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

Choobtashani, M ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1016/j.apsusc.2013.03.144
  3. Publisher: 2013
  4. Abstract:
  5. 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 oxide films in photocatalytic reduction of GO platelets as compared to the evaporated tungsten oxide films was assigned to lower W 5+/W6+ ratio (i.e., a better stoichiometry) and higher surface water content of the sol-gel film. The GO reduction level achieved after 24 h UV-assisted photocatalytic reduction on surface of the sol-gel tungsten oxide film was comparable with the reduction level usually obtainable by hydrazine. The sol-gel tungsten oxide film even showed an efficient photocatalytic reduction of the GO platelets after exposure to the visible light of the environment for 2 days
  6. Keywords:
  7. Graphene oxide ; WO3 Photocatalyst ; XPS ; Better performance ; Chemical exfoliations ; Graphene oxides ; Photocatalytic reduction ; Reduction level ; Room temperature ; Tungsten oxide films ; Tungsten oxide thin films ; Atomic force microscopy ; Oxides ; Photoelectrons ; Platelets ; Sol-gel process ; Sol-gels ; Stoichiometry ; Thermal evaporation ; Thin films ; Titanium sheet ; Tungsten compounds ; X ray photoelectron spectroscopy ; Oxide films
  8. Source: Applied Surface Science ; Volume 276 , 2013 , Pages 628-634 ; 01694332 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0169433213006429