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    How CdS nanoparticles can influence TiO2 nanotube arrays in solar energy applications?

    , Article Applied Catalysis B: Environmental ; Volume 162 , January , 2015 , Pages 210-216 ; 09263373 (ISSN) Qorbani, M ; Naseri, N ; Moradlou, O ; Azimirad, R ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier  2015
    Abstract
    In this study, titanium dioxide (TiO2) nanotube array (TNA) films are fabricated via anodization of titanium (Ti) sheet. After annealing, the films consisted of well ordered, vertically oriented TNAs of 125±6nm diameter, 38±3nm wall thickness, and 2.9±0.3μm in length. Cadmium sulfide (CdS) nanoparticles are deposited on the synthesized TNAs by sequential-chemical bath deposition (S-CBD) method with different immersion cycle (n) to produce heterogeneous TNA/CdS-n (n=10, 20 and 30) nanostructures. UV-visible absorption spectra of the samples revealed that the absorption edge of CdS modified TNAs was shifted to a higher wavelength with respect to the pure TNAs indicating band gap reduction of... 

    Constructing BiVO4/Graphene/TiO2 nanocomposite photoanode for photoelectrochemical conversion applications

    , Article Journal of Electroanalytical Chemistry ; Volume 763 , 2016 , Pages 1-9 ; 15726657 (ISSN) Yousefzadeh, S ; Faraji, M ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    BiVO4/Graphene/TiO2 as a novel nanocomposite photoanode was designed, synthesized and characterized for photoelectrochemical application. BiVO4/Graphene nanocomposite was initially synthesized by photocatalytic process and then, BiVO4/Graphene/TiO2 nanocomposite thin film was prepared by deposition of the BiVO4/Graphene solution onto the surface of sol-gel derived TiO2 thin film. Morphology, crystal structure, surface chemical composition and optical properties of the synthesized BiVO4/Graphene/TiO2 nanocomposite thin film were characterized and compared with the BiVO4/Graphene and pure TiO2 samples. Observations of scanning electron microscopy (SEM) images revealed that the surface of the... 

    The effect of Au/Ag ratios on surface composition and optical properties of co-sputtered alloy nanoparticles in Au-Ag:SiO2 thin films

    , Article Journal of Alloys and Compounds ; Volume 486, Issue 1-2 , 2009 , Pages 22-28 ; 09258388 (ISSN) Sangpour, P ; Akhavan, O ; Zaker Moshfegh, A. R ; Sharif University of Technology
    2009
    Abstract
    Gold-silver alloy nanoparticles with various Au concentrations in sputtered SiO2 thin films were synthesized by using RF reactive magnetron co-sputtering and then heat-treated in reducing Ar + H2 atmosphere at different temperatures. The UV-visible absorption spectra of the bimetallic systems confirmed the formation of alloy nanoparticles. The optical absorption of the Au-Ag alloy nanoparticles exhibited only one plasmon resonance absorption peak located at 450 nm between the absorption bands of pure Au and Ag nanoparticles at 400 and 520 nm, respectively, for the thin films annealed at 800 °C. The maximum absorption wavelength of the surface plasmon band showed a red shift with increasing...