Rational design and synthesis of efficient, stable and low-cost electrocatalysts for oxygen evolution reaction (OER) is critical for renewable energy conversion and storage. Herein, the reduction-engraved strategy was adopted to treat crystalline ferrite nanoparticles, which are highly dispersed on graphene oxide (GO) nanosheets. This reduction treatment generated abundant oxygen vacancies on the surface of nano-scale ferrites and dramatically enhanced their surface area, ensuring that the ferrite nanoparticles possess more accessible active sites for OER, and improve their electronic conductivity. Reduced cobalt/nickel ferrite (Co_0.5Ni_0.5Fe₂O₄, r-CNF), cobalt ferrite (CoFe₂O₄, r-CF) and nickel ferrite (NiFe₂O₄, r-NF) nanoparticles anchoring on the ultrathin GO nanosheets can act as highly active, stable and low-cost OER electrocatalysts in 1.0 M KOH solution. The r-CNF (Co : Ni = 1 : 1) on GO (r-CNFg) shows the best OER performance among the ferrite-based OER electrocatalysts, with an overpotential of 210 mV at 10 mA cm⁻² in 1.0 M KOH solution, much more efficient than that of a commercial benchmark catalyst IrO₂ (230 mV). The catalytic current density of r-CNFg at 1.49 V vs. RHE is about 50 times higher than that of CNF and CNFg. Also, it exhibits prominent electrochemical stability over 500 h in 1.0 M KOH.

中文翻译：

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在氧化石墨烯上使用还原刻蚀铁氧体制备的高效析氧电催化剂†

合理设计和合成用于氧释放反应（OER）的高效，稳定和低成本的电催化剂，对于可再生能源的转化和存储至关重要。在本文中，采用还原刻划策略来处理高度分散在氧化石墨烯（GO）纳米片上的结晶铁氧体纳米粒子。这种还原处理在纳米级铁氧体的表面上产生了大量的氧空位，并显着增加了其表面积，从而确保铁氧体纳米粒子具有更易于接近的OER活性位，并提高了其电子电导率。还原钴/镍铁氧体（Co _0.5 Ni _0.5 Fe ₂ O ₄，r- CNF），钴铁氧体（CoFe ₂ O_{如图4所示}，锚定在超薄GO纳米片上的r- CF）和铁酸镍（NiFe ₂ O ₄，r- NF）纳米颗粒可以在1.0 M KOH溶液中充当高活性，稳定且低成本的OER电催化剂。GO（r- CNFg）上的r- CNF（Co：Ni = 1：1）在铁氧体基OER电催化剂中表现出最佳的OER性能，在1.0 M KOH溶液中10 mA cm ^-2时的过电势为210 mV。，比市售基准催化剂IrO ₂（230 mV）的效率要高得多。r- CNFg在1.49 V vs. RHE时的催化电流密度约为CNF的50倍和CNFg。同样，它在1.0 M KOH中在500小时内表现出突出的电化学稳定性。