Enhancement of photocatalytic properties of Cr2O3-TiO2 mixed oxides prepared by sol-gel method

Cr2O3-TiO2 mixed metal oxides with various compositions were synthesized by sol-gel method and their photocatalytic properties were investigated. A mixture of chromium chloride hexahydrate and titanium butoxide in isopropanol was used as a precursor, and composition was controlled by varying relative concentration of each precursor in a mixture. X-ray diffraction analyses were employed to examine crystalline structure and surface area of synthesized samples was determined by BET method. Optical property of synthesized powders was identified by UV-Vis spectroscopy. Although structure transformation by thermal treatment from anatase to rutile phase was observed for all synthesized samples, the transformation temperature was dependent on composition. Measurement of photocurrent in electrochemical cell was carried out under visible light illumination. It was found that photocatalytic activity under visible light illumination was strongly dependent on sample composition. (C) 2010 Elsevier B.V. All rights reserved.