Co Nanoparticles Embedded in Mesoporous Walls of Carbon Nanoboxes for Rechargeable Zinc-air Batteries

Graphical A novel ZIF-assisted strategy was developed to synthesize Co nanoparticles loaded on mesoporous N-doped carbon support of hollow cubic nanobox constructed by pyrolysis of TA-treated ZIF-67 at high temperature. The Co−NC-800 NBs-based ZABs present higher power density and better stability than commercial Pt/C catalysts. Design of non-noble metal electrocatalysts with high catalytic activity and stability to replace commercial Pt/C is crucial in the commercialization development of Zn-air batteries (ZABs). In this work, Co catalyst nanoparticles coupled with nitrogen-doped hollow carbon nanoboxes were well designed through zeolite-imidazole framework (ZIF-67) carbonization. As a result, the 3D hollow nanoboxes reduced the charge transport resistance, and the Co nanoparticles loaded on nitrogen-doped carbon supports exhibited excellent electrocatalytic performance for oxygen reduction reaction (ORR, E 1/2 =0.823 V vs . RHE), similar to that of commercial Pt/C. Moreover, the designed catalysts showed an excellent peak density of 142 mW cm −2 when applied on ZABs. This work provides a promising strategy for the rational design of non-noble electrocatalysts with high performance for ZABs and fuel cells.