Nanostructured Ni and Fe hydroxides and oxides have drawn significant attention for oxygen evolution reaction (OER) because of their high catalytic efficiency and low cost. Herein, a facile cyclic voltammetry method is reported for the autologous growth of a highly integrated and efficient NiFe-OOH catalyst for OER by electrochemical roughening of Ni foam substrates in 6 M KOH using an iron rod counter electrode. The electrochemical roughening created nanostructured Ni surface with low interfacial electrical resistance and 25 times higher surface area, accompanied by in situ doping of Fe. Electrochemical characterizations revealed that the formed NiFe-OOH catalysts exhibit an extremely low OER onset overpotential of 190 mV and a Tafel slope merely of 48.1 mV dec-1 in 1 M KOH. Further, a NaBH4 reductive treatment was applied to create more surface defects on NiFe-OOH leading to further enhanced catalyst conductivity and a further decrease of the Tafel slope to 34.7 mV dec-1. The electrode demonstrated prolonged electrochemical and mechanical stability at high current densities in industrial 30 wt.% KOH solutions.

中文翻译：

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原位电化学铁掺杂自生生长羟基氧化镍以实现有效的放氧反应

纳米结构的Ni和Fe氢氧化物和氧化物因其高催化效率和低成本而备受氧释放反应（OER）的关注。本文中，报道了一种简便的循环伏安法，该方法通过使用铁棒对电极在6 M KOH中对Ni泡沫基材进行电化学粗化来自生生长用于OER的高度集成且高效的NiFe-OOH催化剂。电化学粗糙化可形成具有低界面电阻和25倍大表面积的纳米结构Ni表面，并伴有Fe的原位掺杂。电化学特征表明，所形成的NiFe-OOH催化剂在1 M KOH中的OEER起始超电势极低，为190 mV，Tafel斜率仅为48.1 mV dec-1。进一步，进行了NaBH4还原处理，以在NiFe-OOH上产生更多的表面缺陷，从而导致催化剂电导率进一步提高，Tafel斜率进一步降低至34.7 mV dec-1。在工业30％（重量）KOH溶液中，该电极在高电流密度下显示出延长的电化学和机械稳定性。