Interfacial engineering of high-curvature NiFe nanocone arrays for accelerated oxygen evolution via tip-induced
Mengdi Li1, Yubin Yuan1, Zongtai Zhou1
1Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China. fmgao@ysu.edu.cn.
Abstract:
In gas-evolving electrocatalysis, the trade-off between mass transfer polarization and intrinsic activity remains a fundamental bottleneck. This work reports the interfacial engineering of high-curvature NiFe bimetallic nanocone arrays (NiFe-HC@NF) via a facile cathodic electrodeposition strategy. Finite element method (FEM) simulations reveal that the high-curvature tips trigger a strong localized electric field, which drives the directional migration and enrichment of OH- ions, thereby suppressing concentration polarization at the reaction interface. This physical enhancement is effectively integrated with the intrinsic Ni-Fe electronic synergistic effects, as verified by XPS, which optimize the surface electronic states for superior intrinsic kinetics. Furthermore, the unique 3D array configuration constructs a superhydrophilic and superaerophobic interface, ensuring ultrafast bubble detachment and maintaining effective active site exposure under vigorous gas-evolving conditions. As a result, the NiFe-HC@NF electrode delivers a low overpotential of 269.8 mV at 500 mA cm-2 and maintains remarkable structural and catalytic integrity for over 400 h at 100 mA cm-2. This study provides a compelling curvature-engineering strategy to break the mass-transport limitations in high-performance alkaline water electrolysis.
