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  Subjects -> CHEMISTRY (Total: 852 journals)
    - ANALYTICAL CHEMISTRY (52 journals)
    - CHEMISTRY (598 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (41 journals)
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    - PHYSICAL CHEMISTRY (69 journals)

CHEMISTRY (598 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 10)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 38)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 18)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 24)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 252)
ACS Photonics     Full-text available via subscription   (Followers: 12)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 23)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chimica Slovenica     Open Access  
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 51)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 57)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 15)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 21)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
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: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
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: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 66)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 15)
American Journal of Chemistry     Open Access   (Followers: 27)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Analyst     Full-text available via subscription   (Followers: 39)
Angewandte Chemie     Hybrid Journal   (Followers: 179)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 229)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
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: 8)
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: 16)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
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   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 326)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
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: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 120)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 85)
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: 2)
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: 3)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 5)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 68)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 7)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 8)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 15)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 70)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 25)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 21)
Chemical Reviews     Full-text available via subscription   (Followers: 184)
Chemical Science     Open Access   (Followers: 22)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 146)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 20)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 42)
Chemistry of Materials     Full-text available via subscription   (Followers: 246)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 10)
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: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
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: 19)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
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: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
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: 5)
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 Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 18)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 64)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
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  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 3)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  

        1 2 3 | Last

Journal Cover Applied Surface Science
  [SJR: 0.93]   [H-I: 125]   [28 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0169-4332
   Published by Elsevier Homepage  [3118 journals]
  • Effect of сopper сoating on fibers made of aluminum alloy, titanium, and
           FeCrAl alloy on surface morphology and activity in CO oxidation
    • Authors: I.V. Lukiyanchuk; V.S. Rudnev; M.M. Serov; B.L. Krit; G.D. Lukiyanchuk; P.M. Nedozorov
      Pages: 1 - 10
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): I.V. Lukiyanchuk, V.S. Rudnev, M.M. Serov, B.L. Krit, G.D. Lukiyanchuk, P.M. Nedozorov
      The catalytic activity of both copper fibers and copper-coated fibers of a diameter of 50–100 μm made of aluminum alloy, technical grade titanium, and FeCrAl alloy in CO oxidation has been estimated. Metal fibers have been fabricated by the method of pendant drop melt extraction (PDME). The fibers copper plating was carried out by chemical and electrochemical methods. The composition and structure of samples and coatings before and after catalytic tests have been characterized by the methods of scanning electron microscopy, energy-dispersive analysis, and X-ray fluorescence analysis. It has been shown that the catalytic activity of copper-coated fibers made of FeCrAl alloy in the reaction of CO oxidation is not inferior to that of copper fibers.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.287
      Issue No: Vol. 436 (2017)
       
  • Fabrication of biomimetic resorption lacunae-like structure on titanium
           surface and its osteoblast responses
    • Authors: Fangjun Huo; Weihua Guo; Hao Wu; Yueting Wang; Gang He; Li Xie; Weidong Tian
      Pages: 11 - 21
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Fangjun Huo, Weihua Guo, Hao Wu, Yueting Wang, Gang He, Li Xie, Weidong Tian
      Biomimetic specific surface structure could improve biological behaviors of specific cells and eventual tissue integration. Featuring titanium surface with structures resembling bone resorption lacunae (RL) can be a promising approach to improve the osteoblast responses and osseointegration of implants. As a most common used dental implant surface, sandblasting and acid etching (SLA) surface has micro-sized structures with dimensions similar to RL, but great differences exist when it comes to shape and contour. In this work, by anodizing titanium substrate in a novel HCOONa/CH3COONa electrolyte, RL-like crater structures were fabricated with highly similar size, shape and contour. Compared with SLA, it was much more similar to RL structure in shape and contour. Furthermore, through subsequent alkali-heat treatment, nano-sized structures that overlaid the whole surface were obtained, which further mimic undercuts features inside the RL. The as-prepared surface was consisted of crystalline titania and exhibited super-hydrophilicity with good stability. In vitro evaluation results showed that the surface could significantly improve adhesion, proliferation and differentiation of MG63 cells in comparison with SLA. This new method may be a promising candidate for biomimetic modification of titanium implant to promote osseointegration.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.282
      Issue No: Vol. 436 (2017)
       
  • Tunable anomalous hall effect induced by interfacial catalyst in
           perpendicular multilayers
    • Authors: J.Y. Zhang; W.L. Peng; Q.Y. Sun; Y.W. Liu; B.W. Dong; X.Q. Zheng; G.H. Yu; C. Wang; Y.C. Zhao; S.G. Wang
      Pages: 22 - 26
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): J.Y. Zhang, W.L. Peng, Q.Y. Sun, Y.W. Liu, B.W. Dong, X.Q. Zheng, G.H. Yu, C. Wang, Y.C. Zhao, S.G. Wang
      The interfacial structures, playing a critical role on the transport properties and the perpendicular magnetic anisotropy in thin films and multilayers, can be modified by inserting an ultrathin functional layer at the various interfaces. The anomalous Hall effect (AHE) in the multilayers with core structure of Ta/CoFeB/X/MgO/Ta (X: Hf or Pt) is tuned by interfacial catalytic engineering. The saturation anomalous Hall resistance (RAH) is increased by 16.5% with 0.1 nm Hf insertion compared with the reference sample without insertion. However, the RAH value is decreased by 9.0% with 0.1 nm Pt insertion. The interfacial states were characterized by the X-ray photoelectron spectroscopy (XPS). The XPS results indicate that a strong bonding between Hf and O for Hf insertion, but no bonding between Pt and O for Pt insertion. The bonding between metal and oxygen leads to various oxygen migration behavior at the interfaces. Therefore, the opposite behavior about the RAH originates from the different oxygen behavior due to various interfacial insertion. This work provides a new approach to manipulate spin transport property for the potential applications.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.114
      Issue No: Vol. 436 (2017)
       
  • Investigation of the adsorption of ozone molecules on TiO2/WSe2
           nanocomposites by DFT computations: Applications to gas sensor devices
    • Authors: Amirali Abbasi; Jaber Jahanbin Sardroodi
      Pages: 27 - 41
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Amirali Abbasi, Jaber Jahanbin Sardroodi
      The adsorption of O3 molecule on the undoped and N-doped TiO2/WSe2 nanocomposites was studied using first principles density functional theory calculations. O3 interaction with TiO2/WSe2 nanocomposites is considered so as to investigate WSe2 effects on the adsorption process. WSe2 favors the adsorption of O3 on TiO2 particles. In other words, WSe2 is conducive to the interaction of O3 molecule with fivefold coordinated titanium sites of TiO2. The effects of vdW interactions were taken into account in order to obtain equilibrium geometries of O3 molecules at TiO2/WSe2 interfaces. For all adsorption configurations, the binding site was positioned on the fivefold coordinated titanium atoms. The results show that the interactions between O3 and TiO2 in TiO2/WSe2 nanocomposites are stronger than those between O3 and bare TiO2, suggesting that WSe2 helps to strengthen the interaction of ozone molecule with TiO2 particles. The results also indicate that the adsorption of the O3 molecule on the N-doped TiO2/WSe2 nanocomposite is more energetically favorable than the adsorption of O3 on the pristine one, representing that the N-doped nanocomposites are more sensitive than the undoped ones. Our DFT results clearly show that the N-doped TiO2/WSe2 nanocomposite would be a promising O3 gas sensor. The electronic structure of the adsorption system was also investigated, including analysis of the total and projected density of states, and charge density differences of the TiO2/WSe2 with adsorbed O3 molecules. The charge density difference calculations indicate that the charges were accumulated over the adsorbed O3 molecule. Besides, the N-doped nanocomposites have better sensing response than the pristine ones. This work was devoted to provide the theory basis for the design and development of novel and advanced O3 sensors based on modified TiO2/WSe2 nanocomposites.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.010
      Issue No: Vol. 436 (2017)
       
  • Temperature dependence of Ni3S2 nanostructures with high electrochemical
           performance
    • Authors: Y.L. Wang; X.Q. Wei; M.B. Li; P.Y. Hou; X.J. Xu
      Pages: 42 - 49
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Y.L. Wang, X.Q. Wei, M.B. Li, P.Y. Hou, X.J. Xu
      Different Ni3S2 nanostructures have been successfully synthesized at different temperatures by a facile and efficient solvothermal method. The Ni3S2 nanostructures with three-dimensional (3D) nanosheets array and silkworm eggs-like morphologies were obtained by adjusting the reaction temperature. A large number of 3D nanosheets are interconnected to form an open network structure with porous of Ni3S2 at 180 °C, and electrochemical tests showed that the special structure exhibited the outstanding specific capacitance (1357 F g −1 at 1 A g−1) and excellent cycling stability (maintained 91% after 3000 cycles). In comparison, the performance of Ni3S2 silkworm eggs-like structure is not very perfect. This may be due to the fact that the 3D nanosheets with porous structure can improve the electrochemical performance by shortening effectively the diffusion path of electrolyte ions and increasing the active sites during charging and discharging. Among them, the reaction temperature is the main factor to control the formation of the 3D nanosheets array. These results indicated the Ni3S2 nanosheets promising applications as high-performance supercapacitor electrode materials.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.270
      Issue No: Vol. 436 (2017)
       
  • Adsorption properties of AlN on Si(111) surface: A density functional
           study
    • Authors: Yinmei Yuan; Ran Zuo; Keke Mao; Binlong Tang; Zhou Zhang; Jun Liu; Tingting Zhong
      Pages: 50 - 57
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yinmei Yuan, Ran Zuo, Keke Mao, Binlong Tang, Zhou Zhang, Jun Liu, Tingting Zhong
      In the process of preparing GaN on Si substrate by MOCVD, an AlN buffer layer is very important. In this study, we conducted density functional theory calculations on the adsorption of AlN molecule on Si(111)-(2 × 2) surface, with the AlN molecule located horizontally or vertically above Si(111) surface at different adsorption sites. The calculations revealed that the lowest adsorption energy was at the N-top-Al-bridge site in the horizontal configuration, with the narrowest band gap, indicating that it was the most preferential adsorption growth status of AlN. In the vertical configurations, N adatom was more reactive and convenient to form bonds with the topmost Si atoms than Al adatom. When the N-end of the AlN molecule was located downward, the hollow site was the preferred adsorption site; when the Al-end was located downward, the bridge site was the most energetically favorable. Moreover, we investigated some electronic properties such as partial density of states, electron density difference, Mulliken populations, etc., revealing the microscale mechanism for AlN adsorption on Si(111) surface and providing theoretical support for adjusting the processing parameters during AlN or GaN production.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.256
      Issue No: Vol. 436 (2017)
       
  • DFT study of the adsorption of 3-chloro-2-hydroxypropyl trimethylammonium
           chloride on montmorillonite surfaces in solution
    • Authors: Zongyi Yang; Wenli Liu; He Zhang; Xinli Jiang; Fanfei Min
      Pages: 58 - 65
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Zongyi Yang, Wenli Liu, He Zhang, Xinli Jiang, Fanfei Min
      The study of the adsorption mechanism of 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTA), which acts as an effective clay minerals hydration inhibitor, can provide an effective approach for the design of novel high-performance inhibitors with favorable molecular structures. Density functional theory (DFT) calculations were performed to investigate the adsorption mechanism of CHPTA on dry and hydrated montmorillonite (MMT) surfaces. The interactions between CHPTA, H2O, and MMT were systematically analyzed. It was found that CHPTA was mainly adsorbed on MMT by hydrogen bonds and especially electrostatic force and that the presence of Na ions favors the adsorption of CHPTA on the Na-(001) surface. In the presence of water molecules, the adsorption of CHPTA was promoted by H2O, which exhibited a cooperative adsorption effect by enhancing the MMT-CHPTA electrostatic force and by forming more hydrogen bonds and HCl bonds among CHPTA, H2O and MMT.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.011
      Issue No: Vol. 436 (2017)
       
  • Densifying carbon nanotubes on assembly surface by the self-contraction of
           silk fibroin
    • Authors: Chunyang Jiang; Xueqin Yang; Jingna Zhao; Qingsong Li; Ke-Qin Zhang; Xiaohua Zhang; Qingwen Li
      Pages: 66 - 72
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Chunyang Jiang, Xueqin Yang, Jingna Zhao, Qingsong Li, Ke-Qin Zhang, Xiaohua Zhang, Qingwen Li
      High densification of carbon nanotubes (CNTs) is important for high utilization efficiency of their superior properties in macroscopic assemblies. However, the conventional “top-down” compressing strategies have met problems to modify CNT assemblies at and below the micrometer scale. Here we report a molecular way to strap CNTs together via the self-contraction of silk fibroin (SF) during its drying process, resulting in a localized densification below the micrometer scale. Importantly, after the thermal removal of SF molecules, the densified assembly was well maintained. The SF-induced densification increased the average strength from 355MPa to 960MPa for CNT fibers, and from 1.45GPa to 1.82GPa for CNT ribbons, which contain much more CNTs on the surface.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.005
      Issue No: Vol. 436 (2017)
       
  • Simultaneously and separately immobilizing incompatible dual-enzymes on
           polymer substrate via visible light induced graft polymerization
    • Authors: Xing Zhu; Bin He; Changwen Zhao; Yuhong Ma; Wantai Yang
      Pages: 73 - 79
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Xing Zhu, Bin He, Changwen Zhao, Yuhong Ma, Wantai Yang
      Developing facile and mild strategy to construct multi-enzymes immobilization system has attracted considerable attentions in recent years. Here a simple immobilization strategy called visible light induced graft polymerization that can simultaneously and separately encapsulate two kinds of enzymes on one polymer film was proposed. Two incompatible enzymes, trypsin and transglutaminase (TGase) were selected as model dual-enzymes system and simultaneously immobilized on two sides of low-density polyethylene (LDPE) film. After immobilization, it was found that more than 90% of the enzymes can be embedded into dual-enzymes loaded film without leakage. And the activities of both separately immobilized enzymes were higher than the activities of mixed co-immobilized enzymes or the sequential immobilized ones. This dual-enzymes loaded film (DEL film) showed excellent recyclability and can retain >87% activities of both enzymes after 4 cycles of utilization. As an example, this DEL film was used to conjugate a prodrug of cytarabine with a target peptide. The successful preparation of expected product demonstrated that the separately immobilized two enzymes can worked well together to catalyze a two-step reaction.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.284
      Issue No: Vol. 436 (2017)
       
  • Insight into the product film formed on Ni-advanced weathering steel in a
           tropical marine atmosphere
    • Authors: Wei Wu; Xuequn Cheng; Huaxing Hou; Bo Liu; Xiaogang Li
      Pages: 80 - 89
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Wei Wu, Xuequn Cheng, Huaxing Hou, Bo Liu, Xiaogang Li
      The product film formed on Ni-advanced weathering steel in a tropical marine environment was investigated in detail through outdoor exposure by using diverse surface analysis techniques combined with electrochemical impedance spectroscopy and scanning kelvin probe measurements. The results showed that the product film was mainly composed of nanophasic goethite in the inner layer and maghemite, akaganeite, and hematite in the outer layer. Moreover, the resistance to atmospheric corrosion gradually increased from the outermost product film to the innermost film. Ni was significantly enriched in the inner layer in the form of the spinel phase NiFe2O4, which transformed lepidocrocite to fine-grained goethite, withstood the invasion of chloridion, and improved the corrosion potential of the product film in a tropical marine atmosphere.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.018
      Issue No: Vol. 436 (2017)
       
  • One-pot, facile fabrication of a Ag3PO4-based ternary Z-scheme
           photocatalyst with excellent visible-light photoactivity and
           anti-photocorrosion performance
    • Authors: Mingyuan Xie; Tailiang Zhang
      Pages: 90 - 101
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Mingyuan Xie, Tailiang Zhang
      Ag3PO4 can-not be widely used as an efficient photocatalyst in practical applications because of its susceptibility to photocorrosion. In this study, a novel, ternary Z-scheme photocatalytic system containing graphene oxide (GO), Ag3PO4 and SnS2 was fabricated by a one-pot, mild, in-situ precipitation method successfully. Using Rhodamine B (RhB) as the target of elimination, GO/Ag3PO4/SnS2 exhibited outstanding photocatalytic and anti-photocorrosion properties compared with those of Ag3PO4, Ag3PO4/SnS2 and GO/Ag3PO4. RhB was thoroughly degraded over the optimized GO/Ag3PO4/SnS2 nanocomposite after only 15 min under visible-light irradiation; this result is approximately 2.14, 3.33 and 5.83 times faster than that of GO/Ag3PO4, Ag3PO4/SnS2 and Ag3PO4, respectively. After three reuses, the photocatalytic activity of the ternary composite slightly decreased but remained 2.36, 4.08 and 12.70 times higher than those of the reused GO/Ag3PO4, Ag3PO4/SnS2 and Ag3PO4, respectively. In this system, the efficient separation and migration of the photoinduced current carriers in Ag3PO4 was realized through a double Z-scheme electron-transfer mechanism in which the GO nanosheets acted as the photocatalyst and electron mediator, thereby enhancing the photoactivity and stability of Ag3PO4. The present study provides a new perspective for enhancing photocatalytic and anti-photocorrosion performances in perishable photocatalysts for organic sewage and other environmental contamination treatments.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.234
      Issue No: Vol. 436 (2017)
       
  • Reference binding energies of transition metal carbides by core-level
           x-ray photoelectron spectroscopy free from Ar+ etching artefacts
    • Authors: G. Greczynski; D. Primetzhofer; L. Hultman
      Pages: 102 - 110
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): G. Greczynski, D. Primetzhofer, L. Hultman
      We report x-ray photoelectron spectroscopy (XPS) core level binding energies (BE’s) for the widely-applicable groups IVb-VIb transition metal carbides (TMCs) TiC, VC, CrC, ZrC, NbC, MoC, HfC, TaC, and WC. Thin film samples are grown in the same deposition system, by dc magnetron co-sputtering from graphite and respective elemental metal targets in Ar atmosphere. To remove surface contaminations resulting from exposure to air during sample transfer from the growth chamber into the XPS system, layers are either (i) Ar+ ion-etched or (ii) UHV-annealed in situ prior to XPS analyses. High resolution XPS spectra reveal that even gentle etching affects the shape of core level signals, as well as BE values, which are systematically offset by 0.2–0.5 eV towards lower BE. These destructive effects of Ar+ ion etch become more pronounced with increasing the metal atom mass due to an increasing carbon-to-metal sputter yield ratio. Systematic analysis reveals that for each row in the periodic table (3d, 4d, and 5d) C 1s BE increases from left to right indicative of a decreased charge transfer from TM to C atoms, hence bond weakening. Moreover, C 1s BE decreases linearly with increasing carbide/metal melting point ratio. Spectra reported here, acquired from a consistent set of samples in the same instrument, should serve as a reference for true deconvolution of complex XPS cases, including multinary carbides, nitrides, and carbonitrides.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.264
      Issue No: Vol. 436 (2017)
       
  • Low-cost and large-scale flexible SERS-cotton fabric as a wipe substrate
           for surface trace analysis
    • Authors: Yanmin Chen; Fengyan Ge; Shanyi Guang; Zaisheng Cai
      Pages: 111 - 116
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yanmin Chen, Fengyan Ge, Shanyi Guang, Zaisheng Cai
      The large-scale surface enhanced Raman scattering (SERS) cotton fabrics were fabricated based on traditional woven ones using a dyeing-like method of vat dyes, where silver nanoparticles (Ag NPs) were in-situ synthesized by ‘dipping-reducing-drying’ process. By controlling the concentration of AgNO3 solution, the optimal SERS cotton fabric was obtained, which had a homogeneous close packing of Ag NPs. The SERS cotton fabric was employed to detect p-Aminothiophenol (PATP). It was found that the new fabric possessed excellent reproducibility (about 20%), long-term stability (about 57 days) and high SERS sensitivity with a detected concentration as low as 10−12 M. Furthermore, owing to the excellent mechanical flexibility and good absorption ability, the SERS cotton fabric was employed to detect carbaryl on the surface of an apple by simply swabbing, which showed great potential in fast trace analysis. More importantly, this study may realize large-scale production with low cost by a traditional cotton fabric.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.288
      Issue No: Vol. 436 (2017)
       
  • Preparing high-adhesion silver coating on APTMS modified polyethylene with
           excellent anti-bacterial performance
    • Authors: Wenfei Li; Yunxiang Chen; Song Wu; Jian Zhang; Hao Wang; Dawen Zeng; Changsheng Xie
      Pages: 117 - 124
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Wenfei Li, Yunxiang Chen, Song Wu, Jian Zhang, Hao Wang, Dawen Zeng, Changsheng Xie
      Silver coating as a broad-spectrum antimicrobial agent was considered to alleviate the inflammation caused by intrauterine device (IUD) in endometrium. In this work, to avoid the damage of silver coating and ensure its antibacterial properties, 3-aminopropyltrimethoxysilane (APTMS) was introduced to modify the polyethylene (PE) substrate for the purpose of improving the adhesion of the silver coating. From the 90° peel test, it could be found that the adhesive strength of silver coating on the APTMS modified PE substrate was nearly 23 times stronger than the silver coating on substrate without surface modification. The dramatically enhanced adhesive strength could be attributed to the formation of continuous chemical bonds between the silver coatings and substrates after surface modification, which had been confirmed by the XPS. Moreover, the standard antibacterial test revealed that the silver coated samples against Staphylococcus aureus (S. aureus) exhibit excellent antibacterial efficacy. Considering the largely enhanced adhesion and the effective antibacterial property, it is reasonable to believe that the silver coating could be considered as a potential candidate for the antibacterial agent in IUD.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.216
      Issue No: Vol. 436 (2017)
       
  • Facile fabrication of Si-doped TiO2 nanotubes photoanode for enhanced
           photoelectrochemical hydrogen generation
    • Authors: Zhenbiao Dong; Dongyan Ding; Ting Li; Congqin Ning
      Pages: 125 - 133
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Zhenbiao Dong, Dongyan Ding, Ting Li, Congqin Ning
      Photoelectrochemical (PEC) water splitting based doping modified one dimensional (1D) titanium dioxide (TiO2) nanostructures provide an efficient method for hydrogen generation. Here we first successfully fabricated 1D Si-doped TiO2 (Ti-Si-O) nanotube arrays through anodizing Ti-Si alloys with different Si amount, and reported the PEC properties for water splitting. The Ti-Si-O nanotube arrays fabricated on Ti-5wt.% Si alloy and annealed at 600°C possess higher PEC activity, yielding a higher photocurrent density of 0.83mA/cm2 at 0V vs. Ag/AgCl. The maximum photoconversion efficiency was 0.54%, which was 2.7 times the photoconversion efficiency of undoped TiO2.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.030
      Issue No: Vol. 436 (2017)
       
  • Surface modification effects of fluorine-doped tin dioxide by oxygen
           plasma ion implantation
    • Authors: Peng Tang; Cai Liu; Jingquan Zhang; Lili Wu; Wei Li; Lianghuan Feng; Guanggen Zeng; Wenwu Wang
      Pages: 134 - 140
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Peng Tang, Cai Liu, Jingquan Zhang, Lili Wu, Wei Li, Lianghuan Feng, Guanggen Zeng, Wenwu Wang
      SnO2:F (FTO), as a kind of transparent conductive oxide (TCO), exhibits excellent transmittance and conductivity and is widely used as transparency electrodes in solar cells. It’s very important to modifying the surface of FTO for it plays a critical role in CdTe solar cells. In this study, modifying effects of oxygen plasma on FTO was investigated systematically. Oxygen plasma treatment on FTO surface with ion accelerating voltage ranged from 0.4 kV to 1.6 kV has been processed. The O proportion of surface was increased after ion implantation. The Fermi level of surface measurement by XPS valance band spectra was lowered as the ion accelerating voltage increased to 1.2 kV and then raised as accelerating voltage was elevated to 1.6 kV. The work function measured by Kelvin probe force microscopy increased after ion implanting, and it was consistent with the variation of Fermi level. The change of energy band structure of FTO surface mainly originated from the surface composition variation. As FTO conduction was primarily due to oxyanion hole, the carrier was electron and its concentration was reduced while O proportion was elevated at the surface of FTO, as a result, the Fermi level lowered and the work function was enlarged. It was proved that oxygen plasma treatment is an effective method to modulate the energy band structure of the surface as well as other properties of FTO, which provides much more space for interface and surface modification and then photoelectric device performance promotion.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.117
      Issue No: Vol. 436 (2017)
       
  • Robust and underwater superoleophobic coating with excellent corrosion and
           biofouling resistance in harsh environments
    • Authors: Mingji Su; Yong Liu; Yuhong Zhang; Zhiguo Wang; Yulin Li; Peixin He
      Pages: 152 - 161
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Mingji Su, Yong Liu, Yuhong Zhang, Zhiguo Wang, Yulin Li, Peixin He
      Underwater superoleophobic surfaces are based on the surface with micro-/nanoscale roughness and hydration layer. But the self-cleaning surfaces are usually mechanically weak and will lose their underwater superoleophobicity when the surfaces are corroded or damaged. In this paper, to overcome these problems, the robust underwater superoleophobic coating (HN/ER-coating) has been fabricated successfully through MPS (methacryloxy propyl trimethoxyl silane)-SiO2/PNIPAM (N-isopropylacryamide) hybrid nanoparticles and epoxy resin (ER) via a simple solution-casting method. The SiO2/PNIPAM hybrid nanoparticles can enhance multiscale roughness and excellent abrasion-resistant property, and the epoxy resin can be used as an interlayer between hybrid nanoparticles and substrates to promote the robustness and corrosion resistance of the coating. The obtained coatings have excellent underwater superoleophobicity, and exhibit highly stability in harsh environments (including acid-base, strong ionic strength, mechanical abrasion). Moreover, this coating can provide protective effect on the substrate in corrosive solution, and may also resist bacterial attachment and subsequent biofilm formation because of the presence of high density PNIPAM polymers. Herein, the developed underwater superoleophobic coating can be applied as an effective platform for the applications in underwater instruments, underwater oil transport, marine oil platform and ships.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.215
      Issue No: Vol. 436 (2017)
       
  • Fabrication of flower-like direct Z-scheme β-Bi2O3/g-C3N4 photocatalyst
           with enhanced visible light photoactivity for Rhodamine B degradation
    • Authors: Liping Zhang; Guohong Wang; Zhenzhong Xiong; Hua Tang; Chuanjia Jiang
      Pages: 162 - 171
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Liping Zhang, Guohong Wang, Zhenzhong Xiong, Hua Tang, Chuanjia Jiang
      A combined hydrothermal-calcination approach is developed to synthesize hierarchical β-Bi2O3/g-C3N4 direct Z-scheme photocatalyst with enhanced visible light photoactivity for Rhodamine B (RhB) degradation. First, Bi2O2CO3 microflowers were hydrothermally prepared using Bi(NO3)3·5H2O as feedstocks, and then a series of β-Bi2O3/g-C3N4 direct Z-scheme photocatalysts were synthesized via a facile calcination method using Bi2O2CO3 and g-C3N4 as precursors. The samples were systematically characterized by various characterization technologies including X-ray diffraction, scanning and transmission electron microscopes, Fourier transform infrared spectroscopy and N2 absorption-desorption equipment. It was found that the g-C3N4 content in the precursors played a key role in affecting the photocatalytic activity of the final products. The β-Bi2O3/g-C3N4 heterojunction exhibited higher photocatalytic activity than single active components (β-Bi2O3 and g-C3N4), indicating the presence of a synergistic effect between two active components in β-Bi2O3/g-C3N4 heterojunction. Among all as-prepared catalysts, the 70 wt.% g-C3N4/Bi2O2CO3 exhibits the highest activity for RhB degradation, and the apparent reaction rate constant k (42.2 × 10−3 min−1) is 3.1 and 1.7 times as high as that of pure β-Bi2O3 (13.5 × 10−3 min−1) and g-C3N4 (25.2 × 10−3 min−1), respectively. The enhanced photocatalytic performance of β-Bi2O3/g-C3N4 heterostructure photocatalysts is mainly due to the high surface area, closely contacted interfaces between the β-Bi2O3 and g-C3N4 component, and the formation of direct Z-scheme structure in the β-Bi2O3/g-C3N4 composites.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.280
      Issue No: Vol. 436 (2017)
       
  • A lattice Boltzmann simulation of coalescence-induced droplet jumping on
           superhydrophobic surfaces with randomly distributed structures
    • Authors: Li-Zhi Zhang; Wu-Zhi Yuan
      Pages: 172 - 182
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Li-Zhi Zhang, Wu-Zhi Yuan
      The motion of coalescence-induced condensate droplets on superhydrophobic surface (SHS) has attracted increasing attention in energy-related applications. Previous researches were focused on regularly rough surfaces. Here a new approach, a mesoscale lattice Boltzmann method (LBM), is proposed and used to model the dynamic behavior of coalescence-induced droplet jumping on SHS with randomly distributed rough structures. A Fast Fourier Transformation (FFT) method is used to generate non-Gaussian randomly distributed rough surfaces with the skewness (Sk), kurtosis (K) and root mean square (Rq) obtained from real surfaces. Three typical spreading states of coalesced droplets are observed through LBM modeling on various rough surfaces, which are found to significantly influence the jumping ability of coalesced droplet. The coalesced droplets spreading in Cassie state or in composite state will jump off the rough surfaces, while the ones spreading in Wenzel state would eventually remain on the rough surfaces. It is demonstrated that the rough surfaces with smaller Sks, larger Rqs and a K at 3.0 are beneficial to coalescence-induced droplet jumping. The new approach gives more detailed insights into the design of SHS.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.200
      Issue No: Vol. 436 (2017)
       
  • A hydrogel-mediated scalable strategy toward core-shell
           polyaniline/poly(acrylic acid)-modified carbon nanotube hybrids as
           efficient electrodes for supercapacitor applications
    • Authors: Qingqing Liu; Zhengyu Bai; Jingbiao Fan; Zhipeng Sun; Hongyu Mi; Qing Zhang; Jieshan Qiu
      Pages: 189 - 197
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Qingqing Liu, Zhengyu Bai, Jingbiao Fan, Zhipeng Sun, Hongyu Mi, Qing Zhang, Jieshan Qiu
      Structural failure of polyaniline (PANI) stemmed from repeated swelling-shrinkage during Faradic process represents an imminent issue hindering the real application of this material for advanced energy storage. Herein, we explore a clean and facile hydrogel-mediated layer-by-layer strategy to conformally coat a layer of oriented PANI nanofibers on multi-walled carbon nanotubes (MWCNTs) where a layer of UV-polymerized poly(acrylic acid) (PAA) hydrogel is first formed in between as electrodes for supercapacitors. Such an intriguing core-shell tri-component structure perfectly alleviates the drawbacks of PANI as well as combines the advantages of MWCNTs. Especially, the hydrogel used increases the adhesion between PANI and MWCNTs, buffers the structural variation of PANI during cycling, and provide extra driving force accelerating electrolyte penetration throughout active materials. Therefore, the well-intergrown hybrids (PANI/P-MWCNT) display high electrochemical performance as compared to PANI and PANI/MWCNT, i.e., an improved capacitance of 612.5 F g–1 at 0.5 A g–1, and excellent cycling behavior of 81.5% capacitance retention at 5 A g–1 over 1500 cycles. Also, the maximum energy density of the PANI/P-MWCNT based symmetric configuration reaches 8.2 Wh kg–1. Significantly, such a hydrogel-bridged design concept may find the important application for the synthesis of competitive candidates for energy storage.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.209
      Issue No: Vol. 436 (2017)
       
  • The oxygen-rich pentaerythritol modified multi-walled carbon nanotube as
           an efficient adsorbent for aqueous removal of alizarin yellow R and
           alizarin red S
    • Authors: Jia-Ying Yang; Xin-Yu Jiang; Fei-Peng Jiao; Jin-Gang Yu
      Pages: 198 - 206
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Jia-Ying Yang, Xin-Yu Jiang, Fei-Peng Jiao, Jin-Gang Yu
      A contrastive work on the removal of two organic dyes, alizarin yellow R (AYR) and alizarin red S (ARS), was carried out by utilizing pentaerythritol modified multi-walled carbon nanotubes (ox-MWCNT-PER) as a highly efficient adsorbent. Various characterization methods such as scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, the Brunauer–Emmett–Teller (BET) analysis and X-ray photoelectron spectroscopy (XPS), were applied for revealing the physical and chemical properties of the as-prepared material. In addition, the adsorption kinetics, isotherms and thermodynamic parameters were also discussed. The results showed that the time required to achieve the adsorption equilibrium for both dyes was about 30min, and the increase in temperature was not favorable to the adsorption process. It was worth noting that the adsorption capacity of ox-MWCNT-PER towards ARS dye was more significant than that towards AYR dye. And the maximum adsorption capacities for ARS and AYR were 257.73mgg−1 and 45.39mgg−1, respectively. The possible adsorption mechanism was also proposed, and the synergistic effects of the hydrogen bonding and the π–π electron stacking interactions between the adsorbents and adsorbates both contributed to the adsorption. It could be proposed that the ox-MWCNT-PER nanocomposite might have some positive effects in removing organic dyes from water treatment in the future.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.029
      Issue No: Vol. 436 (2017)
       
  • Antifouling coatings via plasma polymerization and atom transfer radical
           polymerization on thin film composite membranes for reverse osmosis
    • Authors: Ulrike Hirsch; Marco Ruehl; Nico Teuscher; Andreas Heilmann
      Pages: 207 - 216
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Ulrike Hirsch, Marco Ruehl, Nico Teuscher, Andreas Heilmann
      A major drawback to otherwise highly efficient membrane-based desalination techniques like reverse osmosis (RO) is the susceptibility of the membranes to biofouling. In this work, a combination of plasma activation, plasma bromination and surface-initiated atom transfer radical polymerization (si-ATRP) of hydrophilic and zwitterionic monomers, namely hydroxyethyl methacrylate (HEMA), 2-methacryloyloxyethyl phosphorylcholine (MPC) and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), was applied to generate non-specific, anti-adhesive coatings on thin film composite (TFC) membranes. The antifouling effect of the coatings was shown by short-time batch as well as long-time steady state cultivation experiments with the microorganism Pseudomonas fluorescens. It could be shown that plasma functionalization and polymerization is possible on delicate thin film composite membranes without restricting their filtration performance. All modified membranes showed an increased resistance towards the adhesion of Pseudomonas fluorescens. On average, the biofilm coverage was reduced by 51.4–12.6% (for HEMA, SBMA, and MPC), the highest reduction was monitored for MPC with a biofilm reduction by 85.4%. The hydrophilic coatings applied did not only suppress the adhesion of Pseudomonas fluorescens, but also significantly increase the permeate flux of the membranes relative to uncoated membranes. The stability of the coatings was however not ideal and will have to be improved for future commercial use.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.038
      Issue No: Vol. 436 (2017)
       
  • The catalytic decomposition of thiosulfate by pyrite
    • Authors: Yanhe Nie; Qiang Wang; Futing Zi; Xianzhi Hu; Yunlong Chen; Lixia Guo; Hong Yu
      Pages: 217 - 223
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yanhe Nie, Qiang Wang, Futing Zi, Xianzhi Hu, Yunlong Chen, Lixia Guo, Hong Yu
      The rate-limiting step during catalytic decomposition of thiosulfate by pyrite was studied in detail in this paper. The results show that Co and Ni impurities in synthetic pyrite increase thiosulfate decomposition, but F impurities in synthetic pyrite reduce thiosulfate decomposition. Density functional theory (DFT) showed that Co and Ni impurities increase the pyrite (100) surface Fermi energy and reduce its work function. This allows oxygen to accept electrons more easily, thus accelerating thiosulfate decomposition. Accordingly, Co or Ni impurities in pyrite make the OO bond adsorbed on pyrite (100) surfaces become longer. On pyrite (100) surfaces doped with F, the OO bond length decreases. These experimental results demonstrate that the rate-limiting step is the electron accepting step of oxygen during thiosulfate decomposition on the pyrite surface.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.257
      Issue No: Vol. 436 (2017)
       
  • Fabrication of hierarchical polymer surfaces with superhydrophobicity by
           injection molding from nature and function-oriented design
    • Authors: Can Weng; Fei Wang; Mingyong Zhou; Dongjiao Yang; Bingyan Jiang
      Pages: 224 - 233
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Can Weng, Fei Wang, Mingyong Zhou, Dongjiao Yang, Bingyan Jiang
      A comparison of processes and wettability characteristics was presented for injection molded superhydrophobic polypropylene surfaces from two fabricating strategies. One is the biomimetic replication of patterns from indocalamus leaf in nature. The contact angle of water sitting on this PP surface was measured as 152 ± 2°, with comparable wetting behavior to natural indocalamus leaf surface. The other strategy is the fabrication of superhydrophobic structure by combining methods that produce structures at different length scales. Regarding both the machinability of mold inserts and function-oriented design, three micro-quadrangular arrays and one hierarchical micro-nano cylinder array were designed with the goal of superhydrophobicity. Particularly, a simple approach to the fabrication of hierarchical structures was proposed by combining the anodized plate and the punching plate. The function-oriented design targets as superhydrophobicity were all reached for the designed four structures. The measured contact angles of droplet for these structures were almost consistent with the calculated equilibrium contact angles from thermodynamic analysis. Among them, the contact angle of droplet on the surface of designed hierarchical structure reached about 163° with the sliding angle of 5°, resulting in self-cleaning characteristic. The superhydrophobicity of function-oriented designed polymer surfaces could be modified and controlled, which is exactly the limitation of replicating from natural organisms.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.268
      Issue No: Vol. 436 (2017)
       
  • Design of water-repellant coating using dual scale size of hybrid silica
           nanoparticles on polymer surface
    • Authors: J. Conti; J. De Coninck; M.N. Ghazzal
      Pages: 234 - 241
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): J. Conti, J. De Coninck, M.N. Ghazzal
      The dual-scale size of the silica nanoparticles is commonly aimed at producing dual-scale roughness, also called hierarchical roughness (Lotus effect). In this study, we describe a method to build a stable water-repellant coating with controlled roughness. Hybrid silica nanoparticles are self-assembled over a polymeric surface by alternating consecutive layers. Each one uses homogenously distributed silica nanoparticles of a particular size. The effect of the nanoparticle size of the first layer on the final roughness of the coating is studied. The first layer enables to adjust the distance between the silica nanoparticles of the upper layer, leading to a tuneable and controlled final roughness. An optimal size nanoparticle has been found for higher water-repellency. Furthermore, the stability of the coating on polymeric surface (Polycarbonate substrate) is ensured by photopolymerization of hybridized silica nanoparticles using Vinyl functional groups.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.017
      Issue No: Vol. 436 (2017)
       
  • NiCo2O4 particles with diamond-shaped hexahedron structure for
           high-performance supercapacitors
    • Authors: Yanfang Li; Xiaojuan Hou; Zengxing Zhang; Zhenyin Hai; Hongyan Xu; Danfeng Cui; Serge Zhuiykov; Chenyang Xue
      Pages: 242 - 251
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yanfang Li, Xiaojuan Hou, Zengxing Zhang, Zhenyin Hai, Hongyan Xu, Danfeng Cui, Serge Zhuiykov, Chenyang Xue
      Nickel cobalt oxide (NiCo2O4) particles with a diamond-shaped hexahedral porous sheet structure are successfully synthesized by a facile hydrothermal method, followed by calcination in one step. NiCo2O4-I and NiCo2O4-II particles are prepared using the same method with different contents of urea (CO(NH2)2) and ammonium fluoride (NH4F). The different morphologies of the NiCo2O4-I and NiCo2O4-II particles illustrate that CO(NH2)2 and NH4F play an important role in crystal growth. To verify the influence of NH4F and CO(NH2)2 on the morphology of the NiCo2O4 particles, the theory of crystal growth morphology is analyzed. The electrochemical measurements show that NiCo2O4 particles exhibit a high specific capacitance. At a current density of 1.0mAcm−2, the mass specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes are 690.75 and 1710.9Fg−1, respectively, in a 6M KOH aqueous electrolyte. The specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes remain ∼95.95% and ∼70.58% of the initial capacitance values after 5000 cycles, respectively. According to the two-electrode test, the NiCo2O4-II//AC asymmetric electrodes exhibited an ultrahigh energy density of 64.67Whkg−1 at the power density of 12kWkg-1, demonstrating its excellent application potential as an electrode material for supercapacitors.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.025
      Issue No: Vol. 436 (2017)
       
  • Magnetic porous Fe3O4/carbon octahedra derived from iron-based
           metal-organic framework as heterogeneous Fenton-like catalyst
    • Authors: Wenhui Li; Xiaofeng Wu; Shuangde Li; Wenxiang Tang; Yunfa Chen
      Pages: 252 - 262
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Wenhui Li, Xiaofeng Wu, Shuangde Li, Wenxiang Tang, Yunfa Chen
      The synthesis of effective and recyclable Fenton-like catalyst is still a key factor for advanced oxidation processes. Herein, magnetic porous Fe3O4/carbon octahedra were constructed by a two-step controlled calcination of iron-based metal organic framework. The porous octahedra were assembled by interpenetrated Fe3O4 nanoparticles coated with graphitic carbon layer, offering abundant mesoporous channels for the solid-liquid contact. Moreover, the oxygen-containing functional groups on the surface of graphitic carbon endow the catalysts with hydrophilic nature and well-dispersion into water. The porous Fe3O4/carbon octahedra show efficiently heterogeneous Fenton-like reactions for decomposing the organic dye methylene blue (MB) with the help of H2O2, and nearly 100% removal efficiency within 60 min. Furthermore, the magnetic catalyst retains the activity after ten cycles and can be easily separated by external magnetic field, indicating the long-term catalytic durability and recyclability. The good Fenton-like catalytic performance of the as-synthesized Fe3O4/carbon octahedra is ascribed to the unique mesoporous structure derived from MOF-framework, as well as the sacrificial role and stabilizing effect of graphitic carbon layer. This work provides a facile strategy for the controllable synthesis of integrated porous octahedral structure with graphitic carbon layer, and thereby the catalyst holds significant potential for wastewater treatment.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.151
      Issue No: Vol. 436 (2017)
       
  • Anti-biofouling superhydrophobic surface fabricated by picosecond laser
           texturing of stainless steel
    • Authors: Ke Sun; Huan Yang; Wei Xue; An He; Dehua Zhu; Wenwen Liu; Kenneth Adeyemi; Yu Cao
      Pages: 263 - 267
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Ke Sun, Huan Yang, Wei Xue, An He, Dehua Zhu, Wenwen Liu, Kenneth Adeyemi, Yu Cao
      Anti-biofouling technology is based on specifically designed materials and coatings. This is an enduring goal in the maritime industries, such as shipping, offshore oil exploration, and aquaculture. Recently, research of the relationship between wettability and antifouling effectiveness has attracted considerable attention, due to the anti-biofouling properties of the lotus leaf and shark skin. In this study, super-hydrophobic surfaces (SHSs) with controllable periodic structures were fabricated on AISI304 stainless steel by a picosecond laser, and their anti-biofouling performance were investigated by seawater immersion for five weeks in summertime. The results showed that the specimens with SHS demonstrate significant anti-biofouling effect as compared with the bare stainless steel plate. We observed that nearly 50% decrease of the average microbe attachment area ratio (Avg. MAAR) could be obtained. The micro-groove SHS with more abundant hierarchical micro-nano structures showed better anti-biofouling performance than the micro-pit SHS.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.012
      Issue No: Vol. 436 (2017)
       
  • A comparative DFT study on the dehydrogenation of methanol on Rh(100) and
           Rh(110)
    • Authors: Minhua Zhang; Xingyu Wu; Yingzhe Yu
      Pages: 268 - 276
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Minhua Zhang, Xingyu Wu, Yingzhe Yu
      Numerous density functional theory calculations have been performed to investigate the complete mechanisms of methanol dehydrogenation on Rh(100) and Rh(110) surfaces. The adsorption properties of relevant species were discussed in details. In addition, a comprehensive reaction network including four reaction pathways was built and analyzed. It is found that the initial OH bond scission of CH3OH seems to be more favorable than CH bond cleavage on both Rh(100) and Rh(110) surfaces from the perspective of activation barriers. It is also concluded that path1 (CH3OH→CH3O→CH2O→CHO→CO) is the predominant pathway on both Rh(100) and Rh (110) surfaces. On the whole, in most of the dehydrogenation reactions investigated, the energy barriers on Rh(100) are lower than those on Rh (110). Remarkable differences in the activity and predominant reaction pathway on Rh(100), Rh(110) and Rh(111) indicate that the dehydrogenation of methanol might be structure-sensitive.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.040
      Issue No: Vol. 436 (2017)
       
  • Chlorinated paraffins wrapping of carbon nanotubes: A theoretical
           investigation
    • Authors: Qiuyue Ding; Ning Ding; Xiangfeng Chen; Chi-Man Lawrence Wu
      Pages: 277 - 282
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Qiuyue Ding, Ning Ding, Xiangfeng Chen, Chi-Man Lawrence Wu
      How nanomaterials interact with pollutants is the central for understanding their environmental behavior and practical application. In this work, molecular dynamics (MD) and density functional theoretical (DFT) methods were used to investigated the influence of carbon chain length, degree of chlorination, chain configuration, and chirality of chlorinated paraffin (CP) and diameter of single-walled carbon nanotubes (SWNTs) on the interaction between CPs and SWNTs. The simulation results demonstrated that CP chain length and chlorination degree played considerably important roles in determining interaction strength between SWNTs and CPs. The interaction energies increased with increasing chain length and chlorination degree. The chirality of SWNT exerted negligible influence on the interaction energy between SWNTs and CPs. On the contrary, interaction energy increased with increasing radius of SWNTs due to the surface curvatures. This result was rationalized by considering the decrease in SWNT curvature with increasing radius, which resulted in plane-like CNT wall. The negligible influence of CP chain configurations was attributed to relative flexibility of CP carbon chains, which can wrap on tubes through conformational changes with low-energy barriers. MD results indicated that CPs could adsorb on SWNT surface rapidly in aqueous environment. Charge transfer and electronic density results indicated that the interaction between CPs and SWNTs was physisorption in nature. This work provides fundamental information regarding SWNTs as sorbents for CPs extraction and adsorptive removal from environmental water system.
      Graphical abstract image

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.12.009
      Issue No: Vol. 436 (2017)
       
  • Durable superamphiphobic nano-silica/epoxy composite coating via coaxial
           electrospraying method
    • Authors: Xiaoyan Li; Hui Li; Kai Huang; Hua Zou; Yu Dengguang; Ying Li; Biwei Qiu; Xia Wang
      Pages: 283 - 292
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Xiaoyan Li, Hui Li, Kai Huang, Hua Zou, Yu Dengguang, Ying Li, Biwei Qiu, Xia Wang
      In this study, a durable superamphiphobic nano-silica and epoxy composite coating with good environment resistant was successfully fabricated. Fluorinated nano-silica with low surface energy was prepared by in situ sol-gel method, which can be stably dispersed in the solution. Applying fluorinated nano-silica dispersion as sheath and epoxy solution as core, fluorinated nano-silica/epoxy superamphiphobic composite coating was prepared by a coaxial electrospraying method. Fluorinated nano-silica with uniform nano-size was distributed evenly on the micro epoxy particles, showing a special micro-nano hierarchical structure. Nano-indentation shows evident improvement in modulus and hardness of fluorinated nano-silica/epoxy composite coating than that of raw epoxy. In addition, durability of the superamphiphobic coating was assessed by performing harsh chemical environments immersion and scotch tape test.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.241
      Issue No: Vol. 436 (2017)
       
  • Crystallized InBiS3 thin films with enhanced optoelectronic properties
    • Authors: N. Ali; Arshad Hussain; R. Ahmed; M. Firdaus Bin Omar; M. Sultan; Yong Qing Fu
      Pages: 293 - 301
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): N. Ali, Arshad Hussain, R. Ahmed, M. Firdaus Bin Omar, M. Sultan, Yong Qing Fu
      In this paper, a one-step thermal evaporation approach was used for fabrication of indium bismuth sulphide thin films, and the synergetic effects of co-evaporation of two sources (indium granules and Bi2S3 powders) were investigated using different characterization techniques. X-ray diffraction (XRD) analysis confirmed the crystalline orthorhombic structure for the post-annealed samples. Surface roughness and crystal size of the obtained film samples were increased with increasing annealing temperatures. Analysis using X-ray photoelectron spectroscopy showed the formation of the InBiS3 structure for the obtained films, which is also confirmed by the XRD results. The optical absorption coefficient value of the annealed samples was found to be in the order of 105 cm−1 in the visible region of the solar spectrum. The optical band gap energy and electrical resistivity of the fabricated samples were observed to decrease (from 2.2 to 1.3 eV, and from 0.3 to 0.01 Ω–cm, respectively) with increasing annealing temperatures (from 200 to 350 °C), indicating the suitability of the prepared InBiS3 thin films for solar cell applications.

      PubDate: 2017-12-13T03:39:27Z
      DOI: 10.1016/j.apsusc.2017.11.273
      Issue No: Vol. 436 (2017)
       
  • In-depth understanding of core-shell nanoarchitecture evolution of
           g-C3N4@C, N co-doped anatase/rutile: Efficient charge separation and
           enhanced visible-light photocatalytic performance
    • Authors: Mohamad Azuwa Mohamed; Juhana Jaafar; M.F. M. Zain; Lorna Jeffery Minggu; Mohammad B. Kassim; Mohamad Saufi Rosmi; Nur Hashimah Alias; Nor Azureen Mohamad Nor; W.N. W. Salleh; Mohd Hafiz Dzarfan Othman
      Pages: 302 - 318
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Mohamad Azuwa Mohamed, Juhana Jaafar, M.F. M. Zain, Lorna Jeffery Minggu, Mohammad B. Kassim, Mohamad Saufi Rosmi, Nur Hashimah Alias, Nor Azureen Mohamad Nor, W.N. W. Salleh, Mohd Hafiz Dzarfan Othman
      Herein, we demonstrated the simultaneous formation of multi-component heterojunction consisting graphitic carbon nitride (g-C3N4) and C, N co-doped anatase/rutile mixed phase by using facile sol-gel assisted heat treatment. The evolution of core-shell nanostructures heterojunction formation was elucidated by varying the temperature of heat treatment from 300°C to 600°C. Homogeneous heterojunction formation between g-C3N4 and anatase/rutile mixed phase was observed in gT400 with C and N doping into TiO2 lattice by O substitution. The core-shell nanoarchitectures between g-C3N4 as shell, and anatase/rutile mixed phase as core with C and N atoms are doped at the interstitial positions of TiO2 lattice was observed in gT500. The result indicated that core-shell nanoarchitectures photocatalyst (gT500) prepared at 500 ◦C exhibited the highest photocatalytic activity in the degradation of methyl orange under visible light irradiation. Meanwhile, the possible mechanisms of charge generation, migration, action species and reaction that probably occur at the gT500 sample were also proposed. The photodegradation results of gT500 correlated completely with the results of the PEC and photoluminescence analysis, which directly evidenced improved charge separation and migration as the crucial parameters governing photocatalysis. It is worthy to note that, the simultaneous formation of multicomponent heterojunction with core-shell structure provided an enormous impact in designing highly active photocatalyst with superior interfacial charge transfer.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.229
      Issue No: Vol. 436 (2017)
       
  • Hydrothermal synthesis of BiVO4/TiO2 composites and their application for
           degradation of gaseous benzene under visible light irradiation
    • Authors: Yin Hu; Wei Chen; Jianping Fu; Mingwei Ba; Fuqian Sun; Peng Zhang; Jiyong Zou
      Pages: 319 - 326
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yin Hu, Wei Chen, Jianping Fu, Mingwei Ba, Fuqian Sun, Peng Zhang, Jiyong Zou
      Benzene is currently recognized as one of the most toxic contaminants. Our previously published study revealed that BiVO4/TiO2 is an excellent photocatalyst toward the degradation of benzene. Herein, BiVO4/TiO2 has been synthesized via a sol-gel method and a facile hydrothermal route by adjusting the precursor hydrolysis rate with the use of different acids (CH3COOH, HNO3 and H2SO4). The influence of these acids on the physicochemical characteristics and photocatalytic performance is discussed in detail. X-ray diffraction and N2 sorption analyses confirm that acid has an important effect on the crystalline composition and BET specific surface area. BiVO4/TiO2 synthesized in CH3COOH has better photocatalytic activity for the degradation of gaseous benzene than that in HNO3 and H2SO4 under visible light irradiation. Results of XPS measurement demonstrate that the hydroxyl group in BiVO4/TiO2-CH3COOH is more abundant than that in BiVO4/TiO2-HNO3 and BiVO4/TiO2-H2SO4. The photocurrent signal is investigated by electrochemical measurement, which indicates that more effective separation of photogenerated carriers occurs in the BiVO4/TiO2/CH3COOH system. It is hoped that our work can offer valuable information on the design of TiO2 composites with enhanced properties.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.054
      Issue No: Vol. 436 (2017)
       
  • Three-dimensional porous activated carbon derived from loofah sponge
           biomass for supercapacitor applications
    • Authors: Xiao-Li Su; Jing-Ran Chen; Guang-Ping Zheng; Jing-He Yang; Xin-Xin Guan; Pu Liu; Xiu-Cheng Zheng
      Pages: 327 - 336
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Xiao-Li Su, Jing-Ran Chen, Guang-Ping Zheng, Jing-He Yang, Xin-Xin Guan, Pu Liu, Xiu-Cheng Zheng
      Biomass carbon source is generally cheap, environmentally friendly and readily available in high quality and quantity. In this work, a series of loofah sponge-derived activated carbon (SAC-x) with hierarchical porous structures are prepared by KOH chemical activation and used as electrode materials for supercapacitors. The pore size can be easily controllable by changing the dosage of KOH. The optimized material (SAC-4) exhibits a high specific capacitance of 309.6Fg−1 at 1Ag−1 in the three-electrode system using 6M KOH electrolyte. More importantly, the as-assembled symmetric supercapacitor based on SAC-4 exhibits a high energy density of 16.1Whkg−1 at a power density of 160.0Wkg−1 using 1M Na2SO4 electrolyte. These remarkable results demonstrate the exciting commercial potential of SAC-x for high-performance supercapacitor applications due to their high specific surface area, appropriately porous structure, and the trace heteroatom (O and N) functionalities.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.249
      Issue No: Vol. 436 (2017)
       
  • Sponge-like reduced graphene oxide/silicon/carbon nanotube composites for
           lithium ion batteries
    • Authors: Menglu Fang; Zhao Wang; Xiaojun Chen; Shiyou Guan
      Pages: 345 - 353
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Menglu Fang, Zhao Wang, Xiaojun Chen, Shiyou Guan
      Three-dimensional sponge-like reduced graphene oxide/silicon/carbon nanotube composites were synthesized by one-step hydrothermal self-assembly using silicon nanoparticles, graphene oxide and amino modified carbon nanotubes to develop high-performance anode materials of lithium ion batteries. Scanning electron microscopy and transmission electron microscopy images show the structure of composites that Silicon nanoparticles are coated with reduced graphene oxide while amino modified carbon nanotubes wrap around the reduced graphene oxide in the composites. When applied to lithium ion battery, these composites exhibit high initial specific capacity of 2552 mA h/g at a current density of 0.05 A/g. In addition, reduced graphene oxide/silicon/carbon nanotube composites also have better cycle stability than bare Silicon nanoparticles electrode with the specific capacity of 1215 mA h/g after 100 cycles. The three-dimension sponge-like structure not only ensures the electrical conductivity but also buffers the huge volume change, which has broad potential application in the field of battery.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.070
      Issue No: Vol. 436 (2017)
       
  • Effect of morphology evolution on the thermoelectric properties of
           oxidized ZnO thin films
    • Authors: Shiying Liu; Guojian Li; Lin Xiao; Baohai Jia; Yang Gao; Qiang Wang
      Pages: 354 - 361
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Shiying Liu, Guojian Li, Lin Xiao, Baohai Jia, Yang Gao, Qiang Wang
      The effects of nanowire content on the thermoelectric properties of ZnO films were investigated. The nanowire content of ZnO films was tuned by thermal oxidation of evaporated Zn films. The results showed that hexagonal and polyhedral morphologies on the surface of Zn films can be used to tune the nanowire content of ZnO films. Hexagonal nanoplates with a diameter of 100–350nm readily grew ZnO nanowires with c-axis preferential orientation. Conversely, it was difficult to grow nanowires on polyhedral nanoparticles with diameters of 500–750nm because the meeting of ZnO (101) and (001) facets suppressed nanowire growth. Thermoelectric parameters were strongly affected by nanowire content. In particular, carrier concentration increased with nanowire content. Carrier mobility also increased with nanowire content because the nanowires behaved as channels for electronic migration. The band gap of the films narrowed with increasing nanowire content because the binding energy of O 1s electrons with oxygen vacancies decreased. The maximum power factor of the film with high nanowire content (8.80μW/mK2 at 530K) was approximately 300% higher than that of the film with low nanowire content.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.053
      Issue No: Vol. 436 (2017)
       
  • Synergistic effects of semiconductor substrate and noble metal
           nano-particles on SERS effect both theoretical and experimental aspects
    • Authors: Chen Yang; Pei Liang; Lisha Tang; Yongfeng Zhou; Yanting Cao; Yanxiong Wu; De Zhang; Qianmin Dong; Jie Huang; Peng He
      Pages: 367 - 372
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Chen Yang, Pei Liang, Lisha Tang, Yongfeng Zhou, Yanting Cao, Yanxiong Wu, De Zhang, Qianmin Dong, Jie Huang, Peng He
      As a means of chemical identification and analysis, Surface enhanced Raman spectroscopy (SERS), with the advantages of high sensitivity and selectivity, non-destructive, high repeatability and in situ detection etc., has important significance in the field of composition detection, environmental science, biological medicine etc. Physical model of coupling effect between different semiconductor substrates and noble metal particles were investigated by using 3D-FDTD method. Mechanism and the effects of excitation wavelength, particle spacing and semiconductor substrate types on the SERS effect were discussed. The results showed that the optimal excitation wavelengths of three noble metals of Ag, Au, Cu, were located at 510, 600 and 630nm, respectively; SERS effect of Ag, Au, Cu increases with the decreasing of the inter distance of particles, while the distance of the NPs reaches the critical value of 3nm, the strength of SERS effect will be greatly enhanced. For the four different types of substrate of Ge, Si, SiO2 (glass) and Al2O3, the SERS effect of Ag on SiO2 >Ge>Al2O3 >Si. For Au and Cu nanoparticles, the SERS effect of them on oxide substrate is stronger than that on non-oxide substrate. In order to verify FDTD simulations, taking silver nanoparticles as an example, and silver nanoparticles prepared by chemical method were spinning coating on the four different substrates with R6G as probe molecules. The results show that the experimental results are consistent with FDTD theoretical simulations, and the SERS enhancement effect of Ag-SiO2 substrate is best. The results of this study have important theoretical significance to explain the variations of SERS enhancement on different noble metals, which is also an important guide for the preparation of SERS substrates, especially for the microfluidics. The better Raman effect can be realized by choosing proper substrate type, particle spacing and excitation wavelength, result in expanding the depth and width of SERS application.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.074
      Issue No: Vol. 436 (2017)
       
  • Core-shell SrTiO3/graphene structure by chemical vapor deposition for
           enhanced photocatalytic performance
    • Authors: Chenye He; Xiuming Bu; Siwei Yang; Peng He; Guqiao Ding; Xiaoming Xie
      Pages: 373 - 381
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Chenye He, Xiuming Bu, Siwei Yang, Peng He, Guqiao Ding, Xiaoming Xie
      Direct growth of high quality graphene on the surface of SrTiO3 (STO) was realized through chemical vapor deposition (CVD), to construct few-layer ‘graphene shell’ on every STO nanoparticle. The STO/graphene composite shows significantly enhanced UV light photocatalytic activity compared with the STO/rGO reference. Mechanism analysis confirms the role of special core-shell structure and chemical bond (TiC) for rapid interfacial electron transfer and effective electron-hole separation.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.063
      Issue No: Vol. 436 (2017)
       
  • Structure and hemocompatibility of nanocrystalline titanium nitride
           produced under glow-discharge conditions
    • Authors: Agnieszka Sowińska; Elżbieta Czarnowska; Michał Tarnowski; Justyna Witkowska; Tadeusz Wierzchoń
      Pages: 382 - 390
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Agnieszka Sowińska, Elżbieta Czarnowska, Michał Tarnowski, Justyna Witkowska, Tadeusz Wierzchoń
      Significant efforts are being made towards developing novel antithrombotic materials. The purpose of the presented study was to characterize two variants of nitrided surface layers produced on alloy Ti-6Al-4V in different areas of low-temperature plasma – at the plasma potential (TiNp) or at the cathode potential (TiNc). The layers were characterized in terms of their microstructure, surface topography and wettability, and platelet response to the environment of different pH. The produced layers were of the TiN+Ti2N+αTiN-type, but the layer produced at the plasma potential was thinner, smoother and had lower surface free energy compared with that produced at the cathode potential. Biological evaluation demonstrated more fibrinogen buildup, less platelet adhesion and aggregation, and fewer strongly activated platelets on the TiNp surface compared with those parameters on the TiNc surface and on the titanium alloy in its initial state. Interestingly, both surface types were significantly resistant to fibrinogen adsorption and platelet adhesion in the environment of lower pH. In conclusion, the nitrided surface layer produced at the plasma potential is a promising material and this basic information is critical for further development of hemocompatible materials.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.028
      Issue No: Vol. 436 (2017)
       
  • High-performance flexible surface-enhanced Raman scattering substrates
           fabricated by depositing Ag nanoislands on the dragonfly wing
    • Authors: Yuhong Wang; Mingli Wang; Lin Shen; Xin Sun; Guochao Shi; Wanli Ma; Xiaoya Yan
      Pages: 391 - 397
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yuhong Wang, Mingli Wang, Lin Shen, Xin Sun, Guochao Shi, Wanli Ma, Xiaoya Yan
      Natural dragonfly wing (DW), as a template, was deposited on noble metal sliver (Ag) nanoislands by magnetron sputtering to fabricate a flexible, low-cost, large-scale and environment-friendly surface-enhanced Raman scattering (SERS) substrate (Ag/DW substrate). Generally, materials with regular surface nanostructures are chosen for the templates, the selection of our new material with irregular surface nanostructures for substrates provides a new idea for the preparation of high-performance SERS-active substrates and many biomimetic materials. The optimum sputtering time of metal Ag was also investigated at which the prepared SERS-active substrates revealed remarkable SERS activities to 4-aminothiophenol (4-ATP) and crystal violet (CV). Even more surprisingly, the Ag/DW substrate with such an irregular template had reached the enhancement factor (EF) of ∼1.05×105 and the detection limit of 10−10 M to 4-ATP. The 3D finite-different time-domain (3D-FDTD) simulation illustrated that the “hot spots” between neighbouring Ag nanoislands at the top of pillars played a most important role in generating electromagnetic (EM) enhancement and strengthening Raman signals.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.212
      Issue No: Vol. 436 (2017)
       
  • Stable silicon/3D porous N-doped graphene composite for lithium-ion
           battery anodes with self-assembly
    • Authors: Xiaofu Tang; Guangwu Wen; Yan Song
      Pages: 398 - 404
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Xiaofu Tang, Guangwu Wen, Yan Song
      We fabricate a novel 3D N-doped graphene/silicon composite for lithium-ion battery anodes, with Si nanoparticles uniformly dispersed and thoroughly embedded in the N-doped graphene matrix. The favorable structure of the composite results in a BET surface area and an average mesopore diameter of 189.2m2 g−1 and 3.82nm, respectively. The composite delivers reversible capacities as high as 1132mAhg−1 after 100 cycles under a current of 5Ag−1 and 1017mAhg−1 after 200 cycles at 1Ag−1, and exhibits an improved rate capability. The present approach shows promise for the preparation of other high-performance anode materials for lithium-ion batteries.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.068
      Issue No: Vol. 436 (2017)
       
  • A superhydrophobic EP/PDMS nanocomposite coating with high gamma radiation
           stability
    • Authors: Yan Zhang; Fule Ren; Yujian Liu
      Pages: 405 - 410
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Yan Zhang, Fule Ren, Yujian Liu
      The superhydrophobic coatings with high gamma radiation stability were prepared by using epoxy/polydimethylsiloxane (EP/PDMS) resins as the matrix and silica nanoparticles as the fillers. The nanocomposite coatings exhibit superhydrophobicity with a high water contact angle (WCA) of 154° and a low sliding angle of 7°. With the amount of SiO2 increasing from 0 to 30%, the surface shows the hierarchically structure gradually and its roughness raised from 4nm to 278nm. And little change in the WCA of the coatings (from 155° to 149°) was observed when the pH of the droplets varied from 2 to 14. In addition, the coatings also show good adhesion grade (5B), high hardness (6H) and outstanding stability for high dose gamma radiation.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.019
      Issue No: Vol. 436 (2017)
       
  • Duty cycle dependent chemical structure and wettability of RF pulsed
           plasma copolymers of acrylic acid and octafluorocyclobutane
    • Authors: I. Muzammil; Y.P. Li; X.Y. Li; M.K. Lei
      Pages: 411 - 418
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): I. Muzammil, Y.P. Li, X.Y. Li, M.K. Lei
      Octafluorocyclobutane and acrylic acid (C4F8-co-AA) plasma copolymer coatings are deposited using a pulsed wave (PW) radio frequency (RF) plasma on low density polyethylene (LDPE). The influence of duty cycle in pulsed process with the monomer feed rate on the surface chemistry and wettability of C4F8-co-AA plasma polymer coatings is studied. The concentration of the carboxylic acid (hydrophilic) groups increase, and that of fluorocarbon (hydrophobic) groups decrease by lowering the duty cycle. The combined effect of surface chemistry and surface morphology of the RF pulsed plasma copolymer coatings causes tunable surface wettability and surface adhesion. The gradual emergence of hydrophilic contents leads to surface heterogeneity by lowering duty cycle causing an increased surface adhesion in hydrophobic coatings. The C4F8-co-AA plasma polymer coatings on the nanotextured surfaces are tuned from repulsive superhydrophobicity to adhesive superhydrophobicity, and further to superhydrophilicity by adjusting the duty cycles with the monomer feed rates.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.261
      Issue No: Vol. 436 (2017)
       
  • First-principles study of adsorption-induced magnetic properties of InSe
           monolayers
    • Authors: Zhaoming Fu; Bowen Yang; Na Zhang; Dongwei Ma; Zongxian Yang
      Pages: 419 - 423
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Zhaoming Fu, Bowen Yang, Na Zhang, Dongwei Ma, Zongxian Yang
      In this work we studied the adsorption-induced magnetic behaviors on the two-dimensional InSe monolayer. Six kinds of adatoms (H, B, C, N, O and F) are taken into account. It is found that the InSe with adsorbing C and F have nonzero magnetic moments and good stability. Importantly, the magnetism of C and F modified InSe monolayers completely comes from p electrons of adatoms and substrates. The strength of magnetic exchange interaction can be controlled by changing the coverage of adsorbates. This p-electron magnetic material is thought to have obvious advantages compared to conventional d- or f-electron magnets. Our research is meaningful for practical applications in spintronic electronics and two dimensional magnetic semiconductors.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.286
      Issue No: Vol. 436 (2017)
       
  • Facile synthesis of porous graphene-like carbon nitride nanosheets with
           high surface area and enhanced photocatalytic activity via one-step
           catalyst-free solution self-polymerization
    • Authors: Shikai Wu; Shengwu Wen; Xinmei Xu; Guozhi Huang; Yifan Cui; Jinyu Li; Ailan Qu
      Pages: 424 - 432
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Shikai Wu, Shengwu Wen, Xinmei Xu, Guozhi Huang, Yifan Cui, Jinyu Li, Ailan Qu
      Porous graphite carbon nitride nanosheets (g-C3N4) are achieved via one-step catalyst-free solution self-polymerization from a single melamine precursor. The resultant porous g-C3N4 nanosheets with the best photodegradation capacity provided the surface area of 669.15m2/g, which is superior to the surface area of any other porous g-C3N4 reported. Results showed enhanced adsorption and degradation capacity of methyl orange (MO) under UV-visible light irradiation (λ>350nm) compared to bulk g-C3N4. The MO oxidation of the porous g-C3N4 nanosheets is driven mostly by the participation of holes, and secondly by O2 − and OH radicals. This approach shed lights on porous g-C3N4 production simply by self-polycondensation of single functional monomer. It also provided a low-cost and eco-friendly method to facilely mass-produce g-C3N4 nanosheets with high surface area for many potential applications.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.11.254
      Issue No: Vol. 436 (2017)
       
  • Atomic adsorption on pristine graphene along the Periodic Table of
           Elements – From PBE to non-local functionals
    • Authors: Igor A. Pašti; Aleksandar Jovanović; Ana S. Dobrota; Slavko V. Mentus; Börje Johansson; Natalia V. Skorodumova
      Pages: 433 - 440
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Igor A. Pašti, Aleksandar Jovanović, Ana S. Dobrota, Slavko V. Mentus, Börje Johansson, Natalia V. Skorodumova
      The understanding of atomic adsorption on graphene is of high importance for many advanced technologies. Here we present a complete database of the atomic adsorption energies for the elements of the Periodic Table up to the atomic number 86 (excluding lanthanides) on pristine graphene. The energies have been calculated using the projector augmented wave (PAW) method with PBE, long-range dispersion interaction corrected PBE (PBE+D2, PBE+D3) as well as non-local vdW-DF2 approach. The inclusion of dispersion interactions leads to an exothermic adsorption for all the investigated elements. Dispersion interactions are found to be of particular importance for the adsorption of low atomic weight earth alkaline metals, coinage and s-metals (11th and 12th groups), high atomic weight p-elements and noble gases. We discuss the observed adsorption trends along the groups and rows of the Periodic Table as well some computational aspects of modelling atomic adsorption on graphene.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.046
      Issue No: Vol. 436 (2017)
       
  • Investigation of molybdenum-crosslinker interfaces for affinity based
           electrochemical biosensing applications
    • Authors: Vikramshankar Kamakoti; Nandhinee Radha Shanmugam; Ambalika Sanjeev Tanak; Badrinath Jagannath; Shalini Prasad
      Pages: 441 - 450
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Vikramshankar Kamakoti, Nandhinee Radha Shanmugam, Ambalika Sanjeev Tanak, Badrinath Jagannath, Shalini Prasad
      Molybdenum (Mo) has been investigated for implementation as an electrode material for affinity based biosensing towards devloping flexibe electronic biosensors. Treatment of the native oxide of molybdenum was investigated through two surface treatment strategies namely thiol and carbodiimide crosslinking methods. The binding interaction between cross-linker molecules and Mo electrode surface has been characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and optical microscopy. The efficacy of treatment of Mo with its native oxide using carbodiimide cross linking methodology was established. The carbodiimide cross-linking chemistry was found to possess better surface coverage and binding affinity with Molybdenum electrode surface when compared to thiol cross-linking chemistry.Electrochemical characterization of Mo electrode using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltametry (CV) techniques was performed to evaluate the effect of ionic properties of solution buffer on the Mo electrode’s performance. Affinity based biosensing of C-Reactive Protein (CRP) has been demonstrated on a flexible nanoporous polymeric substrate with detection threshold of 100pg/ml in synthetic urine buffer medium. The biosensor has been evaluated to be developed as a dipstick based point of care device for detection of biomarkers in urine.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.026
      Issue No: Vol. 436 (2017)
       
  • MOF-derived Cu-Pd/nanoporous carbon composite as an efficient catalyst for
           hydrogen evolution reaction: A comparison between hydrothermal and
           electrochemical synthesis
    • Authors: Sakineh Mandegarzad; Jahan Bakhsh Raoof; Sayed Reza Hosseini; Reza Ojani
      Pages: 451 - 459
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Sakineh Mandegarzad, Jahan Bakhsh Raoof, Sayed Reza Hosseini, Reza Ojani
      In this study, a novel catalyst based on Cu-Pd bimetallic nanoparticles supported on nanoporous carbon composite (NPCC) is successfully fabricated through three-step process and used as an electrocatalyst towards hydrogen evolution reaction (HER). At the first step, MOF-199 is synthesized via two distinct strategies; (1) hydrothermal (HT) and (2) electrochemical (EC). Next, the synthesized MOF-199 is used as a template in order to prepare Cu/NPCC by direct carbonization under N2 atmosphere followed by galvanic replacement reaction of Cu metals by PdII ions. All the prepared materials are characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and nitrogen adsorption/desorption measurements. The effect of synthesis method of MOF-199 on the electrocatalytic activity of the final product towards HER is investigated. The electrochemical measurements indicate that Cu-Pd/NPCC derived from the MOF prepared by EC method (Cu-Pd/NPCC/EC) exhibits an enhanced catalytic activity towards HER in H2SO4 solution than the Cu-Pd/NPCC/HT. This improvement may be attributed to using of supporting electrolyte in the preparation of Cu-Pd/NPCC/EC.
      Graphical abstract image

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.034
      Issue No: Vol. 436 (2017)
       
  • Oxidization of Al0.5Ga0.5As(001) surface: The electronic properties
    • Authors: Xiaomin Liu; Zhipeng Wei; Jialin Liu; Wei Tan; Xuan Fang; Dan Fang; Xiaohua Wang; Dengkui Wang; Jilong Tang; Xiaofeng Fan
      Pages: 460 - 466
      Abstract: Publication date: 1 April 2018
      Source:Applied Surface Science, Volume 436
      Author(s): Xiaomin Liu, Zhipeng Wei, Jialin Liu, Wei Tan, Xuan Fang, Dan Fang, Xiaohua Wang, Dengkui Wang, Jilong Tang, Xiaofeng Fan
      AlGaAs materials are used in a variety of cutting-edge devices and the band gap states after the surface oxidization is found with Fermi level pinning. With first-principle calculations, we explore the formation of gap states during the initial stage of native-oxide growth on Al0.5Ga0.5As (001) surface. The results indicate that oxygen adsorption at the bridge sites of Al (Ga)-As satisfies the bond saturation and doesn't lead to any effect on the surface gap states. The breaking of As-As dimer results in the defect states in band gap with Fermi level pining due to the replacement of oxygen. In the oxidization process, it is found that the As-As dimer is very easy to be broken. In addition, the defect states in band gap maybe disappear after the full oxidization of surface with the elimination of unsaturated As on surface. With these gap states, some absorption peaks are found to appear in the range of 0–1eV in the absorption spectra.

      PubDate: 2017-12-27T04:06:03Z
      DOI: 10.1016/j.apsusc.2017.12.043
      Issue No: Vol. 436 (2017)
       
 
 
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