Hierarchically Porous Co/CoxMy (M = P, N) as an Efficient Mott–Schottky Electrocatalyst for Oxygen Evolution in Rechargeable Zn–Air Batteries

Abstract Tailoring composition and morphology of electrocatalysts is of great importance in improving their catalytic performance. Herein, a salt‐templated strategy is proposed to construct novel multicomponent Co/Co x M y (M = P, N) hybrids with outstanding electrocatalytic performance for the oxygen evolution reaction (OER). The obtained Co/Co x M y hybrids present porous sheet‐like architecture consisting of many hierarchical secondary building‐units. The synthetic strategy depends on a facile and effective dissolution–recrystallization–pyrolysis process under NH 3 atmosphere of the precursors, which does not involve any surfactant or long‐time hydrothermal pretreatment. That is different from the conventional methods for the synthesis of hierarchical nitrides/phosphides. Benefitting from unique composition/structure‐dependent merits, the Co/Co x M y hybrids as a typical Mott–Schottky electrocatalyst exhibit good OER performance in an alkaline medium compared with their counterparts, as evidenced by a low overpotential of 334 mV at 10 mA cm −2 and a small Tafel slope of 79.2 mV dec −1 , as well as superior long‐term stability. More importantly, the Co/Co x M y +Pt/C achieves higher voltaic efficiency and several times longer cycle life than conventional RuO 2 +Pt/C catalysts in rechargeable Zn–air batteries. It is envisioned that the present work can provide a new avenue for the development of Mott–Schottky electrocatalysts for sustainable energy storage.