Developing high-efficiency and stable photocatalysts able to accomplish spontaneous overall water splitting, without using sacrificial agents, is the ultimate goal of photocatalytic solar–hydrogen production. Metal-free polymeric carbon nitride (CN) has emerged as a promising alternative for photocatalytic water splitting, owing to its excellent physicochemical properties. In the past decade, various strategies, including thermodynamic and kinetic modifications, have been employed to improve the photocatalytic activity of CN. Among these modification strategies, constructing heterojunctions has stimulated intensive research interest due to the enhanced efficiency of carrier separation, and hence the photocatalytic performance. This article reviews the recent progress of CN-based heterojunction photocatalysts for overall water splitting, highlighting the characteristics and fundamental design principles of different heterojunctions from the viewpoint of interfacial charge properties and energy band offsets. Finally, perspectives on the challenges and opportunities for developing advanced CN-based heterojunction photocatalysts are provided.

开发高效稳定的光催化剂，能够在不使用牺牲剂的情况下实现自发的整体水分解，是光催化太阳能制氢的最终目标。无金属聚合氮化碳（CN）由于其优异的物理化学性质，已成为光催化水分解的有前途的替代品。在过去的十年中，人们采用了各种策略，包括热力学和动力学修饰来提高 CN 的光催化活性。在这些改性策略中，由于载流子分离效率的提高以及光催化性能的提高，构建异质结引起了广泛的研究兴趣。本文综述了 CN 基异质结光催化剂在整体水分解方面的最新进展，从界面电荷特性和能带偏移的角度突出不同异质结的特性和基本设计原则。最后，展望了开发先进的基于 CN 异质结光催化剂的挑战和机遇。