As one of the most efficient, low-cost, and readily available electrocatalysts for oxygen evolution reaction (OER) in alkaline environments, the nickel-iron electrocatalyst is of great significance to commercial water splitting. In this study, NiFe-layered double hydroxide loaded on nickel foam (NiFe-LDH/NF) was synthesized via a simple one-step hydrothermal method, whose OER catalytic performance could be successfully optimized by further electrochemical reconstruction. The results show that NF is an effective precursor to loading crystallized Ni(OH)₂ nanoparticles during hydrothermal synthesis, leading to the generation of high-performance NiOOH during OER reconstruction. Under the optimal Ni:Fe feeding ratio, Ni₂Fe₁-LDH/NF requires an ultra-low OER overpotential of 239 mV at 50 mA cm^-2 and 260 mV at 100 mA cm^-2, whose Tafel slope is only 64.1 mV dec^-1. Impressively, Ni₂Fe₁-LDH/NF also achieves an ultra-low voltage of 1.44 V at 10 mA cm^-2 with excellent long-term stability for overall water splitting. Unlike the previous viewpoint that only Ni species dominate surface reconstruction of NiFe-LDH, in this article the decisive influence related to Fe species on the reconstruction layers’ activity and stability is confirmed by electrochemistry, Raman, and XPS analysis during reconstruction process. During OER reconstruction, the surface Ni:Fe ratios can be "self-adaptively" regulated to an appropriate region, thus the stable reconstruction layers rich in NiOOH can be formed as the protective shells for NiFe-LDH. Furthermore, such "self-adaptive" reconstruction, assisted with appropriate initial Ni:Fe feeding ratios, can also stimulate more Ni³⁺ active sites for OER, benefitting the outstanding catalytic performance of NiFe-LDH/NF for overall water splitting and prospective large-scale application.

作为碱性环境中析氧反应（OER）最有效、成本最低且易于获得的电催化剂之一，镍铁电催化剂对商业水分解具有重要意义。在这项研究中，通过简单的一步水热法合成了负载在泡沫镍上的 NiFe 层状双氢氧化物 (NiFe-LDH/NF)，其 OER 催化性能可以通过进一步的电化学重构来成功优化。结果表明，NF是水热合成过程中负载结晶Ni(OH) ₂纳米粒子的有效前体，导致在OER重建过程中产生高性能NiOOH。在最佳Ni:Fe进料比下，Ni ₂ Fe ₁-LDH/NF 要求在 50 mA cm ^-2 时为 239 mV的超低 OER 过电位，在 100 mA cm ^-2时为260 mV ，其 Tafel 斜率仅为 64.1 mV dec ^-1。令人印象深刻的是，Ni ₂ Fe ₁ -LDH/NF在 10 mA cm ^-2下也实现了 1.44 V 的超低电压         具有出色的整体水分解长期稳定性。与之前认为只有 Ni 物种主导 NiFe-LDH 表面重建的观点不同，本文通过重建过程中的电化学、拉曼和 XPS 分析证实了 Fe 物种对重建层活性和稳定性的决定性影响。在OER重建过程中，表面Ni:Fe比可以“自适应”调节到适当的区域，从而形成富含NiOOH的稳定重建层作为NiFe-LDH的保护壳。此外，这种“自适应”重建，辅以适当的初始 Ni:Fe 进料比，还可以激发更多的 Ni ³⁺OER 的活性位点，有利于 NiFe-LDH/NF 在整体水分解和潜在的大规模应用中的出色催化性能。