低量Yb3+掺杂的TiO2复合纳米粉体的制备及光催化活性

姜洪泉,王鹏,线恒泽. 低量Yb3+掺杂的TiO2复合纳米粉体的制备及光催化活性J]. 化学学报, 2006, 64(2): 145-150.

Preparation and Photocatalytic Activities of Low Amount Yb3+-doped TiO2 Composite Nano-powders

Pure TiO2 and 0.125% (w) Yb3 -doped TiO2 composite nano-particles were prepared by an acid-catalyzed sol-gel method and characterized by the techniques such as XPS, XRD, BET, DRS and SPS. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The mechanisms of effects of low amount Yb3 -doping on the photo-catalytic activity of the composite nano-particles were also discussed. The results show that 0.125% Yb3 -doping can significantly enhance the photocatalytic activity of TiO2 nano-particles. The presence of low amount of Yb3 in TiO2 can inhibit the phase transformation from anatase to rutile, suppress the growth of TiO2 grains, raise the specific surface area, and improve the high temperature stabilization of pores in the composite nano-powders as well. The analytical results of XPS indicate that Yb3 -doping can result in the increase in the density of the surface hydroxyl. The analytical results of SPS confirm that Yb3 -doping can inhibit the recombination of the photo-produced electrons and holes, and improve the light absorption prop-erties of the particle surface. Compared with pure TiO2, the enhanced photocatalytic activity of the Yb3 -doped TiO2 nano-powders can be due to the inhibition of the recombination of the photo-produced e-/h , the increase of the density of the surface hydroxyl and the specific surface area, and the improvement of the light absorption properties of the particle surface.