Synergistic effect of CeO2 modified TiO2 photocatalyst on the enhancement of visible light photocatalytic performance

Abstract A photocatalytic CeO 2 @TiO 2 core–shell nanocomposite with enhanced photocatalytic performance was synthesized via a simple hydrothermal route assisted with the Stober method. The TiO 2 coating layer consisting of fine TiO 2 crystallites contributed most of the surface area of the CeO 2 @TiO 2 nanocomposite. The CeO 2 @TiO 2 nanocomposite exhibited a significantly narrower optical band gap than that of the pure TiO 2 . Photocatalytic studies revealed that the CeO 2 @TiO 2 core–shell nanocomposite displayed higher photocatalytic activity than both CeO 2 nanocubes and TiO 2 in degradation of the organic pollutant Rhodamine B. Such varieties in optical band gap and photocatalytic activity were assigned to the heterojunction interfaces formed in CeO 2 @TiO 2 , which could both promote photoinduced charge separation and suppress the recombination of photogenerated electrons and holes. During the process, the reversible oxidation-reduction in Ce(IV)/Ce(III) redox couples also promoted the efficient electron transfer.