Abstract:

Cerium and silica co-doped nanoscale TiO2 particles were synthesized froma complex compound system of tetrabutyl titanate (TBT), tetraethyl orthosilicate (TEOS) and cerium nitrate hexahydrate (CNH) at 140 ℃. The reaction was carried out in a Teflon-lined steel autoclave with water as the solvent using a sol-gel-hydrothermal method. The obtained materials were characterized by X-ray diffraction, nitrogen adsorption, transmission electron microscopy, UV-visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy as well as X-ray photoelectron spectroscopy. We found that all materials were in the anatase phase, even those calcined at 600 ℃, and that the samples possessed large surface areas. Furthermore, Si and Ce were successfully doped into the bulk TiO2. The photocatalytic activity of the doped material was determined by the degradation of Rhodamine B (RB) using visible light irradiation. Results showed that both Ce-doped TiO2 and Ce-Si co-doped TiO2 had better visible photoactivity than pure TiO2. These particles were all prepared using the same conditions. The highest photocatalytic activity for these samples was obtained using Ce/Ti and Si/Ti molar ratios of 0.010 and 0.10, respectively. These ratios are then considered to be the optimal doping dosages.

Key words: Titania, Ce-Si co-doped, Sol-gel-hydrothermal method, Visible-photocatalysis, Rhodamine B