Oxygen evolution reaction (OER) is a crucial half-reaction for many energy conversion technologies, which requires efficient catalysts to boost its sluggish kinetics. Herein, the FeNi catalyst with a high phosphating level (HP-Fe_xNi_2−xP) is constructed by a three-step synthetic route: (i) hydrothermal deposition of lamellar sheets, (ii) NaBH₄ pretreatment, and (iii) in situ phosphorization. FeNi layered double lamellar hydroxides were synthesized as the pre-catalysts. Then NaBH₄ pretreatment was used to remove the oxide impurities and introduce oxygen vacancies to promote phosphorization in the subsequent process. Finally, HP-Fe_xNi_2−xP nanosheets were achieved, with several advantages like abundant exposed active sites, high conductivity, and accessible mass transport channels. During the OER process, FeNiOOH/HP-Fe_xNi_2−xP interfaces are formed through spontaneous electrochemical activation and surface reconstruction. Benefitting from the synergistic interfacial effect and abundant exposed active sites, the NiFe based catalysts show an overpotential of ≈ 208 mV to reach 10 mA cm⁻² in 1 M KOH, and a stability of 200 h at 1 A cm⁻². Overall, this work reports the rational design and preparation of a highly active OER catalyst, but also provides a general route through NaBH₄ pretreatment, which can be usefully applied to promote phosphorization in other systems of interest for catalytic applications.

析氧反应 (OER) 是许多能量转换技术的关键半反应，需要高效的催化剂来提高其缓慢的动力学。在此，具有高磷化水平的 FeNi 催化剂 (HP-Fe _x Ni _2−x P) 是通过三步合成路线构建的：(i) 层状片材的水热沉积，(ii) NaBH ₄预处理，以及 (iii) )原位磷化。合成了 FeNi 层状双层氢氧化物作为预催化剂。然后采用NaBH ₄预处理去除氧化物杂质并引入氧空位促进后续工艺的磷化。最后，HP-Fe _x Ni _2−x实现了 P 纳米片，具有多个优点，如丰富的暴露活性位点、高电导率和可访问的传质通道。在 OER 过程中，FeNiOOH/HP-Fe _x Ni _2−x P 界面通过自发的电化学活化和表面重构形成。受益于协同界面效应和丰富的暴露活性位点，NiFe 基催化剂在 1 M KOH 中表现出 ≈ 208 mV 的过电势以达到 10 mA cm ^{-2 ，并且在 1 A cm -2}下具有 200 h 的稳定性。_{总的来说，这项工作报告了高活性 OER 催化剂的合理设计和制备，同时也提供了通过 NaBH 4}的一般路线预处理，可有效地用于促进其他感兴趣的催化应用系统中的磷化。