Loading...
Search for: tungsten-oxide-thin-films
0.006 seconds

    The effect of nanocrystalline tungsten oxide concentration on surface properties of dip-coated hydrophilic WO3-SiO2 thin films

    , Article Journal of Physics D: Applied Physics ; Volume 40, Issue 7 , 2007 , Pages 2089-2095 ; 00223727 (ISSN) Naseri, N ; Azimirad, R ; Akhavan, O ; Moshfegh, A. Z ; Sharif University of Technology
    2007
    Abstract
    WO3-SiO2 compound thin films were deposited on glass substrates using the sol-gel method, and then all the samples were dried at 100 °C and annealed at 400 °C in air. The effect of WO3 concentration on the hydrophilicity of WO3-SiO2 compound films was studied for the first time and it was shown that the films containing 85 mol% of the concentration possessed a superhydrophilic surface without UV or visible irradiation. Optical properties of the films such as transmittance, reflectance and bandgap energy were investigated using a UV-visible spectrophotometer. According to atomic force microscopy, the surface ratio was maximized in 85 mol% concentration of WO3 similar to hydrophilicity.... 

    Visible light-induced photocatalytic reduction of graphene oxide by tungsten oxide thin films

    , Article Applied Surface Science ; Volume 276 , 2013 , Pages 628-634 ; 01694332 (ISSN) Choobtashani, M ; Akhavan, O ; Sharif University of Technology
    2013
    Abstract
    Tungsten oxide thin films (deposited by thermal evaporation or sol gel method) were used for photocatalytic reduction of graphene oxide (GO) platelets (synthesized through a chemical exfoliation method) on surface of the films under UV or visible light of the environment, in the absence of any aqueous ambient at room temperature. Atomic force microscopy (AFM) technique was employed to characterize surface morphology of the GO sheets and the tungsten oxide films. Moreover, using X-ray photoelectron spectroscopy (XPS), chemical state of the tungsten oxide films and the photocatalytic reduction of the GO platelets were quantitatively investigated. The better performance of the sol-gel tungsten... 

    Influence of hydrogen reduction on growth of tungsten oxide nanowires

    , Article Journal of Experimental Nanoscience ; Volume 7, Issue 6 , 2012 , Pages 597-607 ; 17458080 (ISSN) Azimirad, R ; Khosravi, P ; Moshfegh, A. Z ; Sharif University of Technology
    2012
    Abstract
    A simple method for synthesising W17O47 nanowires on tungsten oxide thin films deposited by sol-gel method on mica substrate has been reported. After thermally annealing thin films at 700 C in H2 ambient for different durations and subsequently in N2 ambient for 60 min, single-crystalline W17O47 nanowires along h0 01i direction were formed on the surface. Experimental results revealed that annealing under H2 ambient has an important effect on the growth of W17O47 nanowires. According to scanning electron microscopic observations, the synthesised nanowires have ∼70 nm in width and a few microns in length after annealing under H2 ambient for 30min and subsequently under N2 ambient for 60min. A... 

    Synthesis of W17O47 nanothick plates with preferred orientation and their photocatalytic activity

    , Article Surface and Interface Analysis ; Volume 43, Issue 11 , 2011 , Pages 1397-1402 ; 01422421 (ISSN) Azimirad, R ; Khosravi, P ; Moshfegh, A. Z ; Sharif University of Technology
    Abstract
    A simple method for synthesis of W17O47 nanothick plates by annealing sol-gel-deposited tungsten oxide thin films on soda lime substrate has been reported. After heat treatment of the dried thin films at 700 °C in N2 ambient for 60 min, W17O47 nanothick plates with [100] orientation were obtained. The synthesized product was characterized and analyzed by, X-ray diffraction (XRD), SEM, XPS and ultraviolet-visible spectrophotometery. According to SEM observations, nanothick plates grew with random orientations on the surface. In addition, it was observed that some of the nanothick plates were constituted from several nanosheets. XRD analysis determined that the nanothick plates were mainly...