Synergistic N-doping and oxygen vacancy enrichment in Co3O4@GR-N via plasma treatment for efficient oxygen evolution

The development of efficient Metal-Nitrogen-Carbon (M-N-C) electrocatalysts is typically hindered by complex synthesis procedures and high-temperature treatments that often lead to active site aggregation. Herein, we report a facile, room-temperature plasma-driven strategy to engineer a high-performance Co 3 O 4 @GR-N composite, effectively circumventing these limitations. Unlike conventional thermal methods, this strategy utilizes a synergistic N 2 /H 2 plasma atmosphere to simultaneously achieve high-level N-doping of the graphene support and targeted enrichment of oxygen vacancies (O Vs ) in Co 3 O 4 . This dual-optimization creates a robust Co-N-C interface that electronically modulates the active sites while maximizing their exposure. Consequently, the optimized catalyst exhibits significantly enhanced Oxygen Evolution Reaction (OER) performance in alkaline media, delivering a current density of 10 mA cm − 2 at a low overpotential of 325 mV, significantly outperforming its thermally annealed counterparts. This work establishes the plasma strategy as a powerful, generalizable pathway for the precise defect engineering of advanced electrocatalysts without compromising structural integrity.