Rational design and engineering of cost-effective, high-performance reversible oxygen electrocatalysts for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is imperative in advancing the progress of rechargeable metal-air batteries (r-MABs). Herein, nanocomposites based on Co@Ru core@shell nanoparticles embedded within N-doped carbon nanosheets (Co@Ru/CS) are prepared via facile galvanic exchange reactions of RuCl with Co/NC and used as an effective oxygen electrocatalyst for rechargeable zinc-air battery (r-ZAB). Electrochemical studies demonstrate a remarkable bifunctional catalytic performance of Co@Ru/CS towards both ORR and OER, featuring a low potential gap (ΔE) of only 0.69 V between the OER potential (E) at 10 mA cm and half-wave potential (E) of ORR, which is much lower than that of commercial Pt/C + RuO catalysts (0.76 V). Combined studies of experimental characterizations and density functional theory calculations show that the ORR activity arises primarily from the N-doped carbon and CoN moieties in the composites, whereas RuO/CoOOH produced at high electrode potentials is responsible for the OER activity. Co@Ru/CS based r-ZAB exhibits an open circuit voltage of 1.447 V, specific capacity of 781 mAh g, and maximum power density of 115 mW cm at 0.83 V, a performance better than that with commercial Pt/C + RuO (1.412 V, 760.56 mAh g, and 91 mW cm). Results from this research underline the substantial impact of structural engineering on optimizing the electrocatalytic activity of nanocomposites for r-MABs.

中文翻译：

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嵌入氮掺杂碳纳米片中的钴@钌核@壳纳米颗粒作为可逆氧电催化剂


用于析氧反应（OER）和氧还原反应（ORR）的经济高效、高性能可逆氧电催化剂的合理设计和工程对于推动可充电金属空气电池（r-MAB）的进步至关重要。在此，通过 RuCl 与 Co/NC 的简单电交换反应制备了基于 Co@Ru 核@壳纳米颗粒嵌入 N 掺杂碳纳米片 (Co@Ru/CS) 的纳米复合材料，并用作可充电锌的有效氧电催化剂。空气电池（r-ZAB）。电化学研究表明，Co@Ru/CS 对 ORR 和 OER 均具有卓越的双功能催化性能，其特点是 10 mA cm 下的 OER 电位 (E) 与半波电位 (E) 之间的电位差 (ΔE) 仅 0.69 V。 ）的 ORR，远低于商业 Pt/C + RuO 催化剂 (0.76 V)。实验表征和密度泛函理论计算的综合研究表明，ORR 活性主要来自复合材料中的 N 掺杂碳和 CoN 部分，而在高电极电位下产生的 RuO/CoOOH 则负责 OER 活性。 Co@Ru/CS基r-ZAB的开路电压为1.447 V，比容量为781 mAh g，0.83 V时的最大功率密度为115 mW cm，性能优于商用Pt/C + RuO（ 1.412 V、760.56 mAh g 和 91 mW cm）。这项研究的结果强调了结构工程对优化 r-MAB 纳米复合材料电催化活性的重大影响。