One-pot hydrothermal synthesis of noble-metal-free NiS on Zn0.5Cd0.5S nanosheet photocatalysts for high H2 evolution from water under visible light

Abstract

At present, the rational design and facile synthesis of highly active and low-cost photocatalysts are still facing great challenges. Herein, a series of Zn_0.5Cd_0.5S/NiS (x mol%) composite photocatalysts have been synthesized via a simple and mild one-pot hydrothermal method. Compared with pure Zn_0.5Cd_0.5S, the NiS-loaded samples exhibit enhanced photocatalytic hydrogen generation performance, in which the Zn_0.5Cd_0.5S/NiS-5% sample has the highest H₂ production rate of 10 855 ± 461 μmol h⁻¹ g⁻¹ with a quantum yield of 11.82% at 365 nm, which is almost 6.3 times higher than that of pristine Zn_0.5Cd_0.5S. The high activity of the Zn_0.5Cd_0.5S/NiS nanosheets may be attributed to their distinct nanostructure, including a short transfer distance of photoinduced charge carriers, a large number of unsaturated surface atoms, and a large surface area. Moreover, the added NiS nanoparticles served as an effective cocatalyst to promote photoinduced electron transfer and enhance the surface kinetics of H₂ evolution. Our work provides a simple and effective route for the preparation of sulphur-based photocatalysts, which can significantly improve the efficiency of hydrogen production from water.