Developing low-cost and efficient oxygen electrocatalysts for oxygen reduction and evolution reaction (ORR&OER) is critical for various energy conversion technologies. Herein, we report an arc discharge strategy coupled with an controllable oxidation to prepare Co/Co₃O₄ nanoparticles confined in ultrathin O-doped graphitic carbon layer (Co/Co₃O₄@ODGC) as highly active bifunctional oxygen electrocatalysts for Zn-air batteries (ZABs). The resultant Co/Co₃O₄@ODGC shows an impressive ORR performance with a half-wave potential of 0.80 V in 0.1 M KOH. It also exhibits remarkable OER performance with a small overpotential of 300 mV to reach a current density of 10 mA cm⁻². Both experimental studies and theoretical calculations indicate that the high ORR and OER activities are attributed to the synergistic electronic effect between the Co/Co₃O₄ heterostructures and ultrathin O-doped graphitic layer (~1.5 nm). Particularly, the electron redistribution in graphitic layer caused by O-doping and carbon defects significantly decreases the energy barrier for oxygen adsorption/desorption. More attractively, the as-constructed ZABs with Co/Co₃O₄@ODGC cathode show an impressive open voltage (1.60 V), a high power density of 107 mW cm⁻², and good stability without nearly no performance decay for 40 h at 2.0 mA cm⁻². This work provides both fundamental understanding and easy strategy for developing the efficient bifunctional oxygen electrocatalysts for high performance metal-air batteries.

开发用于氧还原和析出反应 (ORR&OER) 的低成本高效氧电催化剂对于各种能量转换技术至关重要。在此，我们报告了一种电弧放电策略与可控氧化相结合，以制备限制在超薄 O 掺杂石墨碳层 (Co/Co ₃ O ₄ @ODGC) 中的Co/Co ₃ O ₄纳米粒子作为 Zn-的高活性双功能氧电催化剂。空气电池（ZAB）。所得的 Co/Co ₃ O ₄ @ODGC 显示出令人印象深刻的 ORR 性能，在 0.1 M KOH 中的半波电位为 0.80 V。它还表现出卓越的 OER 性能，具有 300 mV 的小过电位，可达到 10 mA cm ^-2的电流密度. 实验研究和理论计算表明，高 ORR 和 OER 活性归因于 Co/Co ₃ O ₄异质结构和超薄 O 掺杂石墨层（~1.5 nm）之间的协同电子效应。特别是，由氧掺杂和碳缺陷引起的石墨层中的电子重新分布显着降低了氧吸附/解吸的能垒。更吸引人的是，具有 Co/Co ₃ O ₄ @ODGC 阴极的构建态ZAB 显示出令人印象深刻的开路电压 (1.60 V)、107 mW cm ^-2的高功率密度和良好的稳定性，40 小时内几乎没有性能衰减在 2.0 mA cm ^-2. 这项工作为开发用于高性能金属-空气电池的高效双功能氧电催化剂提供了基本的理解和简单的策略。