Chemical Engineering Journal, Vol.180, 170-177, 2012
V2O5/Al2O3 composite photocatalyst: Preparation, characterization, and the role of Al2O3
An attempt to use Al2O3, as non-semiconductor component to improve the photocatalytic activity of V2O5 was investigated. The composite photocatalysts were synthesized by coprecipitation-calcination process, and then characterized by X-ray powder diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) emission spectra, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectra. The photocatalytic activities of the samples were evaluated by reduction of Cr(VI), nitrobenzene (NB), and degradation of methylene blue (MB). The results indicated that the activity of V2O5 could be improved by coupling with Al2O3. The optimum mole ratio of V/Al was found to be 1:1 and the heat treatment condition was at 800 degrees C for 6 h. The improvement of surface OH group population was assumed to responsible for the enhanced activity. According to the photocatalyst band structure and the redox potentials of the substrates, the photocatalytic reaction processes were finally discussed. (C) 2011 Elsevier B.V. All rights reserved.