Original Article | 2008, Vol.30, No.3, pp. 385-391
Effect of doped SiO2 and calcinations temperature on phase transformation of TiO2 photocatalyst prepared by sol-gel method
Lek Sikong, Jiraporn Damchan, Kalayanee Kooptarnond and Sutham Niyomwas
pp. 385 - 391
Abstract
The purpose of this research was to study the effect of calcinations temperature and SiO2 addition on phase transformation, crystallite size, and photocatalytic activity of SiO2/TiO2 thin films by using indigo carmine as an indicator. The composite particles were prepared by sol-gel method via calcinations at a temperature range of 300-700°C for 2 h, and the composite thin films were prepared by means of spin coating. The microstructure and crystallite size of pure TiO2 and SiO2/TiO2 composite powders were characterized by using XRD, SEM and DTA. It was found that anatase structures were formed at a calcinations temperature range of 300-600°C and mixed phases of anatase and rutile were observed at a temperature of 700°C. Crystallite size of pure TiO2 tends to increase with an increase in calcinations temperature. Doped SiO2 in the TiO2 has an effect on crystal phases and crystallite size of the composite powders and thin films, resulting in the change of the photocatalytic activity of TiO2 .
