Excellent anti-photocorrosion and hydrogen evolution activity of ZnIn2S4-based photocatalysts: In-situ design of photogenerated charge dynamics

Sluggish elimination of photogenerated holes remains a bottleneck problem that usually causes low-utilization efficiency towards photogenerated electron and serious photocorrosion in photocatalytic water splitting system. To overcome these limitations, herein, a p-n-n-type Ni(OH)2/NiIn2S4/ZnIn2S4 (NOH/NIS/ZIS) heterojunction was constructed through an in-situ photochemical transition. On account of the favorable multi-component features, integrating p-n-type NOH/NIS heterojunction into II-type NIS/ZIS heterojunction was an efficient strategy to facilitate the carrier separation, hole-extraction and charge utilization. Consequently, p-n-n-type NOH/NIS/ZIS hybrids exhibited excellent visible-light-driven hydrogen production performance. The highest hydrogen production rate of 5448.3 μmol·h−1·g−1 was 10.6 times higher than that of pure ZIS (516.0 μmol·h−1·g−1). More importantly, successive hole-extraction markedly enhanced the anti-photocorrosion and long-term stability of ZIS. The repeated experiments exhibited an enhanced photocatalytic activity of 106.0 % within four cyclic experiments, far higher than that (−28.7%) of pure ZIS. Our findings may provide a deep insight into the photocorrosion mechanism of sulfides and open a new opportunity for the development of highly-efficient and durable photocatalytic water splitting system.