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CHEMISTRY (619 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 27)
ACS Catalysis     Hybrid Journal   (Followers: 44)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 26)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 41)
ACS Nano     Hybrid Journal   (Followers: 295)
ACS Photonics     Hybrid Journal   (Followers: 14)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 5)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 6)
Advanced Functional Materials     Hybrid Journal   (Followers: 60)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 69)
Advances in Chemical Science     Open Access   (Followers: 18)
Advances in Chemistry     Open Access   (Followers: 22)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 25)
Advances in Environmental Chemistry     Open Access   (Followers: 7)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12)
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Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
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Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 67)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 21)
American Journal of Chemistry     Open Access   (Followers: 31)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 171)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 255)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 24)
Applied Surface Science     Hybrid Journal   (Followers: 32)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access  
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Hybrid Journal   (Followers: 369)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 22)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 134)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 87)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 8)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 10)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 22)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 74)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 197)
Chemical Science     Open Access   (Followers: 26)
Chemical Technology     Open Access   (Followers: 28)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 7)
Chemistry - A European Journal     Hybrid Journal   (Followers: 159)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Hybrid Journal   (Followers: 266)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Cogent Chemistry     Open Access   (Followers: 2)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 6)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (Followers: 1)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 9)
Current Science     Open Access   (Followers: 71)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 3)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  

        1 2 3 4 | Last

Journal Cover
Applied Surface Science
Journal Prestige (SJR): 1.093
Citation Impact (citeScore): 4
Number of Followers: 32  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0169-4332
Published by Elsevier Homepage  [3162 journals]
  • Insight into phosphate doped BiVO4 heterostructure for multifunctional
           photocatalytic performances: A combined experimental and DFT study
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Chhabilal Regmi, Yuwaraj K. Kshetri, Dipesh Dhakal, Jae Kyung Sohng, Federico Rosei, Soo Wohn Lee Doping with non-metals like phosphorous has been extensively investigated to extend radiation absorption and improve the photocatalytic efficiency of TiO2. However, the effect of non-metal doping in BiVO4, whose smaller bandgap (2.4 eV) allows for efficient visible light absorption, has been scarcely investigated. Visible light accounts for 45% of solar energy (as compared to only 5% of UV light) reaching the Earth’s surface. Due to its high efficiency in absorbing visible radiation, BiVO4 can, therefore, be a promising material to replace TiO2. Here we demonstrate the synthesis of phosphate doped visible-light-active BiVO4 by a microwave hydrothermal method as a promising alternative to TiO2. Subsequently, we investigated its photocatalytic activity for the removal of p-amino salicylic acid and ibuprofen, two cases of major pharmaceutical waste, as well as disinfection of multi-drug resistance Staphylococcus aureus bacteria. In addition, the biofilm elimination efficiency of the undoped and phosphate doped BiVO4 was studied by crystal violet staining method. A 70% reduction in the biofilm biomass by phosphate doped BiVO4 was obtained. Also, a 4.1log reduction in the viable cells count was observed within 180 min when Staphylococcus aureus was irradiated with visible light mixed in phosphate doped BiVO4 powder. Under similar irradiation conditions, the degradation efficiency for p-amino salicylic acid and ibuprofen are 81% and 80% respectively, a 40% enhancement as compared to undoped BiVO4. First principle density functional theory calculations show that charge transfer from P to O in the doping site of the BiVO4 is responsible for the enhanced photocatalytic activity.Graphical abstractGraphical abstract for this article
  • Substrate effect on the evolution of surface morphology of BaF2thin films:
           A study based on fractal concepts
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Kavyashree, R.K. Pandey, R.P. Yadav, Manvendra Kumar, H.P. Bhasker, A.K. Mittal, A.C. Pandey, S.N. Pandey Fractal concepts are used to explore how different substrates affect the morphology of deposited barium fluoride (BaF2) thin films. BaF2 thin films of thickness 20 nm are prepared by electron beam evaporation technique at room temperature on glass, silicon and aluminum substrates. The structural properties and surface morphologies are investigated using glancing angle X-ray diffraction (GAXRD) and atomic force microscopy (AFM), respectively. Crystallite size, calculated from the XRD peaks, using the Debye Scherrer’s formula, is found to be significantly less for the case of Si substrate than for Al and glass substrates. Higuchi’s algorithm is applied to extract the fractal dimension of the horizontal and vertical sections of AFM images of the films. From the fractal dimension, the values of Hurst exponent (H) are inferred. For Al and glass substrates we find that H>0.5, which shows that the height fluctuations at neighboring pixels are positively correlated. However, for Si substrate, it is found that H
  • Analysis of dynamic decomposition for barium
           dimethyl-naphthalene-sulfonate on an Al3Mg (0 0 1) surface from
           ab-initio molecular dynamics
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Jun Zhong, Xin Li, Wenze Ouyang, Yuan Tian One important dynamic decomposition pathway for a surface corrosion-inhibitor: barium dimethyl- naphthalene-sulfonate, is investigated on a clean Al3Mg (0 0 1) binary-alloy surface using ab-initio molecular dynamics based upon density functional theory. Each inhibitor molecule is oriented its functional groups of sulfonic-oxygen bases toward the surface, starting at an initial impact velocity. The dynamic decomposition pathway occurs upon molecular collision with the surface, leading to the decomposed fragments that may clearly represent the initial formation stage of additive thin-film on the surface during a plastic substrate deformation. In addition, three important factors: initial impact speed acting on molecule (kinetic effect), substrate temperature (thermal effect) and initial molecular orientation (geometric effect) etc, are employed to analyze their influences on molecular decomposition. An approach of design-of-experiment (DOE) is applied to an analysis of relative importance for each factor and all factor interactions in above, so as to figure out the best way of surface protection. Final DOE analysis indicates that the most significant factor for promoting molecular decomposition on surface is the substrate temperature, i.e., the higher the substrate temperature, the more rapid decomposition of molecule on surface. While initial impact velocity plays a smaller role, and initial molecular orientation performs less importance to molecular decomposition.
  • From stannous oxide to stannic oxide epitaxial films grown by pulsed laser
           deposition with a metal tin target
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mingkai Li, Lilan Zheng, Mi Zhang, Yinyin Lin, Lei Li, Yinmei Lu, Gang Chang, Peter J. Klar, Yunbin He Stannous oxide (SnO) and stannic oxide (SnO2) are both important wide-band-gap semiconductors. To study the conductive mechanism in detail, high quality epitaxial films are essential. Here we propose a simple method to grow high quality epitaxial films of either stannous oxide or stannic oxide on an r-plane sapphire substrate by using pulsed laser deposition with a metallic tin target. The valence state of tin is controlled by tuning the oxygen pressure during the deposition procedure. Metal tin impurities and the transition phase of Sn3O4 are avoided and the growth windows from stannous oxide to stannic oxide are confirmed. For single-crystalline SnO epitaxial film, a rocking curve half-width of 0.22° is obtained, which is better than the 0.46° of that on a YSZ substrate. The minimum roughnesses achieved were 0.37 nm for the SnO2 epitaxial film and 0.84 nm for the SnO epitaxial film. The epitaxial relationship between SnO and the r-sapphire substrate was determined to be SnO [1¯10]//sapphire [1¯21¯0] and SnO [1 1 0]//sapphire [101¯1]. For SnO2, the epitaxial relation is SnO2 [0 1 0]//sapphire [1¯21¯0] and SnO2[1¯01]//sapphire [101¯1]. The band schematics, deduced by combined XPS valence band spectroscopy and optical transmittance spectroscopy, indicated p-type bands of SnO and n-type bands of SnO2. Raman spectroscopy is suggested to be a superior fingerprint of SnO single-crystalline quality, due to its greater sensitivity than X-ray diffraction.
  • Plastic deformation in zinc-blende AlN under nanoindentation: A molecular
           dynamics simulation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yuhong Cui, Haitao Li, Henggao Xiang, Xianghe Peng Using molecular dynamics (MD) simulations, we studied the mechanical response and nanostructure evolution of aluminum nitride with zinc-blende structure (zb-AlN). The defect types and structural evolutions as well as the formation and propagation of prismatic loops were discussed. The generalized stacking fault energy (GSFE) was also calculated to explain the glide of dislocations. It showed that perfect dislocations with Burgers vectors b = 1/2〈1 1 0〉 and Shockley partial dislocations with b = 1/6〈1 1 2〉 occur simultaneously for the indentation on (1 1 0) and (1 1 1) planes. The indentation force-depth (P-h) curve exhibits great compliance compared with that determined by the Hertz theory in the elastic phase. And the first three main drops on the P-h curve are related to dislocation nucleation and expansion. Moreover, a “lasso”-like formation mechanism of prismatic loops was found and the GSFE curves were also analyzed to assess the dislocation slips in zb-AlN. It was found that the dominant dislocation is of shuffle-set with Burgers vector b = 1/2 〈1 1 0〉, by comparing the GSFE along 111 with that along 111.
  • Magnetic Fe3O4@CuO nanocomposite assembled on graphene oxide sheets for
           the enhanced removal of arsenic(III/V) from water
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Kun Wu, Chunyang Jing, Jin Zhang, Ting Liu, Shengjiong Yang, Wendong Wang A magnetic composite adsorbent (Fe3O4@CuO&GO) was fabricated by combining graphene oxide (GO) sheets with Fe3O4 and CuO through coprecipitation. According to the surface characterization results, the introduction of GO not only maintained the favorable properties of the iron-copper (Fe@Cu) composite, such as the excellent magnetic characteristics and abundant hydroxyl groups, but also inhibited the aggregation of nanoscale Fe@Cu oxide particles and thus enhanced the ability of the particles to remove As(III) and As(V) from water. The kinetic data were accurately described by both a pseudo-second-order model and the Elovich model, indicating chemisorption on heterogeneous surfaces, and the Freundlich model was applicable to the equilibrium data. The maximum amounts of adsorbed As(III) and As(V) were determined to be 70.36 and 62.60 mg/g via the Langmuir model, respectively. The adsorption capacity of As(III) was minimally affected by changes in the solution pH, while the adsorption amount of As(V) decreased with the elevated solution pH. Some coexisting anions, especially phosphate, significantly influenced the As removal efficiency. Surface characterizations of the adsorbent and spectroscopic analysis results suggested that As is mainly bound to the hydroxyl groups on the adsorbent through surface complexation. Five consecutive adsorption-regeneration cycles illustrated that this adsorbent can be reused in successive As treatments. The dynamic adsorption-separation treatment of simulated As-contaminated water confirmed that this composite material can be used to remove the excess As from drinking water without causing secondary pollution and is therefore a potential material for use in engineering applications.Graphical abstractGraphical abstract for this article
  • The adsorption, diffusion and capacity of lithium on novel boron-doped
           graphene nanoribbon: A density functional theory study
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Haili Liu, Huilong Dong, Yujin Ji, Lu Wang, Tingjun Hou, Youyong Li Inspired by the experimental synthesis of novel boron-doped graphene nanoribbon (BGNR), we have performed density functional theory (DFT) calculations to reveal the adsorption behaviors of lithium (Li) atoms on BGNR. We systematically studied the adsorption, diffusion and capacity of Li on BGNR with 7 carbon atoms in width. It is found that due to the doping effects of boron (B) atoms, BGNR exhibits a narrower band gap than graphene nanoribbon (GNR) with the same width. Individual Li atom exhibits much stronger binding on BGNR than that on GNR, attributing to the stronger LiC interaction caused by doping of B atoms. A zigzag diffusion path along the growth direction of BGNR is confirmed for diffusion of Li. The maximum theoretical storage capacity of Li on BGNR is determined as 783 mAh/g, which is 15 times than that on GNR with same width (52 mAh/g). Our results demonstrated that doping of B atoms greatly enhances the adsorption and storage performance of Li, which provides a theoretical foundation of researches on the novel BGNR and other similar structures for adsorption and storage of Li.Graphical abstractGraphical abstract for this article
  • Probing surface electronic properties of a patterned conductive STO by
           reactive ion etching
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mi-Jin Jin, Daeseong Choe, Seung Youb Lee, Jungmin Park, Junhyeon Jo, Inseon Oh, Shin-Ik Kim, Seung-Hyub Baek, Cheolho Jeon, Jung-Woo Yoo SrTiO3 (STO) is a highly attractive oxide material due to its flexible tunability of electrical properties. It can be designed to exhibit a high mobility with a tunable carrier concentration by creating oxygen vacancies, or by doping with Nb or La, which substitute the Ti and Sr sites, respectively. Here we show a micro-patterned surface doping of STO by using reactive ion etching (RIE). The creation and pattering of a conductive STO surface were achieved by sequential treatments with Ar and O2 plasma. The patterned conductive surface edge was well defined as confirmed by an electrostatic force microscopy. The electronic characteristics of the RIE treated STO surface were probed by a synchrotron radiation photoemission spectroscopy, which shows the emergence of Ti3+, Ti2+, Ti1+ states and metallic states near the Fermi level. The electrical mobility of the conductive STO surface can be increased up to 12000 cm/V s with a typical sheet carrier concentration around 1013–1014 cm−2. Increasing Ar plasma time elongate the depth of the conductive surface, which reflects the change of magnetoresistance behavior at low temperature. The demonstrated control of the STO surface conductivity along with a large area and high precision patterning method can be widely used for a variety of oxide electronic and spintronic devices.Graphical abstractGraphical abstract for this article
  • Advanced Li-ion hybrid capacitors based on the nanostructured ruthenium
           oxide on MWCNTs
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Peiyu Wang, Guoheng Zhang, Haiyan Jiao, Wanjun Chen, Liwei Liu, Xiangli Wang, Qiong Chen, Xiaoyan Deng, Xiaoping Zheng Here, the porous ruthenium oxide/multi-walled carbon nanocomposite (RuO2/MWCNT) was prepared using a facile precipitation method. The RuO2/MWCNT showed high specific capacity, outstanding rate performance and long cycling stability under a Li-ion organic electrolyte. Thus, advanced Li-ion hybrid capacitors (LIHCs) were successfully constructed with RuO2/MWCNT anode and activated ployaniline derived carbon (APDC) cathode under a Li-ion organic electrolyte. The LIHCs exhibited a highest energy density of 146 Wh kg−1 and a highest power densities of 33 kW kg−1, with excellent cyclic stability (∼100% at 2.0 A g−1 after 15,000 cycles), which exhibited better performance than other LIHCs systems.
  • Preparation of 4,4′-diaminostilbene-2,2′-disulfonic acid derivative/
           PVA/ LDHs composite fluorescent brightener and performances on paper
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Guanghua Zhang, Mingyuan Guo, Yongning Ma, Lun Du, Jing Pei, Guojun Liu In order to improve the anti-aging property and surface strength of high-yield-paper (HYP), a novel composite fluorescent brighter (PFB/PVA/LDH) was successfully synthesized via hydrothermal reaction with 4,4′-diaminostilbene-2,2′-disulfonic acid derivative (PFB), polyvinyl alcohol (PVA) and layered double hydroxides (LDH) as raw materials in this study. The introduction of LDH can effectively shield the ultraviolet to improve the anti-aging performance on one hand, and PVA will enhance the strength of paper though formation of thin film on the other hand. The anti-yellowing property of the as-prepared PFB/PVA/LDH was remarkably excellent than that of pure PFB for the HYP paper. After 70 h aging, the brightness of paper sheets coated with PFB/PVA/LDH is still reached to 91.24 ISO%. Moreover, the composite brighter could form a thin film in the surface of paper sheets to improve its surface strength and smoothness. Compared with blank paper sheets, the surface strength and smoothness of paper sheets treated with 0.4 g m−2 of PFB/PVA/LDH were increased 2.11 m s−1 and 56.8 s, respectively. Based on the characterization and results analysis, it can be inferred that the PFB/PVA/LDH composite can not only improve the paper’s brightness as a fluorescent brightener and anti-aging agent, but also increase its surface strength as a surface sizing agent.
  • Tuning the morphology of Cr2O3:CuO (50:50) thin films by RF magnetron
           sputtering for room temperature sensing application
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): S. Ponmudi, R. Sivakumar, C. Sanjeeviraja, C. Gopalakrishnan, K. Jeyadheepan In the present investigation, for the first time, we report the room temperature gas sensing characteristics of Cr2O3:CuO (50:50) thin films prepared by RF magnetron sputtering technique. The X-ray diffraction data show that the prepared Cr2O3:CuO (50:50) films are amorphous nature. The X-ray photoelectron spectroscopic study confirmed the formation of Cr3+ and Cu2+ states in the films. The growth conditions induce the change in morphology of Cr2O3:CuO (50:50) films from cauliflower like structure to single nanoplate like structure, which may be due to the change in nucleation. The FTIR spectra of Cr2O3:CuO (50:50) thin films exhibit peaks between 431 cm−1 and 774 cm−1 which correspond to the characteristic stretching vibrations of CuO and CrO bonds in the films. Optical study showed the RF power induced red shift in absorption edge, which revealed the systematic reduction in optical energy band gap of the films. The activation energy (ΔE) of Cr2O3:CuO (50:50) thin films estimated from the Arrhenius plot are varied between 0.369 and 0.504 eV. The respective response and recovery times of Cr2O3:CuO (50:50) thin film sensor exposed in 25 ppm of ammonia gas are about 11 and 14 s, while that in 100 ppm, are about 51 and 53 s. The maximum sensor response of 98% was observed for 100 ppm of NH3 gas at room temperature. The present report suggests that the RF magnetron sputtered Cr2O3:CuO (50:50) thin films can perform efficiently as a ammonia gas sensor at room temperature.Graphical abstractGraphical abstract for this article
  • Effect of aminated nanocrystal cellulose on proton conductivity and
           dimensional stability of proton exchange membranes
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Qi Zhao, Yingcong Wei, Chuangjiang Ni, Lele Wang, Baijun Liu, Jing Liu, Mingyao Zhang, Yongfeng Men, Zhaoyan Sun, Haiming Xie, Wei Hu, Yunfeng Lu A functionalized nanocrystal cellulose bearing amino and sulfonic acid groups (Am-sNCC) is prepared through a two-step chemical modification of microcrystal cellulose powders, first by sulfonic acid and then by a 3-trimethoxysilyl propyl ethylenediamine. The structure of Am-sNCC is characterized by Fourier Transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). A sulfonated poly(ether ether ketone ketone) (Ph-SPEEKK) is synthesized via the direct sulfonation of a high-molecular-weight phenylated polymeric precursor under a mild reaction condition. The nanocomposite membranes composed of the Ph-SPEEKK matrix and the Am-NCC additive are successfully prepared by a solution casting method. The properties related to their application for proton exchange membranes are carefully evaluated. The nanocomposite membranes containing Am-sNCC, which served as a performance-enhancing component to form hydrogen bonding networks with the Ph-SPEEKK matrix, exhibited much improved dimensional stability, higher water absorption capacities, higher proton conductivity, better mechanical and fuel cell properties than the Ph-SPEEKK membrane.Graphical abstractThe uniform and flexible composite membranes composed of the Ph-SPEEKK matrix and the functionalized nanocrystal cellulose bearing amino, silane and sulfonic acid groups (Am-sNCC) additive were successfully prepared by a solution casting method. The free high energy SO3 could help the “Grotthus” mechanism for proton transfer, and the “Vehicle” mechanism to work mainly through the water molecules in the membranes. The higher water absorption of the Am-sNCC series membranes resulted from the hydrogen bond between the OH, NH2, SO3H groups and H2O, promoted the proton transportation through “vehicle” mechanism, and thus improved the proton conductivity of the composite membranes. Schematic illustration of suggested mode of proton conduction in membranes.Graphical abstract for this article
  • Bio-surfactant assisted solvothermal synthesis of Magnetic retrievable
           Fe3O4@rGO nanocomposite for photocatalytic reduction of 2-nitrophenol and
           degradation of TCH under visible light illumination
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): S. Mansingh, D.K. Padhi, Kulamani Parida An eco-friendly and bio-surfactant assisted room temperature synthesis has been proposed for preparation of Magnetic retrievable Fe3O4@rGO nanocomposite in Averrhoa carambola leaf extract towards 2-nitrophenol reduction and TCH degradation under visible light illumination. The role of bio-molecules that are present in leaf extract is quite crucial in the process of tuning the morphology and opto-electronic features of Fe3O4 nanoparticles. Additionally, the insitu conversion of GO to rGO and preparation of Fe3O4 from Fe+2 and Fe+3 metal precursors leads to formation Fe3O4@rGO nanocomposite. rGO sheets play the key role in successful transfer and separation of photoexcited charge carrier resulting in better catalytic activity compared to neat Fe3O4. Among the designed nanocomposites 3 wt% loaded rGO i.e. FG-3 shows the best result with 95.85% 20 ppm 2 Nitrophenol reductions and 94.09% 10 ppm TCH degradation under visible light irradiation for 30 and 60 mins respectively. The observed high photocatalytic performance of FG-3 is attributed to synergetic chemistry operating between rGO and Fe3O4 components that causes effective separation and channelization of excitons to active sites and also due to increase in surface area of composite material. The above stated separation efficiency and surface area expansion is well supported by PL/Impedance measurements and BET analysis respectively. Further the phase purity, uniform distribution of nanoparticles and reduction of GO to rGO is well characterised through XRD, FESEM/TEM and Raman/FTIR analysis respectively.Graphical abstractGraphical abstract for this article
  • Surface doping of the LaMg3 alloy with nano-cobalt particles for promoting
           the hydrogenation properties through magnetron sputtering
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Huaiwei Zhang, Li Fu, Weidong Xuan, Zhenguo Ji Surface doping of rare earth-magnesium based alloy with cobalt nano-scale particles through the combination of ball milling and magnetron sputtering methods are introduced in the research. The generation process of the doped sample is composed of three components: alloy surface roughness, cobalt particles doped on the surface and the formation of surface modification coatings. For the hydrogen storage performances, the reversible capacity and cycle stability of the doped sample are improved significantly. Cobalt based intermetallics on the alloy surface can be considered as a catalyst in the hydrogen absorption and desorption process.Graphical abstractGraphical abstract for this article
  • A g-C3N4@ppy-rGO 3D structure hydrogel for efficient
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yinghua Liang, Xing Wang, Weijia An, Yao Li, Jinshan Hu, Wenquan Cui We propose a non-metallic g-C3N4 nanosheet with efficient photo-oxidation and reduction ability that is modified by two non-metallic materials graphene and polypyrrole. The composite was tested by water treatment, including hexavalent chromium and phenol. It offers a visible response, easy recovery, and high stability, with a higher photo-degradation rate than bulk g-C3N4. The photoelectric performance test showed that the composite has a reduced Eg (2.58 eV) that is 0.12 eV lower than g-C3N4 (2.70 eV). The rGH can transfer electrons, and ppy can transfer holes, which helps improve the separation rate of photogenerated charge of the g-C3N4. When ppy and rGH operate concurrently, the separation of the photogenerated charge is greatly improved. In addition, the results of Vb-XPS show that the value of the valence band top of the hybrid hydrogel is more negative than bulk g-C3N4. Therefore, the π-π conjugation of ppy and rGH can effectively improve the utilization rate of visible light, the photogenerated transfer rate, the photocatalysis-oxidation ability, and the change in valence band position of g-C3N4.Graphical abstractGraphical abstract for this article
  • Facile phosphorus-embedding into SnS2 using a high-energy ball mill to
           improve the surface kinetics of P-SnS2 anodes for a Li-ion battery
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Hongsuk Choi, Seungmin Lee, KwangSup Eom Herein, we study the effects of phosphorus-embedding on the surface morphology, surface chemical/electrical microstructure, and electrochemical performance of tin sulfides anodes fabricated by a high-energy ball mill method (HEBM) for lithium-ion battery (LiB). Specifically, phosphorus-embedding into SnS2 enlarges the lattice spacing of the major phases of tin phosphides, which facilitates lithiation and delithiation on the surface. The tin phosphorus sulfide anodes show higher electrochemical LiB performances than a pristine SnS2 electrode. Among the four SnPnS2 (n = 0.2, 0.4, 0.6, and 0.8) anodes, the SnP0.6S2 anode exhibits the highest discharge capacity of 404 mAh g−1 at the 200th cycle (@ 500 mA g−1) and capacity retention of 84% after 200 cycles.
  • Generation of Au nanorods by laser ablation in liquid and their further
           elongation in external magnetic field
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): G.A. Shafeev, I.I. Rakov, K.O. Ayyyzhy, G.N. Mikhailova, A.V. Troitskii, O.V. Uvarov Laser-assisted single-step generation of elongated Au NPs is reported. Laser-generated Au NPs have some fraction of spherical NPs and elongated NPs with aspect ratio of 6–8. The behavior of these NPs in a permanent magnetic field up to 7 Tesla is experimentally studied using in-situ optical absorption spectrometry. It is found that magnetic field causes irreversible changes in the aspect ratio of elongated Au NPs. Residence in magnetic field for time of order of tens minutes is accompanied by further elongation of Au NPs and formation of Au nanowires with aspect ratios up to 17–18. This is corroborated with TEM images of Au NPs before and after the action of magnetic field. The results are interpreted on the basis of interaction of external magnetic field with that of electrons that take part in longitudinal plasmon oscillations in elongated Au NPs.
  • Silicon and silicon-germanium nanoparticles obtained by Pulsed Laser
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): F. Stock, L. Diebold, F. Antoni, C. Chowde Gowda, D. Muller, T. Haffner, P. Pfeiffer, S. Roques, D. Mathiot Semiconductor nanoparticles are of great interest in the area of microelectronics and can also be used in many optoelectrical devices as for example optical converters for photovoltaic applications.Silicon (Si) and silicon-germanium (SiGe) quantum dots can be used as high-energy photon converters, known as “red-shift” photoluminescence (PL) in solar cells in order to improve their efficiency. We report on the possibility to produce SiGe nanoparticles by Pulsed Laser Deposition (PLD) on silicon dioxide substrates. We keep the focus on the control of morphological properties of nanoparticles considering various deposition parameters like temperature, fluence and the amount of deposited material. Si0.5Ge0.5 controlled ratio is obtained by optimizing the amount of matter ablated successively from Si and Ge pure targets. Rutherford Backscattering Spectroscopy (RBS) is used to confirm the stoichiometry of the deposited structures. Morphological characterization is performed by Atomic Force Microscopy (AFM), determining average diameter, height and density of the nanoparticles. In order to confirm the crystalline character of the deposited particles, Raman analyses have been performed, helping in determining the optimal deposition temperature. PLD allows to condense a very small and controlled amount of material during the deposition process, permitting this way the growth of nanostructures in a 10 nm range. With these dimensions, SiGe quantum dots are subject to have a photoluminescent (PL) behaviour. However, no photoluminescence is observed on the deposited nanoparticles.Graphical abstractGraphical abstract for this article
  • Visible-light responsive boron and nitrogen codoped anatase TiO2 with
           exposed {0 0 1} facet: Calculation and experiment
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Rujun Liu, Fan Yang, Yonlong Xie, Ying Yu To fully understand the synergistic effect of B/N codoping on the visible-light photocatalytic activity of anatase TiO2 with exposed {0 0 1} facet, a combination of Density Functional Theory (DFT) calculation by GGA + U method and experiment has been performed. Bader charge and Electronic Location Function (ELF) analysis reveal that there is free electron-gas like behavior around N and neighbor B for B/N-codoped anatase TiO2 with exposed {0 0 1} facet, and its visible-light absorbance increases, which may promote Ti4+ reduction to Ti3+. The results of calculation and experiment demonstrate that B/N codoping leads to the shift of the absorption edge of the TiO2 to lower energy region, and thus makes its photocatalysis active within the wavelength of 600 nm.Graphical abstractGraphical abstract for this article
  • Co1.4Ni0.6P cocatalysts modified metallic carbon black/g-C3N4 nanosheet
           Schottky heterojunctions for active and durable photocatalytic H2
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Rongchen Shen, Wei Liu, Doudou Ren, Jun Xie, Xin Li Efficient separation and utilization of photogenerated electrons as well as holes play decisive roles in boosting photocatalytic hydrogen evolution reaction (HER). To reach this goal, we designed carbon black (CB) and Co1.4Ni0.6P as dual cocatalysts co-modified graphitic carbon nitride for efficient and stable photocatalytic HER. This resulting ternary photocatalyst was synthesized by sonochemical loading and high-temperature phosphatizing. Impressively, the maximum photocatalytic hydrogen-production rate for the ternary photocatalysts could reach 405 μmolh−1g−1, which was 810, 2 and 1.7 times higher than those of pure g-C3N4 (0.5μmolh−1g−1), g-C3N4-Co1.4Ni0.6P (195μmolh−1g−1) and g-C3N4-1% Pt (230 μmolh−1g−1), respectively. Through the test analysis, the enhanced hydrogen-evolution performance was attributed to the synergetic effect between the metallic CB and the low-cost Co1.4Ni0.6P cocatalyst. More interestingly, the Co1.4Ni0.6P cocatalyst could not only decrease the recombination of photogenerated electrons and holes, but also boost absorption in the visible region and the hydrogen-evolution kinetics. Furthermore, the formation of Schottky heterojunctions between metallic CB and g-C3N4 nanosheets could further accelerate the separation and transfer of photogenerated electrons. This work provides a simple and facile strategy to rationally design highly efficient photocatalyst using low-cost nanocarbon materials and high-activity metal phosphide.Graphical abstractGraphical abstract for this article
  • Pt/C@MnO2 composite hierarchical hollow microspheres for catalytic
           formaldehyde decomposition at room temperature
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Dong Sun, Swelm Wageh, Ahmed A. Al-Ghamdi, Yao Le, Jiaguo Yu, Chuanjia Jiang Hierarchical carbon@manganese oxide (MnO2) core-shell heterostructure was fabricated by a facile hydrothermal method with hollow carbon spheres as a sacrificial template, and then deposited with platinum (Pt) nanoparticles (NPs). The as-prepared Pt/C@MnO2 composite catalyst exhibited superb performance for removing formaldehyde (HCHO) at room temperature compared with the Pt loaded on MnO2 microspheres or commercial MnO2. The MnO2 nanosheet-assembled hierarchical architecture endowed Pt/C@MnO2 with larger specific surface area and open porous structure, which not only promotes the high dispersity of Pt NPs but also facilitates the diffusion and adsorption of HCHO onto the catalyst surface. The abundant surface active oxygen species resulted from the activation and dissociation of O2 adsorbed at oxygen vacancies adjacent to Pt NPs, and were identified as the primary active species for converting HCHO into intermediates such as dioxymethylene, formate and carbon monoxide. This work might provide enlightenment for designing morphology-dependent and highly active catalysts for HCHO elimination at ambient temperature.Graphical abstractGraphical abstract for this article
  • Polarization-induced selective growth of Au islands on single-domain
           ferroelectric PbTiO3 nanoplates with enhanced photocatalytic activity
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Chunying Chao, Yisha Zhou, Hao Li, Weiwei He, Wenjun Fa In this work, heterostructured Au@PbTiO3 nanoplates were synthesized successfully via a simple hydrothermal process. It is revealed that Au islands with the size of 8–20 nm selectively deposited on the positively polarized surface of the single-crystal and single-domain PbTiO3 nonaplates. The composite demonstrates an efficient photocatalytic performance toward degradation of Rhodamine B (RhB) solution under UV light. The possible mechanism is that the ferroelectric polarization efficiently separates the photogenerated electrons and holes and reduces the recombination of them. Then, the ferroelectric polarization field urged the electrons concentrated on the positively polarized surface and then transformed oxygen into superoxide radicals to enhance the photocatalytic activity. Recycled activity tests show that the heterostructured Au@PbTiO3 nanoplates would inhibit the photocorrosion behavior and provide high stability.Graphical abstractGraphical abstract for this article
  • The effect of N-doped form on visible light photoactivity of Z-scheme
           g-C3N4/TiO2 photocatalyst
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Juan Li, Bowen Li, Qiuye Li, Jianjun Yang The reasons for the difference of visible light activity between the direct contact g-C3N4/TiO2 Z-scheme composites obtained by one-step or two-step calcination process were investigated in detail by XRD, TEM, XPS, Raman and ESR technologies. TEM results showed that only g-C3N4 obtained by two-step calcination (denoted as CN-TSC) presented the porous structure which was in favor of the light absorption. XPS analysis indicated that interstitial doped N species formed in one-step calcination composite (denoted as CT-OSC) while substitutional N would appear in two-step calcination composite (denoted as CT-TSC). Nevertheless, interstitial N located at the higher position in the band gap of TiO2 and usually acted as the strong capture center of holes which was unfavorable to charge transfer. ESR and Raman results indicated that CT-TSC with some concentration of surface Vo and lower concentration of bulk Vo had excellent charge separation efficiency, according to the surface-enhanced Raman scattering (SERS) results of photo-induced charge-transfer (PICT) enhancement mechanism. And as a result, the visible-light activity for propylene oxidation of CT-TSC was twice higher than that of CT-OSC.Graphical abstractGraphical abstract for this article
  • Carbon-coated Cu-TiO2 nanocomposite with enhanced photostability and
           photocatalytic activity
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Sibo Chen, Xin Li, Wuyi Zhou, Shengsen Zhang, Yueping Fang Carbon-coated Cu-TiO2 nanocomposite (Cu-TiO2@C) was constructed using one-step method of thermal reduction. Their photocatalytic activity for hydrogen production from methanol aqueous solution was investigated. Under UV–vis light irradiation, the hydrogen yield of the 10 mg optimal Cu-TiO2@C reached 269.1 μmol h−1, which was very close to that of Pt@TiO2 (290.8 μmol h−1). The Cu-TiO2@C also displayed much higher photocatalytic stability in comparison with Cu-TiO2 without coated carbon layer. The nano-Cu as photocatalytic active site improve the efficiency of photoinduced carrier separation. The carbon layer with the ability to transfer photogenerated electrons faster and to adsorb hydroxyl radicals more easily, leading to a very significant increase the reaction rate. In addition, the carbon layer can also provide a chemical protection to the Cu nanoparticles and increase the stability of the photocatalysts. The Cu-TiO2@C photocatalyst with the low cost, enhanced photostability and photocatalytic activity is expected to be an excellent nanocomposite t in reforming of biomass or bio-derivatives field.Graphical abstractGraphical abstract for this article
  • Review on manganese dioxide for catalytic oxidation of airborne
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Lei Miao, Jinlong Wang, Pengyi Zhang Indoor formaldehyde (HCHO) pollution is becoming an important issue with the increase of space confinement. Manganese dioxide (MnO2) has attracted great attention due to its high catalytic activity, thermal stability, facile synthesis with low-cost materials and availability in various crystal morphologies. This review covers recent progress on MnO2-based materials for catalytic oxidation of HCHO, with a particular emphasis on the enhancement of the catalytic activity at low temperature. According to different modification strategies, MnO2 catalysts are divided into three categories, namely, single MnO2 (generally showing tunneled or layered structures), doped or composite MnO2, and supported MnO2 catalysts. Specifically, modification of single MnO2, especially layered MnO2, is deeply discussed in terms of morphology control, and defect engineering, aiming at regulating surface active species; doping or composite MnO2 could alter the properties of the catalysts and facilitate the entire reaction process (i.e., adsorption, reaction and desorption), favoring the rate-limiting step from the thermodynamic and kinetic points of view; supporting MnO2 on carriers is necessary for practical application. Moreover, reaction mechanism of HCHO oxidation by single or composite MnO2 is also reviewed. Finally, perspective on the challenges and opportunities for exploring advanced MnO2-based catalysts is presented.
  • Constructing multiple interfaces in polydimethylsiloxane/multi-walled
           carbon nanotubes nanocomposites by the incorporation of cotton fibers for
           high-performance electromagnetic interference shielding and mechanical
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Jie Li, Yan-Jun Tan, Yi-Fu Chen, Hong Wu, Shaoyun Guo, Ming Wang Reflection of electromagnetic waves at multiple interfaces and then absorption in the matrices has been well demonstrated to efficiently improve electromagnetic interference (EMI) shielding of conductive polymer composites (CPC). In this study, a large number of multiple interfaces were constructed in polydimethylsiloxane/multi-walled carbon nanotubes (PDMS/MWCNT) nanocomposites by the incorporation of cotton fibers (CTF). The electromagnetic radiation was efficiently attenuated by the wave reflection at the multiple interfaces and then absorption at the interfaces of PDMS/CTF and CTF/MWCNT in the nanocomposites. The EMI shielding effectiveness (SE) of the PDMS/MWCNT nanocomposites with 2.0 and 3.0 vol% MWCNT increased from ∼16 to ∼30 dB, ∼20 to ∼41 dB by adding 15 vol% CTF, respectively. A relatively dense MWCNT network, which was also formed in the PDMS/MWCNT/CTF nanocomposites because of the volume occupation effect of CTF, resulted in the high electrical conductivity and low percolation threshold. For example, the electrical conductivity of the PDMS/MWCNT nanocomposites with 0.5 vol% MWCNT increased from 1.65 × 10-4 to 0.23 S/m, and the percolation threshold of the composites deceased from 0.44 to 0.2 vol% by the addition of 15 vol% CTF. In addition, the mechanical properties, especially the Young’s modulus and tensile strength, of PDMS/MWCNT nanocomposites were enhanced by the incorporation of CTF and the flexible property was maintained because of the high interfacial interaction between PDMS and CTF and the high aspect ratio of CTF. Furthermore, the samples exhibited highly reliable EMI SE even after bending 6000 times, suggesting the potential application in body protection and flexible electronic devices.Graphical abstractGraphical abstract for this article
  • Core-shell dual-MOF heterostructures derived magnetic CoFe2O4/CuO
           (sub)microcages with superior catalytic performance
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yan-Feng Huang, Xiao-Yi Sun, Shu-Hui Huo, Ying Li, Chongli Zhong The high performance of catalysts relies largely on the meticulous design of hierarchical hollow micro/nanostructures with more active sites and superb structural tenability. Herein, we developed a simple strategy to design and fabricate CoFe2O4/CuO (sub)microcages using core-shell dual-MOF heterostructures (FeII-Co PBAs@HKUST-1) as both the precursor and self-sacrificing template. The derivation of metal oxide composites from dual-MOF heterostructures is challenging, and this method could overcome the difficulty caused by the possible lattice mismatch between the different MOFs. Uniform core-shell dual-MOF structures FeII-Co PBAs@HKUST-1 were first fabricated and then converted to CoFe2O4/CuO (sub)microcages by thermal annealing in air. The resulting CoFe2O4/CuO (sub)microcages were extensively characterized and exhibited remarkable catalytic performance with an excellent stability and magnetic recyclability for the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. In addition, CoFe2O/CuO (sub)microcages were also found to be highly active for catalytic reduction of methylene blue (MB) by NaBH4 in an aqueous solution. The results show that CoFe2O4/CuO (sub)microcages have potential application for organic pollutants degradation and environmental rehabilitation.Graphical abstractGraphical abstract for this article
  • Gradient multifunctional biopolymer thin film assemblies synthesized by
           combinatorial MAPLE
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Natalia Mihailescu, Merve Erginer Haskoylu, Carmen Ristoscu, Müge Sennaroglu Bostan, Mihai Sopronyi, Mehmet S. Eroğlu, Mariana Carmen Chifiriuc, Cosmin Catalin Mustaciosu, Emanuel Axente, Ebru Toksoy Oner, Ion N. Mihailescu Combinatorial Matrix-Assisted Pulsed Laser Evaporation (C-MAPLE) was recently introduced to the fast generation of compositional libraries of two biopolymers in a single-step process, for tissue engineering and regenerative medicine applications.Synchronized laser irradiation of two distinct cryogenic targets, one consisting of Sulfated Halomonas Levan and the other of quaternized low molecular weight Chitosan was used to fabricate compositional gradient coatings for surface functionalization. Synthesized coatings preserved the base material composition as confirmed by Fourier Transform Infrared Spectroscopy. Morphological study by Scanning Electron Microscopy, Atomic Force Microscopy and profilometry correlated with water contact angles measurements demonstrated that the obtained thin coatings have improved surface properties with respect to pure material coatings. Fluorescence microscopy validated the compositional gradient, while in vitro assays evidenced characteristic responses of mouse fibroblasts (L929 cell line) by distinct deposition surface regions. The coagulation test pointed out good properties for Sulfated Halomonas Levan coatings as compared to the case of an increased amount of quaternized low molecular weight Chitosan biopolymer or the control.The antimicrobial effect of the coatings was demonstrated against Escherichia coli and Staphylococcus aureus strains, representative for both Gram negative and Gram positive bacterial species, respectively, mainly involved in implant and nosocomial infections. The assembled nanostructures possess variable anti-biofilm activity along the compositional gradient, with a stronger inhibitory effect on the initial adherence phase of both tested microbial strains, but also against mature Escherichia coli biofilms.It was shown that C-MAPLE can generate discrete areas of blended polymeric composition exhibiting improved surface properties for a broad range of biomedicine applications, e.g. the fabrication of thin bioactive and cell-instructive coatings with anti-adherence properties.
  • Synthesis and modification of Cu-C70 nanocomposite for
           plasmonic applications
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Rahul Singhal, Satakshi Gupta, Ritu Vishnoi, Ganesh D. Sharma Low energy ion irradiation is an interesting tool to accomplish the bulk modifications of different materials. The impact of low energy ion bombardment is studied on Cu-C70 nanocomposite thin films prepared by thermal co-deposition technique. A beam of 180 keV Ar ions was used for this purpose which results in a drastic change in structural, optical and electrical properties. It is demonstrated that surface plasmon resonance (SPR) was successfully induced with ion irradiation initially at a fluence of 3 × 1014 ions cm−2 and is observed to be first red shifted and then blue shifted on increasing fluence of ion irradiation. The results of Raman spectroscopy reveal the progressive transformation of fullerene C70 into amorphous carbon with increasing fluence. The I(D)/I(G) ratio is calculated to analyze amorphous carbon and improved ordering of amorphous carbon at higher fluences is observed. TEM images verified the continuous growth of copper nanoparticles subjected to low energy ion irradiation with increasing fluence which is ascribed to the agglomeration of particles as pointed by EDS mapping images. FTIR results show that the destruction of fullerene C70 matrix is initiated at a fluence of 3 × 1014 ions cm−2, which coincides with the appearance of SPR band. The transformation of fullerene into amorphous carbon and the growth of copper nanoparticles was found to be responsible for increase in conductivity with fluences as confirmed by I-V measurements.Graphical abstractGraphical abstract for this article
  • Interaction between polysaccharide monomer and SiO2/Al2O3/CaCO3 surfaces:
           A DFT theoretical study
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Hui Zhao, Na Qi, Ying Li In the present study, the interaction between a model polysaccharides monomer β-D-glucopyranose with different mineral solid surfaces, including hydroxylated (0 0 1) surface of SiO2, (0 0 0 1) surface of Al2O3 and (1 0 4) surface of CaCO3, were explored by theoretical calculations based on Density Functional Theory (DFT) under periodic boundary conditions. The adsorption geometry of the β-D-glucopyranose monomer (GM) at different solid surface and the interaction energies were analyzed in detail, and the interaction mechanism was determined via electron density differences iso-surface, Mulliken charge, as well as projected density states (PDOS) analysis. Very strong interaction was found between GM and Al2O3 (0 0 0 1) surface, which was mainly attributed to the formation of bridging AlO bonds and H-bonds. There was the bonding between H-1s and O-2p orbitals for the formed hydrogen bonds and hybridization between O-p states and Al-d states for the bridging AlO bonds. The interaction between GM and CaCO3 (1 0 4) surface was mainly attributed to the electrostatic interaction and hydrogen bonded interaction, and was fairly strong, too. But there was only hydrogen bonds between GM and SiO2 surface, which was relative weak. In all the three adsorbed systems, significant charge redistribution was observed which contributed to the interaction between them, though little electron transferred between them. The finding is very meaningful for providing theoretical direction in proceeding sufficient application of diverse kind of natural sugar-based functional substances in many fields.Graphical abstractGraphical abstract for this article
  • A comparison of the influence of CeO2 and In doped CeO2 interlayer on the
           properties of the YGBCO/interlayer/YGBCO tri-layer films deposited by
           pulsed laser deposition
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Shunfan Liu, Wei Wang, Linfei Liu, Tong Zheng, Yijie Li High critical current (Ic) has long been proved important to REBa2Cu3O7−δ (REBCO or RE123) superconductor for the practical applications. To achieve high Ic values, the primary way is to increase the thickness of superconducting layer and to enhance high critical current density (Jc). However, Jc drops precipitously with increasing the thickness of the films. This phenomenon is called the thickness effect, which can be effectively inhibited by fabricating superconductor/interlayer/superconductor tri-layer structure. In this study, a series of YGBCO/CeO2/YGBCO and YGBCO/In doped CeO2 (CeO2 + In)/YGBCO tri-layer films with different interlayer thickness were fabricated. The microstructure, surface morphology and superconducting property of these samples were measured. It was found that all the tri-layer films had pure c-axis orientation. When using CeO2 film as an interlayer, the two YGBCO layers in the tri-layer films were almost completely isolated, resulting in the low Ic values, which were equivalent to the Ic of a single YGBCO layer. While using CeO2 + In film as an interlayer, the Ic values of all the YGBCO/CeO2 + In/YGBCO trilayers were almost double the Ic of a single YGBCO layer, and the Ic values of the trilayers firstly slow increased and then decreased with increasing the thickness of CeO2 + In interlayer. Under the optimal experimental parameters, the Ic value was much higher than that of the a double YGBCO layer without interlayer. The thickness effect of superconducting layer can be effectively inhibited by inserting CeO2 + In interlayer with wide thickness range.
  • Effect of Ti on Ag catalyst supported on spherical fibrous silica for
           partial hydrogenation of dimethyl oxalate
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mengyao Ouyang, Jian Wang, Bo Peng, Yujun Zhao, Shengping Wang, Xinbin Ma A highly efficient Ag catalyst supported on a novel Ti-decorated spherical fibrous silica (Ag/Ti-KCC-1) was synthesized via a facile approach. Characterization of catalysts, including FT-IR, N2 physisorption, TEM, ICP-OES and DRUV–vis was carried out to investigate the physicochemical properties of the catalyst, XPS, H2-TPR, H2-TPD and DMO-TGA were conducted to further elucidate the effect of Ti dopant. It is shown that the Ti additive is able to, (1) inhibit the aggregation of Ag; (2) induce electron transfer from Ti to Ag, which effect the Ag dispersion and the adsorption ability of the reactants on the catalyst surface. Proper amount of Ti additive provided a balanced coverage of both hydrogen and dimethyl oxalate (DMO) on catalyst surface, which is essential in promoting the performance of the catalyst in the hydrogenation of DMO. By using the novel 10Ag/0.02Ti-KCC-1 catalyst, a high MG yield of 93.0% under extremely high WHSV of 1.75 h−1 is achieved.Graphical abstractGraphical abstract for this article
  • Kinetics during endotaxial growth of CoSi2 nanowires and
           islands on Si(0 0 1)
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Bin Leong Ong, Eng Soon Tok We propose a phenomenological growth model describing the morphological evolution of two different (ridge and flat) types of endotaxial CoSi2 islands as a function of growth temperature from 500 °C to 800 °C and for Cobalt coverages from 0.1 monolayer (ML) to 0.5ML. The presence of low energy Type A and Type B CoSi2{1 1 1}-Si{1 1 1} interfaces drives the formation of flat-type islands and ridge-type nanowires respectively. The growth of these nanowires and islands are kinetically constrained, where the islands’ length, width and height are experimentally found to follow the Arrhenius relation with activation energies ranging between 0.4 eV and 1.6 eV. Our model suggests that the islands are kinetically constrained by thermally-activated processes such as island-edge diffusion anisotropy and corner energy-barriers, thereby restricting the adatom transfer between long and short sides of the islands. Consequently, at low growth temperatures, ridge-type nanowires are more dot-like while flat-type islands form small wire-like islands. But at high growth temperatures, the ridge islands form long nanowires while the flat islands become more dot-like instead.Graphical abstractGraphical abstract for this article
  • Relationship between the nano-structure of GaN surfaces and SERS
           efficiency: Chasing hot-spots
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): J.L. Weyher, B. Bartosewicz, I. Dzięcielewski, J. Krajczewski, B. Jankiewicz, G. Nowak, A. Kudelski This work reviews different types of surface structures formed on selectively etched GaN substrates for surface-enhanced Raman scattering (SERS) measurements. A one-to-one correlation between nano-structure and SERS efficiency, represented by the enhancement factor (EF), is shown by comparing SEM images with maps of Raman intensity. In this way, the location of hot-spots (H-Ss) is disclosed, leading to the selection of an optimal technology for manufacturing efficient and uniform SERS platforms. GaN platforms with nano-structures containing bunched pillars and pyramids covered with an Au-Ag plasmonic layer reproducibly show an EF of up to 106 for 4-mercaptobenzoic acid (pMBA) test molecules. Platforms with pits (inverted pyramids) yield an EF of one order of magnitude lower.Graphical abstractGraphical abstract for this article
  • Selective detection of CO at room temperature with CuO nanoplatelets
           sensor for indoor air quality monitoring manifested by crystallinity
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): D.N. Oosthuizen, D.E. Motaung, H.C. Swart The fabrication of sensitive CO gas sensors with low ppm detection is very imperative for human health, since longer exposure to CO gas can lead to dizziness, loss of consciousness and vomiting, and in severe cases death. As a result, herein, we report on the CO room temperature gas sensing characteristics of CuO nanoplatelets based gas sensor synthesized using the hydrothermal method at 100 and 200 °C for various reaction times. A size-dependent contraction on the crystallite sizes, due to the decrease in platelet size, was observed for the CuO nanoplatelets grown at 200 °C, at various reaction times. The crystal quality and crystallinity improved for nanoplatelets prepared at 100 °C and decreased for those prepared at 200 °C at various reactions times. The CuO-B-1 based sensor prepared for 6 h at 200 °C demonstrated enhanced response (Ra-Rg/Ra = 15) and rapid response time (ca. 81 s) towards 20 ppm CO gas (in 35% relative humidity) at room temperature, pleasing multiple parameters required for a good sensor. The improved sensing performance for CuO-B-1 is justified by enhanced crystallinity, resulting from low resistivity and high carrier mobility, which resulted in a more pronounced change in sensor resistance compared to its counterparts. The higher stability for the CuO-B-1 based sensor in the presence of relative humidity makes it a suitable candidate for detection of CO in a normal environment. Furthermore, the possible sensing mechanism of the CuO-B-1 based sensor towards CO gas is discussed.Graphical abstractGraphical abstract for this article
  • Synthesis and visible-light photocatalytic CO2/H2O reduction to methyl
           formate of TiO2 nanoparticles coated by aminated cellulose
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Halidan Maimaiti, Abuduheiremu Awati, Gunisakezi Yisilamu, Dedong Zhang, Shixin Wang For decades, researchers have been looking for a high-efficiency, low-cost, and environment-friendly photocatalyst for CO2 reduction. In this work, we employed SOCl2 chlorination and EDA passivation to decorate the surface of nanocellulose crystals (NCC), and obtained aminated cellulose crystal NCC-EDA. Next, using coordination and dispersion of amino, hydroxyl, and other functional groups at the NCC-EDA surface, the TiO2 nanoparticles synthesized in-situ from Ti(OBu)4 were coated by NCC-EDA via a hydrothermal synthesis approach. Subsequently, the composite photocatalyst TiO2/NCC-EDA with various NCC-EDA contents was fabricated. The structure, optical properties, and photocatalytic CO2 reduction performance of the photocatalyst were measured. The results suggest that the NCC-EDA based composite catalyst has highly efficient electron-hole separation and electron transfer as well as excellent CO2 adsorption ability. The TiO2/NCC-EDA exhibits outstanding photocatalytic CO2 to HCOOCH3 conversion performance. At reaction time of 6 h, the HCOOCH3 yield is 372.85 µmol/g cat, which is 4.5 times the yield of pure TiO2 photocatalyst.Graphical abstractGraphical abstract for this article
  • In-situ preparation of NH2-MIL-125(Ti)/BiOCl composite with accelerating
           charge carriers for boosting visible light photocatalytic activity
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Qingsong Hu, Jun Di, Bin Wang, Mengxia Ji, Yong Chen, Jiexiang Xia, Huaming Li, Yaping Zhao Metal-organic frameworks (MOFs), a new class of porous and crystalline materials, which have drawn increasing attention in diverse areas. The development of highly active MOFs-based photocatalysts have become a research hotspot owing to the tunable semiconducting properties and highly porous nanostructure. The unique roles of photocatalysis by MOFs can be conventionally optimized towards addressing the environment and energy issues. In this paper, NH2-MIL-125(Ti)/BiOCl composite was studied as a novel visible-light responsive photocatalyst for the removal of organic contaminants. The composite displays significantly enhanced photocatalytic activity for contaminant degradation as compared with BiOCl and NH2-MIL-125(Ti), and the optimal NH2-MIL-125(Ti) content is 10 wt%. The remarkable enhancement of the photocatalytic performance can be ascribed to the absorption of visible-light as well as the efficient charge separation and transfer on the interface contact between BiOCl and NH2-MIL-125(Ti). Superoxide radicals and holes were determined to be the main active species in the photocatalytic process via the reactive species trapping experiments and electron spin resonance, and the plausible photocatalytic mechanism is presented. This work aims to provide guidelines for developing more organic-inorganic hybrid materials for environmental remediation.Graphical abstractGraphical abstract for this article
  • Carbon quantum dots sensitized ZnSn(OH)6 for visible light-driven
           photocatalytic water purification
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yuanyuan Zhang, Lili Wang, Manli Yang, Jie Wang, Jinsheng Shi In this study, carbon quantum dots (CQDs) decorated ZnSn(OH)6 (ZSH) micro-spheres with uniform solid, hollow and yolk-shell structures were successfully synthesized by an etching-second growth strategy and facile hydrothermal method. Compared with pure ZSH, ZSH@CQDs composites exhibited obviously enhanced photocatalytic activities for both degradation of organic pollutant and disinfection of staphylococcus aureus. In CQDs decorated composites, ZSH@CQDs with yolk-shell structure presented 70.4% of RhB degradation efficiency under visible light irradiation within 8 h, which was about 10 times higher than that of ZSH samples. ZSH@CQDs with yolk-shell structure also manifested the best photocatalytic inactivation performance under visible light illumination, which could achieve water purification of 100% bacteria disinfection within 16 h. The enhanced photocatalytic activities might be attributed to the unique up-conversion property of CQDs, as well as its efficient charge separation, and a possible mechanism was reasonably proposed. This work could provide a new perspective to design efficient CQDs decorated photocatalysts for water purification.Graphical abstractGraphical abstract for this article
  • The verification of icephobic performance on biomimetic superhydrophobic
           surfaces and the effect of wettability and surface energy
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Wenjuan Cui, Yu Jiang, Kati Mielonen, Tapani A. Pakkanen The fundamental understanding of the icephobic performance of two model superhydrophobic surfaces (lotus and petal surfaces) is important for many industrial applications. The effect of wettability and surface energy on ice adhesion has recently received attention. However, the verification of icephobicity is typically carried out with a single observation method. For this study, rough modified rod-coated surfaces, structured polymer surfaces and nine smooth surfaces with tunable wettability were fabricated. Combining several observation techniques of icephobicity indicate that petal and lotus surfaces lose their superhydrophobicity, being less useful for ice repellency due to poor humidity tolerance in condensation conditions. The ice adhesion of rough surfaces enhanced with increasing hydrophobicity. The increased interface area leads to a reduction of the icephobic performance. The stress concentrator on the lotus surface was better than on the petal surface. In addition, the role of dynamic wettability on ice adhesion was checked. Smooth hydrophobic surfaces were found to be better icephobic materials compared to rough surfaces. The intrinsic surface energy of smooth surfaces is significantly linear with the ice adhesion. High freezing delay times were found for smooth low-density polyethylene resin and fluorinated surfaces.Graphical abstractGraphical abstract for this article
  • The spatial inhomogeneity and X-ray absorption spectroscopy of
           superconducting nanocrystalline boron doped diamond films
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Dinesh Kumar, G. Mangamma, Martando Rath, M.S. Ramachandra Rao The local electrical conductivity and impurity band evolution in superconducting nanocrystalline boron doped diamond (BNCD) film are investigated using conducting atomic force microscopy (C-AFM) and X-ray absorption spectroscopy (XAS). C-AFM has been employed to investigate the local conductivity of superconducting BNCD with Tc = 4.3 K and upper critical field Hc2(0) = 5.2 T. A high local electrical heterogeneity of the BNCD film as evidenced from the C-AFM profile points to the uneven boron uptake during the process of doping. C-AFM also revealed that grain boundaries are the highly conducting regions, possibly, due to the presence of p-type trans-polyacetylene along with the CC and CH bonds in the grain boundaries. From the in-depth XPS profiling of the B 1s spectra we confirmed the macroscopic uniformity of the boron concentration across the depth of BNCD layers. X-ray absorption spectroscopy (XAS) measurements near B K-edge and C K-edge showed formation of in-gap states as a result of heavy boron doping. Near C K-edge, bandgap states at 282.8 eV and 284.1 eV are found which are responsible for superconductivity in the BNCD film. This work explores the non-uniform boron doping and its effect on the conduction band structure of a superconducting BNCD film.
  • Oxygen vacancies in TiO2/SnO x coatings prepared by ball milling followed
           by calcination and their influence on the photocatalytic activity
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Liang Hao, Jiancheng Yan, Sujun Guan, Lijun Cheng, Qian Zhao, Zheng Zhu, Yao Wang, Yun Lu, Jizi Liu We prepared TiO2/SnOx (x = 1, 2) composite coatings through ball milling followed by calcination. The composite coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), spherical aberration corrected scanning transmission microscopy (Cs-corrected STEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and other techniques. Bulk oxygen vacancies in the form of vacancy clusters rather than individual sites were directly observed by Cs-corrected STEM. With an increase in the calcination temperature from 873 K to 1073 K or holding time from five hours to ten hours, the concentration of bulk defects also increased. On the other hand, the photocatalytic activity of the as-prepared samples for degrading MB dye increased with the concentration increase of bulk defects. Sample 973 K-10 h showed the best photocatalytic activity whether under the irradiation of UV light or visible light. With a further increase in the concentration of bulk oxygen vacancies, the photocatalytic activity decreased, although surface Ti3+ defects appeared. In other words, a moderate concentration of bulk defects could benefit the enhancement of the photocatalytic activity of the as-prepared samples. Ball milling followed by calcination is an effective method to introduce defects such as oxygen vacancies.Graphical abstractGraphical abstract for this article
  • Facile preparation of Fe3O4@C/Cu core-shell sub-micron materials for oil
           removal from water surface
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Taiqi Liu, Zhijie Li, Guimei Shi, Qian Zhao, Xu Chen, Xinli Chen, Yilin Li In this paper, we provided a low-cost, high-efficiency and reusable core-shell magnetic sub-micron composite particles (MSMCs) based on Fe3O4 magnetic sub-micron particles (MSMPs) and glucose that was synthesized by hydrothermal method and high temperature carbonization method. Several techniques such as scanning electron microscope, transmission electron microscope, Fourier transform infrared, vibrating sample magnetometer, and thermogravimetric analysis were used in the characterization of the materials. The results indicated that the MSMCs has good dispersion and uniform particle size. It also can floating on the surface of water. The saturation magnetization of the MSMCs is 34 kA/m and the coercive force is 84Oe which make it recover easily under the magnetic field. Its excellent temperature resistance can easily remove absorbed oil on its surface by low temperature fractionation. Those separated particle powder can be reused for many times after drying and oscillation. The MSMCs adsorption capacity of kerosene, diesel and engine oil is 3.05 g/g, 3.25 g/g and 3.38 g/g, and its oil-absorption speed is high. With the above characteristics, the MSMCs can effectively remove oil on a wide ocean surface and avoid secondary pollution.
  • Barrier formation at BaTiO3 interfaces with Ni and NiO
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Daniel M. Long, Andreas Klein, Elizabeth C. Dickey Barium Titanate and Ni-based multilayer ceramic capacitors have wide commercial applicability, and interfaces are critical to the overall device behavior as they can help control unwanted leakage currents. Here we make use of photoemission methods to investigate the electrostatic barriers formed at BaTiO3/Ni(O) interfaces to understand the implications for electron injection. We find the interface Fermi level in BaTiO3 to evolve smoothly during Ni deposition with a Schottky barrier height for electrons of 0.68 eV, whereas with NiO the Fermi level evolves rapidly with an electron injection barrier of 1.49 eV. In-situ poling shows the Schottky barrier at the BaTiO3/Ni interface is not significantly altered by ferroelectric polarization, consistent with the good screening of the Ni electrode. This study presents a direct quantitative measurement of the interface barrier heights and highlights the significance of the oxidation state of the electrode.Graphical abstractGraphical abstract for this article
  • Investigation on the surface layer formed during electrochemical
           modification of pure iron
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Kangnan Fan, Zhuji Jin, Jiang Guo, Zebei Wang, Guannan Jiang This paper presents an experimental and analytical investigation on electrochemical modification of pure iron, aiming to obtain a surface layer which has good machinability for further processing. The microstructures of the modified layer were compared from a relative low current density (10 A/cm2) to high current density (30 A/cm2) and characterized by various detection equipment. A detailed X-ray photoelectron spectroscopy (XPS) analysis was conducted to measure the composition profile of the black film on the modified layer. The results show that, during electrochemical modification, the subsurface formed a loose porous layer covered with a flimsy oxide. At low current density, uniform dissolution was obtained and the surface was not corroded off completely. However, at large current density, due to the strong electrochemical action and uneven flow field, the cross section of pure iron became waved and the surface shape deteriorated. The results of the water contact angle measurements show that the surface hydrophilicity was enhanced by electrochemical modification, which might improve the cooling effect of the machining region. The XPS analysis indicated a bi-layer structure of oxidation film on the modified layer and the outmost Fe3+ species layer was considered to be the oxidation of Fe2+ species from inner layer.Graphical abstractGraphical abstract for this article
  • Selective catalytic reduction of NOx with NH3 over MoO3/Mn-Zr composite
           oxide catalyst
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Zhiming Liu, Zizheng Zhou, Guoliang Qi, Tianle Zhu MO3-doped Mn-Zr composite oxide catalyst has been developed for the NOx reduction by NH3. The introduction of MoO3 exerted significant effect on the activity and N2 selectivity of Mn-Zr composite oxide for the catalytic removal of NOx. The synergistic effect between MoO3 and Mn-Zr contributes to generating more acid sites, which not only suppressed the formation of inactive nitrate but also benefited the adsorption and activation of NH3. Moreover, the strong interaction between MoO3 and MnOx resulted in the decreased redox ability of MnOx and more Mn3+ formed, thus remarkably enhancing the N2 selectivity. Therefore, MO3/Mn-Zr catalyst is active and highly selective for the NOx reduction. The present research shed light on the design of novel NH3-SCR catalyst by adjusting the redox ability and surface acidity.Graphical abstractGraphical abstract for this article
  • Slip trace-induced terrace erosion
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Benjamin Douat, Jérôme Colin, Roberto Bergamaschini, Francesco Montalenti, Michel Drouet, Joël Bonneville, Christophe Coupeau We have investigated the interaction between slip traces and vicinal steps on the Nb(1 1 1) surface under increasing external strain. By exploiting an extended scanning tunneling microscopy analysis, we here show that emerging dislocations at the free-surface can induce the full disappearance of atomic terraces. To shed light on the observed behavior, we have modeled the elastic interaction between a screw dislocation and a vicinal step in the actual experimental configuration. After computing the adatom chemical potential, we show that strain-mediated diffusion on surface causes step erosion, possibly leading to vanishing of full terraces.
  • Electrodeposition of Ni-Mo/Al2O3 nano-composite coatings at various
           deposition current densities
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Morteza Alizadeh, Abbas Cheshmpish In this study, the effect of deposition current density on the characteristics of nickel-molybdenum/alumina coatings processed by an electrodeposition method was investigated. Morphological, elemental and phase evaluations were conducted on the deposited coatings by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction, respectively. Furthermore, the hardness, wear and corrosion behaviors of the prepared coatings were measured. The results showed that the coatings prepared at high current densities, typically at 8 A/dm2, exhibit a porous and rough morphology. Also, the contents of molybdenum and alumina deposited at high current densities are reduced, thus increasing the crystallite size and deteriorating the mechanical properties and corrosion resistance. In this regard, the optimum current density to meet the most desirable properties was found to be 4 A/dm2.Graphical abstractGraphical abstract for this article
  • Competitive adsorption of arsenic and fluoride on {2 0 1}
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Zhen Zhou, Yaqin Yu, Zhaoxia Ding, Meimei Zuo, Chuanyong Jing Elevated arsenic (As) and fluoride (F) in natural water present an urgent environmental concern. The demand for their effective removal underscores the fundamental understanding of their solid-liquid interface chemistry. Herein, the efficiency of {2 0 1} TiO2 in As(III/V) and F was explored using macroscopic and molecular-level techniques. Their adsorption isotherms followed the Langmuir equation, and the maximum adsorption capacity was 50.5, 29.3, and 5.0 mg/g for As(III), As(V) and F, respectively. Their adsorption kinetics of As(III), As(V) and F conformed to the pseudo-second-order model. The XPS and in situ ATR-FTIR results identified that the active adsorption sites on {2 0 1} TiO2 included surface hydroxyl groups, but not oxygen vacancies. As(III/V) and F form bidentate binuclear and monodentate mononuclear structures, respectively, regardless of exposed facets. Integrated with the molecular-level mechanism, the charge distribution multisite complexation model well predicted the pH edge behaviors in mono- and co-component systems. The shift of pHPZC of {2 0 1} TiO2 in competitive adsorption systems signified the formation of inner-sphere complexes. The results of this study shed new lights on the adsorption of coexisting ions using high-index faceted TiO2.Graphical abstractGraphical abstract for this article
  • Improvement of activity, selectivity and H2O&SO2-tolerance of
           micro-mesoporous CrMn2O4 spinel catalyst for low-temperature NH3-SCR of
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Fengyu Gao, Xiaolong Tang, Honghong Yi, Shunzheng Zhao, Jiangen Wang, Tian Gu Cr-Mn mixed-oxide catalysts were prepared by citric acid method for low-temperature NH3-SCR of NOx. Mn(3)Cr(2)Ox (molar ratio) catalyst has an excellent NOx conversion of nearly 100% at 100–225 °C and good N2 selectivity above 70% at 100–200 °C. Results of XRD, BET, and XPS suggested that the micro-mesoporous CrMn2O4 spinel with high specific surface area, more active sites (Mn3+ and Mn4+) and effective electron transfer (Cr5+ + 2Mn3+ ↔ Cr3+ + 2Mn4+) were the important promotion factors for outstanding SCR performance. In-situ DRIFTS experiments indicated the SCR reaction pathway over CrMn2O4 spinel mainly followed the typical ER mechanism at the temperature around 200 °C. The higher Mn–O binding energy and lower dehydrogenation ability were the main reasons for CrMn2O4 spinel with low N2O by-product than Mn3O4. The CrMn2O4 spinel has satisfying tolerance to SO2 and H2O (about 72% NOx conversion at 200 °C for 20 h). In-situ DRIFTS showed SO2 could completely inhibit the adsorption of NO and weaken the adsorption of coordinated NH3 to Lewis acid sites but promote the adsorption of NH4+ to Brønsted acid sites. Analysis of TGA and FTIR results indicated that the sulfation of metal might be the main reason for the decline of SCR activity with SO2. The formation of Cr(III) sulfate could play an important role in protecting Mn active sites away from sulfating. Besides, the transform of HSO3 and SO42− to (H⋯SO42−) can provide new Brønsted acid sites for ionic NH4+, enhancing the SCR activity via fast-SCR (NO2 + NH4+ → NH4NO2 → N2 + H2O).Graphical abstractGraphical abstract for this article
  • Improving the intrinsic properties of rGO sheets by S-doping and the
           effects of rGO improvements on the photocatalytic performance of
           Cu3Se2/rGO nanocomposites
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mohammad Amin Baghchesara, H.R. Azimi, A. Ghorban Shiravizadeh, Mohd Asri Mat Teridi, Ramin Yousefi The effects of S-doping on intrinsic properties of graphene oxide (GO) sheets such as interlayer spacing, reduction level, and electrical resistance and the influence of these properties on the photocatalytic performance of rGO/Cu3Se2 nanocomposites were investigated. A simple chemical method was used to synthesize S-doped GO sheets and a cost-effective co-precipitation method was used to decorate of the NPs on S-doped GO (as S-doped GO/NPs nanocomposites) and undoped GO (as undoped GO/NPs nanocomposites) sheets. X-ray diffraction (XRD) patterns of the products indicated that GO sheets were changed into reduced GO (rGO) sheets during the synthesis process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed more exfoliation for the S-doped rGO sheets in comparison to the undoped rGO. X-ray photoelectron spectroscopy (XPS) indicated that S-doping caused an improve reduction level of rGO. UV–vis results revealed that S-doped rGO/NPs nanocomposites had a band-gap value around 2.2 eV that was bigger than the band-gap value of the undoped rGO/NPs that was around 1.9 eV. Room temperature photoluminescence (PL) results indicated that, the electron-hole recombination rate of S-doped rGO/NPs nanocomposites was lower than the undoped rGO/NPs nanocomposites. The photocatalytic activity under visible light irradiation for degradation of methylene blue (MB) dye showed a significant enhancement photocatalytic performance for S-doped rGO/NPs nanocomposites in comparison to the photocatalytic activity of the undoped rGO/NPs nanocomposites. Brunauer–Emmett–Teller (BET) calculation indicated a specific surface area of 251.6 and 220.7 m2 g−1 for the S-doped and undoped rGO/NPs nanocomposites, respectively. In addition, photoresponse measurements under visible light source irradiation indicated that, the electrical conductivity of rGO as an intrinsic property of the rGO sheets was increased by S-doping. Finally, according to valence band (VB) edge spectroscopy results of the samples, it was understood that a type-II heterostructure was formed by S-doped rGO/NPs with pristine NPs that was another important factor for the enhancement photocatalytic performance of this sample.Graphical abstractGraphical abstract for this article
  • Graphene-templated synthesis of palladium nanoplates as novel
           electrocatalyst for direct methanol fuel cell
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Hujiang Yang, Liang Geng, Yuting Zhang, Gang Chang, Zaoli Zhang, Xiong Liu, Ming Lei, Yunbin He The shape-controlled synthesis of Pd nanocrystals supported on the surface of graphene is of great importance in designing an electrocatalyst for direct methanol fuel cells. This work demonstrates the synthesis and characterization of a novel Pd nanoplate structure templated by graphene (PdNPts/G). The combined use of Poly Vingl Pyrrolidone and a graphene template is critical to successfully obtaining novel palladium nanoplates via a one-step reduction strategy using ascorbic acid as a soft reductant. In particular, owing to the presence of a high surface area to mass ratio of Pd nanoplates with dominant active {1 1 0} crystal facets and the enhanced electron transfer of graphene, the as-prepared PdNPts/G shows superior electrocatalytic activity along with satisfactory stability and greater tolerance over both the commercial Vulcan XC-72 and graphene supported Pd nanoparticles (abbr. PdNPs/V and PdNPs/G, respectively) for methanol electro-oxidation.
  • Dissolution of thin TaV2 during annealing of Ta/TaV2/V tri-layer below the
           order-disorder temperature
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): A. Csík, S.S. Shenouda, Z. Erdélyi, D.L. Beke In this research, we provide first experimental evidence on the dissolution of a thin compound layer sandwiched between the parent materials when it is heated below the order-disorder temperature. The Ta(10 nm)/TaV2(6 nm)/V(30 nm) system, prepared by DC magnetron sputtering, has been chosen to prove the expected simulation results. The samples were investigated mainly by secondary neutral mass spectrometry. The about 6 nm thick TaV2 compound layer was dissolved by annealing at 1025 °C for 1 h. Then, it was reformed by increasing the annealing time to 2–3 h. These results prove our previous computer kinetic Monte Carlo and Kinetic mean field calculations. These findings are important for nanotechnologies utilizing early stages of solid state reactions.Graphical abstractGraphical abstract for this article
  • MWCNTs produced by electrolysis of molten carbonate: Characteristics of
           the cathodic products grown on galvanized steel and nickel chrome
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): S. Arcaro, F.A. Berutti, A.K. Alves, C.P. Bergmann Electrolytic synthesis in molten salts has excellent possibilities for the production of various carbonaceous materials, nevertheless, a study of the synthesis conditions is necessary for that the carbon products obtained is in the carbon nanotube (CNT) structure. In this work, the possibility of production of MWCNTs (multi walled carbon nanotubes) by the electrolytic synthesis of molten salts has been shown. The product structure and morphology can be controlled by choosing the right electrolysis conditions (type of electrode, applied current and electrolysis time). The properties of the produced carbon-containing products were analyzed by XRD, TEM, HRTEM and Raman spectroscopy. A correlation of product properties with synthesis conditions and parameters has been made. When using steel and nickel chrome as cathode, the products have lower levels of defects and are partially filled with metal phase when 1 A and 4 h of electrolytic synthesis were used. The metal phase acts as a catalyst for the nanotubes generation in the electrolytic synthesis from molten salts. Even so, after electrolysis for 4 h, these products are 90% MWCNT. The MWCNT growth on the galvanized steel or nickel-chrome cathodes is similar to an average external diameter of 100–125 nm and internal diameter is 25–40 nm. However, when grown in nickel-chrome cathode, the nanotubes have better quality and smaller walls. No additional treatments are necessary.Graphical abstractGraphical abstract for this article
  • Studied on the graded band-gap copper indium diselenide thin film solar
           cells prepared by electrochemical route
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Ashwini B. Rohom, Priyanka U. Londhe, Jeong In Han, Nandu B. Chaure A graded band-gap CuInSe2 (CIS) thin film solar cell (TFSC) having glass/FTO/CdS/CIS multilayer/Au structure has been fabricated. A simple and low-cost electrodeposition technique is used to deposit the multilayers of CIS onto fluorine doped tin oxide (FTO) coated glass substrate. A conventional three-electrode geometry consisting, FTO, graphite and Ag/AgCl as a working, counter and reference electrodes, respectively was used for electrodeposition. Structural characterization was carried out using X-ray diffraction (XRD) and Raman spectroscopy, which revealed the chalcopyrite tetragonal CIS structure with a quite Cu-rich surface which reduces upon selenization. The morphology of the as grown and selenized CIS multilayer thin films was studied by using atomic force microscopy (AFM) which shows the compact and uniform layer formation. The depth profile distribution of individual elements in both as-grown and selenized CIS multilayer thin films has been determined using secondary ion mass spectroscopy (SIMS). SIMS results revealed that the proposed graded band gap structure is retained even after selenization. The presence of Cu+, In3+ and Se2− oxidation states were confirmed using X-ray photoelectron spectroscopy (XPS). A single layer and multilayer CIS solar cell devices yielded ∼5.10% and ∼7.20% power conversion efficiency, respectively. In the present work, pH 3 buffer solution helps to improve the morphology of CIS layer which gives the better power conversion efficiency as compared to the previously reported value.Graphical abstractGraphical abstract for this article
  • Use of Mn doping to suppress defect sites in Ag3PO4: Applications in
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mohammad Afif, Uyi Sulaeman, Anung Riapanitra, Roy Andreas, Shu Yin The highly active Mn-doped Ag3PO4 photocatalyst was successfully synthesized under coprecipitation method using AgNO3, Na2HPO4·12H2O, and MnSO4·H2O, followed by annealing. The products were characterized using the SEM, XRD, DRS, XPS, and BET. The results showed that the Mn doping decreased the broad absorption in the visible region and increased the atomic ratio of O/Ag. The hydroxyl defects and oxygen vacancies can be suppressed by Mn doping and the photocatalytic activity under visible light irradiation could be improved. This excellent photocatalytic activity was caused by decreasing the recombination of electron and holes due to suppressing the defect sites in the surface of Ag3PO4.Graphical abstractGraphical abstract for this article
  • Photocatalytic reduction of p-nitrophenol over plasmonic M (M = Ag,
           Au)/SnNb2O6 nanosheets
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Junshu Wu, Jinshu Wang, Tianning Wang, Lingmin Sun, Yucheng Du, Yongli Li, Hongyi Li Monodispersed noble metal (Ag, Au) nanoparticles were loaded on layer-structured SnNb2O6 nanosheets and their plasmonic effects in photocatalytic reduction of p-nitrophenol into p-aminophenol via the improvement of visible-light photoabsorption were systematically analyzed. The loading amount of metal nanoparticles could be tuned, as well as the photoreduction reaction rate under visible-light irradiation. It was found that the M (M = Ag, Au)/SnNb2O6 nanosheets were significantly more effective than bare SnNb2O6 nanosheets in promoting p-nitrophenol conversion. On the basis of experimentally investigation of the influence of the localized surface plasmon resonance effect, a possible mechanism for the enhanced photocatalytic activity is proposed. Directly functionalizing SnNb2O6 nanosheet with Ag or Au combines visible-light photoabsorption of SnNb2O6 nanosheets with the unique visible-light sensitized property of noble metal, thus allowing a rapid direct transfer of charge carriers in the composed structures. Our finding will help to establish more energy efficient and robust catalysis process for solar energy harvesting.Graphical abstractVisible-light-driven p-nitrophenol photoreduction over M (M = Ag, Au)/SnNb2O6 catalysts is enhanced owing to the influence of the localized surface plasmon resonance effect.Graphical abstract for this article
  • Fabrication and color-gradient control of colorful superhydrophobic
           materials with mechanical durable, oil/water separation and recyclable
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mengnan Qu, Lili Ma, Lingang Hou, Mingjuan Yuan, Jiao He, Menghui Xue, Yichen Zhou, Xiangrong Liu, Jinmei He The diversity of color and the controllability of color-gradient are both of importance for significantly expanding the practical application of outdoor superhydrophobic coating materials. Herein, a simple method has been proposed to fabricate the colorful superhydrophobic materials with metal oxides. By changing the dosages of metal oxides, the colors of the materials can be well controlled. The resultant materials with multiple colors are experimentally found to be highly robust without significant degradation in the superhydrophobicity, even after various rigorous tests. By virtue of the superior surface wetting properties, the colorful materials can be applied to separate various oil/water mixtures with high efficiency. Furthermore, the obtained materials exhibit outstanding anti-fouling property and favorable reusability, which are crucial for large-scale application of the materials. We greatly anticipate that our strategy will open a new avenue for the colorful superhydrophobic paint and coating research, and accelerate their real applications in the near future.Graphical abstractIn this study, the colorful superhydrophobic materials were successfully fabricated by the combination of any two different kinds of metal oxides and stearic acid with low surface energy. Moreover, the colors of materials are able to be controlled via changing the dosage of metal oxides. The obtained colorful superhydrophobic materials can be applied to effectively separate various oil/water mixtures with high efficiency. Besides, the as-prepared materials exhibit excellent mechanical durability and chemical stability against rigorous tests, meanwhile showing outstanding anti-fouling property and robust reusability. The above mentioned advantages will greatly and truly accelerate and extend the real application of the superhydrophobic materials, especially in the painting and coating area.Graphical abstract for this article
  • Regulation of morphologies and luminescence of β-NaGdF4:Ybc+,Er3+
           upconversion nanoparticles by hydrothermal method and their dual-mode
           thermometric properties
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Lu Yao, Dekang Xu, Yongjin Li, Hao Lin, Shenghong Yang, Yueli Zhang Exploring the thermometric properties of UCNPs is of great importance for non-contact fluoresce thermometers. Ln-doped β-NaGdF4:Yb3+,Er3+ upconversion nanoparticles (UCNPs) have been fabricated by varying the ratio of citric ions to molecules in precursor. Morphology of the as-prepared β-NaGdF4:Yb3+,Er3+ UCNPs turns from hexagonal prisms to agglomerations of smaller particles with decreased dimension. Luminescence intensity decreases and red-to-green ratio increases with increasing ratio of citric ions to molecules. A dual-mode thermometric property has been found in the as-prepared β-NaGdF4:Yb3+,Er3+ UCNPs. The first mode derives from the temperature dependent fluoresce-intensity-ratios of thermally coupled manifolds of Er3+ (2H11/2) and (4S3/2) manifolds, of which the maximum relative sensitivity value is 0.0036 K−1. The other mode derives from temperature dependent red-to-green ratios, which is a linear function of temperature and the maximum relative sensitivity value is 0.0238 K−1. The β-NaGdF4:Yb3+,Er3+ UCNPs with morphology of agglomerations of smaller particles with high surface-to-volume ratios show advanced sensitivities, which are suitable for noncontact optical thermometer.Graphical abstractPH value increase induces morphology revolution of UCNPs, resulting in higher surface-to-volume ratios, decreasing luminescence intensity and increase nonradiative rates, hence the enhanced thermometric property.Graphical abstract for this article
  • A novel CuS/graphene-coated separator for suppressing the shuttle effect
           of lithium/sulfur batteries
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Haipeng Li, Liancheng Sun, Yan Zhao, Taizhe Tan, Yongguang Zhang Herein, we demonstrate a facile synthesis process to fabricate and deposit flower-like CuS/graphene nanocomposite on a multi-functional separator for efficient immobilization of polysulfides of lithium/sulfur (Li/S) batteries. Admirably, as-prepared CuS/graphene composite endows enriched oxygen-functional groups and excellent electrical conductivity for cathode area. The introduction of CuS/graphene-coated separator effectively reduced the dissolution of lithium polysulfides as well as enhanced the integrity of the sulfur cathode for Li/S batteries. The cell with these modified separator delivered an enviable discharge capacity of 1302 mAh g−1 at 0.2 C, as well as an excellent reversible capacity of 760 mAh g−1 after 100 cycles. Furthermore, an outstanding rate capability of 568 mAh g−1 at 3.0 C has been achieved in the cell with CuS/graphene-coated separator. The results reveal that CuS/graphene-coated separator shows an admirable potentiality to boost the performance of next-generation Li/S batteries.Graphical abstractTypical SEM images of CuS/graphene composite and schematic illustration of a Li/S cell configuration with a CuS/graphene-coated separator.Graphical abstract for this article
  • Luminescent Ta doped WO3 thin films as a probable candidate for excitonic
           solar cell applications
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): V.S. Kavitha, S. Suresh, S.R. Chalana, V.P. Mahadevan Pillai Post-annealed undoped and Ta doped (doping concentration 1, 3, 5 and 7 wt%) WO3 thin films are prepared using RF magnetron sputtering technique. All the films are in monoclinic phase with 〈1 0 0〉 as the preferred crystal growth direction and show a nanostructured nature. The fabricated films have a smooth surface with densely packed grains. All the films show good optical transparency in the wavelength region 400−900 nm. Optical constants of the films are calculated from the transmittance and reflectance spectra. All the films show a broad blue emission corresponds to the indirect band to band transition in WO3 under UV excitation. The smooth pin hole free surface, good crystalline quality, moderate band gap energy and bright luminescence of the Ta doped WO3 thin films suggest the possibility of using this material as an energy barrier layer for performance enhancement in excitonic solar cells.Graphical abstractGraphical abstract for this article
  • Polyamide 6.6 separates oil/water due to its dual underwater
           oleophobicity/underoil hydrophobicity: Role of 2D and 3D porous structures
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Pei Zhao, Ning Qin, Carolyn L. Ren, John Z. Wen Porous polyamide functionalized by plasma or various coatings has been investigated for oil/water separation. In literature, polyamide has rarely been studied for oil removal, and this work investigated the performance of bare polyamide 6.6 (nylon 6.6) in terms of the oil/water separation efficiency and the intrusion pressure, inspiring cost-effective solutions for large-scale oil removal in the industry. Both polyamide meshes possessing two-dimensional (2D) one-layer pores and nonwoven fabrics with three-dimensional (3D) irregular pores were found to be able to separate oil/water with a high efficiency above 98.5%. This finding was attributed to the dual underwater oleophobicity and underoil hydrophobicity of these polyamide samples. The roles of 2D and 3D structures in oil/water separation were illustrated, to provide a new insight into filter designing. Due to its greater intrusion pressure, the 3D netting structure was suggested as being more beneficial for oil/water separation than the 2D structure.Graphical abstractGraphical abstract for this article
  • Controlled thermal shrinking of gold nanoparticle-decorated polystyrene
           substrate for advanced surface-enhanced Raman spectroscopy
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Heguang Liu, Yadong Xu, Yuan Li, Nitin Chopra Surface-enhanced Raman spectroscopy (SERS) is a promising technique for future high-sensitivity chemical sensors. The main deficiencies that restrict the large-scale application of SERS lie in its high cost, low reproducibility, and poor signal uniformity. In this letter, we report the primary exploration of a facile dip coating – thermal shrinking method to produce gold (Au) nanoparticle decorated flexible polymer substrate for SERS. Briefly, Au nanoparticles dispersed in DI-water were anchored on to a polystyrene film via controlled dip coating, which was followed by a thermal treatment process to shrink the polymer film. We observe a polymer volume shrinking rate of 20% after heating, which results in a particle density increase of more than 10 times. Significant enhancement of Raman signals was observed for the R6G molecules anchored on the shrunk substrate, demonstrating our methodology is feasible, reliable, and promising for future large-scale application of SERS-based chemical sensors.
  • Ablation target cooling by maximizing the nanoparticle productivity in
           laser synthesis of colloids
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Friedrich Waag, Bilal Gökce, Stephan Barcikowski Even if ultrashort laser pulses are used during the laser synthesis of colloids, a significant amount of laser energy is converted into thermal energy, which results in heating the ablation target and the colloid. To date, little attention has been paid to these heating effects in the literature. This study was focused on measurements of the process temperature during the high-power, ultrashort-pulsed laser ablation of a nickel target in a continuous water flow setup. Time-resolved monitoring of the temperature of the ablation target and of the colloid indicated that there was an initial rapid uptake of thermal energy followed by a thermally-stable state in which there was very little additional heating. Shifting the focal plane from behind the target onto its surface and further into the fluid provided insight concerning the different mechanisms of heat generation, dissipation, and transfer in the laser synthesis of colloids. It even was possible to distinguish the fluence effects and the colloid re-irradiation effects. New possibilities of process control were identified by correlating the productivity of laser ablation at different focal plane shifts with the measured thermal data. Counterintuitively, the temperature of the target was minimized via ablation cooling when the productivity of the process was maximized.Graphical abstractGraphical abstract for this article
  • α-Fe2O3@dopamine core-shell nanocomposites and their highly enhanced
           photoacoustic performance
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Pengwei Li, Zaiqian He, Cuixian Luo, Yue Xiao, Ying Wang, Jie Hu, Gang Li, Huabei Jiang, Wendong Zhang In this work, multifunctional α-Fe2O3@dopamine core-shell nanocomposites consisting of α-Fe2O3 core surrounded by a thin dopamine (DA) shell have been successfully fabricated. The crystal structure, surface morphology and optical properties of the samples were determined by XRD, SEM, TEM and UV–vis, respectively, indicating that the presence of thin DA shell could affect the optical properties of Fe2O3 nanostructures. When it was incubated with NIH3T3 cells and injected in living body, the concave shape Fe2O3@dopamine nanocomposites exhibited the highest cell viability (94.6% within 16 h), and harmless to the living body. Moreover, the concave shape Fe2O3@dopamine nanocomposites also displayed the highest image contrast and distinguishability (3.74 times of control group, and 1.5 times of purchased Au nanoparticles). Thus, α-Fe2O3@dopamine core-shell structures are promising candidates for precise photoacoustic imaging and therapeutic process.
  • Iron/carbon composite microfiber catalyst derived from hemoglobin blood
           protein for lithium-oxygen batteries
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Jun-Seo Lee, Hyun-Soo Kim, Won-Hee Ryu Recycling of bio-waste sources for synthesis of functional electrode materials is an eco-friendly and sustainable approach to realize next-generation energy-storage systems. In this study, we present a fabrication method of Fe/C composite microfibers derived from electrospinning of hemoglobin blood protein, and subsequent calcination, and investigate its functionality as an oxygen electrode catalyst for Li–O2 batteries. We elucidate the thermal decomposition behavior of raw hemoglobin protein and structural evolution after calcination at different temperatures. We successfully fabricated Fe/C composite microfibers with a uniform and flattened shape by electrospinning of a hemoglobin precursor and thermal treatment. Finally, we demonstrated that Li–O2 cells in which the Fe/C composite microfiber catalyst was incorporated in the oxygen electrodes exhibited improved electrochemical performance compared to a pristine reference cell without the catalyst.Graphical abstractGraphical abstract for this article
  • Bio-inspired construction of cellulose-based molecular imprinting membrane
           with selective recognition surface for paclitaxel separation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Hui Zhang, Yuqi Li, Deyong Zheng, Shilin Cao, Lihui Chen, Liulian Huang, Huining Xiao Separating the natural product of paclitaxel from its structural analogs still remains a significant challenge. In this work, a novel molecular imprinting membrane (Cell/SiO2-MIM) with specific recognition sites was hierarchically constructed for paclitaxel (PTX) separation. Inspired by mussel, inorganic silica nanoparticles (SiO2 NPs) were introduced onto the surface of the regenerated cellulose membrane as polymerization platform in an attempt to enhance the permeation flux of the membrane. The specific recognition sites of PTX were constructed on the nanoscale silica surface through the bulk polymerization of vinylpyridine in the presence of PTX as templates, leading to the membrane with the selective recognition ability for the target molecule (PTX). The as-synthesized imprinting membrane exhibited excellent selective adsorption capacity and perm-selectivity towards PTX, with the maximum adsorption amount and separation factor of 46.36 mg/g and 3.77, respectively. Moreover, after six consecutive adsorption and desorption cycles, the membrane maintained the excellent stability and reusability, which facilities its potential application in an industrial scale.Graphical abstractA novel molecularly imprinted membrane (Cell/SiO2-MIM) with specific selective recognition sites for paclitaxel (PTX) separation.Graphical abstract for this article
  • Nanoscale morphology of electrolessly deposited silver metal
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Christopher N. Grabill, Daniel Freppon, Michelle Hettinger, Stephen M. Kuebler Electroless deposition of silver was studied to determine how chemical and physical parameters affect the morphology of the deposited metal. The study was conducted using variations of a silver deposition bath originally described by Danscher. The standard bath produced reflective and electrically conductive metal films comprised of agglomerates of small spheroidal nanoparticles. Removing gum arabic from the bath increased the deposition rate and changed the shape of the agglomerates but did not significantly change the size of the constituent nanoparticles. Replacing the citrate buffer with a dicarboxylate or monocarboxylate, which is less able to chelate Ag+, produced surfaces comprised of larger, more faceted metal particles. The longevity of the bath varied with the choice of carboxylate. A new formulation buffered with maleate exhibited the highest stability, depositing silver for several hours without unwanted spontaneous formation of silver metal in solution. Optical measurements of electrolessly deposited films revealed absorptions associated with silver nanoparticles. Electrical measurements showed that the as-deposited films were five orders of magnitude less conductive than bulk silver, but low-temperature annealing increased the conductivity by four orders of magnitude.Graphical abstractGraphical abstract for this article
  • Effect of laser pulse repetition rate on morphology and magnetic
           properties of cobalt ferrite films grown by pulsed laser deposition
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Fateme Eskandari, Parviz Kameli, Hadi Salamati In this paper, we report a switch of magnetic anisotropy in CoFe2O4 (CFO) films induced by change in laser pulse repetition rate. CFO films were deposited on MgO (0 0 1) substrates using pulsed laser deposition method with 2, 3, 5, 7 and 10 Hz laser pulse repetition rates. Atomic force microscopy images exhibited the film surface aggregation tends to compact shape with large size islands on the surface of the samples deposited by 2 and 3 Hz while the size of islands decreased on the surface of the 5, 7 and 10 Hz CFO films. The hysteresis curve of films indicated magnetic anisotropy and switching of the easy axis direction by changing laser repetition rates. The films grown at 2 and 3 Hz exhibit an in-plane easy axis, while by increasing the laser repetition rate, the easy axis switches to out-of-plane. The Raman spectra showed the rearrangement of Fe3+ and Co2+ cations on octahedral and tetrahedral sites in the structure by changing the laser pulse repetition rate. Change in the strain, morphology evolution and cation distribution are responsible for the change in easy axis direction and existence of shrinking at M–H loops.Graphical abstractGraphical abstract for this article
  • Highly flexible triboelectric nanogenerators fabricated utilizing active
           layers with a ZnO nanostructure on polyethylene naphthalate substrates
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Young Pyo Jeon, Jae Hyeon Park, Tae Whan Kim Atomic force microscopy images showed that layers with a ZnO nanostructure were regularly formed on polyethylene naphthalate (PEN) substrates coated with indium tin oxide. The output voltage of triboelectric nanogenerators (TENGs) containing layers with the ZnO nanostructure and operating in the vertical contact-separation mode was approximately 20 V, which indicated that the power was enhanced by a factor of 2 compared to that of the TENG without such layers. Bending endurance tests on the TENGs demonstrated high stability under the stress caused by bending at an angle of 90°. The average open-circuit voltage of the TENGs operating in the ambient atmosphere was reduced by only 22% after 2000 bendings. This endurance of the TENGs under bending in air could be attributed to the presence of the layers with the ZnO nanostructure.
  • OC+bonds+at+aluminum/polyamide+joint+interface&rft.title=Applied+Surface+Science&rft.issn=0169-4332&">On formation of AlOC bonds at aluminum/polyamide joint interface
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): F.C. Liu, P. Dong, W. Lu, K. Sun Strong dissimilar materials joints consisting of aluminum alloy and polyamide 66 (PA66) plates were produced by a new joining method: friction lap welding (FLW). To understand the key joining mechanism, special samples were made by evaporation of aluminum oxide onto PA66 plates to form an aluminum alloy/PA66 interface. X-ray photoelectron spectroscopy (XPS) was used for characterizing the resulting interfacial chemistry in these aluminum alloy/PA66 samples. Both the Al2p and C1s spectra of XPS confirmed the formation of AlOC bonds at the interface between PA66 and alumina coating. Approximately 23.6% of the Al atoms in the 0.8 nm alumina coating have contributed to the formation of AlOC bonds. The carbonyl group at the PA66 surface played an essential role in the formation of such an AlOC bond. The formation of AlOC bonds was proved to be a key factor for achieving good joint strengths in such metal/polymer joints, providing a direct understanding why aluminum alloys can be directly welded to PA66 plates with superior joint strength.Graphical abstractGraphical abstract for this article
  • Ruthenium coordinated with triphenylphosphine-hyper-crosslinked polymer:
           An efficient catalyst for hydrogen evolution reaction and hydrolysis of
           ammonia borane
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Caili Xu, Hua Wang, Qi Wang, Yi Wang, Yun Zhang, Guangyin Fan By using hyper-crosslinked polymer with triphenylphosphine skeleton (HCP-PPh3) as a matrix, we successfully synthesized an efficient HCP-PPh3-Ru(III) precursor for hydrogen evolution reaction (HER) and ammonia borane (AB) hydrolysis. The generated HCP-PPh3-Ru with a Ru loading of 5.0 wt% displays a high electrochemical performance for HER with an overpotential of 61 mV at a current density of 10 mA cm−2. Moreover, HCP-PPh3-Ru with a Ru loading of 3.5 wt% exhibits the best catalytic activity for AB hydrolysis with a turnover frequency of 402 mol H2 (molRu min)−1. The high catalytic property of the achieved catalyst is probably attributed to the substantial porosity and individual pore structure of support. Furthermore, the P-functional groups in HCP-PPh3 can facilitate the anchoring of Ru functioning as coordination sites to stabilize the small Ru nanoparticles, thereby deduces the high catalytic activity. The present work provides a facile strategy for synthesizing efficient microporous organic polymer stabilized Ru catalyst for HER and aqueous AB decomposition.Graphical abstractGraphical abstract for this article
  • Grain size dependence of the radiation tolerances of nano-amorphous
           Ti-Si-N composite coatings
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Q. Wan, B. Yang, Y.M. Chen, H.D. Liu, F. Ren Materials with large fractions of interfaces (e.g. nanocrystalline materials and multilayered nanofilms) have attracted attention because of their significantly enhanced ability to tolerate severe irradiation environments. In this paper, the microstructure and nanohardness evolutions of Ti-Si-N nano-amorphous composite coatings with grain sizes from 5 nm to 12 nm were investigated using 50 keV He+ ion bombardment at room temperature. All samples contained amorphous layers that caused decreases in hardness. The amorphous layer thickness and hardness decrement first decreased with the grain size and then increased. Results suggested that the nano/amorphous interfaces in Ti-Si-N coatings can effectively promote defect annihilation during irradiation. However, radiation tolerance was optimized in materials with 9 nm grains due to the competition between the increase in free energy and the energy stored in defects (Esto). In addition, this paper proposed a mechanism that explained the associated decrease in hardness. These results provided the theoretical underpinnings for an understanding of nano-composite material radiation behavior under irradiation.Graphical abstractNanohardness of Ti-Si-N coatings decreased as the amorphization occurred after irradiation. The decrement first decreased with the decrease of grain size, then increased as the grain size further decreased to a size smaller than 9 nm. The thickness of amorphous layer and the decrement in hardness revealed similar trend as a function of grain size.Graphical abstract for this article
  • Preparation and characterization of a durable superhydrophobic
           hyperbranched poly(dimethylolbutanoic acid-glycidyl ester of versatic
           acid)/nano-SiO2 coating
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Han Cui, Mingguang Hu, Zhen Yu, Jijun Xiao A novel method combining the use of nano-SiO2 and the hydrophobic hyperbranched polymer, poly(dimethylolbutanoic acid-glycidyl ester of versatic acid) (poly(di-MBA-TM10)), as a binder was proposed for the fabrication of superhydrophobic coatings. The structure of hyperbranched poly(di-MBA-TM10) was characterized along with surface morphology and elemental analysis of coatings via 13C nuclear magnetic resonance (13C NMR), Fourier transform infrared (FTIR), water contact angle (WCA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The resulting superhydrophobic coatings have water contact angles of 169.7° and showed resistance to acidic, alkaline, and neutral media. The superhydrophobic surface was prepared by the embedding method, and it retains its hydrophobicity even after 100 cycles of sanding and knife-scoring. The surface of the coating consists of binary nano and microstructure. SEM showed that the thorn-like protrusions that provide sufficient roughness required for superhydrophobicity were observed on the surface. The XPS and AFM data show that these protrusions are mainly composed of nano-SiO2 aggregates and alkyl chains of hyperbranched poly(di-MBA-TM10). Uniformity of the surface roughness is a key factor to obtain a superhydrophobic coating. A possible mechanism was briefly described here in which the nucleation of nano-SiO2 aggregates provided a synergistic effect for the superhydrophobicity. The results from SEM and AFM showed that the nano-aggregates detected on the superhydrophobic surfaces were the aggregates of individual nano-SiO2. Superhydrophobic surfaces prepared from our embedded method can be used as coatings for funnels to collect rainwater in precision rain gauges.Graphical abstractGraphical abstract for this article
  • Corrosion behavior of a β CuAlBe shape memory alloy containing stress
           induced martensite
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): S. Montecinos, P. Klímek, M. Sláma, S. Suarez, S. Simison The corrosion behavior of a β CuAlBe shape memory alloy containing stress-induced martensite was analyzed after 60 days of immersion in a 3.5% NaCl solution. The stress-induced martensite was retained in the sample after a load-unload compression cycle up to a pseudoelastic deformation of 4.5%. The corrosion of the alloy occurs by dealuminization, where β phase located in the areas between the needles of martensite is dissolved due to the preferential loss of aluminum, and the posterior redeposition of copper takes place.
  • Investigation of complex residual stress states in the near-surface
           region: Evaluation of the complete stress tensor by X-ray diffraction
           pattern decomposition
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Peter Schoderböck The presented work introduces an alternative to the classical sin2Ψ-method for the analysis of complex stress states by X-ray diffraction, with particular focus on the near-surface region. A procedure, based on the multiple hkl-method and implemented with a generalized least square minimization routine according to the Pawley pattern decomposition, is applied for evaluating the complete residual stress tensor in molybdenum sinter-parts after severe plastic deformation. Further, the requirements on the X-ray diffraction setup and the physically meaningful description of the instrumental aberrations are discussed. Finally, the successful implementation is demonstrated.
  • 6H-SiC blistering efficiency as a function of the hydrogen implantation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): N. Daghbouj, B.S. Li, M. Karlik, A. Declemy Blistering phenomenon by H implantation into 6H-SiC and high-temperature annealing is only possible in a surprisingly narrow window of ion fluence. By combining experimental results with Finite Element Method (FEM) modeling, we deduce the fraction of the implanted fluence used to pressurize blister cavities. Moreover, the blistering efficiency depends on the amount of the damage produced during ion implantation because it affects the microstructure of the implanted samples. Maximum efficiency of the H ion implantation is obtained when the vacancy distribution is narrow. After implantation, the vacancies are available to favor the formation of vacancy-rich complexes that are able to trap most implanted H atoms then form H2-filled nano-bubbles. Following annealing, the bubbles are sufficiently close enough to each other to allow an efficient overlap of the stress fields they generate. At higher fluence, the damage concentration becomes very large. Its distribution widens, and either a part of H (which remains) in the bubbles and platelets located outside the layer which contains cracks, is not involved in the formation of cracks or the formation of amorphous layer. After annealing, the amorphous/crystal interface becomes a receiver for the vacancies, resulting in fewer “free” vacancies, and therefore subsequently less H2 for the build up of internal pressure of bubbles and the sustained growth of nano-cracks. The optimization of the smart-cut process usage is when the implantation induces 3.4% of strain maximum out-off-plane.
  • A Z-scheme mechanism of N-ZnO/g-C3N4 for enhanced H2 evolution and
           photocatalytic degradation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yujie Liu, Haixia Liu, Huamin Zhou, Tianduo Li, Lunan Zhang The N-ZnO/g-C3N4 composites prepared by high temperature calcination exhibited excellent performance in both the photocatalytic H2 evolution and photocatalytic degradation of Methylene blue (MB). It can be seen that the absorption range of ZnO extends from ultraviolet light to UV–visible light after N dopant. The combination with g-C3N4 further enhances the absorption range of N-ZnO, thereby increasing the utilization of light. A Z-scheme photocatalytic system mechanism of N-ZnO/g-C3N4 has been proposed for the enhanced H2 evolution and photocatalytic degradation rate. The proper bands position of N-ZnO facilitates the formation of Z-scheme mechanism. The electrons on CB of N-ZnO would migrate to VB of g-C3N4, which can effectively prevent the recombination of electrons and holes. The generation of electrons in CB of g-C3N4 and accumulation of holes in VB of N-ZnO can improve the photocatalytic efficiency.
  • Robust Mg(OH)2/epoxy resin superhydrophobic coating applied to
           composite insulators
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Wenyu Peng, Xuelian Gou, Hongling Qin, Meiyun Zhao, Xinze Zhao, Zhiguang Guo Composite insulators with superhydrophobic coatings can ensure the safe operation of railways, electricity and telecommunication systems. A robust Mg(OH)2/epoxy resin superhydrophobic coating for composite insulators is reported. The coating is fabricated by a simple method, and the water contact angle reaches its maximum value of 155° at the stearic acid loading of 0.285 g. The superhydrophobic property is controlled by different amounts of stearic acid, which influence the surface roughness of the coating. Additionally, the coating shows mechanical stability, chemical durability and a self-cleaning property, allowing it to be stored in water for more than 20 days. In consideration of the above-mentioned advantages, these characteristics make the composite insulators with this coating a better value than the commercial composite insulators, which is of great benefit to global electricity issues.Graphical abstractRobust Mg(OH)2/epoxy resin superhydrophobic coating applied to composite insulators is successfully employed.Graphical abstract for this article
  • ×  1+system&rft.title=Applied+Surface+Science&rft.issn=0169-4332&">Suppressed and enhanced spin polarization in the
           1ML-Pb/Ge(1 1 1)-1  ×  1 system
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Maciej J. Szary, Barbara Pieczyrak, Leszek Jurczyszyn, Marian W. Radny It is shown, based on the density functional theory (DFT), that the spin splitting of surface electronic states induced by a Pb monolayer on the Ge(1 1 1)-1 × 1 surface depends on the bonding structure of the Pb/Ge interface and may be either significant, ∼0.8 eV, (H3/T4) or completely suppressed (T1). It is also shown that for the former the bonding configuration facilitates an emergence of unquenched orbital angular momentum L along Γ-K-M direction, which then lifts the spin degeneracy of the electronic states through the spin-orbit coupling (SOC) of electrons in Pb. Along with the DFT data, we present a complementary analysis conducted withing the orbital Rashba framework, which provides an additional insight into the SOC-induced splitting.Graphical abstractGraphical abstract for this article
  • Quantum confinement luminescence of trigonal cesium lead bromide quantum
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yumeng Zhang, Yuanyuan Li, Yuzhen Liu, Hongxia Li, Jiyang Fan Cesium lead halides are novel and superior optoelectronic materials. Unlike the cases of the widely investigated cubic CsPbXr3 (X = Cl, Br, or I) nanocrystals, people know little about the optical properties of the “zero-dimensional perovskite” Cs4PbX6 nanocrystals. We study the photoluminescence properties of the Cs4PbBr6 quantum dots (QDs) with sizes of only a few nanometers. They exhibit stable wavelength-tunable (from 340 to 378 nm) luminescence stemming from quasi-self-trapped excitons. The spectral characterizations in conjunction with first-principles calculations reveal there is remarkable quantum confinement effect in the Cs4PbBr6 QDs. The large exciton binding energy obtained from both calculation and experiment explains why the trigonal Cs4PbX6 QDs have strong exciton-related absorption and emission at room temperature. This family of wide-gap trigonal cesium lead halide QDs with intrinsic near-UV luminescence have potential applications in short-wavelength photonic nanodevices.Graphical abstractGraphical abstract for this article
  • Polyoxometalate-coupled graphene nanohybrid via gemini surfactants and its
           electrocatalytic property for nitrite
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Shu Chen, Yuanfang Xiang, M. Katherine Banks, Weijian Xu, Chang Peng, Ruoxi Wu A novel graphene oxide (GO)-polyoxometalate (POM) nanohybrid is prepared using gemini surfactants (Gem) as stabilizers for the first time. The electrostatic interactions, chemical structure, and morphology of this Gem-GO-POM nanohybrid are systematically characterized, which have been manifested that the Gem-GO-POM nanohybrid provides uniform distribution of POM nanoparticles on the GO nanosheets and exhibits excellent electrochemical activity and stability due to the use of Gem as linkers and stabilizers. The prepared Gem-GO-POM catalyst used as electrode displays an enhanced electro-oxidation of nitrite compared with pure GO and DTAB-GO-POM hybrid using dodecyl trimethyl ammonium bromide (DTAB) as stabilizers. The proposed nanohybrid structure capitalizes on the enhancing in the oxidation reactions ability of the POM through the Gem linkers to provide more binding sites for POM on the surface of GO.Graphical abstractGraphical abstract for this article
  • Interface engineering of Co3O4 loaded CaFe2O4/Fe2O3 heterojunction for
           photoelectrochemical water oxidation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Jiajia Cai, Song Li, Gaowu Qin Considerable efforts have been made to develop hematite as a promising material for photoelectrochemical (PEC) water splitting. However, the fast recombination of carriers in the bulk and on the surface greatly constrains the solar-to-chemical fuel conversion efficiency. Herein, a precise method was utilized to alleviate the recombination by constructing p-n junction of CaFe2O4/α-Fe2O3 and further modifying with Co3O4. The structural information and chemical composition of the ternary compound were systematically characterized. The photocurrent density at 1.23 V vs RHE (reversible hydrogen electrode) of the photoanode increased by five times compared to the bare α-Fe2O3, and the onset potential also shifted negatively to 0.6 V vs RHE. The formation of p-n junction and surface Co3O4 modification were proven to enhance the charge separation in the bulk and on the surface, respectively. Also the Co3O4 played a bifunctional role of passivating the surface states and accelerating the water oxidation kinetics.Graphical abstractGraphical abstract for this article
  • Texturing commercial epoxy with hierarchical and porous structure for
           robust superhydrophobic coatings
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Shanshan Jia, Songlin Deng, Sha Luo, Yan Qing, Ning Yan, Yiqiang Wu The practical application of superhydrophobic coatings is restricted majorly by stability issues, especially in such cruel conditions as acid rain, pollutant contamination, and mechanical abrasion. In this work, we demonstrated a new type of superhydrophobic coatings with remarkable robustness and versatility using commercial epoxy as main building block. The hierarchical and porous structure was achieved by texturing micrometer-sized pores on the adhesive coatings, in which the SiO2 nanoparticles were embedded. Due to strong substrate adhesion, excellent internal bonding, and micropore cushioning, the as-prepared superhydrophobic adhesive coatings can avoid the consumption of hierarchical structure after each abrasion and tightly anchor itself on substrate as well as soften the pressure during the mechanical force acting on them. The synergistic effect of these three protection mechanisms contributes to preferable mechanical robustness under severe sandpaper abrasions, cyclic tape peels, and knife scratches. This functional coating also can remain superhydrophobic after long-term exposure to a large variety of media, including corrosive solutions, daily consumed liquids, and water at different temperatures. Simultaneously, the epoxy resin has good compatibility with both hard and soft substrates, and thus providing such superhydrophobic adhesive coatings with high versatility for the applications in advanced functional materials. The concept of transforming commercial adhesive into superhydrophobic surface provides a simple and versatile approach to highly robust superhydrophobic materials.Graphical abstractA new type of superhydrophobic adhesive that can be glued to various substrates and shows excellent robustness.Graphical abstract for this article
  • Spin-polarized quantum transport in Fe4N based
           current-perpendicular-to-plane spin valve
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Yu Feng, Zhou Cui, Ming-sheng Wei, Bo Wu Fe4N has been confirmed to possess high spin polarization of 81.3% and low Gilbert damping constant of 0.021 ± 0.02 in the recent experiment. To explore the potential applications of Fe4N in spintronics devices, the current-perpendicular-to-plane spin valve employing Fe4N as electrode and Ag as spacer is simulated to study the spin polarized quantum transport by utilizing the first principles calculations combined with nonequilibrium Green’s function. The project density of states (PDOS), transmission coefficient, spin-polarized current, magnetoresistance (MR) ratio and spin injection efficiency (SIE) as a function of bias voltage are studied. Our calculations reveal that spin down electron is the majority spin polarized electron and the absolute value of MR ratio of Fe4N/Ag/Fe4N at equilibrium reaches up to 174%, and it decreases with the bias increases. Besides, our results indicate that Fe4N/Ag/Fe4N device has stable SIE value of about 40% and stable MR ratios of about 150% when bias increases from 0 V to 0.1 V, and the device has a better performance within this voltage range.
  • Enhanced photocatalytic activity of ternary Ag3PO4/GO/g-C3N4
           photocatalysts for Rhodamine B degradation under visible light radiation
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Jia Yan, Zhilong Song, Xin Wang, Yuanguo Xu, Wenjie Pu, Hui Xu, Shouqi Yuan, Huaming Li Single-component graphitic carbon nitride (g-C3N4) are faced with inadequate visible light absorption and low quantum efficiency arising from the rapid charge recombination, limiting their efficient photocatalytic degradation of organic pollutant under visible light radiation. Here, we demonstrated a ternary photocatalyst composed of Ag3PO4, graphene oxide (GO), and g-C3N4 synthesized by chemical precipitation method, in which Ag3PO4 as the photosensitizer and GO as the cocatalyst that significantly promoted the photocatalytic activity of g-C3N4 for Rhodamine B (RhB) degradation under visible light radiation. The ternary photocatalysts (Ag3PO4/GO/g-C3N4) exhibited enhanced absorption in the visible region and superior photocatalytic activity compared with single-component or binary composite photocatalysts for RhB degradation. The degradation rate toward RhB could reach to 94.8% under visible light irradiation for 50 min, and we found that it was the hole (h+), superoxide radical (O2−) and hydroxyl radical (OH) that played a major role in RhB degradation. Meanwhile, the ternary photocatalyst showed enhanced photocatalytic stability attributing the synergistic effect among them, and the possible mechanism for the enhanced photocatalytic activity and stability was carefully discussed. The present work provides a facile development of a g-C3N4-based ternary photocatalyst system for highly improved photocatalytic activity by coupling a small amount of Ag-based photosensitizer and metal-free GO cocatalyst.Graphical abstractGraphical abstract for this article
  • Nanostructure and photocatalytic properties of TiO2 films deposited at low
           temperature by pulsed PECVD
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): D. Li, S. Bulou, N. Gautier, S. Elisabeth, A. Goullet, M. Richard-Plouet, P. Choquet, A. Granier The nanostructure and photocatalytic properties of TiO2 thin films deposited by PECVD on silicon substrates were investigated. The films were grown at low temperature (
  • A spectroscopy and microscopy study of silicon nanoclusters grown on
           β-Si3N4(0 0 0 1)/Si(1 1 1) interface
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): P. Allegrini, P.M. Sheverdyaeva, D.M. Trucchi, F. Ronci, S. Colonna, P. Moras, R. Flammini Silicon has been grown on the (8 × 8)–reconstructed β-Si3N4(0 0 0 1) surface at 350 °C temperature. The pure Volmer-Weber growth mode has induced the formation of nano-sized silicon clusters randomly distributed on the surface. Synchrotron radiation photoelectron spectroscopy and scanning tunneling microscopy have been employed to study the system. A fit to the photoemission spectra, complemented by topographic information, has allowed us to assign each Si2p and N1s component to the different non equivalent sites of silicon and nitrogen atoms.
  • Structural characterization of as-grown and quasi-free standing graphene
           layers on SiC
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): R.A. Bueno, I. Palacio, C. Munuera, L. Aballe, M. Foerster, W. Strupinski, M. García-Hernández, J.A. Martín-Gago, M.F. López We report on a comparative structural characterization of two types of high quality epitaxial graphene layers grown by CVD on 4H-SiC(0001). The layers under study are a single layer graphene on top of a buffer layer and a quasi-free-standing graphene obtained by intercalation of hydrogen underneath the buffer layer. We determine the morphology and structure of both layers by different complementary in-situ and ex-situ surface techniques. We found the existence of large islands in both samples but with different size distribution. Photoemission electron microscopy (PEEM) measurements were performed to get information about the chemical environment of the different regions. The study reveals that monolayer graphene prevails in most of the surface terraces, while a bilayer and trilayer graphene presence is observed at the steps, stripes along steps and islands.Graphical abstractGraphical abstract for this article
  • Silicone/ZnO nanorod composite coating as a marine antifouling surface
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Mohamed S. Selim, Hui Yang, Feng Q. Wang, Nesreen A. Fatthallah, Yong Huang, Shigenori Kuga The effects of ZnO nanorod (NR) filler distribution and the nano-structured surface on the superhydrophobicity and fouling-release (FR) of silicone nanocoatings were investigated. Incorporation of 0.5 wt% ZnO NR fillers resulted in increasing the non-wettability characteristics and surface roughness and reducing the surface free energy were observed. Thus, an outstanding superhydrophobic nanocomposite coating model was fabricated with stable surface properties, surface innerness toward fouling adhesion, economic savings and prolonging longevity for marine applications. A polydimethylsiloxane/ZnO NR composite was prepared via in-situ technique. ZnO NRs were 30–40 nm wide and 0.5–1 µm long single-crystals with wurtzite structure grown in (0001) direction. Studying the influences of incorporation of different nanofiller concentrations on the surface and FR features was inevitable to achieve surface roughness with minimized free energy. Surface features were considered via water contact angles (WCAs), free energy calculations and atomic force microscopy. Mechanical characteristics were evaluated as a durability factor. Chosen micro-organisms were employed to investigate the nanocomposites' FR and biological characteristics. A tough field trial was performed on the nanocomposites which were immersed (for 6 months) in marine water of a tropical region. The most favorable FR properties with maximum WCA (158°) and minimum free energy (11.25 mN/m) were shown for 0.5 wt% NRs as an excellent distributed surface.Graphical abstractGraphical abstract for this article
  • Fabrication of a molecularly imprinted silylated graphene oxide polymer
           for sensing and quantification of creatinine in blood and urine samples
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): T.S. Anirudhan, J.R. Deepa, Nisha Stanly A graphene oxide (GO)-based electrochemical sensor, trimethyl silane propyl methacrylate-GO copolymerized with 2-hydroxymethacrylate/methyl methacrylate [TMSPMA-GO-co-HEMA/MMA], to detect creatinine (Cn) was fabricated by molecular imprinting technology followed by electrochemical detection. Electrochemical measurements were made by cyclic voltammetry and differential pulse voltammetry. Polymerization of GO-TMSPMA was achieved in the presence of Cn with ethylene glycol dimethacrylate as crosslinker and 2,2′-azobisisobutyronitrile as initiator. The physical and chemical properties of the resulted material were characterized by FTIR spectroscopy, NMR spectroscopy, Raman spectroscopy, XRD, SEM, and AFM. The effective pH for the response of the sensor material was found to be 7.4. The electrode exhibited a response time of ∼2 min, and the limit of detection obtained was 0.1878 mg/dL and the limit of quantification was 0.6122 mg/dL. The fabricated molecular imprinted polymer sensor could be reused several times without decrease in its selectivity. The feasibility of the present sensor in real time was successfully verified by analyzing Cn level in human blood serum and urine samples. By comparing the present sensing method with the traditional Jaffe method, we obtained a linear correlation with a coefficient of 0.9928; this implies that the present biosensor possesses a sensitivity comparable to that of the traditional laboratory method.Graphical abstractGraphical abstract for this article
  • Driving electromagnetic field enhancements in tailored gold surface
           nanostructures: Optical properties and macroscale simulations
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): N.R. Agarwal, P.M. Ossi, S. Trusso Gold thin films with remarkable Surface Enhanced Raman scattering activity strongly dependent on their surface nanostructure were grown by nanosecond pulsed laser ablation. By changing the number of the laser pulses, keeping fixed all the other deposition parameters, we deliberately modified the surface nanostructure of the films. These nanostructured films consist of metallic islands separated from each other by inter-island channels. We observed differences in both island sizes and inter-island channel sizes as a function of the laser pulse number. The different optical properties of the films such as the position of the localized surface plasmon resonance absorption peak red shifts with increasing the laser pulse number. We performed Finite-Difference Time-Domain calculations to gain insight on how the surface nanostructure of the film affects its optical properties at the macroscale. Results indicate that the strongest localization of the electromagnetic field, and hence the strongest SERS enhancement, occurs at the channel-shaped gaps between adjacent metal islands.Larger enhancements are found in coincidence with narrower and deeper gaps. The number distribution of SERS active sites as a function of the calculated SERS enhancement factors, whose values range between 104 and 105, were obtained. Since the inter-island channels are randomly oriented they show no orientation dependence for linearly polarized radiation on a length scale larger than the typical size of the nanostructures, while larger enhancements were observed for circular polarization.
  • Optical TiO2 layers deposited on polymer substrates by the Gas Injection
           Magnetron Sputtering technique
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): R. Chodun, L. Skowronski, S. Okrasa, B. Wicher, K. Nowakowska-Langier, K. Zdunek This work presents decorative TiO2, TiO2/Al layers deposited on poly(methyl methacrylate) (PMMA) substrates. We chose the Gas Injection Magnetron Sputtering (GIMS) technique for layer deposition. Choosing this technique, we expected a lower thermal load of polymer substrate than in other commonly used magnetron techniques. The pulse plasma, generated in the GIMS method, is controlled by a periodical injection of gas dosages in the region of the magnetron target. The process of deposition operated with a 1 Hz frequency of a plasma generation and the life time of plasma was ∼500 ms. Under these conditions, the energetic impact into the substrate, integrated over the time, is lower than during the continuous process, so it should not cause any damage to the polymer surface. For our experiment we deposited a thick ∼700 nm aluminum layer and thin 17–116 nm TiO2 films, which exhibited the interference effect, on non – heated PMMA substrates. The optical properties of the prepared systems were investigated by spectroscopic ellipsometry and spectrophotometric measurements.
  • 3D-multilayer MoS2 nanosheets vertically grown on highly mesoporous cubic
           In2O3 for high-performance gas sensing at room temperature
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Muhammad Ikram, Yang Liu, He Lv, Lujia Liu, Afrasiab Ur Rehman, Kan Kan, WeiJun Zhang, Lang He, Yang Wang, Ruihong Wang, Keying Shi The coupling of MoS2 with In2O3 is a well-known challenge due to the lower stability of MoS2 in the presence of oxygen at high temperature. In the present work, stable mesoporous MoS2@In2O3 composites were designed by a sonochemical reaction and a low temperature hydrothermal method, in which MoS2 nanosheets (NSs) were vertically planted on highly mesoporous In2O3 nanocubes. The mesoporous MoS2@In2O3-II nanocomposite with a MoS2 and In2O3 mass ratio of 1:1 exhibited a high response of 10.3–100 ppm NOx, and ultrafast response time of 1–9 s from 100 to 0.1 ppm. The enhance gas response of MoS2@In2O3-II reveals the synergistic effect of the interfacial transfer of electrons from In2O3 nanocubes to MoS2 NSs, and the highly exposed active edges of vertically aligned MoS2 NSs. The MoS2@In2O3-II sensor is a promising candidate as a gas sensing material due to its excellent structure and outstanding properties at room temperature (RT).Graphical abstractGraphical abstract for this article
  • New insight into alkali resistance and low temperature activation on
           vanadia-titania catalysts for selective catalytic reduction of NO
    • Abstract: Publication date: 1 February 2019Source: Applied Surface Science, Volume 466Author(s): Shuo Zhang, Shaojun Liu, Wenshuo Hu, Xinbo Zhu, Ruiyang Qu, Weihong Wu, Chenghang Zheng, Xiang Gao A series of vanadia-titania catalysts with different vanadia loadings for the selective catalytic reduction (SCR) of NO by ammonia was prepared via incipient impregnation method. The alkali resistance and SCR activity at low temperature has been investigated on the prepared catalysts. Increasing the vanadia loading from 1% to 10%, the NO removal efficiency of the catalysts gained a 70% growth at 200 °C. With the increase of the vanadia loading, the high loading vanadia-titania catalysts exhibited higher ratio of V5+/(V4++V5+), which enhanced the oxidation of NH3 at high temperatures and also improved the standard SCR performance at low temperature. After doping with potassium, V4/Ti catalyst (V2O5 = 4 wt%) displayed the best performance over which 80% initial activity was retained from 300 °C to 400 °C. More acid sites and active vanadium species were retained in the high loading vanadia-titania catalysts, which made them exhibit better low temperature alkali resistance. However, when vanadia content was higher than 4%, the competition of NH3 oxidation severely deactivated the catalytic activity above 250 °C. Additionally, in the presence of SO2 and H2O the SCR performance of the high loading vanadia-titania catalysts were also studied in order to investigate the influence of the actual working conditions.Graphical abstractGraphical abstract for this article
  • Enhanced visible photocatalytic oxidation of NO by repeated calcination of
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): Xiaofeng Wu, Jinshui Cheng, Xiaofang Li, Yuhan Li, Kangle Lv Much attention has been paid to g-C3N4 (gCN), a visible-light-responsive metal-free polymeric photocatalyst. However, bulk gCN suffers from the small BET surface area and quick recombination of carriers. The photocatalytic activity of bulk gCN still needs to be improved. Herein, we systematically studied the effect of post calcination times (PCT) on the visible photoreactivity of bulk gCN towards NO oxidation and hydrogen production. It was found that aggregated gCN nanosheets (gCN-NSs) were formed after repeated calcination of bulk gCN. The BET surface areas of gCN-NSs increased 6.6 times (from 9.1 to 60.5 m2 g−1) after repeated calcination of bulk gCN for 7 times. The exfoliation of bulk gCN by post calcination results in a reduced PL intensity, increased photocurrent, diminished arc radius of EIS Nynquist plot. DFT calculation confirms the enlarged bandgap of gCN after post calcination. After repeated calcination for 7 times, the visible photoreactivity of gCN-NSs towards NO oxidation increased from 20.6% to 35.8% in a continuous reactor, and the hydrogen production rate improved from 31.3 to 764.8 umol g−1 h−1 in a batch reactor, enhanced by a factor of 24.4. The post calcination induced enhancement on the visible photocatalytic activity of gCN-NSs can be attributed to the combined effects of (1) enlarged BET surface area, (2) improved crystallinity, (3) negatively shifted CB position, and (4) exposure of (0 0 2) and (1 0 0) facets for g-CN-NSs which retarded the recombination of electron and hole pairs.Graphical abstractGraphical abstract for this article
  • Ag2O nanoparticles decorated TiO2 nanofibers as a p-n heterojunction for
           enhanced photocatalytic decomposition of RhB under visible light
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): Guo Liu, Guohong Wang, Zhihui Hu, Yaorong Su, Li Zhao TiO2 nanofibers were successfully prepared by electrospinning method using tetrabutyl titanate, glacial acetic acid, PVP and methanol as the precursors. Ag2O/TiO2 composite nanofibers were then prepared by decorating the surface of TiO2 nanofibers with Ag2O nanoparticles (NPs) through a wet-chemical precipitation reaction under a certain amount of AgNO3 and NaOH. The photocatalytic properties of the as-prepared samples were tested by photocatalytic decomposition of RhB aqueous solution under visible light irradiation. Comparing with bare TiO2 nanofibers and pure Ag2O, the Ag2O/TiO2 composite with optimal mass ratio of Ag2O to TiO2 (40 wt%) exhibited the highest photocatalytic activity in decomposition of RhB. The enhanced photocatalytic activity of the composite was attributed to the fast separation of the photo-generated electron-hole pairs in the Ag2O/TiO2 interface in which a p-n heterojunction is formed and the high visible light absorption efficiency of Ag2O/TiO2 nanofibers.Graphical abstractGraphical abstract for this article
  • Room-temperature in situ fabrication and enhanced photocatalytic activity
           of direct Z-scheme BiOI/g-C3N4 photocatalyst
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): Rongan He, Kaiyu Cheng, Zheying Wei, Shiying Zhang, Difa Xu The direct Z-scheme configuration is particularly beneficial for improving the activity of a photocatalyst by fully exploring the superior oxidation or reduction capability of both coupled components of a heterojunction. Herein, a composite of BiOI quantum dots (QDs) and g-C3N4 was fabricated through a precursor in situ transformation method at ambient temperature using a Bi2O3/g-C3N4 composite as the precursor. By reducing the size of the BiOI to the quantum scale, full and intimate contact between the BiOI and g-C3N4 was achieved. In the photocatalytic activity test under visible light, the as-prepared BiOI/g-C3N4 composite outperformed the individual BiOI and g-C3N4. The Z-scheme electron migration played a key role in the performance enhancement of the composite, because carriers with stronger redox capacity were maintained, while the holes and electrons with weaker redox capacity recombined. This research may also help to elucidate the design of photocatalysts.Graphical abstractGraphical abstract for this article
  • Graphene oxide wrapped CH3NH3PbBr3 perovskite quantum dots hybrid for
           photoelectrochemical CO2 reduction in organic solvents
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): Qinglong Wang, Leiming Tao, Xingxing Jiang, Mingkui Wang, Yan Shen Lead halide perovskite have primarily considered as photovoltaic materials for luminescent materials and optoelectronic devices. However, lead halide perovskite is assumed to be unsuitable for photoelectrochemical conversion due to the instability in humid environment or polar solvents. Here, we report graphene oxide (GO) wrapped organic-inorganic lead halide perovskite quantum dots (GO/CH3NH3PbBr3 hybrid) for photoelectrochemical conversion CO2 into solar fuels in nonaqueous media. Graphene oxide can protect CH3NH3PbBr3 QDs from erosion by organic solvent, and also serve as electron transport medium to separate photoinduced electrons and holes. Therefore, a photocurrent increase by ca. 200% can be obtained in the GO/CH3NH3PbBr3 hybrid due to improved electron extraction and transport. The GO/CH3NH3PbBr3 electrode exhibits an effective CO2 reduction capacity to CO, yielding 1.05 μmol cm−2 h−1.Graphical abstractGraphical abstract for this article
  • Enhanced photocatalytic hydrogen production over conjugated polymer/black
           TiO2 hybrid: The impact of constructing active defect states
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): Xiaohu Zhang, Jie Xiao, Cong Peng, Yonggang Xiang, Hao Chen Utilization of noble metal (e.g. Pt, Au) as co-catalyst seems always indispensable for a photocatalytic H2 production catalyst because most semiconductors lack sufficient active sites. Herein, some non-noble metal active states, Ti3+/Ov (oxygen vacancies) and surface amorphization structure, are introduced into anatase TiO2 nanoparticles by ball milling them with TiH2 to prepare black TiO2. And then, an organic/inorganic hybrid (BE-black TiO2) containing a conjugated polymer (BE, a modified poly- benzothiadiazole flake) and black TiO2 is fabricated and investigated for photocatalytic H2 production without noble metal co-catalyst. Compare to BE-TiO2 catalyst, the BE-black TiO2 exhibit a ∼ 30% enhancement for H2 production activity under visible light (λ > 420 nm) irradiation. Combining the structural characterizations, comparison of H2 production rate and electron transfer behavior analysis, it is found that these active states play key role in the enhancement of photoactivity through narrowing the band-gap of TiO2, accelerating photoelectrons transfer from BE to TiO2, acting as electron traps and reaction sites for H2 production.Graphical abstractGraphical abstract for this article
  • Jetting dynamics of Newtonian and non-Newtonian fluids via laser-induced
           forward transfer: Experimental and simulation studies
    • Abstract: Publication date: 28 January 2019Source: Applied Surface Science, Volume 465Author(s): A. Kalaitzis, M. Makrygianni, I. Theodorakos, A. Hatziapostolou, S. Melamed, A. Kabla, F. de la Vega, I. Zergioti Current technological trends in the field of microelectronics have highlighted the requirement to use cost-effective techniques for the precise deposition of highly resolved features. Laser-induced forward transfer (LIFT) meets these requirements and has already been applied for the direct printing of devices and components. However, in order to improve the process’ reproducibility and printing resolution, further research has to be conducted, regarding the rheological characteristics of the printable fluids and their jetting dynamics. In this work, we employ both pump-probe and high-speed imaging in order to investigate the formation and expansion of the liquid bubble, as well as the liquid jet's propagation. Newtonian as well as non-Newtonian fluids are studied and compared, over a wide range of viscosities. Furthermore, a computational model is utilized in order to gain more insight on the transfer mechanisms of the process. The simulation predictions are validated against experimental results, and found to be in good agreement, even in the case of non-Newtonian fluids. The results indicate that such accurate modelling can be developed as a new cost- and time-effective tool for the technique’s optimization.
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