H₂ as a storable fuel can be sustainably generated from direct cleavage of water with a catalytic approach. However, H₂ generation is severely affected by poor catalytic activities and the instability of catalyst materials. Recently, transition-metal-based nitrides (TMNs) have been widely explored because of their intrinsic abilities to catalyze water splitting, wide pH stability, high corrosion resistance, and potential for structural modulations. Most investigations have focused on the design of advanced heterostructures for improving catalytic activity. However, identification of the active sites and decoding the inherent mechanisms are often neglected. Here, we investigate the fundamental aspects of H₂ production to elucidate the cutting-edge progress of TMNs. First, we explore the engineering of the active sites of ordered and disordered structures and the relation with hydrogen evolution reaction activity. Second, we explain the development of advanced oxygen evolution reaction catalysts by focusing on minimizing autoxidation. Third and finally, we discuss complementary strategies for converting unifunctional TMNs to bifunctional catalysts for overall water splitting.

H ₂作为一种可储存的燃料，可以通过催化方法直接分解水来可持续地产生。然而，H ₂生成受到催化活性差和催化剂材料不稳定性的严重影响。最近，过渡金属基氮化物 (TMNs) 因其固有的催化水分解能力、宽 pH 稳定性、高耐腐蚀性和结构调节潜力而被广泛探索。大多数研究都集中在设计先进的异质结构以提高催化活性。然而，活性位点的识别和内在机制的解码往往被忽视。在这里，我们研究了 H ₂的基本方面生产以阐明 TMN 的前沿进展。首先，我们探讨了有序和无序结构的活性位点的工程以及与析氢反应活性的关系。其次，我们通过关注最大限度地减少自氧化来解释先进的析氧反应催化剂的发展。第三也是最后，我们讨论了将单功能 TMN 转化为双功能催化剂以进行整体水分解的补充策略。