Dual electron transfer routes in core-shell double Z-scheme artificial photosynthetic system for improved photoredox activity

Developing artificial photosynthetic system with high activity is significant for long-term solar light conversion. Inspired by the natural Z-scheme photosystem, a ternary core-shell ZnIn2S4/MoO3/MoS2 (ZOS) composite with double Z-scheme junction was prepared by in-situ vulcanization of MoO3 nanosheets. Such in-situ formed intimate interfaces can overcome the high interfacial charge transfer barrier between different composites thus boosting the charge separation efficiency. The dual Z-scheme heterojunction provided dual electron transfer routes and favored the charge transfer. In addition, the ternary core-shell structure offered more spatially separated active sites which also increased the photocatalytic activity. Profiting from these strategies, the optimized ZOS-1 sample afforded 3.71mmol·g−1·h−1 hydrogen evolution rate at 420nm, which was 18.5 and 2.5 times higher than that of MoO3 and ZnIn2S4, respectively. In addition, 88% tetracycline can be eliminated in the solution within 70min in the presence of ZOS-1 sample. This study provides an effective strategy for designing high-efficiency artificial photosynthetic systems under Z-scheme charge transfer routes in photocatalytic reactions.