Space-charge-region reconstructed flower-like ZnIn2S4/layered NiCo-LDH interface: Type-II heterojunction for noble-metal-free visible-light H2 evolution

ZnIn 2 S 4 (ZIS) shows great promise for photocatalytic hydrogen production. however, its performance is severely constrained by rapid charge recombination. To address this issue, we constructed a ZIS/NiCo-LDH heterojunction featuring intimate interfacial coupling and favorable band alignment. This composite achieves a photocatalytic hydrogen evolution rate of 6337.6 μmol g −1 h −1 and maintains stable activity with negligible decay over ten consecutive cycles. Band structure analysis reveals that upon contact between NiCo-LDH and ZIS, the space-charge region is reconstructed at the interface, generating an internal electric field. This electric field promotes the direct migration of photogenerated electrons from the conduction band of NiCo-LDH to that of ZIS to participate in the hydrogen evolution reaction, while holes migrate in the opposite direction. The synergistic regulation of this 3D/2D heterogeneous interface structure effectively suppresses photocorrosion. This work offers a novel strategy for designing efficient and stable precious noble-metal-free heterojunction photocatalysts.