Facile synthesis of three-dimensional NiCo2O4@Co3O4 nanowire array for application in supercapacitors

A three-dimensional NiCo2O4@Co3O4 hybrid array on Ni foam electrode for supercapacitors was synthesised via a facile two-step hydrothermal method, in which the NiCo2O4 was self-assembled on the Co3O4 nanowire grown on Ni foam. Moreover, the electrochemical properties of the binder-free electrodes were studied by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy. Electrochemical characterisations indicated that the unique nano-architecture exhibited excellent electrochemical properties of a high capacitance (1075 F/g), good rate (102.4%), cycling stability (92.6%), which were superior to the pristine Co3O4 nanowire. The results clearly confirmed that growing NiCo2O4 on Co3O4 nanowire could substantially improve the capacitive performance of Co3O4 materials.