Study on preparation and photocatalytic performance of Ag/TiO2 and Pt/TiO2 photocatalysts

The chemical vapor deposition (CVD) and the photoreduction deposition method were used to prepare Ag/TiO2 and Pt/TiO2 photocatalysts. Sur-face characterization and photocatalytic degradation of salicylic acid were investigated. The results suggested that metal ion concentration had great influence on the properties of Ag/TiO2 photocatalyst while the irradiation time had the most significant effect on the properties of Pt/TiO2 photocatalyst. Results from surface and crystal structure analysis of the photocatalysts using powder X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectrometry clearly indicated the successful deposition of silver and platinum on the surface of the pure TiO2 and that the crystal structure of the photocatalysts was anatase. Results of photocatalytic experiments indicated that high pH and low initial concentrations of salicylic acid led to high removal efficiencies. The formation of the intermediate products, 2,5-DHBA and 2,3-DHBA, was observed with 2,5-DHBA concentration being higher than that of 2,3-DHBA under all pH values except at pH 11. (c) 2007 Elsevier B.V. All rights reserved.