To develop highly efficient and low-cost electrocatalysts based on earth-abundant elements for oxygen evolution reaction (OER) is a great challenge for electrocatalytic water splitting. Herein, a unique type of NiFe-based oxide catalyst with abundant defects is successfully synthesized via pulsed laser ablation in a specific atmosphere containing reductive NH3. The catalyst is self-supported and assembled from ultrafine nanoparticles with size of less than 5 nm. X-ray diffraction, transmission electron microscopy, and x-ray photoelectron spectroscopy analyses suggest that the reductive NH3 results in a large number of oxygen and nickel vacancies and lower crystallinity. Consequently, the catalyst exhibits a high-performance OER activity with a low overpotential of 223 mV at 10 mA cm−2 and a small Tafel slope of 35.0 mV dec−1, surpassing most NiFe-based OER electrocatalysts.

中文翻译：

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脉冲激光辅助合成富含缺陷的 NiFe 基氧化物，用于有效的析氧反应

开发基于地球丰富元素的高效低成本电催化剂用于析氧反应（OER）是电催化水分解的巨大挑战。在此，通过脉冲激光烧蚀在含有还原性 NH3 的特定气氛中成功合成了一种独特类型的具有丰富缺陷的 NiFe 基氧化物催化剂。该催化剂是自支撑的，由尺寸小于 5 nm 的超细纳米粒子组装而成。X 射线衍射、透射电子显微镜和 X 射线光电子能谱分析表明，还原性 NH3 导致大量氧和镍空位以及较低的结晶度。因此，该催化剂表现出高性能的 OER 活性，在 10 mA cm-2 时具有 223 mV 的低过电位和 35.0 mV dec-1 的小塔菲尔斜率，