Hierarchical NiCo2S4/ZnIn2S4 heterostructured prisms: High-efficient photocatalysts for hydrogen production under visible-light

Exploring low-cost co-catalyst to ameliorate the photocatalytic activity of semiconductors sets a clear direction for solving energy crisis and achieving efficient solar-chemical energy conversion. In this work, a unique hierarchical hollow heterojunction was constructed by in-situ growing ZnIn 2 S 4 nanosheets on the porous NiCo 2 S 4 hollow prisms through a low temperature solvothermal method, in which NiCo 2 S 4 with semi-metal property acted as non-noble metal co-catalyst. NiCo 2 S 4 co-catalyst was innovatively encapsulated in ZnIn 2 S 4 , which not only relieved the light shielding effect caused by the large loading amount of co-catalyst, but also supplied abundant active sites for H 2 evolution. The hierarchical hollow heterostructure of NiCo 2 S 4 /ZnIn 2 S 4 provided a highly efficient channel for charge transfer. Combining these advantages, NiCo 2 S 4 /ZnIn 2 S 4 composite demonstrated excellent photocatalytic activity. In the absence of sacrificial agent, the NiCo 2 S 4 /ZnIn 2 S 4 photocatalyst achieved a remarkable improved H 2 yield of 0.77 mmol g − 1 h −1 under visible light irradiation (λ > 400 nm), which is 6.6 times greater than that of ZnIn 2 S 4 . Besides, NiCo 2 S 4 even exhibited better performance on the H 2 evolution improvement of ZnIn 2 S 4 than precious metal Pt. This work will offer novel insights into the reasonable design of non-noble metal photocatalysts with respectable activity for water splitting.