Highly efficient, non-precious and stable electrocatalysts for both oxygen (O₂) reduction reaction (ORR) and oxygen evolution reaction (OER) have drawn attention as alternatives to noble-metal catalysts. The rational construction of dual-functional catalysts is meaningful because most nanomaterials can perform only a single electrocatalytic activity. Herein, nitrogen (N)-doped carbon (C) nanotubes encapsulating CoNi alloy (CoNi@NCNTs) nanoparticles coupled with a cobalt (Co) and nickel (Ni) dual atom hybrid are successfully designed and synthesized through a simple metal–organic-framework-assisted strategy, which are explored as a catalyst for ORR and OER. The optimized catalyst exhibits highly efficient bifunctional catalytic activity with a low voltage spacing of 0.78 V between an overpotential of 370 mV (at 10 mA/cm²) toward OER and a half-wave potential of 0.822 V toward ORR, as well as high durability. The excellent electrocatalytic performance should be attributed to the advantages of uniformly dispersed CoNi alloy nanoparticles, highly conductive nitrogen-doped carbon nanotubes and the formation of metal–N _x species. This work provides a novel strategy for rationally designing bifunctional catalysts for reversible energy conversion.

中文翻译：

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合理设计CoNi合金和原子Co / Ni复合材料作为高效电催化剂

氧气（O _2）的高效，非贵重且稳定的电催化剂还原反应（ORR）和析氧反应（OER）作为贵金属催化剂的替代品已引起关注。合理构造双功能催化剂是有意义的，因为大多数纳米材料只能执行单个电催化活性。在此，通过简单的金属-有机框架成功设计并合成了包封CoNi合金（CoNi @ NCNTs）纳米颗粒的掺氮（N）的碳（C）纳米管，并结合了钴（Co）和镍（Ni）双原子杂化物。辅助策略，可作为ORR和OER的催化剂。经过优化的催化剂表现出高效的双功能催化活性，在370 mV（在10 mA / cm ^2时）的超电势之间具有0.78 V的低电压间隔）朝向OER的方向）和0.822 V的半波电位（朝向ORR的方向），以及高耐久性。出色的电催化性能应归因于均匀分散的CoNi合金纳米颗粒，高导电性氮掺杂碳纳米管和金属-N _x物种形成的优势。这项工作为合理设计可逆能量转化的双功能催化剂提供了一种新颖的策略。