Boosting Oxygen Electrocatalysis of CoC₈N₈ via Axial Coordination

The quest for efficient and durable catalysts using abundant resources has garnered significant interest in the field of bifunctional oxygen electrocatalysis. In this work, the electrocatalytic performances of CoC₈N₈ bilayers with and without O/S axial coordination toward oxygen reduction and oxygen evolution have been systematically investigated via density functional theory calculations. Our results demonstrate the stacking manner influences the catalytic performance. Furthermore, the presence of axial coordination modulates the oxygen bifunctional electrocatalysis. According to the thermodynamic analysis, the CoC₈N₈ bilayer with O axial coordination delivers the outstanding performances toward oxygen reduction and oxygen evolution, as reflected by the small overpotentials of 0.37 and -0.36 V, being superior than the benchmark materials of Pt and IrO₂, respectively. Conversely, the introduction of S axial coordination degrades the thermodynamic activity of oxygen electrocatalysis. This work opens a new path for designing the efficient electrocatalysts via modification of coordination environment.