Interface engineering of S-scheme ZnIn₂S₄/Ni-MOF-74 heterostructures for boosted photocatalytic hydrogen production

ZnIn₂S₄ (ZIS) is a low-cost semiconductor with tunable morphology, suitable for visible-light water splitting, but limited by photocorrosion and low catalytic efficiency. To address these issues, we report an in-situ synthesis of ZIS/Ni-MOF-74 heterostructures, integrating 2D ZIS with Ni-MOF-74 to form a stable, efficient interface. This direct growth method preserves the MOF's structure and offers an alternative to post-synthetic assembly. The resulting composite achieves a hydrogen evolution rate five times higher than pristine ZIS and an apparent quantum efficiency (AQE) of 22,8 ± 1,2 % at 420 nm. Photocatalytic cycling confirms the material's stability. Spectroscopic analyses support an S-scheme charge transfer mechanism within the heterostructure. This work not only demonstrates a promising material for solar-driven hydrogen production and water purification but also encourages further exploration of sulfide-MOF combinations for broader photocatalytic applications.