Because of its importance in enhancing charge separation and transfer, built-in electric field engineering has been acknowledged as an effective technique for improving photocatalytic performance. Herein, a stable p–n heterojunction of 2D/2D (2D: two-dimensional) Co₃O₄/ZnIn₂S₄ with a strong built-in electric field is precisely constructed. The Co₃O₄/ZnIn₂S₄ heterojunction exhibits a higher visible-light photocatalytic hydrogen (H₂) evolution rate than the individual components, which is primarily attributed to the synergy effect of improved light absorption, abundant active sites, short charge transport distance, and high separation efficiency of photogenerated carriers. Furthermore, the photoelectrochemical studies and density functional theory (DFT) calculation results demonstrate that the enhanced interfacial charge separation and migration induced by the generated built-in electric field are the critical reasons for the boosted photocatalytic performance. This research might pave the way for the rational design and manufacturing of 2D/2D heterojunction photocatalysts with extremely efficient photocatalytic performance for solar energy conversion.

由于其在增强电荷分离和转移方面的重要性，内置电场工程已被公认为提高光催化性能的有效技术。在此，精确构建了具有强内建电场的 2D/2D（2D：二维）Co ₃ O ₄ /ZnIn ₂ S _{4的稳定 p-n 异质结。}Co ₃ O ₄ /ZnIn ₂ S ₄异质结表现出更高的可见光光催化氢（H ₂) 的演化速率高于单个组分，这主要归因于提高的光吸收、丰富的活性位点、较短的电荷传输距离和光生载流子的高分离效率的协同效应。此外，光电化学研究和密度泛函理论（DFT）计算结果表明，由产生的内建电场引起的增强的界面电荷分离和迁移是提高光催化性能的关键原因。该研究可能为合理设计和制造具有高效光催化性能的 2D/2D 异质结光催化剂铺平道路，用于太阳能转换。