Developing active and stable non-precious metal bifunctional electrocatalysts towards the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) still remains a crucial challenge. Herein, we propose a simple strategy of integrating atomically dispersed and nanoscaled Co species embedded in micro-/mesoporous carbon nanosheet/nanotube architecture. Revealed by control and SCN^- poisoning experiments, N species and atomically dispersed Co species are the main active centers for ORR; whereas the metal Co nanocrystals are the chief active species for OER. Additionally, the balanced micro/mesopore distribution offers fast mass diffusion, and carbon nanosheet/nanotube architecture supplies favorable 3D electrical conduct. As a result, the as-prepared CoNC (1:4) exhibits a positive half-wave potential of 0.87 V (vs RHE) for ORR, and a low potential of 1.55 V (vs RHE) at 10 mA cm^-2 for the OER. Importantly, the flexible Zn-air battery using the catalyst exhibits a peak power density of 117 mW cm⁻², a higher round-trip efficiency of 68% cycling at 2 mA/cm^-2, and an excellent cycling stability with 3% decrease after 126 cycles test. This work provides a general strategy to design bifunctional catalysts by integrating atomically dispersed and nanoscaled transitional metal species together with N-doped micro-/mesoporous 3D carbon.

开发用于氧还原反应（ORR）和氧释放反应（OER）的活性和稳定的非贵金属双功能电催化剂仍然是一项关键挑战。在这里，我们提出了一个简单的策略，将嵌入微/中碳纳米片/纳米管结构中的原子分散和纳米级Co物种进行整合。由控制和SCN显示^-中毒实验中，N物种和原子分散的Co物种是ORR的主要活性中心。而金属Co纳米晶体是OER的主要活性物种。此外，平衡的微孔/中孔分布提供了快速的质量扩散，并且碳纳米片/纳米管架构提供了良好的3D导电性。其结果是，所制备的浓度（1：4）表现出0.87 V（VS RHE）对ORR，和1.55 V（VS RHE）的在10mA厘米的低电位的正半波电势^-2的OER。重要的是，使用该催化剂的柔性Zn-空气电池的峰值功率密度为117 mW cm ^-2，在2 mA / cm ^-2时具有68％的更高循环效率，并具有出色的循环稳定性，经过126次循环测试后降低了3％。这项工作提供了一种通过将原子分散的纳米级过渡金属物种与N​​掺杂的微/介孔3D碳分子整合在一起来设计双功能催化剂的一般策略。