Cost‐effective production of efficient and robust oxygen evolution electrocatalysts is of primary importance in developing renewable energy technologies. Herein, we develop a simple and efficient method for exploring high‐performance oxygen evolution reaction (OER) electrocatalysts by engineering the surface structure of ferrite nanoparticles on carbon nanotube support through a reduction‐engraved strategy. After the reduction treatment, abundant oxygen vacancies localized on the surface of the ultrafine ferrite nanoparticles favorably affect their electronic structure, assuring a rapid charge transfer, and expose more active sites. In 1.0 m KOH solution, the reduced composites exhibit superior OER electrocatalytic activity to IrO₂, affording a current density of 10 mA cm⁻² at overpotentials of merely 214 mV for Co_0.5Ni_0.5Fe₂O₄@o‐MWCNT (r‐CNFc), 221 mV for CoFe₂O₄@o‐MWCNT (r‐CFc), and 216 mV for NiFe₂O₄@o‐MWCNT (r‐NFc). It is worth mentioning that r‐CNFc could afford a current density of 100 mA cm⁻² at an overpotential of 256 mV, which is approximately ten times higher than that of CNFc at the same overpotential (10.6 mA cm⁻²). These catalysts also exhibit long‐term stability evaluated by controlled‐current electrolysis at least for 120 h. These results demonstrate an efficient method for constructing high‐performance and durable OER electrocatalysts by reducing mixed metal spinel oxides on the conductive support.

中文翻译：

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设计二元/三元铁氧体纳米粒子的表面结构作为高性能的氧分解反应电催化剂

在开发可再生能源技术中，经济高效地生产高效，强大的析氧电催化剂至关重要。本文中，我们通过还原刻划策略设计了碳纳米管载体上的铁氧体纳米颗粒的表面结构，从而开发了一种用于探索高性能氧释放反应（OER）电催化剂的简单有效的方法。还原处理后，位于超细铁氧体纳米颗粒表面的大量氧空位有利于影响其电子结构，确保快速电荷转移，并暴露出更多的活性位。在1.0  m KOH溶液中，还原后的复合材料表现出优于IrO _2的OER电催化活性，电流密度为10 mA cmCo _0.5 Ni _0.5 Fe ₂ O ₄ @ o-MWCNT（r-CNFc）的过电位仅为214 mV ^-2，CoFe ₂ O ₄ oo MWCNT（r-CFc）的过电位仅为214 mV和NiFe _2的216 mV O ₄ @ o-MWCNT（r-NFc）。值得一提的是，r-CNFc在256 mV的超电势下可以提供100 mA cm ^-2的电流密度，这是在相同的超电势（10.6 mA cm ^-2）下CNFc的电流密度的大约十倍。）。这些催化剂还显示出至少120 h的可控电流电解可评估的长期稳定性。这些结果表明，通过还原导电载体上的混合金属尖晶石氧化物，可以有效地构建高性能和耐用的OER电催化剂。