A NiS co-catalyst decorated ZnInS/g-CN type-II ball-flower-like nanosphere heterojunction for efficient photocatalytic hydrogen production.

Promoting the separation of photogenerated electron-hole pairs and enhancing the charge carrier transfer are critical in photocatalysis. In our work, a ball-flower-like NiS/ZnInS/g-CN photocatalyst fabricated by a hydrothermal method exhibited superior performance for photocatalytic water splitting. The optimized 2.0% NiS/ZnInS/g-CN rivaled noble metal based Pt/g-CN and showed an apparent quantum efficiency (AQE) of 24.3% at 420 nm, with a H yield of 4.135 mmol g h, which was 30.4 and 9.51 times that of pure g-CN and binary ZnInS/g-CN composites, respectively. The experimental and characterization results suggested that the heterojunction formed between ZnInS/g-CN and the decorating NiS co-catalyst cooperatively suppressed the electron-hole recombination and facilitated the charge carrier transfer, thus resulting in significant improvement of the H evolution performance. Moreover, the increased specific surface area and the enhanced visible-light absorption also contributed to superior water splitting performance. The prepared ternary catalytic system with the heterojunction and non-noble metal co-catalyst has great potential as an alternative to noble metals for achieving cost-efficient water splitting systems.