LAUSR

Abstract Development of highly active and earth-abundant cocatalysts to replace scarce noble-metals is of great importance to realize large-scale and cost-efficient photocatalytic H 2 evolution reactions. Herein, we report that amorphous WS x cocatalyst grown on the CdS surface by a facile solution-based photochemical reduction method is an effective alternative for Pt cocatalyst and lead to superior photocatalytic H 2 evolution performances. Under visible light irradiation (≥420 nm), the optimized CdS/WS x (12%) photocatalyst achieved a high initial H 2 evolution rate of 761 μmol h −1 , which is the 17 times faster than that of CdS alone. Notably, the WS x cocatalyst shows a nearly 5 times higher activity than that of Pt in catalyzing H 2 evolution on CdS at same loading amount. An apparent quantum efficiency (AQE) of 14.7% was achieved over CdS/WS x (12%) at 420 nm. Moreover, CdS/WS x (12%) photocatalyst is relatively stable for 20 h H 2 evolution reactions, showing the robustness of WS x cocatalyst. Based on the results of photoelectrochemical and PL measurements, it was proposed that the amorphous WS x not only can rapidly capture photogenerated electrons from excited CdS for enhancing the charge separation efficiency, but also promote the H + reduction to H 2 . Considering its high activity, easy-preparation, and low cost, the amorphous WS x cocatalyst would hold great potential in designing high-performance semiconductor/WS x photocatalysts for large-scale H 2 production using renewable energy sources.