The carbon-based electrocatalyst for rechargeable zinc-air battery not only needs bifunctional activities to oxygen reduction and evolution reactions, but also requires a high graphitization degree to maintain an excellent stability. Herein, a simple and scale-up strategy is developed to synthesize a highly active and stable electrocatalyst (Co@N-CNT) through a solid-state thermal conversion process, derived from a single and easy-to-get precursor (cobaltic Prussian blue analogue). The Co particles trapped inside the tips are the growth sites of the carbon nanotubes and greatly improve the catalytic activity. This kind of special structure helps Co@N-CNT to achieve remarkable bifunctional activities comparable to the noble metal counterparts and superior durability. Interestingly, Co@N-CNT is proved to have no single-atom Co sites on the carbon nanotube. In combination with electrochemical tests, X-ray absorption spectroscopy and theoretical calculations, Co@graphitic N-C is considered to be the best ORR active site while Co@pyridinic N-C is the best OER active site.

用于可充电锌空气电池的碳基电催化剂不仅需要具有氧还原和析出反应的双功能活性，而且需要高石墨化度以保持优异的稳定性。在此，开发了一种简单且按比例放大的策略，通过固态热转化过程合成高活性且稳定的电催化剂（Co@N-CNT），该过程源自单一且易于获得的前体（钴普鲁士蓝）。类似物）。捕获在尖端内的 Co 颗粒是碳纳米管的生长位点，大大提高了催化活性。这种特殊的结构有助于 Co@N-CNT 实现与贵金属对应物相当的显着双功能活性和卓越的耐用性。有趣的是，Co@N-CNT 被证明在碳纳米管上没有单原子 Co 位点。结合电化学测试、X射线吸收光谱和理论计算，Co@graphitic NC被认为是最好的ORR活性位点，而Co@pyridinic NC是最好的OER活性位点。