Sulfur Vacancy‐Engineered NiCoB/ZnIn ₂ S ₄ Schottky Junctions for Synergistic Charge Separation and Photocatalytic Hydrogen Evolution

Abstract The strategic design of heterostructured interfaces between semiconductors significantly improves charge carrier mobility, offering a viable pathway to boost hydrogen generation efficiency in photocatalytic systems. In this study, Coulombic interaction‐guided assembly strategy is employed to design a novel composite photocatalyst, which is composed of sulfur vacancy‐engineered ZnIn ₂ S ₄ (ZnIn ₂ S ₄ ‐Vs)and NiCoB,NiCoB/ZnIn ₂ S ₄ ‐Vs. With visible light irradiation, the composite demonstrated H ₂ production efficiency of 9352.63 µmol g ⁻¹ h ⁻¹ , surpassing the efficiencies of ZnIn ₂ S ₄ ‐Vs and NiCoB counterparts by 6 times and 7 times, respectively. This remarkable rising in photocatalytic hydrogen production efficiency arises from three pivotal contributors: 1) The composite material exhibited a 3D flower‐like microsphere morphology, which remarkably boosted the density of active sites; 2) Light reflection and scattering effects induced by the self‐assembled 2D nanosheets constituting the nanoflower architecture effectively enhance the harvesting capability of the composite materials; 3) Schottky heterojunction formed at the interface between NiCoB and ZnIn ₂ S ₄ ‐Vs facilitates charge carrier separation, thereby elevating photocatalytic activity. This research provided a novel paradigm for developing high‐performance photocatalysts via a tripartite strategy integrating defect engineering, Schottky heterojunction design, and metal catalysis, offering an innovative pathway to optimize charge dynamics and catalytic efficiency.