An amorphous NiSx film as a robust cocatalyst for boosting photocatalytic hydrogen generation over ultrafine ZnCdS nanoparticles

Abstract

Optimization of cocatalysts is promising and of great significance in enhancing photocatalytic H₂ generation from the perspective of understanding the charge separation, surface reaction kinetics, and distribution of active sites. Herein, we synthesize a class of well-formed hybrid photocatalysts by coupling amorphous NiS_x films to ultrafine ZnCdS nanoparticles for greatly boosting the photocatalytic activity as well as the outstanding stability and repeatability. Under visible-light irradiation, the highest H₂ evolution rate of the as-synthesized NiS_x/ZnCdS photocatalyst achieved is 67.75 mmol g⁻¹ h⁻¹, which is 28.8 times higher than that of Pt/ZnCdS. Further detailed characterization reveals that the amorphous NiS_x film as an excellent cocatalyst not only improves the spatial separation of the photoinduced carriers but also collects electrons and enlarges the reduction reaction space. This work could provoke interest in understanding the spatial charge migration in the cocatalyst system with an amorphous film structure, thus developing high-performance low-cost composite photocatalysts for H₂ production.