Hierarchical Co3O4@ZnWO4 core/shell nanostructures on nickel foam: Synthesis and electrochemical performance for supercapacitors

To improve the electrochemical properties of Co3O4 for supercapacitors application, a hierarchical Co3O4@ZnWO4 core/shell nanowire arrays (NWAs) material is designed and synthesized successfully via a facile two-step hydrothermal method followed by the heat treatment. Co3O4@ZnWO4 NWAs exhibits excellent electrochemical performances with areal capacitance of 4.1 F cm−2 (1020.1 F g−1) at a current density of 2 mA cm−2 and extremely good cycling stability (99.7% of the initial capacitance remained even after 3000 cycles). Compared with pure Co3O4 electrodes, the results prove that this unique hierarchical hybrid nanostructure and reasonable assembling of two electrochemical pseudocapacitor materials are more advantageous to enhance the electrochemical performance. Considering these remarkable capacitive behaviors, the hierarchical Co3O4@ZnWO4 core/shell NWAs nanostructure electrode can be revealed promising for high-performance supercapacitors.