Ultra dispersed Co supported on nitrogen-doped carbon: An efficient electrocatalyst for oxygen reduction reaction and Zn-air battery

Transition metal supported on nitrogen-doped carbon stands for a typical type of highly effective oxygen reduction reaction (ORR) catalyst. Herein, ultra-dispersed Co loaded on nitrogen-doped carbon (Co-NC 900) was made up via a sacrificial template pyrolysis method, in which g-C3N4 was employed as a directional two-dimensional (2-D) template, and triethylenediamine and benzimidazole were served as the ligands. The Co-NC-900 has a unique crumpled layer structure and exhibits higher electrocatalytic performance for ORR with a positive half-wave potential of 0.838 V in alkaline solution, which is superior to that of Pt/C (0.808 V vs RHE). Moreover, the Zn-air battery assembled with the Co-NC-900 displayed an ultrahigh specific power of 160 mW cm(-2) and can stably operate for a long term. It also displayed robust charging-discharging cycling performance after 45 h, which was better than commercial Pt/C electrode. This work not only provides a simple and low-cost approach for the preparation of layered porous materials but also opens a new way to improve the electrocatalytic performance of nonprecious-metal materials. (C) 2021 Elsevier Ltd. All rights reserved.