Abstract One of the crucial issues in rechargeable zinc-air batteries is to explore low-cost, highly efficient bifunctional electrocatalysts for the oxygen reduction/evolution reaction. Here, the unique NiCo alloy nanoparticles encapsulated in the multi-dimensional nitrogen-doped carbon architecture (NiCo/MNC) is reported as an effective bifunctional catalyst for rechargeable zinc-air batteries. The multi-dimensional nitrogen-doped carbon architecture was synthesized through the rapid calcination of two-dimensional graphitic carbon nitride (g-C3N4) and one-dimensional multi-walled carbon nanotubes (MWCNTs). The g-C3N4 serves as the nitrogen source and the precursor for N-doped carbon nanosheets (NCSs). Simultaneously, NCSs can intertwine with MWCNTs to further obtain the multi-dimensional architecture with a large specific surface area. The synergistic effect between multi-dimensional nitrogen-doped carbon architectures and NiCo alloy nanoparticles endowed the NiCo/MNC with a positive half-wave potential of 0.83 V (vs. RHE: Reversible Hydrogen Electrode) for oxygen reduction reaction and a low potential of 1.61 V (vs. RHE) at the current density of 10 mA cm−2 for oxygen evolution reaction. Moreover, the zinc-air battery assembled with NiCo/MNC as the air-cathode exhibited a high-power density of 135.2 mW cm−2, a specific capacity of 701.7 mAh g−1, and an excellent stability in charging/discharging cycle test (over 115 h). The prepared catalyst could potentially serve to take the place of precious metal catalysts in rechargeable zinc-air batteries.

中文翻译：

---

NiCo合金纳米粒子封装在多维N掺杂碳结构中作为可充电锌空气电池的高效双功能催化剂

摘要 可充电锌空气电池的关键问题之一是探索低成本、高效的双功能电催化剂用于氧还原/析出反应。在这里，封装在多维氮掺杂碳结构 (NiCo/MNC) 中的独特 NiCo 合金纳米粒子被报道为可充电锌空气电池的有效双功能催化剂。多维氮掺杂碳结构是通过二维石墨氮化碳（g-C3N4）和一维多壁碳纳米管（MWCNTs）的快速煅烧合成的。g-C3N4 作为氮源和 N 掺杂碳纳米片 (NCS) 的前体。同时，NCSs 可以与 MWCNTs 交织，进一步获得具有大比表面积的多维结构。多维氮掺杂碳结构和 NiCo 合金纳米粒子之间的协同效应赋予 NiCo/MNC 0.83 V 的正半波电位（相对于 RHE：可逆氢电极）进行氧还原反应和 1.61 的低电位V (vs. RHE) 在 10 mA cm-2 的电流密度下用于析氧反应。此外，以NiCo/MNC作为空气阴极组装的锌空气电池表现出135.2 mW cm-2的高功率密度、701.7 mAh g-1的比容量和优异的充放电循环测试稳定性（超过 115 小时）。所制备的催化剂有可能替代可充电锌空气电池中的贵金属催化剂。