Abstract Exploring highly efficient and low-cost bifunctional electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is significant for the development of renewable energy. Here, Co9S8 nanospheres with hollow structure anchored on N and S dual-doped graphene oxide (Co9S8-NSGO) are synthesized by solvothermal strategy. After pyrolyzed, advanced bifunctional electrocatalysts with feature of sea-island architecture of Co9S8 polyhedrons evenly dispersed on N and S co-doped graphene sheets (Co9S8-NSG) are obtained, in which Co9S8 polyhedrons stem from the derivative of Co9S8 nanospheres. Ascribed to large surface area, sea-island structure of uniform dispersion of Co9S8 nanoparticles on graphene, synergistic effect between Co9S8 and graphene and more active sites based N and S doping, the as-prepared Co9S8-NSG catalyst exhibits excellent OER performance with a small overpotential (240 mV at 10 mA cm−2) and satisfactory ORR performance with half-wave potential (0.79 V). Notably, a zinc-air battery using Co9S8-NSG as air cathode shows high peak power density (120 mW cm−2) and outstanding cycling stability (120 h at 10 mA cm−2).

中文翻译：

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中空 Co9S8 球体衍生的多面体均匀锚定在 N、S 掺杂的石墨烯上，用于高效氧电催化剂

摘要 探索用于析氧反应（OER）和氧还原反应（ORR）的高效低成本双功能电催化剂对于可再生能源的发展具有重要意义。在这里，通过溶剂热策略合成了锚定在 N 和 S 双掺杂氧化石墨烯 (Co9S8-NSGO) 上的具有中空结构的 Co9S8 纳米球。热解后，获得了具有海岛结构的先进双功能电催化剂，Co9S8 多面体均匀分散在 N 和 S 共掺杂石墨烯片（Co9S8-NSG）上，其中 Co9S8 多面体来源于 Co9S8 纳米球的衍生物。归因于大表面积、Co9S8 纳米粒子在石墨烯上均匀分散的海岛结构、Co9S8 与石墨烯之间的协同效应以及更多基于 N 和 S 掺杂的活性位点，所制备的 Co9S8-NSG 催化剂表现出优异的 OER 性能，具有较小的过电位（10 mA cm-2 时为 240 mV）和具有半波电位（0.79 V）的令人满意的 ORR 性能。值得注意的是，使用 Co9S8-NSG 作为空气阴极的锌空气电池显示出高峰值功率密度（120 mW cm-2）和出色的循环稳定性（10 mA cm-2 时为 120 小时）。