Photocatalytic hydrogen production is considered as an ideal approach to solve global energy crisis and environmental pollution. Graphitic carbon nitride (g-C₃N₄) has received extensive consideration due to its facile synthesis, stable physicochemical properties, and easy functionalization. However, the pristine g-C₃N₄ usually shows unsatisfactory photocatalytic activity due to the limited separation efficiency of photogenerated charge carriers. Generally, introducing semiconductors or co-catalysts to construct g–C₃N₄–based heterojunction photocatalysts is recognized as an effective method to solve this bottleneck. In this review, the advantages and characteristics of various types of g–C₃N₄–based heterojunction are analyzed. Subsequently, the recent progress of highly efficient g–C₃N₄–based heterojunction photocatalysts in the field of photocatalytic water splitting is emphatically introduced. Finally, a vision of future perspectives and challenges of g–C₃N₄–based heterojunction photocatalysts in hydrogen production are presented. Predictably, this timely review will provide valuable reference for the design of efficient heterojunctions towards photocatalytic water splitting and other photoredox reactions.

光催化制氢被认为是解决全球能源危机和环境污染的理想途径。石墨氮化碳（gC ₃ N ₄）由于其易于合成、稳定的物理化学性质和易于功能化而受到广泛关注。然而，由于光生载流子的分离效率有限，原始的 gC ₃ N ₄通常表现出不令人满意的光催化活性。通常，引入半导体或助催化剂来构建 g–C ₃ N ₄基于异质结的光催化剂被认为是解决这一瓶颈的有效方法。在这篇综述中，分析了各种基于g-C ₃ N ₄的异质结的优点和特点。随后，重点介绍了高效g-C ₃ N ₄基异质结光催化剂在光催化分解水领域的最新进展。最后，对 g–C ₃ N ₄未来前景和挑战的展望提出了用于制氢的基于异质结光催化剂。可以预见，这一及时的综述将为设计用于光催化水分解和其他光氧化还原反应的高效异质结提供有价值的参考。