Synergistic Kinetics Acceleration and Mass Transport by Nanocone‐Nanoneedle Hierarchical Electrodes for Efficient Anion Exchange Membrane Water Electrolysis

Abstract Efficient hydrogen production via water electrolysis is hindered by the sluggish kinetics of the oxygen evolution reaction (OER) and mass transport limitations. Herein, a nanocone‐nanoneedle hierarchical Ni‐CoFe 2 O 4 electrode grown on nickel foam (NF) is reported to address these challenges. The high‐curvature architecture induces a strong localized electric field enhancement, promoting the accumulation of electrolyte ions and reactants at the tips, thereby significantly accelerating the OER kinetics. Moreover, the nanostructured design facilitates rapid gas bubble detachment, minimizing active site blockage and enabling sustained performance at high current densities. The incorporation of Co as an electronic promoter modulates the local electronic structure, enhancing interfacial electron transfer from Ni/Fe to O species. When integrated into an anion exchange membrane water electrolyzer (AEMWE), the electrode achieves a low cell voltage of 1.75 V at 1.0 A∙cm −2 and maintains stable operation for over 220 h under practical conditions. This work highlights the synergistic impact of structural and electronic engineering in advancing high‐performance OER electrocatalysts with enhanced mass transport characteristics.