Abstract: Lanthanum-doped TiO2, photocatalysts La3+-TiO2, were prepared by coprecipitation and sol-gel methods. Rhodamine B was used as the reactant to evaluate the photocatalytic activity of the catalyst samples. The results showed that the La3+-TiO2 catalyst prepared by coprecipitation exhibited obviously higher photocatalytic activity. The optimum preparation conditions of coprecipitation were lanthanum ions doped of 1%, calcination temperature of 800 ℃, and calcination time of2 h. The best catalyst samples were characterized byX-raydiffraction, N2 adsorption-desorption measurement, scanning electron microscopy, and electron probe microanalyses. The two photocatalysts prepared by coprecipitation and sol-gel both had mixed crystal structure of anatase and rutile, and the anatase contents were 80% and 70%, respectively. The higher photocatalytic activity of the La3+-TiO2 catalyst prepared by coprecipitation was mainly attributed to its more regular structure of anatase, larger crystal size, and hierarchical macro/mesoporous structure.

Key words: photocatalyst, lanthanum doping, titanium dioxide, coprecipitation, sol-gel method