The slow progress of the oxygen evolution reaction (OER) is a key challenge in advancing water splitting as a viable technology for sustainable hydrogen production. Utilizing a self-standing NiFe layered double hydroxide (LDH) is a promising approach to address the slow kinetics of OER. Herein, the oxidized Fe-containing NiFe-LDH supported on Ni foam (O–NiFe-LDH@NF) is developed through corrosion engineering and aging. The growth mechanism is studied by adjusting urea content, hydrothermal temperature and time. It is revealed that the transformation of Fe to Fe in Fe-containing NiFe-LDH and the increase of Fe content leads to lattice contraction. Furthermore, detailed experiments and theoretical simulations illustrate that the substantial Fe content and lattice shrinkage promote the generation of Ni in high oxidation state and enhance the adsorption affinity toward the reaction species. Consequently, O–NiFe-LDH@NF exhibits enhanced OER activity and stability, with an exceptionally low overpotential of 197 mV and 354 mV observed at the current densities of 10 and 500 mA cm, respectively, and remarkable stability over 300 h. This approach can be generalized for designing advanced electrocatalysts.

中文翻译：

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晶格收缩驱动设计高效稳定的O-NiFe层状双氢氧化物电催化剂用于水氧化

析氧反应（OER）的缓慢进展是推进水分解作为可持续制氢的可行技术的关键挑战。利用自立式 NiFe 层状双氢氧化物 (LDH) 是解决 OER 缓慢动力学问题的一种有前途的方法。在此，通过腐蚀工程和老化开发了负载在泡沫镍上的氧化含铁NiFe-LDH（O-NiFe-LDH@NF）。通过调节尿素含量、水热温度和时间研究其生长机理。结果表明，含Fe的NiFe-LDH中Fe向Fe的转变以及Fe含量的增加导致晶格收缩。此外，详细的实验和理论模拟表明，大量的Fe含量和晶格收缩促进了高氧化态Ni的生成，并增强了对反应物种的吸附亲和力。因此，O-NiFe-LDH@NF表现出增强的OER活性和稳定性，在10和500 mA cm的电流密度下分别观察到197 mV和354 mV的极低过电势，并且在300小时内具有显着的稳定性。这种方法可以推广用于设计先进的电催化剂。