Oxygen‐Rich Cobalt–Nitrogen–Carbon Porous Nanosheets for Bifunctional Oxygen Electrocatalysis

Abstract Metal–nitrogen–carbon (M–N–C) materials have attracted much interest in bifunctional oxygen‐involving electrocatalysis for rechargeable Zn–air batteries. Such M–N–C electrocatalysts with M–N x sites show good activity for the oxygen reduction reaction (ORR) but moderate activity for the oxygen evolution reaction (OER). Herein, an oxygen‐rich M–N–C material (O–Co–N/C) with a highly porous nanosheet structure is reported as a bifunctional oxygen electrocatalyst, which is prepared by the direct pyrolysis of ultrathin CoO nanosheets decorated with zeolitic imidazolate framework‐8 nanoparticles under an inert atmosphere. Particularly, Co nanoparticles in the O–Co–N/C electrocatalyst contain both Co–N x and Co–O x coordination environments to provide intrinsic active sites for the ORR and OER, respectively. Furthermore, electrochemical studies show that the O–Co–N/C catalyst retains comparable ORR activity to common M–N–C materials with a half‐wave potential of 0.85 V vs the reversible hydrogen electrode and better OER activity with an overpotential of 0.29 V at the current density of 10 mA cm −2 . This study provides insights into the development of effective oxygen‐involving electrocatalysts with bifunctional metal active centers coordinated by both nitrogen and oxygen atoms.