Abstract: Mesoporous anatase TiO2-SO2-4 with high thermal stability was synthesized without organic templates. The sample was characterized using X-ray diffraction, N2 adsorption, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy, and its photocatalytic activity was tested. SO2-4 that is bonded to free -OH on pore walls of metatitanic acid during the calcination acts as the pore structure-directing agent and pore structure support. After calcination at 500 ℃, the mesoporous TiO2-SO2-4 has a surface area of 202.2 m2/g and an average pore diameter of 2.8 nm. The electron inductive effect of S=O in TiO2-SO2-4 not only makes adjacent Ti a superacidic center but also causes a red shift of the adsorption spectrum of the sample by 30 nm. Its photocatalytic activity is also enhanced obviously.

Key words: mesoporous titanium dioxide, metatitanic acid, photocatalytic, sulphate anion, superacid