Efficient charge transfer in cadmium sulfide quantum dot-decorated hierarchical zinc sulfide-coated tin disulfide cages for carbon dioxide photoreduction.

Constructing hybrid photocatalysts with advanced structures and controllable compositions is a promising way to improve CO photoreduction performance. In this work, SnS nanosheets are grown on ZnS polyhedron cages to fabricate hierarchical ZnS@SnS double-shelled heterostructured cages. This design integrates ZnS cages and SnS nanosheets into a stable heterostructured hybrid catalyst with a hierarchical double-shelled cage-like architecture, possessing abundant active sites, quick charge separation/migration, and high CO adsorption capacity. Benefiting from these advantages, the optimized hierarchical ZnS@SnS heterostructured cages exhibit significant gas-phase CO photoreduction activity with a CO generation rate of 95.38 μmol gh and 72.4% CO selectivity, which are greatly improved in comparison with those of pure ZnS cages and nanosheet-assembled SnS particles. Furthermore, charge carrier separation efficiency and visible light harvesting ability are further improved by constructing a ZnS@SnS/CdS type-I/type-II complex heterostructured system through surface decoration of CdS quantum dots. The optimized ZnS@SnS/CdS hybrid exhibits a CO generation rate of 155.57 μmol gh and an excellent selectivity of 80.4%. This work is conducive to the design and manufacture of advanced hybrids for solar energy utilization and photocatalytic reactions.