Two-dimensional (2D) semiconductor heterojunctions are considered as an effective strategy to achieve fast separation of photoinduced carriers. Herein, a novel CoWO₄/g-C₃N₄ (CWO/CN) p—n junction was synthesized using an electrostatic self-assembly method. The constructed 2D/2D p—n heterostructure had a rich hetero-interface, increased charge density, and fast separation efficiency of photoinduced carriers. The in-situ Kelvin probe force microscopy confirmed that the separation pathway of photoinduced carriers through the interface obeyed an II-scheme charge transfer mechanism. Experimental results and density functional theory calculations indicated the differences of work function between CWO and CN induced the generation of built-in electric field, ensuring an efficient separation and transfer process of photoinduced carriers. Under the optimized conditions, the CWO/CN heterojunction displayed enhanced photocatalytic H₂ generation activity under full spectrum and visible lights irradiation, respectively. Our study provides a novel approach to design 2D/2D hetero-structured photocatalysts based on p—n type semiconductor for photocatalytic H₂ generation.

二维（2D）半导体异质结被认为是实现光致载流子快速分离的有效策略。在此，使用静电自组装方法合成了一种新型CoWO ₄ /gC ₃ N _{4 (CWO/CN) p-n结。}构建的2D/2D p-n异质结构具有丰富的异质界面、增加的电荷密度和光生载流子的快速分离效率。现场的开尔文探针力显微镜证实光诱导载流子通过界面的分离途径遵循II型电荷转移机制。实验结果和密度泛函理论计算表明，CWO和CN之间的功函数差异导致了内建电场的产生，确保了光生载流子的有效分离和转移过程。在优化条件下，CWO/CN异质结在全光谱和可见光照射下分别表现出增强的光催化H _{2生成活性。}我们的研究提供了一种基于 p-n 型半导体设计用于光催化 H ₂生成的 2D/2D 异质结构光催化剂的新方法。