Ultrathin FeNiO_xH_y nanoflake arrays with the thickness of only ~4.5 nm were prepared on Ni foam (NF) via a facile hydrothermal reaction. The oxygen evolution reaction (OER) properties of the obtained sample (FeNiO_xH_y/NF) were investigated under alkaline conditions (1.0 M KOH). The optimized FeNiO_xH_y/NF displays extremely small overpotentials of only 195 and 306 mV to achieve the current densities of 10 and 1000 mA cm⁻², respectively, and shows almost no potential attenuation during the 160 hours of stability test even the current density is up to 1000 mA cm⁻², demonstrating brilliant OER catalytic activity and durability. FeOOH and the NiOOH produced from the in situ oxidation of the surface Ni atoms of the NF substrate are the active sites. The synergistic effect between FeOOH and NiOOH is responsible for the high performances. To our knowledge, the high activity and stability of FeNiO_xH_y/NF catalyst outperform almost all of the OER catalysts reported to date. These informative findings are valuable not only for understanding the mechanism of OER but also for the design of cheap transition metal catalysts for industrial water electrolysis at high current densities.

中文翻译：

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负载在泡沫镍上的氢氧化镍铁纳米片阵列具有出色的催化特性，可在高电流密度下释放氧气

通过便捷的水热反应在镍泡沫（NF）上制备了厚度仅为〜4.5 nm的超薄FeNiO _x H _y纳米片阵列。在碱性条件（1.0 M KOH）下研究了所得样品的氧析出反应（OER）性质（FeNiO _x H _y / NF）。经过优化的FeNiO _x H _y / NF分别显示出仅195和306 mV的极小的超电势，以分别实现10和1000 mA cm ^-2的电流密度，并且在160小时的稳定性测试中，即使是电流，也几乎没有潜在的衰减。密度高达1000 mA cm ^-2，证明了出色的OER催化活性和耐久性。由NF基底的表面Ni原子的原位氧化产生的FeOOH和NiOOH是活性位点。FeOOH和NiOOH之间的协同作用是高性能的原因。据我们所知，FeNiO _x H _y / NF催化剂的高活性和稳定性优于迄今为止报道的几乎所有OER催化剂。这些有益的发现不仅对于了解OER的机理，而且对于设计用于高电流密度工业水电解的廉价过渡金属催化剂的设计都是有价值的。