Laser-induced rapid construction of Co/N-doped honeycomb-like carbon networks as oxygen electrocatalyst used in zinc-air batteries

Abstract

Metal-organic frameworks (MOFs) template method is a general strategy for synthesising metal-nitrogen-doped carbon catalysts, especially in oxygen electrocatalysts. However, the traditional heat treatment method that transforms MOFs into carbon material requires high temperature, long preparation time, and a harsh gas environment. Herein, we reported a laser-induced carbonized strategy (LIC) that rapidly converts the MOFs into conductive carbon network structures in milliseconds ambient conditions. Interestingly, through LIC, the ZIF-67 derived Co/N-doped honeycomb-like carbon networks present a better bifunctional electrocatalyst performance than the carbon catalyst treated by the traditional carbonization process. This could ascribe to their high specific surface area (SSA) and unique honeycomb-like opening channel structure, which is beneficial for electrolyte storage and mass transfer process. Furthermore, the effect of precursor MOFs size on the catalytic properties was investigated for the laser-induced derived materials. Finally, to better study practical application, the optimized Co/N-doped honeycomb-like carbon networks as catalytic layer was assembled in zinc-air batteries, endowing long cycling stability (220 h) and high specific capacity (780 mA h g−1). This work provides a cost-effective approach for the rapid construction of electrocatalysts for energy conversion and storage applications.