Hierarchical micro/nanostructured Co3O4@MnCo2O4 core-shell nanowire arrays on Ni foam for electrochemical energy storage

Abstract

In this work, hierarchical micro/nanostructured Co3O4@MnCo2O4 nanowire arrays supported on nickel foam were prepared via a facile hydrothermal process for the first time, in which the hydrothermally synthesized Co3O4 nanowire arrays served as the scaffold, anchoring the MnCo2O4 nanosheets. When evaluated as binder-free electrodes for supercapacitors, the optimized Co3O4@MnCo2O4 hybrid electrodes exhibited a remarkable electrochemical performance with a high specific capacitance of 736.5 F g−1 at a current density of 1 mA cm−2, nearly two times than that of the pristine Co3O4 electrode (370.67 F g−1). Moreover, the Co3O4@MnCo2O4 hybrid electrode exhibited superior cycling stability with 76.95% retention over 3000 cycles at a current density of 10 mA cm−2. Since the excellent supercapacitive performance of Co3O4@MnCo2O4 hybrid electrode could be attributed to the unique core-shell architecture and the synergistic effect of the Co3O4 nanowires and the ultrathin MnCo2O4 nanosheets, Co3O4@MnCo2O4 nanowire arrays hold great potentials for the applications in the field of electrochemical energy storage.