Interface-optimized Rh-ZnO/rGO/ZnS heterostructure constructed via Rh-induced dynamic micro-cell growth for efficient photocatalytic hydrogen evolution

Photocatalytic water splitting for H2 generation is considered most effective for the comprehensive utilization of solar energy. H2 produced by utilizing the ZnO-ZnS heterostructure still faces serious challenges because of its fast combination of photogenerated carriers and non-negligible photo-corrosion. In this study, we devise an original synthesis strategy for the Rh-ZnO/rGO/ZnS heterostructure via Rh-induced micro-cell growth and the dynamic ion-exchange process. Given the in-situ formation of the interfaces between the heterostructure and Rh atoms, the as-prepared heterostructure based on the solid-state Z-scheme demonstrates rapid carrier migration, low overpotential, and reduced photo-excited charge carrier combination due to the synergetic effect, which presents excellent performance in solar-driven H2 generation. The stable Schottky junctions between Rh and the ZnO-ZnS heterostructure further facilitate the catalytic performance. Therefore, this work provides a promising viewpoint on the Z-scheme heterostructure for photocatalytic water splitting. •A novel micro-cell strategy is proposed to ameliorate heterostructure interfaces.•Harder Schottky barriers are obtained in the Rh-ZnO/rGO/ZnS heterostructure.•The Rh-ZnO/rGO/ZnS heterostructure manifests enhanced H2 evolution capacity.