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

A photocatalytic CeO2@TiO2 core-shell nanocomposite with enhanced photocatalytic performance was synthesized via a simple hydrothermal route assisted with the Stober method. The TiO2 coating layer consisting of fine TiO2 crystallites contributed most of the surface area of the CeO2@TiO2 nanocomposite. The CeO2@TiO2 nanocomposite exhibited a significantly narrower optical band gap than that of the pure TiO2. Photocatalytic studies revealed that the CeO2@TiO2 coreeshell nanocomposite displayed higher photocatalytic activity than both CeO2 nanocubes and TiO2 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 CeO2@TiO2, 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. (C) 2017 Elsevier B.V. All rights reserved.