Enhanced bifunctional photocatalytic CO2 reduction and H2 evolution utilizing Cu-doped ZnIn2S4 nanosheets via cation exchange reaction

Abstract

In this study, Cu-doped ZnIn2S4 nanosheets were synthesized through cation exchange reactions to enhance the dual-functional photocatalytic processes of CO2 reduction and hydrogen evolution. The optimized Cu doping levels in Cu-ZIS samples significantly improved the photocatalytic performance, resulting in enhanced H2-evolution rates and increased selectivity in CO2 reduction, particularly in the production of C2H4 and CO. Characterization techniques confirmed the successful integration of Cu into the ZIS lattice, thereby improving charge transfer and separation within the material. Mechanistic studies indicated that Cu doping enhanced light absorption, charge transfer efficiency, and introduced shallow energy levels, consequently reducing charge carrier recombination and improving overall catalytic performance. These findings highlight the substantial potential of Cu-doped ZnIn2S4 nanosheets for sustainable dual-functional applications in solar energy conversion.