Cu2WS4 with high-exposure {0 0 1} surfaces promotes efficient charge separation in ZnIn2S4

The spatial segmentation of photogenerated carriers is crucial for achieving efficient photocatalytic H 2 production (PHP) rates in photocatalyst. Design studies of crystalline catalyst facets and selective morphology control can facilitate the development of catalysts that expose more advantageous active facets. Herein, Cu 2 WS 4 /ZnIn 2 S 4 composites are constructed by growing ZnIn 2 S 4 nanosheets in situ on Cu 2 WS 4 with largely exposed {0   0   1} surface. Experiments and density functional theory calculations demonstrate that the electrons of ZnIn 2 S 4 flowed to the {0   0   1} surface of Cu 2 WS 4 , and the holes vectorially migrated to the {1   0   1} surface, during the reaction process, resulting in efficient spatial separation of the photogenerated carriers. The Cu 2 WS 4 /ZnIn 2 S 4 achieves a PHP rate of 23.67 mmol g −1 h −1 , 13.44-fold increase compared with pure ZnIn 2 S 4 . This report combines the advantages of the high-energy activity of the Cu 2 WS 4 {0   0   1} surface to morphologically control the ratio of the {0   0   1}/{1   0   1} surfaces so that ZnIn 2 S 4 can contact a larger area of the {0   0   1} surface. Furthermore, under the influence of crystallographic effects on the {0   0   1} and {1   0   1} surfaces, electrons and holes of ZnIn 2 S 4 are transferred to different crystalline facets, promoting the redox reaction. This paper provides effective ideas for the rational design of photocatalysts with efficient carrier space separation.