been developed by using trimethylphosphate and a Lewis or Brønsted acid catalyst, such as iron triflate or Aquivion, respectively. The unreacted trimethylphosphate and the Aquivion resin can be recycled without loss of yield and activity. This methodology can be extend to the ethylation, isopropylation, or butylation of polyols in good yields.
      PubDate: 2018-01-10T07:00:24.095448-05:
      DOI: 10.1002/cssc.201701841
       
  • Pt islands on 3D nut-like PtAg nanocrystals for efficient formic acid
           oxidation electrocatalysis
    • Authors: Hui Xu; Pingping Song, Bo Yan, Jin Wang, Caiqin Wang, Yukihide Shiraishi, Ping Yang, Yukou Du
      Abstract: Precise control of the structure offers a great opportunity to efficiently tune the catalytic performances of nanomaterials, enabling them enhancement in both activity and durability. We herein achieve a new class of Pt islands on 3D nut-like PtAg nanocrystals by exploiting the lower electronegativity of Ag and in conjunction with the galvanic replacement of catalytically active Pt to Ag tops. Those nanostructures with Pt nanoparticles coated, exposed facet, active surface composition enhance formic acid oxidation electrocatalysis with the optimized PtAg1 nuts achieved a factor of 4.0 and 2.4 in mass and specific activities (1728.3 mA mg-1 and 3.31 mA cm-2) relative to that of the commercial Pt/C (431.2 mA mg-1 and 1.41 mA cm-2), respectively. Moreover, such 3D PtAg1 nuts also display great enhancement in durability with less decay for at last 500 cycles, showing the great potential to serve as the promising catalysts for fuel cells and beyond. Our work provides a fundamental insight on the effect of morphology towards liquid fuel electrooxidation, which may pave a new way for the fabrication of highly efficient electrocatalysts for fuel cells.
      PubDate: 2018-01-09T07:20:44.14359-05:0
      DOI: 10.1002/cssc.201702409
       
  • Across the Board: Xinchen Wang
    • Authors: Xinchen Wang
      Abstract: In this series of articles, the board members of ChemSusChem discuss recent research that they consider of exceptional quality and importance for sustainability. In this entry, Prof. Xinchen Wang discusses the investigations of a printable Z-scheme system for photocatalytic water splitting by the pioneer, Prof. Kazunari Domen, who has been constantly contributing to this field for about 40 years. The recent achievement of an overall water splitting system has exceeded the solar-to-hydrogen energy efficiency of 1% by integrating efficient hydrogen and oxygen evolution photocatalysts with charge-transport channel.
      PubDate: 2018-01-09T07:15:31.233551-05:
      DOI: 10.1002/cssc.201702348
       
  • Oxygen Reduction Reaction for Generating H2O2 via Piezo-catalytic Process
           over BiOCl
    • Authors: Wenzhong Wang; Dengkui Shao, Ling Zhang, Songmei Sun
      Abstract: Oxygen reduction reaction (ORR) for generating H2O2 via green pathways have gained much attention in recent years. Herein, we introduce a piezo-catalytic approach to obtain H2O2 over BiOCl via ORR pathway. The piezoelectric response of BiOCl was directly characterized by piezoresponse force microscope (PFM). The BiOCl exhibits efficient catalytic performance for generating H2O2 (28 µmol/h ) only from O2 and H2O, which is above the average level of H2O2 produced by solar-to-chemical process. A piezo-catalytic mechanism was proposed: with ultrasonic waves, an alternating electric field will be generated over BiOCl, which can drive charge carriers (electrons) to interact with O2 and H2O, then to form H2O2.
      PubDate: 2018-01-09T02:51:04.973275-05:
      DOI: 10.1002/cssc.201702405
       
  • Hybrid-organic-inorganic anatase as a bifunctional catalyst for enhanced
           production of HMF from glucose in water
    • Authors: Carlos A. S. Lanziano; Silvia F. Moya, Dean H. Barrett, Reginaldo Guirardello, Felipe de Souto da Silva, Roberto Rinaldi, Cristiane Barbieri Rodella
      Abstract: Herein, we report a synthetic route for the preparation of hybrid-organic-inorganic anatase (hybrid-TiO2) via a facile hydrothermal synthesis method employing citric acid. The synthetic approach results in a high surface area nanocrystalline anatase polymorph of TiO2. The uncalcined hybrid-TiO2 is directly studied here as the catalyst for the conversion of glucose into HMF. In the presence of the hybrid-TiO2, HMF yields up to 45% at glucose conversions up to 75% were achieved in water at 130 oC in a monophasic batch reactor. As identified by Ti K-edge XANES, hybrid-TiO2 contains a large fraction of five-fold coordinatively unsaturated Ti(IV) sites, which act as the Lewis acid catalyst for the conversion of glucose into fructose. As citric acid is anchored in the structure of hybrid-TiO2, carboxylate groups seem to catalyze the sequential conversion of fructose into HMF. The fate of citric acid bounded to anatase and the Ti(IV) Lewis acid sites throughout recycling experiments is also investigated. In a broader context, the contribution outlines the importance of hydrothermal synthesis for the creation of water-resistant Lewis acid sites for the conversion of sugars. Most importantly, the utilization of the hybrid-TiO2 with no calcination step contributes to dramatically decreasing the energy consumption in the catalyst preparation.
      PubDate: 2018-01-08T12:50:27.889026-05:
      DOI: 10.1002/cssc.201702354
       
  • A Perspective Review on the Materials and Mechanisms of Photo-Assisted
           Chemical Reactions under Light and Dark: Can it be called as Day-Night
           Photocatalysis'
    • Authors: Sakar Mohan; Nguyen Chinh-Chien, Vu Manh-Hiep, Trong-On Do
      Abstract: The photo-assisted catalytic reaction, conventionally known as photocatalysis, is blooming into the field of energy and environmental applications. It is widely known that the discovery of TiO2-assited photochemical reactions has led to achieve several unique applications such as degradation of pollutants in water and air, hydrogen production through water splitting, fuel conversion, cancer treatment, anti-bacterial activity, self-cleaning glasses and concrete, etc. These multifaceted applications of this phenomenon can be enriched and expanded further if this process is equipped with more tools and functions. The term 'photo'-assisted catalytic reactions clearly emphasizes that the photons are required to activate the catalyst, where this can be transcended even into dark if the electrons are stored in the material for the later use to continue the catalytic reactions in the absence of light. This can be achieved by equipping the photocatalyst with a so-called electron storage material as to break the present limitations in 'photo'-assisted catalytic reactions. In this context, this perspective article sheds lights on the materials and mechanism of the materials that perform photocatalytic reactions under light and dark conditions. The manifestation of such material systems could be an unparalleled technology in near future that would possibly make foot prints in all the sphere of the catalytic sciences.
      PubDate: 2018-01-08T10:20:23.258008-05:
      DOI: 10.1002/cssc.201702238
       
  • Fabrication of Cu2O-based Materials for Lithium-ion Batteries
    • Authors: Huan Pang; Qin Yuan Li, Li Zhang, Huai Guo Xue
      Abstract: The improvement of the performance of advanced batteries has played a key role in the energy research community since its inception. Therefore, it is necessary to explore excellent materials for applications in advanced batteries. Among the variety of materials applied in batteries, cuprous oxide and its composites stand out because of their specific characteristics (polymorphic forms, controllable structure, high cycling capacity, etc.). Thus, cuprous oxide and its composites will be fully introduced in this review for their applications in advanced batteries. It is believed that, in the future, both the study and the impact of cuprous oxide and its composites will be much more profound and lasting.
      PubDate: 2018-01-06T00:35:45.359507-05:
      DOI: 10.1002/cssc.201702325
       
  • Towards Sustainable Production of Formic Acid from Biomass for Getting
           Hydrogen and Fuels
    • Authors: Dmitri Bulushev; Julian R.H. Ross
      Abstract: Formic acid is a widely used commodity chemical. It can be used as a safe, easily handled and transported source of hydrogen or CO for different reactions including those producing fuels. The review includes historical aspects of formic acid production. It shortly analyzes the production based on traditional sources such as CO, methanol and methane. However, the main emphasis is done to the sustainable production of formic acid from biomass and biomass-derived products via hydrolysis, wet and catalytic oxidation processes. New strategies of low temperature synthesis from biomass may lead to utilization of formic acid for production of fuel additives such as methanol, upgraded bio-oil, gamma-valerolactone and its derivatives, as well as synthesis gas used for Fischer-Tropsch synthesis of hydrocarbons. Some technological aspects are considered.
      PubDate: 2018-01-06T00:35:41.121604-05:
      DOI: 10.1002/cssc.201702075
       
  • Bifunctional Pyridinium-Based Ionic liquid Immobilized
           [In2(dpa)3(1,10-phen)2]: Efficacy of Supported Ionic Liquid Phase Metal
           Organic Framework Catalyst for CO2 Fixation Reactions
    • Authors: Robin Babu; Jintu Francis Kurisingal, Jong-San Chang, Dae-Won Park
      Abstract: A pyridinium-based ionic liquid-decorated 1D MOF (IL-[In2(dpa)3(1,10-phen)2]) was developed as a bifunctional heterogeneous catalyst system for CO2-oxirane coupling reactions. An aqueous-microwave route was employed as competent with the hydrothermal pathway for the synthesis of [In2(dpa)3(1,10-phen)2] MOF, and the IL-[In2(dpa)3(1,10-phen)2] catalyst was synthesized using the covalent post functionalization method. Due to the synergetic effect of dual functional sites, including Lewis acid sites (coordinatively unsaturated indium sites) and I- ion in IL functional sites, IL-[In2(dpa)3(1,10-phen)2] displayed high catalytic activity for CO2-epoxide cycloaddition reactions under mild and solvent free conditions. Microwave pulses were employed for the first time for MOF-catalyzed CO2-epoxide cycloaddition reactions resulting in a high turnover frequency (TOF), ranging from 2000 to 3100 h-1. The catalyst had excellent reusability while maintaining continuous high selectivity. Furthermore, only a small amount of leaching was observed from the spent catalyst. A plausible reaction mechanism based on the synergistic effect of dual functional sites that effectively catalyze the CO2-epoxide cycloaddition reaction is proposed.
      PubDate: 2018-01-06T00:30:32.877678-05:
      DOI: 10.1002/cssc.201702193
       
  • MoS2/MoOx Nanostructure Decorated Activated Carbon Cloth for Enhanced
           Supercapacitor Performances
    • Authors: Fitri Nur Indah Sari; Jyh-Ming Ting
      Abstract: MoS2/MoOx nanostructures have been grown on activated carbon cloth through a facile one-step microwaved-assisted hydrothermal. The growth of MoS2/MoOx on activated carbon cloth create a unique structure that favors ions intercalation. The conductive activated carbon cloth, MoO3-x, and monoclinic MoO2 provide fast electron transport while the MoS2 nanosheets/MoO3-x nanoparticles nanostructure improves the capacitance. As a result, MoS2/MoOx nanostructure decorated activated carbon cloth shows high specific capacitance of 230 F g-1 at a scan rate of 5 mV s-1 with low contact resistance ~1.91 ohm. Moreover, the activated carbon cloth acts as a template for the growth of perpendicular MoS2 layer, giving an excellent utilization rate of the active material MoS2/MoOx. We also demonstrate that MoS2/MoOx/ activated carbon cloth nanocomposite shows excellent electrochemical stability with retention up to 128% after 1500 cycles. Finally, we show that the use of microwaved-assisted hydrothermal-synthesized MoS2/MoOx/ activated carbon cloth nanocomposite an alternative and clean route to improve the kinetics of the intercalation redox reaction.
      PubDate: 2018-01-04T01:26:04.520135-05:
      DOI: 10.1002/cssc.201702295
       
  • A Co2P/WC Nano-Heterojunction Covered by N-Doped Carbon as High Efficient
           Electrocatalyst for Hydrogen Evolution Reaction
    • Authors: Yang-Guang Li; Ya Gao, Zhong-Ling Lang, Fei-Yang Yu, Hua-Qiao Tan, Gang Yan, Yong-Hui Wang, Yuan-Yuan Ma
      Abstract: Hydrogen evolution reaction (HER), which produces clean hydrogen through the electrochemical process, screams for more non-precious-metal electrocatalysts to lower the consumption of energy. Herein, we report a new Co2P/WC nano-heterojunction that consists of cobalt phosphide and tungsten carbide composite phases coated by few-layer N-doped graphitic carbon shells (abbr. Co2P/WC@NC). The composite was prepared by one-step annealing of the polyoxometalate Na9(NH4)5[{(B-α-PW9O34)Co3(OH) (H2O)2(Ale)}2Co]·35H2O (Co7P6W18) and dicyandiamide (DCA). Such preparation method realizes the simultaneous phosphorization for Co and carbonization for W in a confined space, so as to isolate a Co2P/WC nano-heterojunction phase for the first time. Co2P/WC @NC facilitates the hydrogen generation in the electrolysis process, which only needs a small overpotential of 91 mV to reach the current density of 10 mA cm-2 in the acid solution, which brings excellent HER performance, a fantastic Tafel slope (40 mV dec-1) and superior durability over a period of 50 h. Theoretical calculations show that the Co2P, WC, and NpyridinicC dopants in the material synergistically promoted the HER activity. Meanwhile, Co2P/WC@NC nano-heterojunction shows good HER performance in the whole pH range of electrolytes and considerable durability in acid media containing transition metal ions, which may attract more attention to the exploration and optimization of nano-heterojunction catalysts in HER.
      PubDate: 2018-01-02T08:22:07.206402-05:
      DOI: 10.1002/cssc.201702328
       
  • An efficient metal-free catalyst for oxidative dehydrogenation reaction:
           Activated carbon decorated with few-layer graphene
    • Authors: Yajie Zhang; Jiangyong Diao, Junfeng Rong, Jiayun Zhang, jingxin Xie, Fei Huang, Zhimin Jia, Hongyang Liu, Dangsheng Su
      Abstract: Activated carbon (AC) has been widely used in catalysis field because of its low-cost, scalable production, high specific surface area and abundant exposed edge. Due to the amorphous structure, traditional AC is unstable in presence of O2 at high temperature, which hinders the application of AC catalysts in oxidative dehydrogenation (ODH) of alkanes. In this work, partially graphitic AC decorated with few-layer graphene is facilely fabricated by the simple high-temperature calcination. The graphitic transformation significantly enhances the anti-oxidation property, long-term stability of AC during the ODH reaction, and especially increases the graphitic edge areas where the active ketonic carbonyl groups are selectively formed in the ODH reactions. A high reactivity with 41.5 % selectivity and 13.2% yield to C4 alkenes are obtained at 450oC over the optimized catalyst, which is superior to all the previous reported carbon catalysts and shows a great potential for industrial application
      PubDate: 2018-01-02T06:20:35.001682-05:
      DOI: 10.1002/cssc.201702178
       
  • Selective Hydrodeoxygenation of Alkyl Lactates to Alkyl Propionates with
           Fe-based Bimetallic Supported Catalysts
    • Authors: Santosh Govind Khokarale; Jian He, Leonhard Schill, Song Yang, Anders Riisager, Saravanamurugan Shunmugavel
      Abstract: Hydrodeoxygenation (HDO) of methyl lactate (ML) to methyl propionate (MP) were performed with various base metal supported catalysts. A high yield of 77% MP was obtained with bimetallic Fe-Ni/ZrO2 in methanol at 220 C at 50 bar H2. A synergic effect of Ni increased the yield of MP significantly when using Fe-Ni/ZrO2 instead of Fe/ZrO2 alone. Moreover, the ZrO2 support contributed to improve the yield as a phase transition of ZrO2 from tetragonal to monoclinic occurred after metal doping giving rise to fine dispersion of the Fe and Ni on the ZrO2, implying the higher catalytic activity of the material. Intriguingly, it was observed that Fe-Ni/ZrO2 also effectively catalyzed methanol reforming to produce in situ H2, followed by HDO of ML, yielding 60% MP at 220 C with 50 bar N2 instead of H2. Fe-Ni/ZrO2 also catalyzed HDO of other short chain alkyl lactates to the corresponding alkyl propionates in high yields around 70%. No loss of activity of Fe-Ni/ZrO2 occurred in five consecutive reaction runs demonstrating the high durability of the catalyst system.
      PubDate: 2017-12-29T09:25:30.361001-05:
      DOI: 10.1002/cssc.201702411
       
  • N-Annulated Perylene Based Hole-Transporters for Perovskite Solar Cells:
           the Significant Impacts of Lateral Substituents
    • Authors: Peng Wang; Yang Li, Rui Zhu, Junting Wang, Ze-Sheng Li, Niansheng Xu, Jidong Zhang
      Abstract: Perylene derivatives are a family of well-known organic electron-transporting materials with excellent photochemical and thermal stabilities, and have been widely used in various optoelectronic devices. In this work, two diphenylamine functionalized N-annulated perylenes are reported for the first time as a new class of hole-transporting materials (HTMs) for perovskite solar cells. With the aid of joint theoretical and experimental studies, we uncover that the HTM employing the methoxyphenyl lateral substituent features a closer stacking distance and a better aggregate connectivity in the solid film than the counterpart with the bulky 2-hexyldecyl lateral substituent, contributing to a higher hole mobility and a remarkably enhanced device performance of perovskite solar cells. This work demonstrates the significant influence of lateral substituents of HTMs on the intermolecular packing and solid microstructure, giving a clear clue on the molecular design of high performance organic semiconductors.
      PubDate: 2017-12-29T05:26:28.663552-05:
      DOI: 10.1002/cssc.201702379
       
  • Flower-like VS4/rGO Composite: an Energy Storage Material for Aluminum-ion
           Battery
    • Authors: Shuqiang Jiao
      Abstract: The flower-like VS4/rGO (reduced graphene oxide) composite was prepared by a typical hydrothermal method, which was investigated as cathode for aluminum-ion battery with non-inflammable and non-explosive ionic liquid electrolytes. The charge/discharge performance measurements were carried out in a voltage range of 0.1~2.0 V vs. Al/AlCl4-, which suggests the initial charge/discharge specific capacity approaching 491.57 and 406.94 mA h g-1, respectively, at a current density of 100 mA g-1. Additionally, in the cycling performance, discharge capacity has been observed to remain over 80, 70 and 60 mA h g-1 at current densities of 100, 200 and 300 mA g-1 after 100 cycles, respectively. The results of coulombic efficiency over 90% after 100 cycles and high capacity retained indicate a favorable cathode material for novel rechargeable aluminum-ion battery.
      PubDate: 2017-12-29T03:55:28.625288-05:
      DOI: 10.1002/cssc.201702270
       
  • Hydrothermally induced O-doping and porous structure of graphitic carbon
           nitride with highly ordered architecture and dramatically enhanced
           photocatalytic property
    • Authors: Chao Wang; Huiqing Fan, Xiaohu Ren, Jiangwei Ma, Jiawen Fang, Weijia Wang
      Abstract: As an amorphous or semi-crystalline material, graphitic carbon nitride (g-C3N4) displays poor photocatalytic activity due to the rapid recombination of photo generated charge carriers, which is mainly caused by the high density of defects in the graphitic structure. In this work, a porous O-doped g-C3N4 nanosheet (P-CNO) with highly ordered architecture is fabricated by introducing a novel hydrothermal treatment to the precursor before the final thermal condensation. The photocatalytic hydrogen evolution rate (HER) and HER per surface area of P-CNO are 13.9 times and 1.7 times higher than that of bulk g-C3N4. The improved photocatalytic activity is ascribed to the synergistic effect of O-doping, porous sheet-like morphology and increased crystallinity. This work also provides a new approach for synthesis of other polymer-based photocatalysts with high crystallinity and excellent performances.
      PubDate: 2017-12-29T02:25:51.341178-05:
      DOI: 10.1002/cssc.201702278
       
  • Polyethylene Glycol-[60]fullerene-based Materials for Perovskite Solar
           Cells with Improved Moisture Resistance and Reduced Hysteresis
    • Authors: Juan L. Delgado; Silvia Collavini, michael saliba, wolfgang tress, philippe holzhey, sebastian voelker, konrad domanski, silver turren-cruz, amita ummadisingu, shaik zakeeruddin, anders hagfeld, Michael Graetzel
      Abstract: A series of [60]fullerenes covalently functionalized with the polyethylene glycol polymer (PEG) is presented. These novel [60]fullerene-based materials have been incorporated as additives in CH3NH3PbI3 (MAPbI3), the most common organic-inorganic perovskite used in perovskite solar cells. The extensive photovoltaic study performed using these materials shows beneficial effects on the performance of these cells, reducing hysteresis and increasing stability against moisture, thereby retaining up to 97% of their initial power conversion efficiency at ambient atmosphere.
      PubDate: 2017-12-28T21:55:34.721041-05:
      DOI: 10.1002/cssc.201702265
       
  • A strategy to boost H2 generation ability of MOFs—inside-outside
           decoration for the separation of electron and holes
    • Authors: Yang Wang; Lianjie Ling, Wei Zhang, Kejian Ding, Yu Yu, Wubiao Duan, Bo Liu
      Abstract: Inhibiting the recombination of electron and holes plays an essential role in photocatalytic process, particularly for MOFs which had long been expected as high efficient photocatalysts. Herein, we introduce a new strategy to make efficient separation of electron and holes for MOFs-based photocatalyst, UiO-66-NH2. At first, encapsulate Pt NPs into UiO-66-NH2 (Pt@U6N) to shorten the electrons transport distance inside, then using graphene oxide to wrap the external surface of Pt@U6N to felicitate the superficial electrons transfer. The designed structure was found possess superior H2 generation ability than sole inside/outside decoration, highlighting the enhanced property strongly correlates with the inhibited recombination of electron and holes by the inside-outside modification strategy. These findings suggest a synergistic effect of Pt NPs and graphene oxide on UiO-66-NH2 and revealed a new modification strategy to enhance the photocatalytic activity for photocatalysts.
      PubDate: 2017-12-28T06:56:05.75368-05:0
      DOI: 10.1002/cssc.201702316
       
  • Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide
           Mineralisation
    • Authors: Katie J. Lamb; Mark R. Dowsett, Konstantinos Chatzipanagis, Zhan Wei Scullion, Roland Kröger, James D. Lee, Pedro M. Aguiar, Michael North, Alison Parkin
      Abstract: The Cover Feature shows how sun, seawater, and waste aluminium can be combined to enable the electrochemical mineralisation of carbon dioxide. More information can be found in the Full Paper by Lamb, Dowsett, et al.
      PubDate: 2017-12-28T05:51:17.325706-05:
      DOI: 10.1002/cssc.201702376
       
  • Ruthenium Ion-Complexed Graphitic Carbon Nitride Nanosheets Supported on
           Reduced Graphene Oxide as High-Performance Catalysts for Electrochemical
           Hydrogen Evolution
    • Authors: Yi Peng; Wanzhang Pan, Nan Wang, Jia-En Lu, Shaowei Chen
      Abstract: Invited for this month′s cover is the group of Prof. Dr. Shaowei Chen at the University of California, Santa Cruz. Based on the Chinese legend of Niulang () and Zhinü (), the image shows a hybrid consisting of reduced graphene oxide and ruthenium ions-complexed graphitic carbon nitride nanosheets that can serve as effective catalysts toward the hydrogen evolution reaction. The Full Paper itself is available at 10.1002/cssc.201701880.“Based on the Chinese legend of Niulang and Zhinü…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201701880. View the Front Cover here: 10.1002/cssc.201702374.
      PubDate: 2017-12-28T05:50:32.187269-05:
      DOI: 10.1002/cssc.201702375
       
  • A potential liquid organic hydrogen carrier: 2-(n-methylbenzyl)pyridine
           with fast H2 release and stable activity in consecutive
           hydrogenation-dehydrogenation cycles
    • Authors: Jinho Oh; Kwanyong Jeong, Tae Wan Kim, Hyunguk Kwon, Jeong Woo Han, Ji Hoon Park, Young-Woong Suh
      Abstract: For H₂ storage based on reversible hydrogenation and dehydrogenation of a liquid organic hydrogen carrier (LOHC), we herein demonstrate a potential of 2-(n-methylbenzyl)pyridine (MBP) with the H₂ storage density of 6.15 wt%. This material and the corresponding perhydro product (H12-MBP) exist in liquid state at room temperature. Remarkably, H₂ release is much faster from H12-MBP over Pd/C than from the benchmark perhydro benzyltoluene over Pt/C at lower temperatures than 270 °C due to the addition of N atom into the benzene ring. Since this positive effect is unfavorable to the hydrogenation reaction, more Ru/Al₂O₃ catalyst or prolonged reaction time would be applied for complete H₂ storage. Experiments for repeated hydrogenation/dehydrogenation cycles reveal that reversible H₂ storage and release are possible without degradation of the pair MBP/H12-MBP. The prepared MBP satisfies the requirements in chemical stability, handling properties, and cytotoxicity test.
      PubDate: 2017-12-28T02:01:46.232327-05:
      DOI: 10.1002/cssc.201702256
       
  • Connection between Lithium Coordination and Lithium Diffusion in
           Pyr12O1FTFSI Ionic Liquid Electrolytes
    • Authors: Guinevere Giffin; Arianna Moretti, Sangsik Jeong, Kartik Pilar, Marc Brinkkoetter, Steve Greenbaum, Monika Schoenhoff, Stefano Passerini
      Abstract: The use of highly concentrated ionic liquid-based electrolytes results in improved rate capability and capacity retention at 20°C, as compared to Li+-dilute systems, in Li-metal and Li-ion cells. This work explores the connection between the bulk electrolyte properties and the molecular organization to give insight into the concentration dependence of the Li+ transport mechanisms. Below 30 mol%, the Li+-containing species are primarily smaller complexes (one Li+ cation) and the Li+ ion transport is mostly derived from the vehicular transport. Above 30%, where the viscosity is substantially higher and the conductivity lower, the Li+-containing species are a mix of small and large complexes (one and more than one Li+ cation, respectively). The overall conduction mechanism likely changes to favor structural diffusion via the exchange of anions in the first Li+ solvation shell. The good rate performance is likely directly influenced by the presence of the larger Li+ complexes, which promote Li+-ion transport (as opposed to Li+-complex transport) and increase the Li+ availability at the electrode.
      PubDate: 2017-12-27T21:55:30.764544-05:
      DOI: 10.1002/cssc.201702288
       
  • One-step Synthesis of Nb2O5/C/Nb2C (MXene) Composites and Their Use as
           Photocatalysts for Hydrogen Evolution
    • Authors: Tongming Su; Rui Peng, Zachary D. Hood, Michael Naguib, Ilia N. Ivanov, Jong Kahk Keum, Zuzeng Qin, Zhanhu Guo, Zili Wu
      Abstract: Abstract: Hydrogen production through facile photocatalytic water splitting is regarded as a promising strategy for solving global energy problems. Transition metal carbides (MXenes) have recently drawn attention as potential co-catalyst candidates for photocatalysts. Here, we report niobium pentoxide/carbon/niobium carbide (MXene) hybrid materials (Nb2O5/C/Nb2C) as photocatalysts for hydrogen evolution from water splitting. The Nb2O5/C/Nb2C composites were synthesized by a one-step CO2 oxidation of Nb2CTx. Nb2O5 grew homogeneously on Nb2C after mild oxidation during which some amorphous carbon also formed. With an optimized oxidation time of 1.0 h, the Nb2O5/C/Nb2C shows the highest hydrogen generation rate (7.81 μmol*h-1gcat-1), which is 4 times as high as that of pure Nb2O5. The enhanced performance of Nb2O5/C/Nb2C can be attributed to the intimate contact between the Nb2O5 and the conductive Nb2C, and the separation of photogenerated charge carriers at the Nb2O5/Nb2C interface, showing the promise of transition metal carbide as co-catalysts for photocatalytic hydrogen production.
      PubDate: 2017-12-27T12:50:24.185119-05:
      DOI: 10.1002/cssc.201702317
       
  • Novel Starbon/HACS-supported N-heterocyclic carbene-iron(III) catalyst for
           efficient conversion of fructose to HMF
    • Authors: Avtar Singh Matharu; Suleiman Ahmed, Badriya Al-Monthery, Duncan Macquarrie, Yoon-Sik Lee, Yohan Kim
      Abstract: : Iron-nitrogen heterocyclic carbenes (Fe-NHCs) have come to the fore because of their ability to be employed in diverse catalytic applications ranging from C-C cross-coupling and C-X bond formation to substitution, reduction, polymerization, and dehydration. The detailed synthesis, characterisation and application of novel heterogeneous Fe-NHC catalysts immobilised on mesoporous expanded starch and Starbon™ 350 for facile fructose to HMF conversion is reported. Both catalyst types showed good performance for the dehydration of fructose to HMF when the reaction was explored at 100 ◦C and varying time (10 min, 20 min, 0.5 h, 1 h, 3 h and 6 h): Fe-NHC S350, highest HMF yield, 81.7 % (t=0.5 h), TOF=169 h-1, fructose conversion of 95 % and HMF selectivity of 85.7 %, and; Fe-NHC expanded HACS, highest yield, 86 % (t=0.5 h), TOF=206 h-1, fructose conversion of 87 % and HMF selectivity of 99 %. An iron-loading of 0.26 and 0.30 mmol/g was achieved for the Fe-NHC expanded starch and Fe-NHC Star-bon™ 350, respectively.
      PubDate: 2017-12-27T09:25:37.991062-05:
      DOI: 10.1002/cssc.201702207
       
  • Ruthenium Ion-Complexed Graphitic Carbon Nitride Nanosheets Supported on
           Reduced Graphene Oxide as High-Performance Catalysts for Electrochemical
           Hydrogen Evolution
    • Authors: Yi Peng; Wanzhang Pan, Nan Wang, Jia-En Lu, Shaowei Chen
      Abstract: The Front Cover shows the production of hydrogen gas when electrons and protons meet on ruthenium ion-complexed graphitic carbon nitride nanosheets supported on graphene surface. The image is based on an ancient Chinese legend of Niulang () and Zhinü (). Niulang was a human cowherd and Zhinü was a fairy from heaven. They fell in love with each other. Yet their love was banned by the fairy's queen, who forcefully separated them by the Silver River. The lovers were only able to see each other once a year, on the 7th day of the 7th lunar month, with the help of a flock of magpies that formed a bridge. More information can be found in the Full Paper by Peng et al.
      PubDate: 2017-12-27T04:52:21.594994-05:
      DOI: 10.1002/cssc.201702374
       
  • Bioinspired Mesoporous Chiral Nematic Graphitic Carbon Nitride
           Photocatalysts modulated by Polarized Light
    • Authors: Wensheng Lin; Wei Hong, Lu Sun, Di Yu, Dingshan Yu, Xudong Chen
      Abstract: The Cover Feature shows the chiral nematic graphitic carbon nitride with photocatalytic activity modulated by circularly polarized light. In their work, the authors synthesized mesoporous g-C3N4 materials for photcatalytic hydrogen evolution. More information can be found in the Communication by Lin et al.
      PubDate: 2017-12-27T04:52:13.446124-05:
      DOI: 10.1002/cssc.201702377
       
  • Rapid Formation of a Disordered Layer on Monoclinic BiVO4:
           Co-catalyst-free Photoelectrochemical Solar Water Splitting
    • Authors: Jung Kyu Kim; Yoonjun Cho, Myung Jin Jeong, Ben Levy-Wendt, Dongguen Shin, Yeonjin Yi, Dong Hwan Wang, Xiaolin Zheng, Jong Hyeok Park
      Abstract: Surface disordered layer is plausible approach to improve the photoelectrochemical performance of TiO2. However, the formation of a crystal disordered layer in BiVO4 and its effectiveness towards photoelectrochemical water splitting has remained a big challenge. Here, we report a rapid solution process (within 5 seconds) that is capable of forming a few nanometre-thick disordered layer on the surface of BiVO4 nanoparticles using a specific solution with controllable reducing power. The disordered layer on BiVO4 alleviates charge recombination at the electrode/electrolyte interface and greatly reduces the on-set potential, which in turn results in a photocurrent density of around 2.3 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE). This value is 2.1 times higher than that of bare BiVO4. The enhanced photoactivity is attributed to the increased charge separation and transfer efficiencies, which provide an effective avenue for resolving an intrinsic drawback of bare BiVO4 such as short hole diffusion length of around 100 nm and poor surface oxygen evolution reactivity.
      PubDate: 2017-12-23T12:10:31.623374-05:
      DOI: 10.1002/cssc.201702173
       
  • Annealing-Free Cr2O3 Electron-Selective Layer for Efficient Hybrid
           Perovskite Solar Cells
    • Authors: Jia Dong; jihuai Wu, Jinbiao Jia, Leqing Fan, Miaoliang Huang, Jianming Lin, Xin He, Zhang Lan
      Abstract: The electron-selective layer (ESL) plays a pivotal role in the high-performance of perovskite solar cells (PSCs). In this report, amorphous dispersible chromium oxide (Cr2O3) nanosheets are synthesized by a facile solvothermal reaction, and Cr2O3 ESL is prepared by spin-coating Cr2O3 ink on FTO substrates without further annealing process. Using the Cr2O3 as electron-selective layer and Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 as light-absorption layer, a planar hybrid perovskite solar cell is fabricated. The spin-coating speed is optimized, the structure and morphology of samples are observed, the photoelectrical properties of ESLs are characterized and the photovoltaic behaviors of devices are measured. Results show that the as-prepared Cr2O3 layer have high optical transmittance and superb electron extraction and carrier transport property. The planar hybrid PSC based on the optimal Cr2O3 ESL achieves a power conversion efficiency of 16.23%, which is comparable with the device based on conventional high-temperature-calcined TiO2 ESL. This research demonstrate a novel, low-cost and facile Cr2O3 electron-selective material for high-effective perovskite solar cells.
      PubDate: 2017-12-20T22:36:04.244745-05:
      DOI: 10.1002/cssc.201701864
       
  • The Past, Present, and Future of Sustainable Chemistry
    • Authors: David J. Smith
      Abstract: A new decade: To mark 10 years since the launch of ChemSusChem and to welcome you to Volume 11, this Editorial features the thoughts of some of the journal's Editorial Board members on the current status of the field of sustainable chemistry, and looks at its future prospects.
      PubDate: 2017-12-19T07:10:32.35389-05:0
      DOI: 10.1002/cssc.201702329
       
  • Synthesis, Characterization and Photoelectrochemical-Catalytic Studies of
           a Water Stable Zinc-based Metal-organic Framework
    • Authors: Muhammad Altaf; Manzar Sohail, Muhammad Mansha, Naseer Iqbal, Muhammad Sher, Atif Fazal, Nisar Ullah, Anverhusein A. Isab
      Abstract: Metal-organic frameworks (MOFs) represent modern class of porous materials, which can be assembled in modular manner using different metal ions and organic linkers. Due to tunable structural properties, these materials are found to be useful for gas storage and separation technologies as well as catalytic applications. Herein we report the preparation of cost-effective zinc-based MOF ([Zn(bpcda)(bdc)]n) using N,N'-bis(pyridin-4-ylmethylene)cyclohexane-1,4-diamine, and benzene dicarboxylic acid linkers. Noteworthy, this new material exhibits remarkable photoelectrochemical (PEC) catalytic activity in water splitting for the evolution of oxygen. Notably, for the first time we showed that this non-noble metal-based MOF without any immobilization on other supports or containing metal particles produced highest photocurrent density, of 30 μA.cm-2 at 0.9 V with appreciable stability and negligible photo-corrosion. Advantageously, for this oxygen evolution process, no external reagents or sacrificial agents are required in the aqueous electrolyte solution.
      PubDate: 2017-12-18T01:45:35.12265-05:0
      DOI: 10.1002/cssc.201702122
       
  • Acid-catalysed conversion of carbohydrates into value added small
           molecules in aqueous media and ionic liquids
    • Authors: Iurii Bodachivskyi; Unnikrishnan Kuzhiumparambil, D. Bradley Glen Williams
      Abstract: Biomass is the only realistic major alternative source (to crude oil) of hydrocarbon substrates for the commercial synthesis of bulk and fine chemicals. Within biomass, terrestrial sources are the most accessible, and therein lignocellulosic materials are most abundant. While lignin shows promise for the delivery of certain types of organic molecules, cellulose is a biopolymer with significant potential for conversion into high volume and high value chemicals. This review covers the acid-catalysed conversion of lower value (poly)carbohydrates into valorised organic building block chemicals (platform molecules). It focuses on those conversions performed in aqueous media or ionic liquids. It does this to provide the reader with a perspective on what can be considered a best case scenario, i.e. that the overall process is as sustainable as possible.
      PubDate: 2017-12-17T21:51:08.243794-05:
      DOI: 10.1002/cssc.201702016
       
  • Towards the Shell Biorefinery: Sustainable Synthesis of the Anti-Cancer
           Alkaloid Proximicin A from Chitin
    • Authors: Jon Sperry; Ning Yan, alejandro sadiq, Xi Chen
      Abstract: A shell biorefinery would involve fractionation of crustacean shells and incorporation of the components into value-added products, particularly those that contain nitrogen. In a proof-of-concept study that validates this concept, the anti-cancer alkaloid proximicin A has been synthesized from the chitin-derived platform chemical 3-acetamido-5-acetylfuran (3A5AF). This study accentuates the leading role chitin is likely to play in the sustainable production of nitrogen-containing fine chemicals that are not directly attainable from lignocellulose.
      PubDate: 2017-12-16T01:28:55.729155-05:
      DOI: 10.1002/cssc.201702356
       
  • Highly Efficient Gas Phase Oxidation of Renewable Furfural to Maleic
           Anhydride over Plate VPO Catalyst
    • Authors: Yugen Zhang; Xiukai Li, Jogie Ko
      Abstract: Maleic anhydride (MAnh) and its acids are critical intermediates in chemical industry. The synthesis of maleic anhydride from renewable furfural is one of the most sought after processes in the field of sustainable chemistry. We report a plate vanadium phosphorous oxide (VPO) catalyst synthesized by a hydrothermal method with glucose as a green reducing agent for furfural oxidation to MAnh in gas phase. The plate VPOHT catalyst has a preferentially exposed 200 crystal plane and exhibited dramatically enhanced activity, selectivity and stability as compared to conventional VPO catalysts and other state-of-the-art catalytic systems. At 360 ºC reaction temperature with air as an oxidant, about 90% yield of MAnh was achieved at 10 vol% of furfural in the feed, a furfural concentration value that is much higher than those (< 2 vol%) reported for other catalytic systems. The catalyst showed good long term stability and there was no decrease in activity and selectivity for MAnh in the time-on-steam duration of 25 h. The high efficiency and catalyst stability established this system very prominent for the synthesis of maleic anhydride from renewable furfural.
      PubDate: 2017-12-15T04:51:18.845158-05:
      DOI: 10.1002/cssc.201701866
       
  • Heterojunction Engineering for High Efficiency Cesium-Formamidinium Double
           Cation Lead Halide Perovskite Solar Cells
    • Authors: Yihui Wu; Peng Wang, Shubo Wang, Zenghua Wang, Bing Cai, Xiaojia Zheng, Yu Chen, Ningyi Yuan, Jianning Ding, Wen-Hua Zhang
      Abstract: It is essential to minimize the interfacial trap states and improve the carrier collection for high efficiency perovskite solar cells (PSCs). Herein, we present a facile method to construct a p-type graded heterojunction (GHJ) in the normal PSCs by deploying a gradient distribution of hole-transporting materials (PTAA in this case) in the shallow perovskite layer. The formation of the GHJ structure facilitates charge transfer and collection, passivates interfacial trap states, thus delivering a power conversion efficiency (PCE) of 20.05% along with steady output efficiency of 19.3%, which is among the highest efficiencies for Cs-Formamidinium (Cs,FA) lead halide PSCs. Moreover, the unencapsulated devices based on these (Cs,FA) lead halide perovskites show excellent long-term stability, more than 95% of their initial PCE can be retained after 1440 h' storage under the ambient conditions. This study may provide an effective strategy to fabricate high efficiency PSCs with great stability.
      PubDate: 2017-12-15T03:04:59.929128-05:
      DOI: 10.1002/cssc.201702221
       
  • Sustainable carbon/carbon supercapacitors operating down to -40°C in
           aqueous electrolyte made with cholinium salt
    • Authors: Qamar Abbas; François Béguin
      Abstract: Cholinium chloride at a concentration of 5 mol kg-1 in water is proposed as low cost and environmentally friendly aqueous electrolyte enabling to extend the operating range of carbon/carbon supercapacitors (SCs) down to -40°C. This solution exhibits a pH close to neutrality (pH = 6.1) and high conductivity of 88 mS cm-1 at 24°C. The supercapacitors demonstrate a high capacitance of 126 F g-1 (per mass of one electrode) and long life span at voltages up to 1.5 V. At -40°C, the carbon/carbon SCs display excellent electrochemical characteristics featured by slightly reduced capacitance of 106 F g-1 and negligible ohmic losses. As compared to previous works, where anti-freezing additives were introduced in traditional neutral electrolytes, the low solubility of the salt and related poor conductivity of the solution is no longer an issue, which makes the cholinium salt aqueous solutions very promising for SCs operating at sub-ambient temperature conditions.
      PubDate: 2017-12-14T13:10:37.27311-05:0
      DOI: 10.1002/cssc.201701957
       
  • Achieving efficient electrocatalytic hydrogen evolution activity based on
           ultrafine and highly-dispersed RuPx encapsulated in N, P co-doped hollow
           carbon nanospheres
    • Authors: Jing-Qi Chi; Wen-Kun Gao, Jia-Hui Lin, Bin Dong, Kai-Li Yan, Jun-Feng Qin, Bin Liu, Yong-Ming Chai, Chen-Guang Liu
      Abstract: The ultrafine RuPx nanoparticles (NPs) encapsulated in uniform N, P co-doped hollow carbon nanospheres (RuPx@NPC) have been synthesized through a facile route of using aniline-pyrrole polymer nanospheres to disperse Ru ions with followed gas phosphorization process. The as-prepared RuPx@NPC exhibits uniform core-shell hollow nanospherical structures with ultrafine RuPx NPs as core and N, P co-doped carbon (NPC) as shell. So this strategy integrates many advantages of designing hollow nanostructures, providing conductive substrate and doping non-metal element. The obtained ultrathin NPC shell at high temperature can not only protect the high active phase of RuPx NPs from aggregation and corrosion in the electrolyte but also make the variation in the electronic structures and greatly improve charge transfer rate by N, P co-doping. The optimized RuPx@NPC sample at 900 °C exhibits Pt-like HER performance and long-time durability in acidic, alkaline and neutral solution. It requires a small overpotential of only 51 mV, 74 mV and 110 mV at 10 mA cm-2 in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS, respectively. So this work provides a new way to design unique phosphide-doped carbon heterostructures through inorganic-organic hybrid method as excellent HER electrocatalysts.
      PubDate: 2017-12-14T10:11:32.315676-05:
      DOI: 10.1002/cssc.201702010
       
  • Cyclopentanone derivatives from 5-hydroxymethylfurfural via
           1-hydroxyhexane-2,5-dione as intermediate
    • Authors: Bartosz Wozniak; Anke Spannenberg, Yuehui Li, Sandra Hinze, Johannes Gerardus de Vries
      Abstract: An efficient strategy for the conversion of biomass derived 5-hydroxymethyl-furfural (HMF) to 2-hydroxy-3-methylcyclopent-2-enone (MCP) via intramolecular aldol condensation of 1-hydroxyhexane-2,5-dione (HHD) has been developed. Further transformations of MCP towards the diol, enol acetate, levulinic acid and N-heterocyclic compounds are also reported.
      PubDate: 2017-12-13T06:07:53.752046-05:
      DOI: 10.1002/cssc.201702100
       
  • MnCo2O4/MoO2 Nanosheets Grown on Ni foam as Carbon- and Binder-free
           Cathode for Lithium-Oxygen Batteries with Long Life and High Efficiency
    • Authors: Xuecheng Cao; Zhihui Sun, Xiangjun Zheng, Chao Jin, Jinghua Tian, Xiaowei Li, Ruizhi Yang
      Abstract: Carbon is usually used as cathode material for Li-O2 batteries. However, the discharge product, such as Li2O2 and LiO2, could react with carbon to form insulating lithium carbonate layer, resulting in cathode passivation and capacity fading. To solve this problem, the development of non-carbon cathode is highly demanded. Herein, we have successfully synthesized MnCo2O4 (MCO) nanoparticles anchored on porous MoO2 nanosheets that are grown on Ni foam (current collector) (MCO/MoO2@Ni), acting as a carbon- and binder-free cathode for Li-O2 batteries, in an attempt to improve the electrical conductivity, electrocatalytic activity and durability. This MCO/MoO2@Ni electrode delivers excellent cyclability (more than 400 cycles) and rate performance (voltage gap of 0.75 V at 5000 mA g-1). Notably, the battery with this electrode exhibits a high energy efficiency (higher than 85 %). The advanced electrochemical performance of MCO/MoO2@Ni can be attributed to its high electrical conductivity, excellent stability and super electrocatalytic activity. This work offers a new strategy to fabricate high-performance Li-O2 batteries with non-carbon cathode materials.
      PubDate: 2017-12-13T05:12:32.666086-05:
      DOI: 10.1002/cssc.201702240
       
  • Magnetic Field Enhanced 4-electron Pathway by the Well-aligned Co3O4/ECNFs
           Design in the Oxygen Reduction Reaction
    • Authors: Zheng Zeng; Tian Zhang, Yiyang Liu, Wendi Zhang, Ziyu Yin, Zuowei Ji, Jianjun Wei
      Abstract: The sluggish reaction kinetics of oxygen reduction reaction (ORR) has been the limiting factor for fuel energy utilization, hence it is desirable to develop a high performance electrocatalysis with a 4-electron pathway ORR. Here, we report a constant low-current (50 μA) electrodeposition technique to develop a uniform Co3O4 film formation at the well-aligned electrospun carbon nanofibers (ECNFs) with a time-dependent growth mechanism. This work also reports a new finding of milli-Tesla (mT) magnetic field induced enhancement of electron exchange number of the ORR at glassy carbon electrode modified with the Co3O4/ECNFs catalyst. The magnetic susceptibility of the unpaired electrons in Co3O4 improves the kinetics and efficiency of electron transfer reactions in ORR, which shows a 3.92-electron pathway in the presence of a 1.32 mT magnetic field. This research presents a potential revolution of traditional electrocatalysts by simply applying an external magnetic field on metal oxides as replacement of noble metals to reduce the risk of the fuel cell degradation and maximize its energy output.
      PubDate: 2017-12-12T13:35:59.383699-05:
      DOI: 10.1002/cssc.201701947
       
  • Electrodeposition of Nickel Composite Nanoparticles for Alkaline Hydrogen
           Evolution Reaction: Correlating Electrocatalytic Behavior and Chemical
           Composition Obtained by XPS
    • Authors: Shasha Tao; Florent Yang, Jona Schuch, Wolfram Jaegermann, Bernhard Kaiser
      Abstract: Ni Nanoparticles (NPs) consisting of Ni, NiO and Ni(OH)2 have been formed on Ti substrates by electrodeposition as electrocatalysts for the hydrogen evolution reaction (HER) in alkaline solution. The deposition parameters including the potential range and the scan rate were varied, and the resulting NPs were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy. Additionally, the chemical composition of the NPs changes using different conditions, and it was found that the catalytic activity increases with an increasing amount of NiO. From these data optimized NPs have been synthesized; the best sample shows an onset potential of ~ 0 V and an overpotential (η) of 197 mV at a cathodic current density of 10 mA cm-2 as well as a small Tafel slope of 88 mV dec-1 in 1 M KOH, which are comparable values to a Pt-foil. These NPs consist of about 25% Ni and Ni(OH)2 each, as well as of about 50% of NiO. This implies, that in order to obtain a successful HER electrocatalyst, active sites with differing composition have to be close to each other to promote different reaction steps. Long-time measurements (30h) show an almost complete transformation of the highly active catalyst compound consisting of Ni0, NiO and Ni(OH)2 to the less active Ni(OH)2 phase. Nevertheless, the here employed electrodeposition of non-precious metal/metal oxide combination compounds represents a promising alternative to Pt-based electrocatalysts for the water reduction to hydrogen.
      PubDate: 2017-12-11T10:50:53.407098-05:
      DOI: 10.1002/cssc.201702138
       
  • Molecular Design of Efficient Organic D-A-π-A Dye Featuring
           Triphenylamine as Donor Fragment for Application in Dye-Sensitized Solar
           Cells
    • Authors: Anders Hagfeldt; Parnian Ferdowsi, Yasemin Saygili, Weiwei Zhang, Tomas Edvinsson, Ladislav Kavan, Javad Mokhtari, Shaik M. Zakeeruddin, Michael Grätzel
      Abstract: We designed, synthesized and characterized a novel metal-free organic sensitizer, suitable for the application in dye-sensitized solar cells (DSSCs), both experimentally and theoretically. The structure of the novel donor-acceptor-π-bridge-acceptor (D-A-π-A) dye has triphenylamine (TPA) segment and 4-(Benzo[c][1,2,5] thiadiazol-4-ylethynyl) benzoic acid (BTEBA). The triphenylamine unit is widely used as electron donor for the photosensitizers due to its outstanding characteristics, i.e. the non-planar molecular configuration and excellent electron donating capability while 4-(Benzo[c][1,2,5] thiadiazol-4-ylethynyl) benzoic acid is used as electron acceptor unit. We investigated the influence of iodide/triiodide, Cobalt(bpy)32+/3+ and Copper(tmby)22+/+complexes as redox electrolytes on the DSSC device performance. The maximal monochromatic incident photon to current conversion efficiency (IPCE) reached up to 81%. The solar light to electrical energy conversion efficiency of the devices with Cu(tmby)22+/+ reached up to 7.15%. The devices with Co(bpy)3 and Iodide/triiodide electrolytes showed 5.22% and 6.14% efficiency, respectively. The lowest device performance of Co(bpy)33+/2+ based electrolyte is attributed to the increased charge recombination process.
      PubDate: 2017-12-11T05:50:29.459735-05:
      DOI: 10.1002/cssc.201701949
       
  • Towards Sustainable H2 Production: Rational Design of Hydrophobic
           Triphenylamine-based Dyes for Sensitized Ethanol Photoreforming
    • Authors: Alessio Dessì; Matteo Monai, Matteo Bessi, Tiziano Montini, Massimo Calamante, Alessandro Mordini, Gianna Reginato, Cosimo Trono, Paolo Fornasiero, Lorenzo Zani
      Abstract: Donor-acceptor dyes are a well-established class of photosensitizers, used to enhance visible light harvesting in solar cells and in direct photocatalytic reactions, such as H2 production by photoreforming of sacrificial electron donors (SEDs). Amines - typically triethanolamine (TEOA) - are commonly employed as SEDs in such reactions. Dye-sensitized photoreforming of more sustainable, biomass-derived alcohols, on the other hand, was only recently reported using methanol as the electron donor. In this work, several rationally designed donor-acceptor dyes were used as sensitizers in H2 photocatalytic production, comparing the efficiency of TEOA and EtOH as SEDs. In particular, the effect of hydrophobic chains in the spacer and/or the donor unit of the dyes was systematically studied. The H2 production rates were higher when TEOA was used as SED, while the activity trends were dependent on the SED used. With TEOA, the best performance was obtained using a sensitizer (AD418) endowed with just one bulky hydrophobic moiety, propylenedioxythiophene (ProDOT), placed on the spacer unit. In the case of EtOH, the best performing sensitizers (TTZ4-5) were the ones featuring a thiazolo[5,4-d]thiazole internal unit, needed for enhancing light harvesting, and carrying alkyl chains on both the donor part and the spacer unit. The results are discussed in terms of reaction mechanism, interaction with SED and structural/ electrochemical properties of the sensitizers.
      PubDate: 2017-12-11T05:26:55.807821-05:
      DOI: 10.1002/cssc.201701707
       
  • Revealing the Chemistry between Bandgap and Binding Energy for Pb/Sn-based
           Trihalide Perovskite Solar Cell Semiconductors
    • Authors: Arpita Varadwaj; Pradeep R. Varadwaj, Koichi Yamashita
      Abstract: A relationship between reported experimental bandgaps (solid) and presently DFT-calculated binding energies (gas) is established for the first time for each of the four ten-membered lead (or tin) trihalide perovskite solar cell semiconductor series examined in this study, including CH3NH3PbY3, CsPbY3, CH3NH3SnY3 and CsSnY3, where Y = I(3 - x)Brx=1-3, I(3 - x)Clx=1-3, Br(3-x)Cl x=1-3, and IBrCl. The relationship unequivocally provides a new dimension for the fundamental understanding of the optoelectronic features of the solid state solar cell thin films using the 0 K gas-phase energetics of their corresponding molecular building blocks.
      PubDate: 2017-12-08T04:26:37.737226-05:
      DOI: 10.1002/cssc.201701653
       
  • Tracking Ionic Rearrangements and Interpreting Dynamic Volumetric Changes
           in Two-Dimensional Metal Carbides Supercapacitors: A Molecular Dynamics
           Simulation Study
    • Authors: Kui Xu; Zifeng Lin, Céline Merlet, Pierre-Louis Taberna, Ling Miao, Jianjun Jiang, Patrice Simon
      Abstract: We present a molecular dynamics simulation study achieved on two-dimensional (2D) Ti3C2Tx MXenes in an [EMIM]+[TFSI]- ionic liquid electrolyte. Our simulations reproduce the different patterns of volumetric change observed experimentally for both the negative and positive electrodes. The analysis of ionic fluxes and structure rearrangements in the 2D material provide an atomic scale insight into the charge and discharge processes in the layer pore and confirm the existence of two different charge storage mechanisms at the negative and positive electrodes. The ionic number variation and the structure rearrangement contribute to the dynamic volumetric changes of both electrodes: negative electrode expansion and positive electrode shrinkage.
      PubDate: 2017-12-06T12:36:39.075042-05:
      DOI: 10.1002/cssc.201702068
       
  • Efficient Yttrium(III) Chloride-Treated TiO2 Electron Transfer Layers for
           Performance-Improved and Hysteresis-Less Perovskite Solar Cells
    • Authors: Minghua Li; Yahuan Huan, Xiaoqin Yan, Zhuo Kang, Yan Guo, Yong Li, Xinqin Liao, Ruxiao Zhang, Yue Zhang
      Abstract: Hybrid organic–inorganic metal halide perovskite solar cells have attracted widespread attention, owing to their high performance, and have undergone rapid development. In perovskite solar cells, the charge transfer layer plays an important role for separating and transferring photogenerated carriers. In this work, an efficient YCl3-treated TiO2 electron transfer layer (ETL) is used to fabricate perovskite solar cells with enhanced photovoltaic performance and less hysteresis. The YCl3-treated TiO2 layers bring about an upward shift of the conduction band minimum (ECBM), which results in a better energy level alignment for photogenerated electron transfer and extraction from the perovskite into the TiO2 layer. After optimization, perovskite solar cells based on the YCl3-treated TiO2 layers achieve a maximum power conversion efficiency of about 19.99 % (19.29 % at forward scan) and a steady-state power output of about 19.6 %. Steady-state and time-resolved photoluminescence measurements and impedance spectroscopy are carried out to investigate the charge transfer and recombination dynamics between the perovskite and the TiO2 electron transfer layer interface. The improved perovskite/TiO2 ETL interface with YCl3 treatment is found to separate and extract photogenerated charge rapidly and suppress recombination effectively, which leads to the improved performance.Delete hysteresis' Efficient and hysteresis-less perovskite solar cells are prepared by using YCl3-treated TiO2 electron transfer layers. The YCl3 treatment increases the film conductivity and raises the lower boundary of the TiO2 conduction band. The average device efficiency reaches approximately 18.82 %, owing to better energy level alignment and favorable charge transfer.
      PubDate: 2017-12-06T06:10:38.568957-05:
      DOI: 10.1002/cssc.201701911
       
  • Nitrogen-doped carbon supported Co catalysts: An effective none-noble
           metal catalyst for the upgrade of biofuels
    • Authors: Liang Jiang; Peng Zhou, Chanjuan Liao, Zehui Zhang, Shi wei Jin
      Abstract: A new method has been developed for the deoxygenation of vanillin to produce 2-methoxy-4-methylphenol (MMP) as a promising liquid fuel over a heterogeneous non-noble metal catalyst. The nitrogen-doped carbon supported Co nanoparticles (Co/N-C-600) exhibited high activity and stability for the deoxygenation of vanillin into MMP under mild conditions (150 oC, 10 bar H2). Nearly quantitative MMP yield was obtained in iso-propanol after 8 h at 150 oC and 10 bar H2 pressure. According to the distribution of products with time, the deoxygenation of vanillin into MMP mainly underwent the hydrogenation of vanillin into vanillyl alcohol and the subsequent hydrogenolysis of vanillyl alcohol into MMP, and the latter was the rate-determining step, which had a much higher active energy. Moreover, after being recycled several times, the loss of catalytic activity was negligible, which demonstrated that the Co/N-C-600 catalyst had the property of resistance to deactivation.
      PubDate: 2017-12-06T04:05:41.408453-05:
      DOI: 10.1002/cssc.201702078
       
  • Kinematic Modelling of Mechanocatalytic Depolymerization of
           α-Cellulose and Beechwood
    • Authors: Martin Kessler; Robert Woodward, Narumi Wong, Roberto Rinaldi
      Abstract: Mechanocatalytic depolymerization of lignocellulose presents a promising method for the solid-state transformation of acidified raw biomass into water-soluble products (WSP). However, the mechanisms underlining the utilization of mechanical forces in the depolymerization is poorly understood. Herein, we applied a kinematic model of the milling process to assess the energy dose transferred to cellulose in its mechanocatalytic depolymerization performed under varied conditions (rotational speed, milling time, ball size and substrate loading). The data set was compared against the apparent energy dose results generated from the kinematic model and revealed key features of the mechanocatalytic process. At low energy dose, a rapid rise in the WSP yield associated with the apparent energy dose was observed. However, at a higher energy dose obtained by extended milling duration or high milling speeds, the formation of a substrate cake layer on the mill vials appear to buffer the mechanical forces, preventing full cellulose conversion into WSP. By contrast, for beechwood, there exists a good linear dependence between the WSP yield and the energy dose provided to the substrate over the entire range of WSP yield. As the formation of a substrate cake in depolymerization of beechwood is less severe compared to that observed for the cellulose, the current results verify the hypothesis regarding the negative effect of a substrate layer formed on the mill vials upon the depolymerization.
      PubDate: 2017-12-05T06:31:50.454856-05:
      DOI: 10.1002/cssc.201702060
       
  • Approaches to electrolyte solvent selection for Poly-anthraquinone
           sulphide (PAQS) organic electrode material
    • Authors: Satyajit Phadke; Mingli Cao, meriem anouti
      Abstract: Organic materials such as polyanthraquinone sulphide (PAQS) are receiving increased attention as electrodes for energy storage systems due to their good environmental compatibility, high rate capability and large charge storage capacity. However, one of their limits is the solubility in organic solvents composing the electrolytes. In this study, solubility of PAQS has been tested in 17 different solvents using UV-vis spectroscopy. Results show that PAQS exhibits a very wide range of solubility according to the nature of solvent and the obtained trend agrees well with the predictions from Hansen solubility analysis. In the second part of this study, the transport properties of electrolytes and electrochemical characterisation of PAQS as electrode material in selected pure or mixture of solvents with 1M LiTFSI as salt have been made in half-cells by galvanostatic method. In a methylglutaronitrile (2MeGLN) based electrolyte which exhibits low solubility of PAQS it appears that the capacity fade is intricately linked to the large irreversibility of the second step of the redox process. While, standard cyclic carbonate solvents mixture (EC and PC), lead to rapid capacity fade in the initial 10-15 cycles due to their high solubilizing ability. Finally, it is shown that a pure linear alkylcarbonate (DMC) or binary mixture of ethers (DOL/DME) based electrolyte is much more compatible for enhanced capacity retention in PAQS with more than 120 mAh.g-1 for 1000 cycles at 4C.
      PubDate: 2017-12-04T22:00:39.337942-05:
      DOI: 10.1002/cssc.201701962
       
  • Ultrafine VS4 Nanoparticles Anchored on Graphene Sheets as a High-Rate and
           Stable electrode Material for Sodium Ion Batteries
    • Authors: Qiang Pang; Yingying Zhao, Yanhao Yu, Xiaofei Bian, Xudong Wang, Yingjin Wei, Yu Gao, Gang Chen
      Abstract: Size and conductivity of the electrode materials play a significant role in improving the kinetics of sodium ion batteries. Various characterizations demonstrate that size-controllable VS4 nanoparticles are successfully anchored on graphene sheets (GS) surfaces by a simple cationic surfactant-assisted hydrothermal method. When used as an electrode material for sodium ion batteries, these VS4/GS nanocomposites show large specific capacity (349.1 mA∙h∙g-1 after 100 cycles), excellent long-term stability (84% capacity retention after 1200 cycles), and high rate capability (188.1 mA∙h∙g-1 at 4000 mA∙g-1). A large proportion of the capacity is contributed by capacitive processes. This remarkable electrochemical performance is attributed to synergistic interactions between nanosized VS4 particles and a highly conductive graphene network that provided short diffusion pathways for Na+ ions and large contact areas between the electrolyte and electrode, resulting in much improved electrochemical kinetic properties.
      PubDate: 2017-12-04T10:00:24.130373-05:
      DOI: 10.1002/cssc.201702031
       
  • Electrocatalytic Alloys for CO2 Reduction
    • Authors: Jingfu He; Noah J. Johnson, Aoxue Huang, Curtis Berlinguette
      Abstract: Electrochemically reducing CO2 into fuels using renewable energy is a contemporary global challenge. Catalysts that can mediate the conversion with low overpotential and high selectivity is required. Pure metals have been studied for catalyzing these conversions for decades, but alloys have recently gained attention as a new parameter space for catalyst discovery. The appealing aspect of these systems is that the relative metal content can be tuned to alter the electronic and geometric structure around the active sites to potentially achieve higher product selectivities and efficiencies. We summarize the current status in the understanding of various mixed-metal/alloy compositions that have been evaluated for electrocatalytic CO2 reduction and attempt to distill structure-property relationships that can guide new catalyst discovery.
      PubDate: 2017-12-04T06:30:43.563961-05:
      DOI: 10.1002/cssc.201701825
       
  • Insights into MOF Reactivity: Chemical Water Oxidation Catalysis
           [Ru(tpy)(dcbpy)OH2]2+ Modified Metal-Organic Framework
    • Authors: Shaoyang Lin; Alireza K Ravari, Jie Zhu, Pavel Usov, Meng Cai, Spencer R Ahrenholtz, Yulia Pushkar, Amanda Morris
      Abstract: Investigation of chemical water oxidation was conducted on the [Ru(tpy)(dcbpy)OH2]2+ (tpy = 2,2′:6′,2′′-terpyridine, dcbpy = 5,5′-dicarboxy-2,2′-bipyridine) -doped UiO-67 metal-organic framework (MOF). The MOF catalyst exhibited single site reaction pathway with similar kinetic behavior as the homogeneous Ru complex. The reaction was first order with respect to both the concentration of Ru catalyst and cerium ammonium nitrate (CAN), with kcat = 3 (±2) ×10-3 M-1s-1 in HNO3 (pH 0.5). The common degradation pathways of ligand dissociation and dimerization were precluded by MOF incorporation, leading to sustained catalysis and greater reusability as opposed to the molecular catalyst in homogeneous solution. Lastly, at the same loading (~97 nmol/mg), samples of different particle size generated the same amount of oxygen (~100 nmol) indicative of in-MOF reactivity. The results suggest that the rate of redox hopping charge transport is sufficient to promote chemistry throughout the MOF particulates.
      PubDate: 2017-12-02T00:35:31.624184-05:
      DOI: 10.1002/cssc.201701644
       
  • Coffee waste templating of metal ion substituted cobalt oxides for oxygen
           evolution reaction
    • Authors: Mingquan Yu; Candace Chan, Harun Tüysüz
      Abstract: A facile and scalable method using coffee waste grounds as hard template was developed to fabricate nanostructured Co3O4 for the oxygen evolution reaction (OER). Co3O4 incorporated with different valent metals (M = Cu, Ni, Fe, Cr and W, M/Co: 1/4) were also prepared with similar sheet-like structure comprising nanosized crystallites. After a detailed characterization using X-ray diffraction, electron microscopy and nitrogen sorption, the oxides were employed as OER electrocatalysts. Substitution of octahedral and tetrahedral sites of the spinel structure with divalent and trivalent transition metals (Cu, Ni, Fe and Cr) increases the activity of Co3O4 for OER, while the incorporation of hexavalent W leads to a second crystal phase and significantly higher electrocatalytic performance. Furthermore, this method is easily scaled up for mass production of Co3O4 with the same nanostructure, which is highly desirable for large-scale application.
      PubDate: 2017-12-01T11:35:24.970195-05:
      DOI: 10.1002/cssc.201701877
       
  • Selective hydrogenolysis of furfural-derivative 2-methyltetrahydrofuran
           into pentanediol acetate and pentanol acetate over Pd/C and Sc(OTf)3
           co-catalytic system
    • Authors: Kun Zhang; Xing-Long Li, Shi-Yan Chen, Hua-Jian Xu, Jin Deng, Yao Fu
      Abstract: It is of great significance to convert platform molecules and their derivatives into high value-added alcohols which had multitudinous applications. We systematically studied the conversion of 2-methyl tetrahydrofuran (MTHF), which obtained from furfural, to 1-pentanol acetate (PA) and 1,4-pentandiol acetate (PDA) in this paper. The reaction parameters such as the species of Lewis acid, reaction temperature, hydrogen pressure, etc. were investigated and discussed in detail. 1H-NMR analysis and reaction dynamics were also conducted to help clarify the reaction mechanism. Results suggested that the cleavage of primary alcohol acetate was harder to occur than that of secondary alcohol acetate with the main product being PA. A yield of 91.8% PA (150 C, 3 MPa H2, for 30 min) was achieved by using Pd/C + Sc(OTf)3 co-catalytic system and 82% yield of PDA was achieved (150 C, for 30 min) by using Sc(OTf)3 catalyst, respectively. Simultaneously, the efficient conversion of acetic esters to alcohols by simple saponification were carried out and obtained a good yield.
      PubDate: 2017-12-01T01:35:50.840553-05:
      DOI: 10.1002/cssc.201702073
       
  • Computational screening of doped αMnO2 catalysts for the oxygen
           evolution reaction
    • Authors: Vladimir Tripkovic; Heine Anton Hansen, Tejs Vegge
      Abstract: Minimizing energy and materials costs for driving the oxygen evolution reaction (OER) is paramount for the commercialization of water electrolysis cells and rechargeable metal-air batteries. Using density functional theory calculations, we analyze the structural stability, catalytic activity and electronic conductivity of pure and doped αMnO2 for the OER. As a model surface, we investigate the (110) and (100) facets, on which we identify three possible active sites: a coordination unsaturated, bridge and bulk site. We evaluate the performance of pure and Cr, Fe, Co, Ni, Cu, Zn, Cd, Mg, Al, Ga, In, Sc, Ru, Rh, Ir, Pd, Pt, Ti, Zr, Nb and Sn doped αMnO2. At each site and for each dopant, we impose the preferred valence by adding/subtracting electron donors (hydrogens) and electron acceptors (hydroxyls). From a subset of stable dopants, we identify Pd doped αMnO2 as the only catalyst that can outperform pristine aMnO2. We also discuss approaches to increase the electron conductivity as pure αMnO2 is a narrow band-gap material.
      PubDate: 2017-11-30T06:00:50.66025-05:0
      DOI: 10.1002/cssc.201701659
       
  • Bismuth vanadate photoelectrodes with high photovoltage behave as
           photoanode and photocathode in photoelectrochemical cells for water
           splitting
    • Authors: Wayler S. dos Santos; Mariandry Rodriguez, Júlia M. O. Khoury, Luíza A. Nascimento, Rebecca J. P. Ribeiro, João P. Mesquita, Adilson C. Silva, Francisco G. E. Nogueira, Marcio Cesar Pereira
      Abstract: Using dual-photoelectrode photoelectrochemical (PEC) devices based on earth-abundant metal oxides for the unbiased water splitting is an attractive way for producing the green H2 fuel, but challenging due to low photovoltages generated by PEC cells. Here we demonstrate that this problem can be solved by coupling the n-type BiVO4 with n-type Bi4V2O11 to create a virtual p/n junction due to the formation of a hole inversion layer at the semiconductor interface. Thus, photoelectrodes with high photovoltage outputs were synthesized. The photoelectrodes exhibited features of p- and n-type semiconductors when illuminated under an applied bias, suggesting their use as photoanode and photocathode in a dual-photoelectrode PEC cell. This concept was proved by connecting the 1 mol% W-doped BiVO4/Bi4V2O11 photoanode with the undoped BiVO4/Bi4V2O11 photocathode, which produced a high photovoltage of 1.54 V, sufficient to drive the stand-alone water splitting with 0.95% efficiency.
      PubDate: 2017-11-29T14:30:36.347572-05:
      DOI: 10.1002/cssc.201701929
       
  • Interfacial Engineering of Supported Liquid Membranes by Vapor
           Cross-Linking for Enhanced Separation of Carbon Dioxide
    • Authors: Li-Yun Kong; Wei-Da Shan, Sheng-Li Han, Tao Zhang, Lang-Chong He, Kuan Huang, Sheng Dai
      Abstract: Supported liquid membranes (SLMs) based on ionic liquids (ILs) with not only high gas permeability and selectivity, but also high stability under high pressure, are highly desired for gas separation applications. In this work, permeable and selective polyamide network (PN) layers are deposited on the surface of SLMs by utilizing the cross-linking reaction of trimesoyl chloride, which was pre-dispersed in the SLMs, and vapor of amine linkers. The vapor cross-linking method makes it easy to control the growth and aggregation of PN layers, owing to the significantly reduced reaction rate, and thereby ensuring the good distribution of PN layers on the surface of SLMs. With rational choice of amine linkers and optimization of vapor cross-linking conditions, the prepared sandwich-like PN@SLMs with ILs embedded homogeneously within polymeric matrices displayed much-improved CO2 permeability and CO2/N2 selectivity in relation to the pristine SLMs. Moreover, those SLMs with ILs impregnated into porous supports physically displayed improved stability under high pressure after vapor cross-linking, because the PN layers formed on the surface of SLMs help prevent the ILs from being squeezed out. This interfacial engineering strategy represents a significant advance in the surface modification of SLMs to endow them with promising applications in CO2 capture.SLM dunk! A vapor cross-linking strategy was developed for the surface modification of supported liquid membranes (SLMs) based on ionic liquids. Permeable and selective polyamide network layers were deposited on the surface of SLMs. The prepared composite membranes showed significantly improved performance for the selective separation of CO2 from N2, or enhanced stability against transmembrane pressure difference, in relative to pristine SLMs.
      PubDate: 2017-11-29T08:01:34.924403-05:
      DOI: 10.1002/cssc.201701851
       
  • Cascade production of lactic acid from universal types of sugars catalyzed
           by lanthanum triflate
    • Authors: Dajiang Liu; Kwang Ho Kim, Jian Sun, Blake Simmons, Seema Singh
      Abstract: Lignocellulosic biomass conversion to value-added platform chemicals in the non-toxic, water-tolerant Lewis acid, and water solutions bears the hallmark of green chemistry. Lactic acid derived from biomass is an important chemical building block for biodegradable polymers such as polylactide. Herein, a universal method of converting lignocellulosic sugars to lactic acid using catalytic amount of water-stable Lewis acid La(OTf)3 is demonstrated. The lignocellulosic sugars studied in this work include 1) pyrolytic sugars from pyrolysis oil, and 2) sugars derived from ionic liquid (IL)-pretreated biomass. Under moderate conditions (250 °C, 1 h), levoglucosan (major pyrolytic sugar), glucose and xylose were converted to lactic acid with the carbon-based molar yields of 75%, 74% and 61% respectively. Furthermore, ~49 mol% (based on levoglucosan) and ~74 wt% (relative to pretreated biomass) of lactic acid were obtained from the conversion of pyrolytic sugars and sugar rich fraction after lignin removal from switchgrass, respectively. To the best of our knowledge, this is the first time to convert pyrolytic sugar into lactic acid by chemocatalysis and also lignocellulosic sugars are converted to lactic acid without hydrolysis. This approach could potentially be extended to other lignocellulosic sugars after simple removal of lignin from biomass pretreatment, rendering moderate to high yields of lactic acid.
      PubDate: 2017-11-27T00:52:55.971191-05:
      DOI: 10.1002/cssc.201701902
       
  • High loading solubilization and upgrading of poly(ethylene terephthalate)
           in low cost bifunctional ionic liquid
    • Authors: Jian Sun; Dajiang Liu, Robert P. Young, Alejandro G. Cruz, Nancy G. Isern, Timo Schuerg, John R. Cort, Blake A. Simmons, Seema Singh
      Abstract: High loading solubilization and efficient upgrading polyethylene terephthalate (PET) is of significant importance but challenging and most solvents for PET are highly toxic. In this work, we demonstrate for the first time that a low cost (~$1.2/kg) and biocompatible ionic liquid (IL), cholinium phosphate ([Ch]3[PO4]) can play bifunctional roles in PET solubilization and glycolytic degradation. High loading of PET (10 wt%) is readily dissolved in [Ch]3[PO4] at relatively low temperatures (120 °C, 3h) and even in water-rich conditions. In depth analysis of PET-IL solution reveals that the high PET solubilization in [Ch]3[PO4] can be ascribed to significant PET depolymerization. Acid precipitation yields terephthalic acid as the dominant depolymerized monomer with a theoretical yield of ~95%. Further exploration shows that in the presence of ethylene glycol, [Ch]3[PO4] catalyzed glycolysis of PET can efficiently occur with ~100% PET conversion and ~60.6% bis(2-hydroxyethyl)terephthalate (BHET) yield under metal free conditions. The IL can be reused at least three times without an apparent decrease in activity. NMR analysis reveals that strong hydrogen bond interactions between EG and the IL play an important role for EG activation and promotion of the glycolysis reaction. This study opens up avenues for exploring environmentally benign and efficient technology of ILs for solubilizing and recycling postconsumer polyester plastics.
      PubDate: 2017-11-27T00:51:15.958892-05:
      DOI: 10.1002/cssc.201701798
       
  • Complementary strategies towards the aqueous processing of high-voltage
           LiNi0.5Mn1.5O4 lithium-ion cathodes: Crosslinking CMC and phosphoric acid
           treatment
    • Authors: Matthias Kuenzel; Dominic Bresser, Thomas Diemant, Diogo Viera Carvalho, Guk-Tae Kim, Juergen Behm, Stefano Passerini
      Abstract: Increasing the environmental benignity of lithium-ion batteries is one of the greatest challenges for their large-scale deployment. Toward this end, we present herein a strategy to enable the aqueous processing of high-voltage LiNi0.5Mn1.5O4 (LNMO) cathodes, which are considered highly, if not the most, promising for the realization of cobalt-free next generation lithium-ion cathodes. Combining the addition of phosphoric acid with the crosslinking of sodium carboxymethyl cellulose by means of citric acid, aqueously processed electrodes with excellent performance are produced. The combined approach offers synergistic benefits, resulting in stable cycling performance and excellent coulombic efficiency (98.96%) in lithium metal cells. Remarkably, this approach can be easily incorporated into standard electrode preparation processes with no additional processing step.
      PubDate: 2017-11-24T09:56:34.268732-05:
      DOI: 10.1002/cssc.201702021
       
  • Capacitance Assisted Sustainable Electrochemical Carbon Dioxide
           Mineralisation
    • Authors: Katie Lamb; Mark Dowsett, Konstantinos Chatzipanagis, zhan Scullion, roland kroger, james lee, pedro aguiar, Michael North, alison parkin
      Abstract: An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte has been constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5% carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially-relevant gas stream and a solar panel as an effectively zero-carbon energy source.
      PubDate: 2017-11-24T06:25:31.893841-05:
      DOI: 10.1002/cssc.201702087
       
  • Micelle-assisted electrodeposition of mesoporous Fe-Pt smooth thin films
           onto various substrates and their electrocatalytic activity towards
           hydrogen evolution reaction
    • Authors: Eloy Isarain-Chávez; Maria Dolors Baró, Carlos Alcantara, Salvador Pané, Jordi Sort, Eva Pellicer
      Abstract: Mesoporous Fe-Pt thin films are obtained by micelle-assisted electrodeposition onto metallic substrates with dissimilar activity (namely, gold, copper, and aluminum seed-layers evaporated on Si/Ti) under constant applied potential (E= -1.1 V vs. Ag/AgCl) and deposition time (600 s). The amphiphilic triblock copolymer Pluronic P-123 is used as a soft-template to guide the formation of mesopores. The occurrence of pores (ca. 7 nm in diameter) with narrow size distribution, regularly distributed over the surface, is observed in all cases. Despite the applied conditions being the same, the roughness and the amount of Fe incorporated in the films are influenced by the substrate nature. In particular, ultra-smooth films containing a larger amount of Fe (21 wt.%) are achieved when deposition takes place on the Au surface. X-ray diffraction analyses reveal that Pt and Fe are alloyed to a certain extent, although some iron oxides/hydroxides also unavoidably form. The resulting films have been tested as electocatalysts in the hydrogen evolution reaction (HER) in alkaline media. The mesoporous Fe-rich Fe-Pt films on Au show excellent HER activity and cyclability.
      PubDate: 2017-11-22T10:20:29.903074-05:
      DOI: 10.1002/cssc.201701938
       
  • Impact of Flue Gas Compounds on Microalgae and Mechanisms for Carbon
           Assimilation and Utilization - A Review
    • Authors: Arun Krishna Vuppaladadiyam; Joseph G Yao, Nicholas Florin, Anthe George, Xiaoxiong Wang, Leen Labeeuw, Yuelu Jiang, Ryan W. Davis, Ali Abbas, Peter Ralph, Paul S. Fennell, Ming Zhao
      Abstract: In order to shift the world to a more sustainable future, it is necessary to phase out the use of fossil fuels and focus on the development of low-carbon alternatives. However, this transition is slow so there still exists a large dependence on fossil-derived power and therefore CO2 release. Owing to the potential for assimilating and utilizing CO2 to generate carbon neutral products such as biodiesel, the application of microalgae technology to capture CO2 from flue gases has gained significant attention over the past decade. Microalgae offer a more sustainable source of biomass energy over conventional fuel crops since they grow more quickly and do not adversely affect food supply. This review focuses on the technical feasibility of combined carbon fixation and microalgae cultivation for carbon reuse. We appraise a range of different C metabolisms and the impact of flue gas compounds on microalgae. Fixation of flue gas CO2 is found to be dependent on the selected microalgae strain and on flue gas compounds/concentrations. Additionally, we assess current pilot-scale demonstrations of microalgae technology for CO2 capture as well as discuss its future prospects. Practical implementation of this technology at an industrial-scale still requires significant research, necessitating multidiscipline R&D to demonstrate its viability for CO2 capture from flue gases at the commercial level.
      PubDate: 2017-11-22T06:50:22.991437-05:
      DOI: 10.1002/cssc.201701611
       
  • Continuous flow synthesis of supported magnetic iron oxide nanoparticles
           for efficient isoeugenol conversion to vanillin
    • Authors: María Dolores Marquez; Pepijn Prinsen, Hangkong Li, Kaimin Shih, Antiono Ángel Romero Reyes, Rafael Luque
      Abstract: This work presents the synthesis of iron oxide nanocatalysts supported on mesoporous Al-SBA-15 using a continuous flow set-up. The magnetic solid nanoparticles were tested as catalysts for the oxidative disruption of isoeugenol using hydrogen peroxide as the oxidant, showing all high activity (63-88 % conversion) and fare selectivity to vanillin (44-68 %). The nanoparticles exhibited good magnetic properties, whensynthesized at continuous flow temperatures not exceeding 190 °C, which is important to enable their efficient separation from reaction mixtures. The use of microwave irradiation reduced the reaction times drastically, but had negative effects on the catalyst re-usability.
      PubDate: 2017-11-21T15:20:22.463654-05:
      DOI: 10.1002/cssc.201701884
       
  • Bioinspired Mesoporous Chiral Nematic Graphitic Carbon Nitride for
           Ultrahigh Photocatalytic Activity with Polarized Light Modulations
    • Authors: Wensheng Lin; Wei Hong, Lu Sun, Di Yu, Dingshan Yu, Xudong Chen
      Abstract: Endowing materials with chirality and exploring the responses of the material under circularly polarized light (CPL) can gain further insight into the physical and chemical properties of the semiconductors, thus expand the optoelectronic applications. Herein we report a bioinspired mesoporous chiral nematic graphitic carbon nitride (g-C3N4) for efficient hydrogen evolutions with polarized light modulations based on chiral nematic cellulose nanocrystal films through silica templating. The mesoporous nematic chiral g-C3N4 exhibits an ultrahigh hydrogen evolution rate of 219.9 μmolh-1 and a high enhancement factor of 54.9 when compared to the bulk g-C3N4 under λ>420 nm irradiation. Furthermore, the chiral g-C3N4 exhibits unique photocatalytic activity modulated by CPL within the absorption region. This CPL-assisted photocatalytic regulation strategy holds great promises for a wide range of applications including optical devices, asymmetric photocatalysis and chiral recognition/separation.
      PubDate: 2017-11-21T11:20:34.433643-05:
      DOI: 10.1002/cssc.201701984
       
  • Highly Efficient Perovskite Solar Cells Based on Zn2Ti3O8 Nanoparticles as
           Electron Transporting Material with Efficiency over 17%
    • Authors: Zhong-Ning Chen; Aiying Pang, Deli Shen, Mingdeng Wei
      Abstract: Developing ternary metal oxides as electron transporting layers (ETL) for perovskite solar cell is highly challenging in the field of third-generation photovoltaics. In this study, highly mesoporous zinc titanate oxide (Zn2Ti3O8) scaffold synthesized by ion-exchange method has been successfully used as ETL for the fabrication of methyl ammonium lead halide (CH3NH3PbI3) perovskite solar cells. The optimized devices exhibit 17.21% power conversion efficiency (PCE) with open circuit voltage (Voc) of 1.02 V, short-circuit current density (Jsc) of 21.97 mA cm-2 and fill factor (FF) of 0.77 under AM 1.5 G sunlight (100 mW cm−2). The PCE is obviously higher than that based on mesoporous TiO2 (ST01) layer (η = 14.93%), which is ascribed to deeper conductive band of Zn2Ti3O8 nanoparticles, better light absorption and smaller charge recombination. The devices stored for 100 days at ambient temperature with humidity of 10% show excellence stability with only 12% reduction of the PCE. The charge transmission kinetic and long-term stability parameters of the ZTO-based perovskite film growth are discussed as well.
      PubDate: 2017-11-21T08:50:52.960249-05:
      DOI: 10.1002/cssc.201701779
       
  • Bio-derived muconates via cross-metathesis and their conversion to
           terephthalates
    • Authors: Erisa Saraci; Lan Wang, Klaus Theopold, Raul Francisco Lobo
      Abstract: Renewable terephthalic acid or its precursors can be obtained via Diels-Alder cycloaddition and further dehydrogenation of biomass-derived muconic acid. We have investigated the synthesis of dialkyl muconates via cross-metathesis. We show that Ru-catalyzed cross-coupling of sorbates with acrylates—which can be bio-sourced—proceeds selectively to yield up to 41% di-ester muconates using very low catalyst amounts (0.5 - 3.0 mol.%) and no solvent. In the optimized procedure, the muconate precipitates as a solid and is easily recovered from the reaction medium. GC-MS and NMR analysis showed that this method delivers exclusively the trans,trans isomer of dimethyl muconate. The Diels-Alder reaction of dimethyl muconate with ethylene was studied in various solvents to obtain the 1,4-bis(carbomethoxy) cyclohexene. The cycloaddition proceeded in very high conversion (77 - 100%) and yield (70 − 98%) in all solvents investigated, methanol and tetrahydrofuran being the best. Next, the aromatization of 1,4-bis(carbomethoxy) cyclohexene to dimethyl terephthalate over Pd/C catalyst resulted in up to 70% yield in tetrahydrofuran and an air atmosphere. Due to the high yield of the reaction of dimethyl muconate to 1,4-bis(carbomethoxy) cyclohexene, no separation step is needed before the aromatization. This is the first time that cross-metathesis has been used to produce bio-derived trans,trans-muconates as precursors to renewable terephthalates.
      PubDate: 2017-11-20T21:50:47.396858-05:
      DOI: 10.1002/cssc.201701874
       
  • Pyran-bridged indacenodithiophene: A novel building block for constructing
           efficient A-D-A type nonfullerene acceptor for polymer solar cells
    • Authors: Renqiang Yang; Shuguang Wen, Yao Wu, Yingying Wang, Yi Li, Ling Liu, Huanxiang Jiang, Zhitian Liu
      Abstract: In recent years, nonfullerene acceptors have attracted much attention due to their great potential for achieving high performance polymer solar cells. In this paper, a novel ladder type building block of pyran-bridged indacenodithiophene (PDT) has been designed for constructing A-D-A nonfullerene acceptors through introducing oxygen atoms into the commonly used indacenodithiophene (IDT) unit. The key step for the synthesis of PDT unit is accomplished by a BBr3-mediated tandem cyclization-deprotection reaction to construct the pyran-ring. In this approach, a novel molecular acceptor PTIC was successfully synthesized and applied in polymer solar cell device. Compared to the IDT-based acceptor, PTIC exhibits higher HOMO levels and wider optical bandgap at 550-800 nm. Polymer solar cells devices fabricated with PBDB-T:PTIC as active layer show a power conversion efficiency (PCE) of 7.66%. The introduction of oxygen atoms would be an effective approach for the modification of acceptor materials for polymer solar cells.
      PubDate: 2017-11-19T22:16:08.670735-05:
      DOI: 10.1002/cssc.201701917
       
  • Effect of Tetrahydrofuran on the Solubilisation and Depolymerisation of
           Cellulose in a Biphasic System
    • Authors: Changwei Hu; Zhicheng Jiang, Pingping Zhao, Jianmei Li, Xudong Liu
      Abstract: The dissolution of cellulose from biomass is a crucial but complicated issue for the utilisation of biomass resources, because of the extreme insolubility of cellulose. Herein, a biphasic NaCl-H2O-tetrahydrofuran system was studied, where most of the pure microcrystalline cellulose (M-cellulose, 96.6% conversion at 220 oC) and that contained in actual biomass were converted. Nearly a half of O(6)H***O(3) intermolecular hydrogen bonding could be broken by THF in H2O-THF co-solvent system, whereas the cleavage of O(2)H***O(6) intramolecular hydrogen bonding by H2O was significantly inhibited. In NaCl-H2O-THF system, THF could significantly promote the effects of both H2O and NaCl on the disruption of O(2)H***O(6) and O(3)H***O(5) intramolecular hydrogen bondings, respectively. In addition, THF could protect and transfer the cellulose-derived products to organic phase through forming hydrogen bonding between oxygen atom in THF and hydrogen atom of C4-O-H in glucose or aldehyde group in 5-hydroxymethylfurfural (HMF), which can lead more NaCl to combine with -OH of M-cellulose and further disrupt hydrogen bonds in M-cellulose, thereby improving the yield of small molecular weight products (especially HMF) and further promoting the dissolution of cellulose. As a cheap and reusable system, NaCl-H2O-THF system may be a promising approach for the dissolution and further conversion of cellulose in lignocellulosic biomass without any enzymes, ionic liquid nor conventional catalyst.
      PubDate: 2017-11-17T04:55:24.735051-05:
      DOI: 10.1002/cssc.201701861
       
  • Catalytic Transfer Hydrogenation of Biomass-Derived Carbonyls over
           Hafnium-Based Metal-Organic Frameworks
    • Authors: Avelino Corma; Pilar García-García, Sergio Rojas-Buzo
      Abstract: A series of highly crystalline, porous, hafnium-based metal-organic frameworks (MOFs) have shown to catalyze the transfer hydrogenation reaction of levulinic ester to produce γ-valerolactone using isopropanol as hydrogen donor and the results are compared with the zirconium-based counterparts. The role of the metal center in Hf-MOFs has been identified and reaction parameters optimized. NMR studies with isotopically labeled isopropanol evidences that the transfer hydrogenation occurs via a direct intermolecular hydrogen transfer route. The catalyst, Hf-MOF-808, can be recycled several times with only a minor decrease in catalytic activity. Generality of the procedure was shown by accomplishing the transformation with aldehydes, ketones and α,β-unsaturated carbonyl compounds. The combination of Hf-MOF-808 with the Brønsted acidic Al-Beta zeolite gives the four-step one-pot transformation of furfural to γ-valerolactone in good yield of 72%.
      PubDate: 2017-11-15T06:50:23.736792-05:
      DOI: 10.1002/cssc.201701708
       
  • Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of
           Lignin over Super Lewis Acid Combined with Metal Catalysts
    • Authors: Hongliang Wang; Huamin Wang, Eric Kuhn, Melvin P. Tucker, Bin Yang
      Abstract: Super Lewis acids containing the triflate anion [e.g., Hf(OTf)4, Ln(OTf)3, In(OTf)3, Al(OTf)3] and noble metal catalysts (e.g., Ru/C, Ru/Al2O3) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote oxygenation reactions catalyzed by super Lewis acids.The biggest Lewiser: Super Lewis acids and noble metals form an efficient catalytic system that can overcome the energy barrier for conversion of lignin into high yield jet-fuel range hydrocarbons. Metal triflates mediate rapid ether bond cleavage through selective bonding to the etheric oxygen, whereas the noble metal catalyzes the subsequent hydrogenation reaction, eliminating functional groups.
      PubDate: 2017-11-14T12:45:22.716058-05:
      DOI: 10.1002/cssc.201701567
       
  • Role of bismuth in the electro-kinetics of silicon photocathodes for solar
           rechargeable vanadium redox flow batteries
    • Authors: Cristina Flox; Sebastián Murcia-López, Nina M. Carretero, Carles Ros, Juan Ramón Morante, Teresa Andreu
      Abstract: The ability of crystalline Si to photo-assist the V3+/V2+ cathodic reaction under simulated solar irradiation, combined with the effect of Bi have led to important electrochemical improvements. Besides the photo-voltage supplied by the photovoltaics, additional decrease in the onset potentials, high reversibility of the V3+/V2+ redox pair and improvement in the electro-kinetics have been attained thanks to the addition of Bi. In fact, Bi0 deposition has shown to slightly decrease the photocurrent, but the significant betterment in the charge transfer, reflected in the overall electrochemical performance clearly justifies its use as additive in a photo-assisted system for maximizing the efficiency of solar charge to battery.
      PubDate: 2017-11-14T09:51:00.424496-05:
      DOI: 10.1002/cssc.201701879
       
  • The three-dimensional-structure of twisted benzo[ghi]perylene-triimide
           dimer as a non-fullerene acceptor for inverted perovskite solar cells
    • Authors: Priyadharsini Karuppuswamy; Hung-Cheng Chen, Pen-Cheng Wang, Chao-Ping Hsu, Ken-Tsung Wong, Chih Wei Chu
      Abstract: In this work, we introduced benzo[ghi]perylenetriimide (BPTI) derivatives including monomer and twisted dimer (t-BPTI) as an alternative electron transport layer (ETL) material to replace the commonly used PC61BM in inverted planar heterojunction perovskite solar cells. Moreover, the double ETL layer was applied in our perovskite solar cells with structure of glass/ITO/PEDOT:PSS/perovskite/BPTI/C60 or PDI-C4/BCP/Al. Use of a double ETL layer structure can effectively eliminate the leakage current. The devices with the t-BPTI/C60 double ETL layer yield an average power conversion efficiency of 10.73% and a maximum efficiency of 11.63%. The device based on the complete non-fullerene electron acceptors of t-BPTI/PDI-C4 as double ETL achieved maximum efficiency of 10.0%. Besides, it is found that the utilization of alloy t-BPTI+BPTI as ETL can effectively reduce the hysteresis effect of perovskite solar cells. The results suggest that BPTI based electron transport materials are potential alternatives for widely used fullerene acceptors in PSCs.
      PubDate: 2017-11-12T22:45:24.902476-05:
      DOI: 10.1002/cssc.201701827
       
  • Ruthenium Ion-Complexed Graphitic Carbon Nitride Nanosheets Supported on
           Reduced Graphene Oxide as High-Performance Catalysts for Electrochemical
           Hydrogen Evolution
    • Authors: Shaowei Chen; Yi Peng, Wanzhang Pan, Nan Wang, Jia-En Lu
      Abstract: Carbon-based materials are promising, low-cost electrocatalysts toward hydrogen evolution reaction (HER), although the catalytic performance needs to be further improved before commercialization. In this study, ruthenium ions are incorporated into carbon nitride-reduced graphene oxide hybrids forming C3N4-rGO-Ru composites through RuN coordination. The incorporation of Ru ions, at a loading of 1.93 at.%, leads to electron redistribution within the materials and dramatically enhances the HER performance, as compared to C3N4, C3N4-rGO, and C3N4-Ru, with an overpotential of only 80 mV to reach the current density of 10 mA/cm2, a Tafel slope of 55 mV/dec, and an exchange current density of 0.462 mA/cm2. This performance is highly comparable to that of Pt/C, and ascribed to the positive shift of the conduction band of the composite, where the charge carrier density increases by over 200 times, as compared to that of C3N4, leading to a lower energy barrier of hydrogen evolution. The results suggest a new strategy in the design and engineering of functional nanocomposites for effective HER electrocatalysis by embedding select metal ions into the carbon-based molecular skeletons.
      PubDate: 2017-11-09T14:25:38.553431-05:
      DOI: 10.1002/cssc.201701880
       
  • Isocyanate-free approach to water-borne polyurea dispersions and coatings
    • Authors: Shuang Ma; Ellen van Heeswijk, Bart Noordover, Rafael Sablong, Rolf van Benthem, Cor Koning
      Abstract: In this work, an isocyanate-free approach to produce polyureas from diamines and dicarbamates as monomers is reported. A side reaction limiting molecular weight during the diamine/dicarbamate polymerization, viz. N-alkylation of amine end-groups, is investigated. Mitigation of the N-alkylation, either by enhancing the carbamate aminolysis rate or by substitution of dimethylcarbamates with more sterically hindered diethylcarbamates, affords polyureas with sufficiently high molecular weights to assure satisfactory mechanical properties. Stable polyurea dispersions with polyamines as internal dispersing agents are prepared, and the properties of the corresponding coatings are evaluated.
      PubDate: 2017-11-08T09:56:13.891588-05:
      DOI: 10.1002/cssc.201701930
       
  • Molybdenum-doping augments platinum-copper oxygen reduction
           electrocatalyst
    • Authors: Nicolas Alonso-Vante; Yun Luo, Björn Kirchhoff, Donato Fantauzzi, Laura Calvillo, Luis Alberto Estudillo-Wong, Gaetano Granozzi, Timo Jacob
      Abstract: Improving the efficiency of Pt-based oxygen reduction reaction (ORR) catalysts while also reducing costs remains an important challenge in energy research. To this end, we synthesized highly stable and active carbon-supported Mo-doped PtCu (Mo-PtCu/C) nanoparticles (NPs) from readily available precursors in a facile one-pot reaction. Mo-PtCu/C displays two- to four-fold higher ORR half-cell kinetics than reference PtCu/C and Pt/C materials - a trend which was confirmed in proof-of-concept experiments using a H2/O2 micro-laminar fuel cell. This Mo-induced activity increase mirrors observations for Mo-PtNi/C NPs and possibly suggests an emerging trend. Electrochemical accelerated stability tests revealed that dealloying is greatly reduced in Mo-PtCu/C in contrast to the binaries PtCu/C and PtMo/C. Supporting DFT studies suggest that Mo-PtCu's exceptional stability can be attributed to oxidative resistance of Mo-doped atoms. Furthermore, our calculations revealed that oxygen can induce segregation of Mo to the catalytic surface where it effects beneficial changes to the surface's oxygen adsorption energetics in context of the Sabatier principle.
      PubDate: 2017-11-07T13:20:25.974927-05:
      DOI: 10.1002/cssc.201701822
       
  • A New Pentiptycene-Based Dianhydride and Its High-Free-Volume Polymer for
           CO2 Removal
    • Authors: Ahmad Arabi Shamsabadi; Farzad Seidi, Mohammad Nozari, Masoud Soroush
      Abstract: In addition to possessing excellent chemical, mechanical and thermal stability, polyimides and polyetherimides have excellent solubility in many solvents, rendering them suitable for membrane preparation. In this paper, we report the synthesis and characterization of two new monomers [a pentiptycene-based dianhydride (PPDAn) and a pentiptycene imide-containing diamine (PPImDA)], and a pentiptycene-based polyimide [PPImDA-4, 4′-hexafluoroisopropylidene diphthalic anhydride (PPImDA-6FDA)]. The products are characterized using FTIR, 1H NMR, GPC, mass spectroscopy, XPS, TGA, DSC, BET, and XRD. The high molecular-weight PPImDA-6FDA has remarkable thermal stability and excellent solubility in common organic solvents. It also has an extraordinarily high fractional free-volume (0.233) due to the presence of −C(CF3)2− units, the rigid diamine, and the pentiptycene moiety in the polymer structure. It has a high CO2 permeability (812 Barrer) due to its poor chain-packing caused by its rigid groups veiling the influence of the etheric oxygen in its backbone. It has the highest CO2 permeability among all reported pentiptycene-containing polymers (about 6 times higher than the most permeable one) without sacrificing the selectivity. The high free-volume, good microporosity, high solubility in many solvents, and remarkable thermal stability of PPImDA-6FDA point to the great potential of this polymer for CO2 removal.
      PubDate: 2017-11-06T01:15:29.71814-05:0
      DOI: 10.1002/cssc.201701491
       
  • Hierarchical Core-Shell Nickel Cobaltite Chestnut-like Structures as High
           Activity Bi-functional Catalysts for Rechargeable Metal-Air Batteries
    • Authors: Dong Un Lee; Moon Gyu Park, Zachary Paul Cano, Wook Ahn, Zhongwei Chen
      Abstract: Nano-engineered hierarchical core-shell chestnut-like structures have been successfully synthesized as a bi-functionally active electrocatalyst for rechargeable metal-air battery applications. Both the morphology and composition of the catalyst have been optimized by the facile hydrothermal reaction, resulting in the 10-hour treated sample to perform significantly enhanced activity towards facilitating both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Specifically, the catalyst demonstrated -0.28, and 0.60 V vs. SCE at the ORR half-wave potential and the OER current density of 10 mA cm-2, respectively. The resulting ORR/OER potential difference of 0.90 V was the smallest among other catalysts synthesized at 2, 6, and 12 hours. The excellent bi-functional activity of the catalyst is attributed to the nano-scale porous morphology and the spinel nickel cobaltite composition, which improved the active site exposure and transport of reactants and charges during the oxygen reactions.
      PubDate: 2017-11-05T21:55:36.914228-05:
      DOI: 10.1002/cssc.201701832
       
  • High lithium insertion voltage single-crystal H2Ti12O25 nanorods as high
           capacity and high rate lithium-ion battery anode material
    • Authors: Qiang Guo; Li Chen, Zizhao Shan, Wee Siang Vincent Lee, Wen Xiao, Zhifang Liu, Jingjing Liang, Gaoli Yang, Junmin Xue
      Abstract: H2Ti12O25 holds great promise as high voltage anode material for advanced lithium-ion battery application. In order to enhance its electrochemical performance, controlling crystal orientation and morphology is one of the effective ways to cope the slow Li+ diffusion inside H2Ti12O25 with severe anisotropy. In this report, Na2Ti6O13 nanorods, prepared with Na2CO3 and anatase TiO2 in molten NaCl medium, were used as a precursor in the synthesis of long single-crystal H2Ti12O25 nanorods with reactive facets. As-prepared H2Ti12O25 nanorods with the diameter of 100-200 nm show higher charge (extraction) specific capacity and better rate performance as compared to the previously reported system. The reversible capacity of H2Ti12O25 was 219.8 mAh g-1 at 1C after 100 cycles, 172.1 mAh g-1 at 10 C and 144.4 mAh g-1 at 20 C after 200 cycles, respectively, which were higher than those of H2Ti12O25 prepared by conventional soft-chemical method. Moreover, as-prepared H2Ti12O25 nanorods exhibited superior cycle stability of more than 94% capacity retention with a nearly 100% coulombic efficiency, after 100 cycles at 1C. Based on the above results, long single-crystal H2Ti12O25 nanorods synthesized in molten NaCl with outstanding electrochemical characteristic holds a significant amount of promise for hybrid electric vehicles and energy storage system.
      PubDate: 2017-11-04T07:25:31.62671-05:0
      DOI: 10.1002/cssc.201701479
       
  • H2-assisted CO2 thermochemical reduction on La0.9Ca0.1FeO3-δ
           membranes: a kinetics study
    • Authors: Xiao-Yu Wu; Ahmed F. Ghoniem
      Abstract: Kinetics data for CO2 thermochemical reduction in an isothermal membrane reactor is required to identify the rate-limiting steps. Here, we report a detailed reaction kinetics study on this process supported by an La0.9Ca0.1FeO3-δ (LCF-91) membrane. The dependence of CO2 reduction rate on various operating conditions is examined such as CO2 concentration on the feed side, fuel concentrations on the sweep side and temperatures. CO2 reduction rate is proportional to the oxygen flux across the membrane, and the measured maximum fluxes are 0.191 and 0.164 μmol cm-2 s-1 with 9.5% H2 and 11.6% CO on the sweep side at 990oC, respectively. Fuel is used to maintain the chemical potential gradient across the membrane and CO is used by construction to derive the surface reaction kinetics. This membrane also exhibits stable performances for 106 hours. A resistance-network model is developed to describe the oxygen transport process and the kinetics data are parameterized using the experimental values. The model shows a transition of the rate limiting step between the surface reactions on the feed side and the sweep side depending on the operating conditions.
      PubDate: 2017-11-04T00:30:29.307743-05:
      DOI: 10.1002/cssc.201701372
       
  • Electrochemical Synthesis of Ammonia from Water and Nitrogen: A
           Lithium-Mediated Approach Using Lithium-Ion Conducting Glass Ceramic
    • Authors: Kwiyong Kim; Seung Jong Lee, Dong-Yeon Kim, Chung-Yul Yoo, Jang Wook Choi, Jong-Nam Kim, Youngmin Woo, Hyung Chul Yoon, Jong-In Han
      Abstract: Lithium-mediated reduction of dinitrogen is a promising way to evade electron-stealing hydrogen evolution, a critical challenge which limits faradaic efficiency (FE) and thus hinders the success of traditional protic solvent-based ammonia electro-synthesis. In this study, we propose a viable illustration to realize the lithium-mediated pathway using lithium-ion conducting glass ceramic, which can be divided into three successive steps: (i) lithium deposition, (ii) nitridation, and (iii) ammonia formation. Ammonia was successfully synthesized from molecular nitrogen and water, yielding a maximum FE of 52.3%. With a comparable ammonia synthesis rate to previously reported approaches, the fairly high FE demonstrates the possibility of using this nitrogen fixation strategy as a substitute for the firmly established, yet exceedingly complicated and expensive technology, and in so doing represents a next-generation energy storage system.
      PubDate: 2017-11-03T09:55:28.071443-05:
      DOI: 10.1002/cssc.201701975
       
  • Binder-free hybrid titanium-niobium oxide/carbon nanofiber mats for
           lithium-ion battery electrodes
    • Authors: Aura Tolosa; Simon Fleischmann, Ingrid Grobelsek, Antje Quade, Eunho Lim, Volker Presser
      Abstract: This study introduces the synthesis of free-standing, binder-free, titanium-niobium oxide/carbon hybrid nanofibers for Li-ion battery applications. The one-pot synthesis offers a significant reduction of processing steps and avoids the use of environmentally unfriendly binder materials, making the approach highly sustainable. Tetragonal Nb2O5/C and monoclinic Ti2Nb10O29/C hybrid nanofibers synthesized at 1000 °C presented the highest electrochemical performance, with capacity values of 243 and 267 mAh∙g-1, respectively normalized to the electrode mass. At 5 A∙g-1, the Nb2O5/C and Ti2Nb10O29/C hybrid fibers maintained 78% and 53 % of the initial capacity, respectively. The higher rate performance and stability of tetragonal Nb2O5, compared to monoclinic Ti2Nb10O29, relates to the low energy barriers for Li+ transport in this crystal structure, with no phase transformation. The improved rate performance resulted from the excellent charge propagation in the continuous nanofiber network.
      PubDate: 2017-11-03T03:55:51.587337-05:
      DOI: 10.1002/cssc.201701927
       
  • Hard carbons for sodium ion battery anodes: Synthetic strategies, material
           properties, and storage mechanisms
    • Authors: Malik Wahid; Dhanya Puthusseri, Yogesh Gawli, Neha Sharma, Satishchandra B. Ogale
      Abstract: Na-ion batteries are attracting great interest lately due to their potential as viable future alternatives for Li-ion batteries in view of much higher earth abundance of Na over Li. Although both the battery systems have basically similar chemistries, the key celebrated negative electrode in Li-battery, namely graphite, is unavailable for Na-ion battery due to larger size of Na-ion. This need is satisfied by the so-called "hard carbon" which can internalize the larger Na-ion and has the desirable electrochemical properties. Unlike graphite with its specific layered structure however, hard carbon occurs in diverse microstructural states. In this mini-review we seek to elucidate the connections between precursor choices, synthetic protocols, microstructural states, and performance features of hard carbon forms in the context of Na-ion battery application. Deriving from the pertinent literature employing classical and modern structural characterization techniques, we discuss various issues related to microstructure, morphology, defects, and heteroatom doping. Finally, an outlook is presented suggesting the emergent research directions.
      PubDate: 2017-11-03T02:55:28.055838-05:
      DOI: 10.1002/cssc.201701664
       
  • Highly Efficient and Robust Enantioselective Liquid-Liquid Extraction of
           1,2-Amino Alcohols Utilising VAPOL- and VANOL-based Phosphoric Acid Hosts.
           
    • Authors: Johannes Gerardus de Vries; Erik B. Pinxterhuis, Jean-Baptiste Gualtierotti, Sander J. Wezenberg, Ben L. Feringa
      Abstract: The large-scale production of enantiopure compounds in a cost-effective and environmentally friendly manner remains one of the major challenges of modern day chemistry. The resolution of racemates via enantioselective liquid-liquid extraction was developed as a suitable solution but has remained largely underused due to a lack of highly efficient and robust chiral hosts to mediate the process. This paucity of hosts can in part be attributed to a feeble understanding of the underlying principles behind these processes hindering the design of more efficient selectors. Herein, we present an in depths study of a previously untested class of hosts, VAPOL and VANOL derived phosphoric acids, for the efficient enantioselective liquid-liquid extraction of 1,2-amino alcohols. A systematic investigation of extraction parameters was conducted revealing many key interactions, while DFT calculations illustrate the binding modes for the 1:1 complexes that are involved in chiral recognition. The resulting, now optimised, procedures, are highly robust and easy to implement. They are also easily scalable as was demonstrated by U-tube experiments.
      PubDate: 2017-11-01T12:20:33.787357-05:
      DOI: 10.1002/cssc.201701896
       
  • A functional hydrogenase mimic chemisorbed onto FTO electrodes; a strategy
           towards water splitting devices
    • Authors: riccardo Zaffaroni; Remko Detz, Jarl Ivar van der Vlugt, Joost Reek
      Abstract: In this contribution, we describe the preparation, characterization and immobilization studies of a benzene dithiolale di-iron hydrogen evolving catalyst, first step towards the development of water splitting devices based on molecular components. FTO (fluorine doped tin oxide), was chosen as the preferred electrode material due to its conductive properties and electrochemical stability. We also report, the use of FTO nano-crystals to greatly improve the surface area of commercially available FTO whilst preserving the properties of the material. Catalyst modified electrodes are shown to be competent for electrocatalytic hydrogen evolution from acidic aqueous media at relatively low overpotential (500 mV) with a Faradaic efficiency close to unity, representing the first hydrogen evolving electrodes based on di-iron hydrogenase synthetic models. We show that the catalyst operates at roughly 160 mV lower overpotentials, yet with similar rates, when immobilized onto the electrode surface.
      PubDate: 2017-10-27T10:35:40.077056-05:
      DOI: 10.1002/cssc.201701757
       
  • Review of natural product-derived carbon dots: from natural products to
           functional materials
    • Authors: Xinyue Zhang; Mingyue Jiang, Na Niu, Zhijun Chen, Shujun Li, Shouxin Liu, Jian Li
      Abstract: Nature provides an almost limitless supply of natural sources, which inspires scientists to develop new materials with novel applications and less environmental impact. Recently, much attention has focused on preparing natural product-derived carbon dots (NCDs) because of several advantages of natural products. First of all, natural products are renewable and have good biocompatibility. Secondly, Natural products contain heteroatoms, which facilitates the fabrication of heteroatom-doped NCDs without addition of external heteroatom sources. Finally, some natural products can be used to prepare NCDs in very green and simple way, compared to traditional methods for carbon dots from man-made carbon sources. NCDs have shown tremendous potential in many fields, including biosensing, bioimaging, optoelectronics and photocatalysis. However, there have been no reviews that specifically cover NCDs. To address this deficiency, we now provide a review of recent progress in the synthesis, properties and applications of NCDs. The challenges and future direction of NCD-based materials research in this booming field will also be discussed.
      PubDate: 2017-10-26T04:30:26.139026-05:
      DOI: 10.1002/cssc.201701847
       
  • Imidazolium based Ionic liquids as efficient reagents for lignin C-O bond
           cleavage
    • Authors: Marina Thierry; Amel Majira, Bruce Pégot, Laurent Cézard, Flavien Bourdreux, Gilles Clément, François Perreau, Stéphanie Boutet-Mercey, Patrick Diter, Giang Vo-Thanh, Catherine Lapierre, Paul-Henri Ducrot, Emmanuel Magnier, Stephanie Baumberger, betty cottyn
      Abstract: Lignin chemical demethylation in ionic liquids was investigated using pure lignin-model monomers and dimer together with dioxan isolated lignins from poplar, miscanthus and maize. Different methylimidazolium ionic liquids (ILs) were compared, according to two different heating processes, microwave irradiation and conventional heating in sealed tube. The conversion yield and influence of the treatments on lignin structure were assessed by 31P NMR, size exclusion chromatography and thioacidolysis. The acidic IL [HMIM][Br] was shown to be an effective combination solvent/reagent for the demethylation and even depolymerisation of lignin. The relatively mild reaction conditions, the clean work-up, and the ability to reuse the ionic liquid made the described procedure an attractive and new green method for the lignin conversion to produce phenol-rich lignin oligomers.
      PubDate: 2017-10-19T04:45:35.953679-05:
      DOI: 10.1002/cssc.201701668
       
  • Electrochemical Behavior of Pyridinium and N-Methyl Pyridinium Cations in
           Aqueous Electrolyte for CO2 Reduction
    • Authors: Estelle Lebègue; Julia Agullo, Daniel Bélanger
      Abstract: We examined the electrochemical reduction of aqueous pyridinium and N-methyl pyridinium ions in the absence and presence of CO2 and studied the electrolysis reaction products on glassy carbon, Au and Pt electrodes. Unlike pyridinium, N-methyl pyridinium is not electroactive at the Pt electrode. The electrochemical reduction of the two pyridine derivatives was found to be irreversible on glassy carbon. These results confirmed the essential role of the N-H bond of the pyridinium cation. In contrast, the electrochemical response of N-methyl pyridinium ion at glassy carbon electrode suggests that a specific interaction seems to occur between the glassy carbon surface and the aromatic ring of the pyridinium derivative. For all electrodes, an enhancement of current was observed in presence of CO2. However, NMR analyses of the solutions following electrolysis have not shown the formation of methanol or other possible by-products of the reduction of CO2 in the presence of both pyridinium derivative ions.
      PubDate: 2017-10-12T12:25:22.027244-05:
      DOI: 10.1002/cssc.201701745
       
  • Encapsulating Co2P@C Core-Shell Nanoparticles in Porous Carbon Sandwich: a
           Nitrogen and Phosphorus Dual-Doped PH-Universal Electrocatalysts for
           High-efficient Hydrogen Evolution
    • Authors: YuanYuan Yang; XiongYi Liang, Feng Li, ShuWen Li, XinZhe Li, Siu-Pang Ng, Chi-Man Lawrence Wu, Rong Li
      Abstract: A new, highly-efficient and pH-universal sandwich-architecture HER electrocatalysts, constructed by 0-dimensional N and P dual-doped core-shell Co2P@C nanoparticles embedded into a 3-dimensional porous carbon sandwich (Co2P@N,P-C/CG), was synthesized by a facile two-step method of hydrothermal carbonization (HTC) and pyrolysis. Owing to the synergistic effect of N, P-codoped Co2P@C core-shell and sandwich-nanostructural substrates, it increases the interfacial electron transfer rate and the number of active sites. Because of the presence of high surface area and large porous sizes, it improves the mass transfer dynamics. This nanohybrid shows remarkable electrocatalytic activity toward the HER in wide pH value, with good stability. The computational study and experiments reveal that the carbon atoms closed to N and P heteroatoms dopants on the shell of Co2P@N,P-C are the effective active sites for HER catalyst, and Co2P and N, P dopants synergistically optimize the binding free energy of H* on the active sites.
      PubDate: 2017-10-12T10:25:28.977874-05:
      DOI: 10.1002/cssc.201701705
       
  • Polymeric Redox-Active Electrodes for Sodium-Ion Batteries
    • Authors: Naiara Fernández; Paula Sánchez-Fontecoba, Elizabeth Castillo-Martínez, Javier Carretero-González, Teófilo Rojo, Michel Armand
      Abstract: Polymer binding agents are critical for the good performance of the electrodes of Na- and Li-ion batteries during cycling as they hold the electroactive material together to form a cohesive assembly because of their mechanical and chemical stability as well as adhesion to the current collector. New redox-active polymer binders that insert Na+ ions and show adhesion properties were synthesized by adding polyether amine blocks (Jeffamine) based on mixed propylene oxide and ethylene oxide blocks to p-phenylenediamine and terephthalaldehyde units to form electroactive Schiff-base groups along the macromolecule. The synthetic parameters and the electrochemical properties of these terpolymers as Na-ion negative electrodes in half cells were studied. Reversible capacities of 300 mAh g−1 (50 wt % conducting carbon) and 200 mAh g−1 (20 wt % conducting carbon) were achieved in powder and Cu-supported electrodes, respectively, for a polySchiff-polyether terpolymer synthesized by using a poly(ethylene oxide) block of 600 g mol−1 in place of one third of the aniline units. The new redox-active polymers were also used as a binding agent of another anode material (hard carbon), which led to an increase of the total capacity of the electrode compared to that prepared with other standard fluorinated polymer binders such as poly(vinylidene) fluoride.Binding agreement: A new redox-active polymer binder inserts Na+ ions and shows adhesive properties. This new material is synthesized by adding polyether amine groups onto mixed propylene oxide and ethylene oxide blocks to make p-phenylenediamine and terephthalaldehyde units and form electroactive Schiff-base groups along the macromolecule.
      PubDate: 2017-10-12T06:40:34.248134-05:
      DOI: 10.1002/cssc.201701471
       
  • Single-Atom Catalysts of Precious Metals for Electrochemical Reactions
    • Authors: Jiwhan Kim; Hee-Eun Kim, Hyunjoo Lee
      Abstract: Single-atom catalysts (SACs), in which metal atoms are dispersed on the support without forming nanoparticles, have been used for various heterogeneous reactions and most recently for electrochemical reactions. In this Minireview, recent examples of single-atom electrocatalysts used for the oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), hydrogen evolution reaction (HER), formic acid oxidation reaction (FAOR), and methanol oxidation reaction (MOR) are introduced. Many density functional theory (DFT) simulations have predicted that SACs may be effective for CO2 reduction to methane or methanol production while suppressing H2 evolution, and those cases are introduced here as well. Single atoms, mainly Pt single atoms, have been deposited on TiN or TiC nanoparticles, defective graphene nanosheets, N-doped covalent triazine frameworks, graphitic carbon nitride, S-doped zeolite-templated carbon, and Sb-doped SnO2 surfaces. Scanning transmission electron microscopy, extended X-ray absorption fine structure measurement, and in situ infrared spectroscopy have been used to detect the single-atom structure and confirm the absence of nanoparticles. SACs have shown high mass activity, minimizing the use of precious metal, and unique selectivity distinct from nanoparticle catalysts owing to the absence of ensemble sites. Additional features that SACs should possess for effective electrochemical applications were also suggested.Down to the atom: Single-atom catalysts, in which metal atoms are dispersed on the support without forming nanoparticles, have recently been used for electrochemical reactions. In this Minireview, recent examples of single-atom electrocatalysts for reactions including oxygen reduction, hydrogen oxidation, hydrogen evolution, formic acid oxidation, and methanol oxidation are introduced.
      PubDate: 2017-10-10T04:30:36.459334-05:
      DOI: 10.1002/cssc.201701306
       
  • Nitrogen-Doped Carbon Nanotubes Derived from Metal-Organic Frameworks for
           Potassium-Ion Battery Anodes
    • Authors: Peixun Xiong; Xinxin Zhao, Yunhua Xu
      Abstract: To tackle the issue of the poor rate capability of graphite anodes for potassium-ion batteries (KIBs), nitrogen-doped carbon nanotubes (NCNTs) with an edge-open layer-alignment structure were synthesized using a simple and scalable approach of pyrolyzing cobalt-containing metal-organic frameworks. The unique structure enables a facile and fast intercalation of K ions. As anodes of KIBs, the NCNTs demonstrated a superior rate capability by a high capacity retention of 102 mA h g-1 at a high current density of 2000 mA g-1 and a good stability without obvious capacity loss over 500 cycles at 2000 mA g-1. Our findings would help to develop high performance anode materials for potassium-ion batteries as large-scale and low-cost energy storage systems.
      PubDate: 2017-10-10T00:50:22.203168-05:
      DOI: 10.1002/cssc.201701759
       
  • Niobium Doped Lanthanum Strontium Ferrite as A Redox Stable and
           Sulfur-Tolerant Anode for Solid Oxide Fuel Cells
    • Authors: Zhe Lü; Jingwei Li, Bo Wei, Zhiqun Cao, Xing Yue, Yaxin Zhang
      Abstract: A novel Nb-doped lanthanum strontium ferrite perovskite oxide La0.8Sr0.2Fe0.9Nb0.1O3-δ (LSFNb) is evaluated as anode material of solid oxide fuel cell (SOFC). The effects of Nb partial substitution on the crystal structure, electrical conductivity and valence of Fe ions are studied. A good structural stability of LSFNb in severe reducing atmosphere at 800 °C is found, suggesting that high valent Nb can effectively promote the stability of lattice structure. The ratio of Fe2+ increases after Nb doping as confirmed by the results of XPS. The maximum power density of a thick Sc-stabilized zirconia (ScSZ) electrolyte supported single cell reached 241.6 mW·cm-2 at 800 °C using H2 as fuel. The cell exhibited excellent stability for continuously 100 h operation without detectable degeneration. SEM images clearly revealed the exsolutions on LSFNb surface after operation. Meanwhile, LSFNb particles agglomerated obviously during long-term stability test. Impedance spectra suggested that both LSFNb anode and (La0.75Sr0.25)0.95MnO3-δ (LSM)/ScSZ cathode exhibited an activation process during long-term test, through which the ability of charge transfer increases obviously. Meanwhile, low-frequency resistance (RL) mainly attributed by anode (80%) significantly increased, probably due to the agglomeration of LSFNb particles. The LSFNb anode exhibits excellent anti-sulfuring poisoning ability and redox stability. These results demonstrate that LSFNb is a promising anode material for SOFC.
      PubDate: 2017-10-04T08:15:30.791593-05:
      DOI: 10.1002/cssc.201701638
       
  • Designing CdS mesoporous networks on MOF derived Co-C@Co9S8 double-shelled
           nanocages as a redox-mediator-free Z-scheme photocatalyst with superior
           photocatalytic efficiency
    • Authors: D. Amaranatha Reddy; Hanbit Park, Madhusudana Gopannagari, Eun Hwa Kim, Seunghee Lee, D. Praveen Kumar, Tae Kyu Kim
      Abstract: Designing porous nanostructures with unprecedented functions and an effective ability to harvest the maximum energy region of the solar spectrum and suppress the charge-carrier recombination rate is offering promising potential for sustainable energy production. Herein, we report a new, highly active, noble-metal-free, and redox-mediator-free Z-scheme photocatalyst, CdS/Co-C@Co9S8, for H2 production through water splitting under solar irradiation. The designed photocatalytic system contains open 3D CdS mesopores as a light absorber for wider solar light harvesting. Metal-organic-framework-derived cobalt nanocrystal-embedded few-layered carbon@Co9S8 double-shelled nanocages were used as a co-semiconductor to hamper the photo charge-carrier recombination by accelerating the photogenerated electrons and holes from the other semiconductor. The optimized catalyst shows a H2 evolution rate of 26.69 mmol·g-1·h-1 under simulated solar irradiation, which is 46 times higher than that of as-synthesized CdS mesoporous nanostructures. The apparent quantum yield reached 7.82 % at λ=425 nm in 5 h. The spectacular photocatalytic activity of CdS/Co@C-Co9S8 reflects the favorable suppression of the charge-carrier recombination rate, as determined by photoluminescence, photocurrent, and impedance analyses. We believe that the findings reported here may inspire the design of novel noble-metal-free porous nanohybrids for sustainable H2 production.
      PubDate: 2017-10-03T07:35:47.447998-05:
      DOI: 10.1002/cssc.201701643
       
  • The enhanced photocatalytic hydrogen evolution of NiCoP/g-C3N4 with the
           improved separation efficiency and charge transfer efficiency
    • Authors: Lingling Bi; Xupeng Gao, Lijing Zhang, Dejun Wang, Xiaoxin Zou, Tengfeng Xie
      Abstract: NiCoP has caused wide attention in the field of electrocatalysis, while there is little concern on photocatalysis study and its photocatalytic mechanism. Herein we reported a simple one-pot synthesis method of NiCoP/g-C3N4 as highly efficient photocatalyst for hydrogen production from water for the first time. Remarkably, the excellent photocatalytic activity is obtained for the 50 mg NiCoP/g-C3N4 (1643 molg-1h-1), which is 21 times higher than that of bare g-C3N4. The excellent performance is due to the synergistic effect of the improved separation efficiency and the effective charge transfer efficiency. The photogenerated charge behavior is characterized by the surface photovoltage, the transient photovoltage and the photoluminescence spectroscopy. The photogenerated charge transport property is researched by the electrochemical impedance spectroscopy and polarization curve. Moreover, the effective charge transfer efficiency was measured according to the mimetic apparent quantum yield. Specifically, the novel SPV and TPV measurements that added 10 vol% triethanolamine-water solution into the testing system were measured to simulate the real atmosphere for photocatalytic reaction, which can directly provide the actual photogenerated charge transfer process. This work may provide an efficient theoretical basis to design transition metal phosphide cocatalyst modified photocatalysts. Finally, the possible photocatalytic mechanism was proposed and discussed in detail.
      PubDate: 2017-10-02T08:20:20.452586-05:
      DOI: 10.1002/cssc.201701574
       
  • Low-polarization lithium oxygen battery using
           N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium
           bis(trifluoromethanesulphonyl) imide (DEMETFSI) ionic liquid electrolyte
    • Authors: Ulderico Ulissi; Giuseppe Antonio Elia, Sangsik Jeong, Franziska Mueller, Jakub Reiter, Nikolaos Tsiouvaras, Yang-Kook Sun, Bruno Scrosati, Stefano Passerini, Jusef Hassoun
      Abstract: The room temperature molten salt mixture of N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl) imide (DEMETFSI) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is herein reported as electrolyte for application in lithium oxygen batteries. The DEMETFSI-LITFSI solution is studied in terms of ionic conductivity, viscosity, electrochemical stability and compatibility with lithium metal at 30°C, 40°C and 60°C. The electrolyte shows suitable properties for application in lithium oxygen battery, allowing a reversible, low-polarization discharge-charge performance with a capacity of about 13 Ah per gram of carbon in the positive electrode and coulombic efficiency approaching 100%. The reversibility of the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) is demonstrated by ex situ XRD and SEM studies. Furthermore, the study of the cycling behavior of the lithium oxygen cell using the DEMETFSI-LITFSI electrolyte at increasing temperatures (from 30°C to 60°C) evidences enhanced energy efficiency together with morphology changes of the deposit. In addition, the use of carbon-coated Zn0.9Fe0.1O (TMO-C) lithium-conversion anode in an IL-based Li-ion oxygen configuration is preliminarily demonstrated.
      PubDate: 2017-09-29T08:42:41.400739-05:
      DOI: 10.1002/cssc.201701696
       
  • Exploring the reaction pathways of bio-glycerol hydro-deoxygenation to
           propene over Molybdena-based catalysts
    • Authors: Vasiliki Zacharopoulou; Efterpi Vasiliadou, Angeliki A Lemonidou
      Abstract: One-step glycerol reaction with hydrogen, selectively forming propene, is a novel and particularly challenging catalytic pathway that has not yet been thoroughly explored in the open literature. Molybdena-based catalysts are active and selective to C-O bond scission; propene is the only product in the gas phase, under the standard reaction conditions, impeding further hydrogenation to propane. Within this context, this work focuses on exploration of the reaction pathways and the investigation of various parameters, affecting the catalytic performance, such as the role of hydrogen on the product distribution and the effect of the catalyst pretreatment step. Under hydrogen atmosphere, propene is primarily produced via 2-propenol formation, while under inert atmosphere propanal and glycerol dissociation products are mainly formed. Reaction most likely proceeds through a reverse Mars van Krevelen mechanism, as the partially reduced Mo species drive the reaction to the formation of the desired product.
      PubDate: 2017-09-28T10:30:44.058516-05:
      DOI: 10.1002/cssc.201701605
       
  • Interface Manipulation Improving Plasmon-Coupled Photoelectrochemical
           Water Splitting on α-Fe2O3 Photoanodes
    • Authors: Zhe Xu; Zhongwen Fan, Zhan Shi, Mengyu Li, Jianyong Feng, Lang Pei, Chenguang Zhou, Junkang Zhou, Lingxia Yang, Wenchao Li, Guangzhou Xu, Shicheng Yan, Zhigang Zou
      Abstract: Plasmon resonance effect of metal nanoparticles (NPs) offers a promising route to improve the solar energy conversion efficiency of semiconductors. Here, we found that the hot electrons generated by plasmon resonance effect of Au NPs tend to inject into the surface states instead of the conduction band of Fe2O3 photoanodes, then the severe surface recombination occurs. Such an electron transfer process seems to be independent on external applied potentials, but is sensitive to metal-semiconductor interface properties. Passivating the surface states of Fe2O3 by a non-catalytic Al2O3 layer can construct an effective resonant energy transfer interface between Ti-doped Fe2O3 (Ti-Fe2O3) and Au NPs. In such a Ti-Fe2O3/Al2O3/Au electrode configuration, the enhanced photoelectrochemical water splitting performance can be attributed to the following two factors: (1) in non-light-response wavelength range of Au NPs, both relaxing Fermi pinning effect by Al2O3 passivation layer and higher work function of Au enlarged band bending, thus promoting the charge separation. (2) In light-response wavelength range of Au NPs, the effective resonant energy transfer contributes to the light harvesting and conversion. The interface manipulation proposed in our study may provide a new route to design efficient plasmonic PEC devices for energy conversion
      PubDate: 2017-09-21T21:20:51.705638-05:
      DOI: 10.1002/cssc.201701679
       
  • NIR Absorbing Metal-Free Organic, Porphyrin, and Phthalocyanine Dyes for
           Panchromatic DSCs
    • Authors: Phillip Brogdon; Hammad Cheema, Jared Heath Delcamp
      Abstract: Dye-sensitized solar cells (DSCs) are a promising source of renewable energy. However, power conversion efficiency (PCE) of devices has been limited largely by the difficulty of producing electricity using photons from the near-infrared (NIR) spectral region. Metal-free organic sensitizers frequently employ strong electron donating or withdrawing moieties to tune the optical band gap to allow the absorption of lower energy wavelengths in charge transfer systems while porphyrins and phthalocyanines use substituents to shift the Soret and Q bands toward lower energy absorption. Very few devices employing precious metal free dyes have been able to achieve panchromatic, NIR photon conversion for electricity generation at wavelengths>750 nm despite a tremendous number of sensitizers published over last 25 years. This minireview seeks to compile a summary of these sensitizers to encourage assimilation, analysis and development of efficient future NIR sensitizers. Herein, we discuss common synthetic strategies, optical properties and electronic properties of the most successful panchromatic organic sensitizers in this regard.
      PubDate: 2017-09-19T13:40:32.723807-05:
      DOI: 10.1002/cssc.201701441
       
  • Anion Exchange Membranes for Alkaline Fuel Cell Applications: The Effects
           of Cations
    • Authors: Zhe Sun; Bencai Lin, Feng Yan
      Abstract: Alkaline anion exchange membrane fuel cells (AEMFCs) are attracting great attention, because of their potential use of non-precious electrocatalysts. Anion exchange membrane (AEM) is one of the key components of AEMFCs. An ideal AEM should possess high hydroxide conductivity and sufficient long-term durability at elevated temperatures in high pH solutions. This review provides recent progresses of alkaline stability behavior of cations (including quaternary ammonium, imidazolium, guanidinium, pyridinium, tertiary sulfonium, phosphonium, benzimidazolium and pyrrolidinium) and their analogous AEMs, which have been investigated by both experimental studies and theoretical calculations. Effects, including conjugated effect, steric hindrance effect, σ−π hyperconjugative effect and electron effect on the alkaline stability of cations and their analogous AEMs have been discussed. The attempt of this article is to give an overview of some key factors, for future design of novel cations, and their analogous AEMs with high alkaline stability.
      PubDate: 2017-09-18T10:40:40.577073-05:
      DOI: 10.1002/cssc.201701600
       
  • Green and sustainable route to carbohydrate vinyl ethers for accessing
           bio-inspired materials with a unique microspherical morphology
    • Authors: Konstantin Rodygin; Irina Werner, Valentine P. Ananikov
      Abstract: Synthesizing chemicals and materials based on renewable sources is one of the main tasks of modern science. Carbohydrates represent excellent renewable natural raw materials, that are eco-friendly, inexpensive and biologically compatible. Herein, we developed a green vinylation procedure for carbohydrates using readily available calcium carbide. Various carbohydrates were utilized as starting materials resulting in mono-, di- and tetra-vinyl ethers in high to excellent yields (81-92 %). The synthesized bio-based vinyl ethers were utilized as monomers in free radical and cationic polymerizations. A unique combination of smooth surface and intrinsic microcompartments was achieved in the synthesized materials. Two types of bio-based materials were prepared involving microspheres and "Swiss cheese" polymers. Scanning electron microscopy with built-in ion beam cutting was applied to reveal the spatial hierarchical structures in three-dimensional space.
      PubDate: 2017-09-12T05:21:44.227869-05:
      DOI: 10.1002/cssc.201701489
       
  • Catalytic upgrading of ethanol to n-butanol: A progress in catalyst
           development
    • Authors: Xianyuan Wu; Geqian Fang, Yuqin Tong, Dahao Jiang, Zhe Liang, Wenhua Leng, Liu Liu, Pengxiang Tu, Hongjing Wang, Jun Ni, Xiaonian Li
      Abstract: In view that n-butanol as fuel additive has more advantageous physico-chemical properties compared to ethanol, ethanol valorization to n-butanol via homogeneous or heterogeneous catalysis has received great attention over the last decades both in the scientific and industrial fields. This paper reviewed the recent progress in catalyst development for upgrading ethanol to n-butanol, which involves homogeneous catalysts such as Iridium and Ruthenium complexes catalysts and heterogeneous catalysts mainly including metal oxides, hydroxyapatite (HAP) and especially supported metal catalysts. The structure-performance relationship of catalysts and underlying reaction mechanism were critically examined. Future research directions on the catalyst design and improvement were also proposed.
      PubDate: 2017-09-12T03:21:19.653865-05:
      DOI: 10.1002/cssc.201701590
       
  • Rational Design of Sulfur-Doped Copper Catalysts for the Selective
           Electroreduction of Carbon Dioxide to Formate
    • Authors: Yun Huang; Yilin Deng, Albertus Denny Handoko, Gregory K L Goh, Boon Siang Yeo
      Abstract: The selective electroreduction of CO2 to formate (or formic acid) is currently of great interest in the field of renewable energy utilization. In this work, we designed a sulfur-doped Cu2O-derived Cu catalyst, and showed that the presence of sulfur could significantly tune the selectivity of Cu from producing a myriad of CO2 reduction products to almost exclusively formate. Sulfur is doped into the Cu catalysts by dipping the Cu substrates into ammonium polysulfide solutions. Catalyst films with the highest sulfur content of 2.7 atom% showed the largest formate current density (jHCOO-) of -13.9 mA/cm2 at -0.9 V vs. RHE, which is ~46 times larger than that previously reported on Cu(110) surfaces. At -0.8 V vs. RHE, the Faradaic efficiency of formate was maintained at ~75% for 12 h of continuous electrolysis. By analyzing how the jHCOO- and jH2 of the catalysts evolved with different sulfur content, we show that sulfur doping efficaciously increases formate production, while suppressing the hydrogen evolution reaction. Ag-S and Cu-Se catalysts did not exhibit any significant enhancement towards the reduction of CO2 to formate. This demonstrates clearly that sulfur and copper acted synergistically to promote the selective formation of formate. A hypothesis of the role of sulfur is proposed and discussed.
      PubDate: 2017-09-07T09:21:31.786827-05:
      DOI: 10.1002/cssc.201701314
       
  • Angelica Lactones: from Biomass-Derived Platform Chemicals to Value-Added
           Products
    • Authors: Arlene Correa; Carolina G. S. Lima, Júlia Monteiro, Thiago Melo Lima, Marcio Webber Paixão
      Abstract: The upgrading of biomass-derived compounds has arisen in recent years as a very promising research field in both academia and industry. In this sense, a lot of new processes and products have been developed, often involving levulinic acid as a starting material or intermediate. In the last few years, though, other scaffolds have been receiving growing attention, in special, angelica lactones. Considering these facts and the emergent applications of said molecules, in this review we will discuss their preparation and applications - the use of these frameworks as starting materials in organic synthesis to produce potential bioactive compounds will be covered, as well as their arising use as the foundation to highly regarded compounds such as liquid alkanes with prospective use as fuels and polymers.
      PubDate: 2017-08-21T10:00:39.20312-05:0
      DOI: 10.1002/cssc.201701469
       
 
 
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