LAUSR

Hierarchical structure design and use of cocatalyst are effective strategies to improve the photocatalytic performance of semiconductor catalysts. Herein, 0D NiSe2 nanoparticles decorated 2D ZnIn2S4 ultrathin nanosheet‐assembled microflowers using a facile solvothermal approach are synthesized. The as‐obtained NiSe2/ZnIn2S4 nanocomposites exhibit enhanced visible‐light photocatalytic H2‐evolution activity of 1487 µmol (g h)–1, three times higher than that of pure ZnIn2S4. The hierarchical structure of ZnIn2S4 microflowers exposes more surface‐active sites and enhances light harvesting. Meanwhile, the formation of heterojunctions between ZnIn2S4 nanosheets and NiSe2 nanoparticles creates a space‐charge separation region that facilitates the transfer and separation of photoinduced electrons and holes, resulting in improved photocatalytic H2 production. This work provides a promising strategy for designing and constructing 0D/2D heterojunctions for efficient solar‐driven energy conversion.