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Synthesis of narrow band gap (V2O5)x-(TiO2)1-x nano-structured layers via micro arc oxidation

Bayati, M. R ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.apsusc.2009.11.048
  3. Abstract:
  4. V2O5-TiO2 layers with a sheet-like morphology were synthesized by micro arc oxidation process for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). Phase structure and chemical composition of the layers were also studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. It was revealed that the composite layers had a sheet-like structure average thickness of which was about 100 nm depending on the applied voltage. The layers consisted of anatase, rutile, and vanadium pentoxide phases fractions of which varied with the applied voltage. The optical properties of the layers were also examined employing a UV-vis spectrophotometer. It was found that the absorption edge of the grown composite layers shifted toward the visible wavelengths when compared to MAO-synthesized pure titania layers. The band gap energy of the composite layers was calculated as 2.58 eV. Furthermore, photo-catalytic performance of the layers was examined by measuring the decomposition rate of methylene blue under ultraviolet and visible irradiations. The results demonstrated that about 90% and 68% of methylene blue solution was decomposed after 120 min ultraviolet and visible irradiations over the composite layers, respectively
  5. Keywords:
  6. Vanadium oxides ; Ceramics ; Photo-catalysis ; Titanium oxide ; Vanadium oxide ; Absorption edges ; Applied voltages ; Atomic force microscopes ; Band gap energy ; Chemical compositions ; Composite layer ; Decomposition rate ; Methylene blue ; Methylene blue solution ; Micro arc oxidation ; Nano-structured layer ; Narrow band gap ; Photo-catalytic ; Scanning electron microscopes ; Sheet-like ; Sheet-like structure ; TiO ; Titania layers ; UV-vis spectrophotometers ; Micro arc oxidation ; Vanadium pentoxide ; Visible irradiation ; Visible wavelengths ; Catalysis ; Cavity resonators ; Ceramic materials ; Energy gap ; Irradiation ; Microscopes ; Morphology ; Optical properties ; Oxidation ; Oxide minerals ; Scanning electron microscopy ; Surface topography ; Synthesis (chemical) ; Titanium ; Titanium dioxide ; Titanium oxides ; Vanadium ; Vanadium alloys ; Vanadium compounds ; X ray diffraction ; X ray photoelectron spectroscopy
  7. Source: Applied Surface Science ; Volume 256, Issue 9 , 2010 , Pages 2903-2909 ; 01694332 (ISSN)
  8. URL: http://www.sciencedirect.com/science/article/pii/S0169433209016602