Abstract The oxygen evolution reaction (OER) is a half-reaction of water electrolysis, and the OER performance of an electrocatalyst is significantly related to its energy conversion efficiency. Due to their high OER activity, transition metal-based nanomaterials have become potential low-cost substitutes for Ir/Ru-based OER electrocatalysts in an alkaline environment. Herein, holey Fe3O4-coupled Ni(OH)2 sheets (Ni(OH)2-Fe H-STs) were easily achieved by a simple mixed-cyanogel hydrolysis strategy. The two-dimensional (2D) Ni(OH)2-Fe H-STs with ca. 1 nm thickness have a high specific surface area, abundant unsaturated coordination atoms, and numerous pores, which are highly favorable for electrocatalytic reactions. Meanwhile, the introduction of Fe improves the conductivity and regulates the electronic structure of Ni. Due to their special structural features and synergistic effect between the Fe and Ni atoms, Ni(OH)2-Fe H-STs with an optimal Ni/Fe ratio show excellent OER activity in a 1 M KOH solution, which significantly exceeds that of the commercial RuO2 nanoparticle electrocatalyst. Furthermore, Ni(OH)2-Fe H-STs can be grown on nickel foam (NF), and the resulting material exhibits enhanced OER activity, such as a small overpotential of 200 mV and a small Tafel slope of 56 mV dec−1, than that of Ni(OH)2-Fe H-STs without NF.

中文翻译：

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在泡沫镍上直接生长多孔 Fe3O4 偶联的 Ni(OH)2 片以进行析氧反应

摘要 析氧反应（OER）是水电解的半反应，电催化剂的OER性能与其能量转换效率显着相关。由于其高 OER 活性，过渡金属基纳米材料已成为碱性环境中 Ir/Ru 基 OER 电催化剂的潜在低成本替代品。在此，多孔 Fe3O4 偶联的 Ni(OH)2 片（Ni(OH)2-Fe H-STs）可以通过简单的混合氰凝胶水解策略轻松实现。二维 (2D) Ni(OH)2-Fe H-STs 1 nm 厚度具有高比表面积、丰富的不饱和配位原子和众多孔隙，非常有利于电催化反应。同时，Fe的引入提高了电导率并调节了Ni的电子结构。由于其特殊的结构特征和 Fe 和 Ni 原子之间的协同作用，具有最佳 Ni/Fe 比的 Ni(OH)2-Fe H-STs 在 1 M KOH 溶液中表现出优异的 OER 活性，显着超过商业 RuO2 纳米粒子电催化剂。此外，Ni(OH)2-Fe H-STs 可以在镍泡沫 (NF) 上生长，所得材料表现出增强的 OER 活性，例如 200 mV 的小过电位和 56 mV dec-1 的小塔菲尔斜率, 而不是没有 NF 的 Ni(OH)2-Fe H-STs。