Fabrication of a ternary NiS/ZnInS/g-CN photocatalyst with dual charge transfer channels towards efficient H evolution.

As a renewable green energy, hydrogen has received widespread attention due to its huge potential in solving energy shortages and environment pollution. In this paper, a one-step solvothermal method was applied to grow ultra-thin g-CN (UCN) nanosheets and NiS nanoparticles on the surface of ZnInS (ZIS). A ternary NiS/ZnInS/ultra-thin-g-CN composite material with dual high-speed charge transfer channels was constructed for the advancement of the photocatalytic H generation. The optimal ternary catalyst 1.5wt.%NiS/ZnInS/ultra-thin-g-CN (NiS/ZIS/UCN) achieved a H evolution yield reached to 5.02 mmolgh, which was 5.23 times superior than that of pristine ZnInS (0.96 mmolgh) and even outperform than that of the best precious metal modified 3.0 wt%Pt/ZnInS (4.08 mmolgh). The AQY at 420 nm could be achieved as high as 30.5%. The increased photocatalytic performance of NiS/ZIS/UCN could be ascribed to the type-I heterojunctions between intimated ZIS and UCN. In addition, NiS co-catalyst with large quantity of H evolution sites, could result in efficient photo-induced charges separation and migration. Furthermore, the NiS/ZIS/UCN composite exhibited excellent H evolution stability and recyclability. This work would also offer a reference for the design and synthesis of ternary co-catalyst with heterojunction composite for green energy conversion.