The development of a facile method to construct a high-performance electrode is of paramount importance to the application of alkaline water electrolysis. Here, we report that the activity of nickel foam (NF) towards the oxygen evolution reaction (OER) can be enhanced remarkably through simple immersion in a ferric nitrate (Fe(NO₃)₃) solution at room temperature. During this immersion process, the oxidation of the NF surface by NO₃⁻ ions increases the near-surface concentrations of OH⁻ and Ni²⁺, which results in the in situ deposition of a highly active amorphous Ni-Fe hydroxide (a-NiFeO_xH_y) layer. Specifically, the OER overpotential of the NF electrode decreases from 371 mV (bare NF) to 270 mV (@10 mA·cm⁻² in 0.1 M KOH) after immersion in a 20 mM Fe(NO₃)₃ solution for just 1 min. A longer immersion time results in further increased OER activity (196 mV@10 mA·cm⁻² in 1 M KOH). The overall water splitting properties of the a-NiFeO_xH_y@NF electrode were evaluated using a two-electrode configuration. It is worth noting that the current density can reach 25 mA·cm⁻² in 6 M KOH at an applied voltage of 1.5 V at room temperature.

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构造高性能电极的简便方法的开发对于碱性水电解的应用至关重要。在这里，我们报告通过在室温下简单地浸入硝酸铁（Fe（NO ₃）₃）溶液中，可以显着提高泡沫镍（NF）对析氧反应（OER）的活性。在此浸渍处理，通过NO的NF表面的氧化₃ ^-离子增加OH的近表面浓度^-和Ni ²⁺，这导致就地高活性的无定形镍-铁氢氧化物的沉积（A-NiFeO _X ħ _ÿ） 层。具体而言，将NF电极的OER过电势在20 mM Fe（NO ₃）₃溶液中浸泡1分钟后，从371 mV（裸NF）降至270 mV（@ ^MmA在0.1 M KOH中为10 mA·cm ^-2）。。较长的浸泡时间导致OER活性进一步提高（在1 M KOH中为196 mV @ 10 mA·cm ^-2）。使用两电极配置评估了a-NiFeO _x H _y @NF电极的总水分解性能。值得注意的是，在室温下，在1.5 V的施加电压下，在6 M KOH中的电流密度可以达到25 mA·cm ^-2。

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