Boosting the photocatalytic activity of ZnIn₂S₄-based photocatalyst for H₂ evolution using porous ZnWO₄ nanoflakelets as a cocatalyst

ZnIn2S4 is considered one of most promising green catalysts for visible light driven photocatalytic H-2 generation, but it suffers from relatively low photocatalytic performance. Here, we for the first time report the design and preparation of an efficient ZnIn2S4-based catalyst using porous ZnWO4 as cocatalyst (denoted ZIS/PZW). ZIS/PZW consists of flower-like microspheres composed of ZnIn2S4 nanosheets embedded with porous ZnWO4 nanoflakelets. The as-synthesized ZIS/PZW showed excellent photocatalytic performance for H-2 generation with an optimal hydrogen production rate of 8.86 mmol g(-1) h(-1). Further investigation revealed that the porous ZnWO4 cocatalyst could lead to the formation of dense contact sites with ZnIn2S4 nanosheets, thus benefiting electron migration. The hydrogen generation rate was found to be 2.15 times higher than that when solid ZnWO4 nanoparticles acted as cocatalyst. Our work highlights the importance of finely designing cocatalysts and provides a new route for the further development of high-efficiency ZnIn2S4-based photocatalysts for H-2 generation.