Facile fabrication of NiWO4/ZnIn2S4 p-n heterojunction for enhanced photocatalytic H2 evolution

Construction heterojunction has been demonstrated to be a potential strategy to facilitate the activity of single component photocatalyst due to the enhanced light absorption, accelerated charge separation and so on. Herein, a NiWO4/ZnIn2S4 p-n heterojunction was prepared via a facile physical solvent evaporation method. In the binary system, the p-n heterojunction formed between NiWO4 and ZnIn2S4 can boost the charge separation. Besides, the introduction of NiWO4 can induce more electrochemically active surface area and decrease the overpotential of H2 evolution. In addition, the water angle contact (WAC) of ZnIn2S4 was reduced from 58.6° to 12.1°, suggesting a better hydrophilic surface. The photocatalytic activity tests indicated that the obtained composite exhibited excellent H2 evolution activity than NiWO4 or ZnIn2S4 alone. 10.7 %-NiWO4/ZnIn2S4 has a superior H2 production rate of 30.51 mmol·g−1·h−1, 4.42 folds higher than that of pure ZnIn2S4 (5.63 mmol·g−1·h−1). Meanwhile, the microstructure of 10.7 %-NiWO4/ZnIn2S4 is well preserved after reaction. This work provides experimental basis for the development of ZnIn2S4 based heterojunction for high-efficiency photocatalytic H2 evolution.