Zn_0.1Cd_0.9S/NiS heterojunction photocatalysts for enhanced H₂ production and glucose conversion

The well-designed photocatalyst is a reasonable strategy to realize the photocatalytic H₂-production and biomass conversion. In this work, the noble-metal-free Zn_0.1Cd_0.9S/NiS (SNS) composite was successfully prepared by in-situ chemical bath deposition of NiS nanoparticles on Zn_0.1Cd_0.9S (ZCS) nanorods surface for photocatalytic H₂-production using glucose as electron donors for effective utilization of holes. Our results show that the synergistic effect of NiS and ZCS largely improves the absorption and utilization of light, and the photogenerated electrons transfer from NiS to ZCS to effectively separate the photogenerated carriers for the enhanced photocatalytic H₂-production as the one-dimensional nanorods is conducive to the transmission of photogenerated carriers. The optimized catalyst (SNS20) has the highest H₂ production rate (12.77 mmol·g⁻¹·h⁻¹), which is 6.7 times that of pure ZCS nanorods. In particular, its apparent quantum efficiency (AQE) at 350 nm reaches 12.74%. The glucose conversion increases from 25.7% to 49.9% and lactic acid selectivity reaches 95%. During three cycles, the SNS20 shows the stable H₂-production rate, which remains 12 mmol·g⁻¹·h⁻¹ after three cycles. And the glucose conversion still remains above 40%. This work provides a reasonable strategy for designing heterojunction photocatalyst to improve the performance for the synergy of photocatalytic H₂-production and biomass conversion.