Facile Route of P‐doped Defect‐rich Manganese‐cobalt Oxide Spinel with Enhanced Oxygen Evolution Reaction Performance

Abstract Phosphorus dopants and defects were successfully introduced to a manganese‐cobalt oxide (MCO) spinel via plasma treatment in the presence of NaH 2 PO 2 . High‐energy electrons generated by plasma can produce oxygen vacancy and embed phosphorus into the spinel. To balance the charge of lattice phosphorus, manganese and cobalt atoms left their original sites and deposited as MnO and CoP, thereby forming a disordered structure. Meanwhile, the oxidation state of cobalt increased. These changes provided extra active sites for electrochemical reaction and improved electrical conductivity. In addition, tunnels were formed on the surface, thus favoring mass transport in the electrolyte. Compared with pristine MCO, the spinel doped with phosphorus via plasma treatment showed higher oxygen evolution reaction performance, with a lower onset potential of 1.45 V, higher current density of 25.32 mA cm −2 at 1.75 V, and smaller Tafel slope of 118.7 mV dec −1 . These findings can facilitate the development of high‐activity electrocatalysts with dopants and defects for energy storage and conversion systems.