Preparation of Porous Graphene@Mn3O4 and Its Application in the Oxygen Reduction Reaction and Supercapacitor

Porous graphene has been recognized as a promising material for applications in electrochemical applications. Engineering the porous graphene-based hierarchical and hybrid structures is a promising way to further improve the electrochemical performances. Here, we reported a rational design of the porous graphene@Mn3O4 (PGM) structure for the applications in both the oxygen reduction reaction (ORR) and supercapacitor. Thanks to the efficient porous graphene substrate and rational decoration of Mn3O4, the catalytic performance of as-prepared PGM is comparative to that of Pt/C when used as electrocatalysts for the ORR, showing a relatively positive onset and half-wave potential (0.89 and 0.81 V) and a large diffusion-limiting current density (5.85 mA cm–2). In addition, PGM also shows good specific capacitance (208.3 F g–1), cycle stability, and rate performance when used in the supercapacitor electrodes and asymmetric device (maximum energy density of 30.1 Wh kg–1 and power density of 9500 W kg–1).