The cooperative p-n heterojunction and Schottky junction in Au-decorated hierarchical CuS@SnS2 hollow cubes for boosted charge transport and CO2 photoreduction.

• The hierarchical CuS@SnS 2 p-n heterojunction hollow cubes were fabricated. • The synergy of hollow cubes and p-n heterojunction enhanced photocatalytic CO 2 reduction. • The addition of Au nanoparticles was conducive to binding and reducing CO 2 molecules. • The synergy of p-n heterojunction and Schottky junction accelerated charge transfer and separation. During the photocatalytic CO 2 reduction process, fast charge transport, abundant active sites, and high visible light utilization in photocatalysts are key to achieving excellent CO 2 conversion efficiency. In this work, we have designed and prepared hierarchical CuS@SnS 2 p-n heterostructure hollow cubes for photocatalytic CO 2 reduction. First, a monolayer of CuS was in situ generated on the pre-prepared Cu 2 O cubes to construct core–shell Cu 2 O@CuS cubes by sulfidation of Cu 2 O cubes. The following etching process led to the formation of CuS hollow cubes. Finally, the hierarchical CuS@SnS 2 p-n heterostructure hollow cubes were obtained by growing SnS 2 nanosheets on the CuS hollow cubes. The prepared CuS@SnS 2 p-n heterostructure hollow cubes showed an improved photocatalytic CO 2 reduction activity compared with the bare CuS and SnS 2 control samples. The p-n heterojunction formed between SnS 2 and CuS as well as its hollow structure enhanced the charge carrier separation efficiency and the light absorption capacity of the hybrid catalyst. Furthermore, after the decoration of Au nanoparticles, the formed Schottky junction further discouraged the charge carrier recombination. Thus, the cooperative p-n heterojunction and Schottky junction greatly facilitated photocatalytic CO 2 reduction, and exhibiting the maximum CO and CH 4 yields of 140.1 and 77.5 μmol g−1 h−1, respectively. This work presents an efficient design of high-performance catalysts for photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]