Fabrication of a Concave Cubic Z-Scheme ZnIn2S4/Cu2O Heterojunction with Superior Light-Driven CO2 Reduction Performance

The photocatalytic CO2 reduction technology can effectively decrease the CO2 content in air while converting CO2 into high-value-added chemicals and turning waste into treasure. In this study, Cu2O with a concave cubic structure was fabricated by selective etching, and ZnIn2S4 nanosheets were successfully loaded on it uniformly, which significantly elevated its catalytic activity. The maximum CO yield of 9.98 μmol/g/h was obtained on the Z-scheme ZIS/Cu2O-0.3 photocatalyst, which was 3.7 and 4.3 times as high as the bare Cu2O concave cube and ZnIn2S4, respectively. The excellent photocatalytic performance could be attributed to the construction of Z-scheme heterojunction which facilitated the efficient separation of electron–hole pairs, a large specific surface area that provided an abundance of reactive sites, and positive visible light response.