Abstract: Mesoporous metatitanic acid was prepared from industrial TiOSO4 solution without using templates. Then Si-doped mesoporous SO2-4/TiO2 with high thermal stability was synthesized by impregnating mesoporous metatitanic acid with tetraethylorthosilicate solution and calcination. The calcined samples were characterized usingX-raydiffraction, N2 adsorption and desorption, scanning electron microscopy,X-rayphotoelectron spectroscopy, and infrared spectroscopy. The photocatalytic activity of Si-doped SO2-4/TiO2 for the degradation of methylene blue was tested. Tetraethylorthosilicate that was adsorbed in the pores of metatitanic acid formedTi-O-Sibond by reaction withfree-OHon the pore walls of metatitanic acid during calcination. Silicon atoms introduced into the framework of TiO2 act as the pore structure support, and thus the thermal stability of mesoporous SO2-4/TiO2 was improved. The sample calcined at 700 ℃ for2 hhad a surface area of 189 m2/g and an average pore diameter of 2.8 nm. The photocatalytic activity of the sample calcined at 400 ℃ was excellent.

Key words: mesoporous titanium dioxide, silicon doping, dipping, thermal stability, photocatalysis