Enhanced charge transfer and photocatalytic carbon dioxide reduction of copper sulphide@cerium dioxide p-n heterojunction hollow cubes

Abstract

Hollow structure hybrids have gained considerable attention for their ability to reduce CO₂ owing to their rich active sites, high gas adsorption ability, and excellent light utilization capacity. Herein, a template-engaged strategy was provided to fabricate copper sulphide@cerium dioxide (CuS@CeO₂) p-n heterojunction hollow cube photocatalysts using Cu₂O cubes as a sacrificial template. The sequential steps of loading of CeO₂ nanolayer, sulfidation, and etching reaction facilitate the formation of CuS@CeO₂ p-n heterojunction hollow cubes. Compared with the single CuS, CeO₂, and their physical mixture, the CuS@CeO₂ p-n heterojunction hollow cube photocatalyst expresses a higher performance toward photocatalytic CO₂ reduction under solid-gas reaction conditions due to the faster separation of photogenerated charges. The further enhanced performance of CuS@CeO₂ p-n heterojunction hollow cubes was achieved by decorating pt nanoparticles due to the fact that Pt nanoparticles had a high electron affinity and CO₂ adsorption capacity, and the highest CO and CH₄ yields of the optimized hybrid reached 195.8 μmol g^-1 h^-1 and 19.96 μmol g^-1 h^-1, respectively. This work might provide a strategy for designing and synthesizing efficient hollow heterostructured photocatalysts for solar energy conversion and utilization.

Keywords: CO(2) photoreduction; CuS@CeO(2); Hollow cubes; P-n heterojunction.