Cu-based mutlinary sulfide nanomaterials for photocatalytic applications

Due to their environmentally benign elemental components, suitable bandgap and high absorption coefficient in the visible-light range, Cu-based multinary sulfides exhibit excellent photocatalytic properties. Moreover, the adjustable atomic structure and unique electronic state of Cu-based multinary sulfide semiconductors can boost their ability to absorb visible light. In this review, we provide a summary of recent progress in photocatalytic applications of Cu-based multinary sulfide nanomaterials, including Cu-based ternary sulfides (CuInS₂, CuIn₅S₈, Cu₃SnS₄, CuFeS₂, etc.) and Cu-based quaternary sulfides (CuZnInS, Cu₂ZnSnS₄, CuZnGaS, CuInGaS, etc.). We start with a review of the bandgap alignments of Cu-based ternary sulfides and Cu-based quaternary sulfides, which are the key factors for the photocatalytic activity of semiconductor photocatalysts. Then, we discuss the advancements in photocatalytic applications of Cu-based multinary sulfide photocatalysts, including photocatalytic H₂ production, CO₂ reduction, organic synthesis and degradation of pollutants and photoelectrochemical H₂ production. Finally, we end this review with a summary of the current challenges and opportunities of Cu-based multinary sulfides in future studies.