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(WO3)x-(TiO2)1-x nano-structured porous catalysts grown by micro-arc oxidation method: Characterization and formation mechanism

Bayati, M. R ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.matchemphys.2010.06.020
  3. Publisher: 2010
  4. Abstract:
  5. Very recently, we fabricated (WO3)x-(TiO 2)1-x layers via micro-arc oxidation process under different applied voltages. Morphological and topographical studies, accomplished by SEM and AFM techniques, revealed that the pores size as well as the surface roughness increased with the voltage. Phase structure and chemical composition of the layers were also investigated by XRD and XPS and the results showed the grown layers consisted of titanium and tungsten oxides. It was found that WO3 dispersed in the TiO2 matrix and also doped into the TiO2 lattice. In addition, optical properties of the synthesized layers were studied employing a UV-vis spectrophotometer. Band gap energy of the layers was approximately determined as 2.87 eV. Finally, methylene blue was selected as a model material and its degradation rate on the surface of the layers was measured to determine the photocatalytic efficiency. The degradation rate constants were measured as 2.2 × 10-2 and 0.9 × 10-2 min-1 under ultraviolet and visible irradiations
  6. Keywords:
  7. Ceramics ; Films ; Methylene blue ; Micro-arc oxidation ; Photocatalysis ; Porous ; AFM ; Applied voltages ; Band gap energy ; Chemical compositions ; Degradation rate ; Degradation rate constants ; Formation mechanism ; matrix ; Microarc oxidation ; Model materials ; Nano-structured ; Photocatalytic efficiency ; Porous catalysts ; SEM ; TiO ; Tungsten oxide ; UV-Vis spectrophotometers ; Visible irradiation ; XPS ; XRD ; Ceramic materials ; Degradation ; Optical properties ; Oxidation ; Surface roughness ; Titanium ; Titanium oxides ; Tungsten ; Rate constants
  8. Source: Materials Chemistry and Physics ; Volume 124, Issue 1 , 2010 , Pages 203-207 ; 02540584 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0254058410004797