For practical hydrogen (H₂) production via water electrolysis, large-scale design and fabrication of catalysts for high-efficiency electrochemical transformation of hydroxyl ions to oxygen in alkaline environment is of paramount importance to reduce energy losses. Using anodization, electroplating, and sequential electrodeposition, we herein realized a universal approach to vertically assemble 2D Fe-Ni hydroxide nanosheets on nickel foam surface as catalyst for oxygen evolution reaction (OER). The electrode exhibited OER onset overpotentials (η) of ~ 190 mV and a low η of ~ 270 mV at a current density of 100 mA cm⁻² in KOH electrolyte, making it one of the most active OER catalysts reported so far. The FeNi films deposited via sequential deposition are highly ordered, and electrode is stable even under long term or large current density operation. Based on the results of theoretical calculation, dielectric force microscopy (DFM) analysis, and capacitance measurements, we found that 2D Fe-Ni hydroxide-loaded electrode with enhanced conductivity facilitates the sufficiently conversion of active sites and ensures optimal adsorption energies for intermediates of OER, as a result of structural effects as well as introduction of optimal amount of Fe on surface.

对于通过水电解生产实际的氢气（H ₂），大规模设计和制造用于在碱性环境中将氢氧根离子高效转化为氧的催化剂，对于减少能量损失至关重要。使用阳极氧化，电镀和顺序电沉积，我们在本文中实现了一种通用方法，可在镍泡沫表面上垂直组装2D Fe-Ni氢氧化物纳米片，作为氧气析出反应（OER）的催化剂。在100 mA cm ^-2的电流密度下，电极的OER起始超电势（η）为〜190 mV，低η为〜270 mV。在KOH电解质中的应用，使其成为迄今为止报道的最具活性的OER催化剂之一。通过顺序沉积法沉积的FeNi膜是高度有序的，并且即使在长期或大电流密度操作下，电极也稳定。基于理论计算，介电力显微镜（DFM）分析和电容测量的结果，我们发现具有增强电导率的二维Fe-Ni氢氧化物负载电极可促进活性位点的充分转化，并确保OER中间体的最佳吸附能，是由于结构效应以及在表面上引入最适量的铁所致。