Water electrolysis is a promising strategy to produce green hydrogen. However, this process is hampered by the high cost of precious electrode and the sluggish kinetics of oxygen evolution reaction (OER). Thus, it is desirable for developing an efficient and low-cost OER electrocatalyst. Herein, N and Fe co-doped CoO nanoparticles (Co_xFe_yO-N), rich of O vacancies and the interface of CoO/Co_xN, were successfully prepared via the annealing of Fe doped cobalt-based coordination polymers in an NH₃ atmosphere. The ratio of Co²⁺ and Fe³⁺ was systematically varied, and Co_0.89Fe_0.11O-N possesses the highest OER activity in 1.0 M KOH. Furthermore, through growth of the resultant Co_0.89Fe_0.11O-N onto nickel foam, the corresponding OER activity can be further enhanced with the overpotential of 360 mV at current density of 50 mA cm⁻². The superior OER activity of Co_0.89Fe₁₁O-N originates from the presence of oxygen vacancies and CoO/Co_xN interface. During the reaction, CoO-N was partially oxidized into Co₃O₄, which accompanies CoO to co-catalyze OER. The study provides new insights for the preparation and understanding the active sites for Co-based catalysts for OER.

水电解是产生绿色氢的一种有前途的策略。然而，该过程受到贵重电极的高成本和氧气析出反应（OER）反应迟缓的动力学的阻碍。因此，期望开发有效且低成本的OER电催化剂。本文中，通过Fe掺杂的钴基配位聚合物在NH _3中的退火，成功地制备了N和Fe共掺杂的CoO纳米颗粒（Co _x Fe _y O-N），富含O空位和CoO / Co _x N的界面。气氛。系统地改变了Co ²⁺和Fe ³⁺的比例，Co _0.89 Fe _0.11ON在1.0 M KOH中具有最高的OER活性。此外，通过将所得的Co _0.89 Fe _0.11 O-N生长到泡沫镍上，在50mA cm ^-2的电流密度下具有360mV的过电势，可以进一步提高相应的OER活性。Co _0.89 Fe ₁₁ O-N优异的OER活性源自氧空位和CoO / Co _x N界面的存在。在反应过程中，CoO-N被部分氧化成Co ₃ O ₄，并与CoO共同催化OER。该研究为制备和了解OER的Co基催化剂的活性位点提供了新的见解。