Developing cost-effective, highly-active and robust electrocatalysts is of vital importance to supersede noble-metal ones for both hydrogen evolution reactions (HERs) and oxygen reduction reactions (ORRs). Herein, a unique vanadium-mediated space confined strategy is reported to construct a composite structure involving Co/Co₉S₈ nanoparticles anchored on Co–N-doped porous carbon (VCS@NC) as bifunctional electrocatalysts toward HER and ORR. Benefitting from the ultrafine nanostructure, abundant Co–N_x active sites, large specific surface area and defect-rich carbon framework, the resultant VCS@NC exhibits unexceptionable HER catalytic activity, needing extremely low HER overpotentials in pH-universal media (alkaline: 117 mV, acid: 178 mV, neutral: 210 mV) at a current density of 10 mA cm⁻², paralleling at least 100 h catalytic durability. Notably, the VCS@NC catalyst delivers high-efficiency ORR performance in alkaline solution, accompanied with a quite high half wave potential of 0.901 V, far overmatching the commercial Pt/C catalyst. Our research opens up novel insight into engineering highly-efficient multifunctional non-precious metal electrocatalysts by a metal-mediated space-confined strategy in energy storage and conversion system.

中文翻译：

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钒介导的超细 Co/Co9S8 纳米粒子锚定在 Co-N 掺杂的多孔碳上，可实现高效的析氢和氧还原反应

开发具有成本效益、高活性和稳健的电催化剂对于在析氢反应 (HER) 和氧还原反应 (ORR) 中取代贵金属催化剂至关重要。在此，报道了一种独特的钒介导的空间受限策略来构建复合结构，该复合结构涉及锚定在 Co-N 掺杂多孔碳 (VCS@NC) 上的 Co /Co ₉ S ₈纳米颗粒作为 HER 和 ORR 的双功能电催化剂。受益于超细纳米结构，丰富的 Co-N _x活性位点、大比表面积和富含缺陷的碳骨架，所得的 VCS@NC 表现出无与伦比的 HER 催化活性，在 pH 通用介质（碱性：117 mV，酸性：178 mV，中性：210 mV）中需要极低的 HER 过电位) 在 10 mA cm ^-2的电流密度下，至少具有 100 小时的催化耐久性。值得注意的是，VCS@NC 催化剂在碱性溶液中提供高效的 ORR 性能，伴随着 0.901 V 的相当高的半波电位，远远超过商业 Pt/C 催化剂。我们的研究为通过能量存储和转换系统中金属介导的空间限制策略设计高效多功能非贵金属电催化剂开辟了新的视角。