Self-Adaptive Electrode with an Engineered Catalyst–Substrate Interface for Ampere-Level Water Splitting

During water electrolysis, overpotential can trigger side reactions that lead to electrode degradation. This issue becomes more pronounced in ampere-level electrolyzers, where intense bubble evolution induces local electrochemical overloading, resulting in elevated local overpotentials. Moreover, stress fluctuations arising from intense bubble evolution impose delamination forces on the overpotential-damaged catalyst layer, thereby further exacerbating electrode degradation. To address these coupled issues, we developed a self-adaptive electrode featuring an engineered catalyst–substrate interface. This self-adaptivity allows the catalyst layer to rapidly modulate its state in response to the elevated overpotential, thereby maintaining a stable performance. Meanwhile, the engineered catalyst–substrate interface suppresses catalyst layer delamination, ensuring structural stability. At the molecular level, such a self-adaptive transformation arises from a locally disordered coordination environment, in which Ni centers are coordinated by different ligands. Beyond self-adaptivity, this locally disordered coordination environment also endows the catalyst layer with superior bifunctional activity toward overall water splitting, surpassing that of conventionally ordered Ni–O–M or Ni–Ni configurations. As a result, the as-prepared electrode demonstrates practical potential under both intermittent and continuous operation, sustaining a stable performance at 0.5 A cm–2 for up to 3000 h. Even under a higher current density of 1.5 A cm–2, considerable stability is retained.