Bimetallic NiCo2S4 Nanorod Cocatalyst Modified the Flower-Like Zn3In2S6 Microsphere for Visible-Light-Driven High-Efficiency Photocatalytic Hydrogen Production

Establishing Schottky barriers is a key tactic for enhancing the separation of photogenerated charge carriers and improving photocatalytic efficiency. Herein, a self-assembled metal cocatalyst, NiCo2S4 nanorod, is loaded onto the flower-like Zn3In2S6 microsphere via a hydrothermal method. Under visible light irradiation, the NiCo2S4/Zn3In2S6 composite material achieves a peak H-2 production rate of 3436.72 mu mol g(-1) h(-1) within 6 h, marking a 5.4 times greater increase compared to pristine Zn3In2S6. This outperforms the maximum H-2 production rate of Pt/Zn3In2S6-1% within the same 6-hour timeframe, which is 3323.05 mu mol g(-1) h(-1). Additionally, the apparent quantum efficiency reaches 7.86% at 420 nm. The outstanding photocatalytic activity stems from the synergistic effects between the visible-light-active Zn3In2S6 and the conductive cocatalyst NiCo2S4, facilitating spatial electrical promotion. In particular, the formation of a Schottky junction at the interface of NiCo2S4/Zn3In2S6 enables prompt electron transfer to NiCo2S4 nanorods, preventing backflow and thereby promoting the efficient separation of photogenerated charge carriers. Finally, a plausible reaction mechanism is proposed, drawing from the electrochemical characterization results. Thus, this research provides a new approach for designing metal-semiconductor photocatalysts that are efficient in photocatalytic H-2 production through water splitting.