Preparation and characterization of silica-doped titania photocatalyst through sol-gel method

Silica-doped nanocrystalline titania powders were prepared using the sol-gel technique. The influence of dopant concentration on the phase transition and grain growth was studied. Subsequently the sample was studied at a constant dopant concentration to investigate the effect of calcination temperature on the pholoactivity of titania. It was found that 30SiO(2)/TiO2 (30 denotes the weight percent of SiO2) fired at 800 degreesC has a higher photoactivity than other samples with different silica content and different calcination temperature. The effect of addition of silica was to increase the photoactivity by suppressing the phase transformation of titania from anatase to rutile and forming oxygen vacancies in titania. (C) 2002 Elsevier Science B.V. All rights reserved.