To utilize the solar light more efficiently and enhance the photocatalytic performance of TiO₂, nickel and silicon co-doped TiO₂ was synthesized from a compound system of tetrabutyl titanate (TBT), tetraethyl orthosilicate (TEOS) and nickel nitrate hexahydrate (NNH) at 140 ℃, which then was annealed at 400 ℃. The reaction was performed in a Teflon-lined steel autoclave with acetic acid as solvent using a non-aqueous method. The as-obtained materials were characterized by X-ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), as well as UV-visible diffuse reflectance spectroscopy (UV-vis DRS). It was found that all the as-obtained materials were of an anatase phase, which is the TiO₂ phase with the highest photocatalytic activity among anatase, rutile and brookite. One sample possessed the largest surface area of 303.3 m²•g^－1. Furthermore, nickel and silicon were all introduced into the bulk of TiO₂. The visible photocatalytic performance of the obtained materials was evaluated by rhodamine-B decomposition. The results showed that the photocatalytic activity of Ni-Si co-doped TiO₂ was higher than that of TiO₂ or Ni-doped TiO₂, which was enhanced with increasing the nickel and silicon contents and then decreased, reaching the maximum at the Ni/Ti and Si/Ti molar ratios of 0.01 and 0.20, respectively. The enhanced visible photocatalytic performance was attributed to the synergetic effect of nickel and silicon co-doping.

Key words: anatase TiO₂, co-doping, nonaqueous system, visible photocatalysis, rhodamine-B