Abstract： To discuss the effect of CeO₂ on structure and photocatalytic performance of LaCoO₃, ultrafine mixed powders of CeO₂-LaCoO₃ with the amounts of substance ratio of Ce and La of 0.1, 0.3 and 0.5 were synthesized by the method of sol-gel combining with vacuum drying and heat treatment. The particles were characterized by the methods of TG - DTA, XRD, XPS, IR, specific surface area and TEM. The photocatalytic performance was evaluated under the degradation reaction of methyl orange taking an ultraviolet lamp with the power of 10 W as the light source. The results show that the adding of Ce has no obvious effect on perovskite structure of powders. The crystal phase of powders is composed of LaCoO₃ and CeO₂. The existing of CeO₂ phase enhances photocatalytic performance of particles. The powders with the amount of substance ratio of Ce and La of 0.3 show the best photocatalytic performance, and the degradation rate of methyl orange can reach 92.5%.

Keywords: cerium dioxide; lanthanum cobaltate; sol-gel method; crystal structure; photocatalytic degradation