Abstract: TiO2／SiO2 composite powders were prepared using two－step sol－gel method, with tetrabutyl titanate and tetraethyl orthosilicate as the main raw materials, and its photo catalytic properties for degradation of active brilliant red X－3B solution were researched through Ti∶Si molar ratio, calcined temperature, initial concentration and photocatalyst dosage. The results indicated that the TiO2／SiO2 composite powders of n单位Ti)∶n单位 Si)∶6∶1, calcined at 500 ℃ had the best photo catalytic activity, and the photocatalytic activity of the composite were higher than that of pure TiO2 under the same conditions; moreover, it was found that degradation rate of active brilliant red X－3B solution decreased with its initial concentration increasing, and the optimum dosage of composite photocatalysts was 1.6 g／L when the initial concentration of active brilliant red X－3B solution was 25 mg／L.

Key words: titania单位 TiO2), silica单位 SiO2), sol－gel method, active brilliant red X－3B, photo catalytic degradation