Morphology Engineering of Fe‐Doped NiCoP for Enhanced Water Splitting

ABSTRACT Alkaline water electrolysis technologies have enabled the production of carbon‐free hydrogen at the megawatt scale. However, cost‐effective catalysts with scalable synthesis capabilities are essential to achieve hydrogen production rates comparable to those of blue and grey hydrogen. This study reports the development of an optimal bifunctional electrocatalyst via facile in situ growth of Fe‐doped NiCoP on nickel foam with varying Fe content. Needle‐like structures decorated with nanoflakes uniformly grow on the nickel foam, and Fe incorporation effectively tailors the surface electronic structure. This unique structure significantly enhances the electrochemical surface area, exposing more accessible active sites and boosting activity for water‐splitting reactions. Owing to its numerous active sites, large surface area, and optimized doping ratio, Fe‐NiCoP with a cobalt‐to‐iron molar ratio of 5:1 demonstrates ultralow overpotentials of 41 mV and 104 mV at 10 mA cm ^{− 2} for the hydrogen and oxygen evolution reactions, respectively. The electrocatalyst assembled in a water‐splitting cell exhibits a cell voltage of 1.55 V at 10 mA cm ⁻² , outstanding durability, and performance comparable to that of other reported transition‐metal‐based bifunctional electrocatalysts.