Photocatalytic reduction of CO2 over Sm-doped TiO2 nanoparticles

Highly efficient photocatalytic reduction of CO2is essential for solving the greenhouse effect and energy crisis.In this paper,the Sm-TiO2nanocomposites were successfully prepared via sol-gel method.The CO2photoreduction activities of synthesized samples were tested under irradiation for 6 h and the results indicate that the 0.5% Sm-TiO2catalyst has superior performance and stability.The CO and CH4 yields of0.5% Sm-TiO2catalyst are 55.47 and 3.82 μmol/g·cat respectively,which are 5.02 and 2.67 times the yield of TiO2.The possible mechanism of Sm doped TiO2was investigated through comprehensive characterization and photoetectrochemical analysis,After the Sm doping,the photo-generated electrons in TiO2could migrate to Sm 4 f,and some of them can be captured by reducing Sm3+o Sm2+,which can lower the recombination rate of electron and hole pairs.Therefore,the enhanced photocatalytic performance could be ascribed to large specific surface area,fast separation rate of electron-hole pairs and high visible light response.This report provides some meaningful attempts in researching the CO2photocatalytic reduction.