2D/2D heterointerface engineering of Ni2P/ZnIn2S4 photocatalysts for enhanced photocatalytic H2 evolution

Zinc indium sulfide (ZnIn2S4) possesses excellent photosensitivity and a suitable band structure, exhibiting superior photocatalytic activity under visible light. However, rapid recombination of photogenerated carriers and sulfide poisoning inhibit its photocatalytic hydrogen production performance. In this study, Ni2P nanosheets as cocatalysts were assembled onto the surface of ZnIn2S4 nanoflowers (Ni2P@ZnIn2S4) for photocatalytic H2 production. The 6 wt% Ni2P@ZnIn2S4 with the optimal ratio exhibited a significantly enhanced photocatalytic H2 evolution activity (5.82 mmol g−1 h−1), which is twice that of ZnIn2S4 (2.85 mmol g−1 h−1) and 1.14 times that of Pt/ZnIn2S4 (5.11 mmol g−1 h−1). In addition, the apparent quantum efficiency (AQE) of Ni2P@ZnIn2S4 reaches 5.70 % and 1.03 % at 370 and 456 nm. According to the experimental data and DFT calculation, the improvement in the catalytic performance of Ni2P@ZnIn2S4 is attributed to the following points: 1) ZnIn2S4 nanoflowers composed of 2D nanosheets can improve light absorption, enhance charge and mass transfer, and increase the specific surface area. 2) 2D Ni2P as a co-catalyst could better couple with the 2D sheet unit of ZnIn2S4, improving charge transport, suppressing photogenerated carrier recombination, and providing Ni active sites for surface redox reactions. These synergistic effects highlight the spatial separation and interfacial transfer of photogenerated carriers between semiconductors and cocatalysts achieved through two-dimensional nanosheet heterostructures, providing an effective solution to the carrier recombination problem. © 2025 The Authors.