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.