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Thermally stable SiO2-doped mesoporous anatase TiO2 with large surface area and excellent photocatalytic activity.

Research paper by Chenxu C He, Baozhu B Tian, Jinlong J Zhang

Indexed on: 28 Jan '10Published on: 28 Jan '10Published in: Journal of Colloid and Interface Science



Abstract

A thermally stable SiO(2)-doped mesoporous TiO(2) with high crystallinity was prepared by a templating method. The content of SiO(2) dopant was varied from 3% to 20%. The gels were characterized by TG-DTA analysis. And the resultant catalysts were investigated by various physicochemical techniques, such as WAXRD, Raman spectroscopy, N(2) adsorption-desorption, TEM, FT-IR, and XPS. The WAXRD, TEM, and Raman measurements suggest that the SiO(2) dopant can enhance the thermal stability of the anatase phase remarkably. Rutile phase did not present at all even at 1000 degrees C when the SiO(2) content was up to 15%. N(2) adsorption-desorption results show that the SiO(2)-doped samples have uniform pore diameters and large specific surface area, which is beneficial for photocatalytic reaction. The photocatalytic activities of the samples were evaluated by degradation of Rhodamin-6G solution under UV irradiation. The results show that the SiO(2)-doped mesoporous TiO(2) have better activity than commercial P25. Especially, the 15% SiO(2)-doped mesoporous TiO(2) exhibited much higher photocatalytic activity than P25 in a large range of calcination temperatures, even at 900 degrees C. The excellent photocatalytic activity of the samples can be attributed to the high anatase crystallinity, large specific surface area, preserved surface hydroxyl groups and mesoporous channels.