Scalable Anode With Corrosion‐constructed NiFeOxHy Interlayer for Highly Efficient and Stable Water Electrolysis

ABSTRACT The alkaline oxygen evolution reaction (OER) is a key process limiting the energy efficiency of hydrogen production via anion exchange membrane water electrolysis. It is crucial to develop a cost‐effective anode with high activity and stability. This study proposes a corrosion‐coupled pulsed electrodeposition technique to fabricate a nickel‐iron hydroxide composite catalytic layer (NiFeO x H y /Ni(OH) 2 ) on a nickel felt substrate. It should be noted that the transition layer is formed via the in situ corrosion process, which strengthens adhesion between the active layer and substrate, thus improving structural stability. Furthermore, the dynamic dissolution and redeposition of iron is realized during pulsed electrodeposition, which optimizes the electronic structure and accelerates phase reconstruction. The NiFeO x H y /Ni(OH) 2 catalyst exhibits an ultralow overpotential of 195.8 mV at 10 mA cm − 2 and remarkable long‐term stability, operating for 1200 h at 1000 mA cm − 2 with no significant performance decay. An anion exchange membrane electrolyzer with 4 cm × 4 cm anode is fabricated, which enabled 1000 mA cm − 2 at a low cell voltage of 1.86 V. Finally, comprehensive experiments proving the high scalability of such method, providing a cost‐effective approach for fabricating large‐area, high‐activity anodes. This work provides insights and experimental basis for designing durable anodes for industrial water electrolysis.