Abstract: A CdS/CeO₂ heterojunction nano-photocatalyst was prepared by hydrothermal method, the physical and chemical properties were characterized by XRD, HR-TEM, UV-vis, etc., photocatalytic performance for CO₂ reduction was evaluated, and the reaction mechanism was deduced. The results showed that the CdS/CeO₂ heterojunction nano-photocatalyst could widen the visible light absorption range and reduce the band gap of the catalyst compared with single CdS nano-particle and single CeO₂ nano-particle. It could effectively delay the recombination of electron-hole pairs, reduce the arc radius and the transfer resistance of electron hole pairs, and thus improve the visible light sensing range and photocatalytic activity of the catalyst. It was proved that the heterojunction nanostructures prepared by semiconductor composite could effectively improve the photocatalytic activity of the catalyst of CO₂ reduction. The heterojunction nano-photocatalyst CdCe-100 was prepared by adding 100 mg CeO₂ nano-particles into 1 mmol Cd (OOCCH₃)₂·2H₂O aqueous solution, the yield of CO and CH₃OH for CO₂ reduction was 213 μmol/g and 1 534 μmol/g, respectively, and the catalytic activity of CdCe-100 remained above 93% after six times of reuse.

Key words: photocatalytic, CO₂ reduction, cadmium sulfide, cerium dioxide, heterojunction, methanol