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

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. (C) 2018 Elsevier B.V. All rights reserved.