Electronic modulation of CoFeP@NiFe LDH hierarchical nanosheets for industrial water electrolysis at an ultra-low voltage of 1.67 V

Anion exchange membrane water electrolysis (AEMWE) is regarded as a highly promising technology for industrial hydrogen production. The development of efficient and stable anodic oxygen evolution reaction (OER) catalysts is crucial for advancing this technology. In this work, a heterojunction catalyst was constructed by means of the vertical anchoring of NiFe LDH onto larger CoFeP nanosheets. This heterojunction structure modulates the electronic structure, thereby enhancing conductivity and optimizing the efficiency of adsorption/desorption of reaction intermediates. Furthermore, the hierarchical nanosheet morphology facilitates bubble detachment and exposes more active sites, collectively enhancing the electrocatalytic activity. The CoFeP@NiFe LDH electrode requires an overpotential of only 268 mV to achieve a current density of 100 mA cm −2 and maintains stability for 100 h, demonstrating superior performance to most reported NiFe LDH catalysts. When employed in an anion exchange membrane (AEM) electrolyzer with PtC as the cathode, the CoFeP@NiFe LDH anode achieved a current density of 1.0 A cm −2 at a cell voltage of just 1.67 V, significantly outperforming the benchmark RuO 2 || PtC system. This work provides a practical strategy for designing high-performance anodic catalysts for advanced AEMWE systems.