Electrochemical performance of mesoporous ZnCo2O4 nanosheets as an electrode material for supercapacitor

摘要

The mesoporous ZnCo2O4 nanosheets were synthesized via a facile hydrothermal method and subsequent thermal annealing treatment. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N-2 adsorption/desorption isotherms (BET) to obtain information about its crystal structure, morphology, and BET surface area, respectively. The nanosheets present hexagonal shape with mesoporous structure in nature. The obtained mesoporous ZnCo2O4 nanosheets exhibit a high specific surface area of 191.64 m(2)/g. The electrochemical properties of the mesoporous ZnCo2O4 nanosheets were investigated by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) in 6 mol/L KOH aqueous electrolyte. The ZnCo2O4 nanosheets show a high specific capacity of 835.26 F/g at the current density of 1.0 A/g, as well as good cycle stability with specific capacitance remaining 73.28% of the initial value after 1000 continuous charge-discharge cycles under the current density of 8 A/g. These superior electrochemical features demonstrate that the mesoporous ZnCo2O4 nanosheet is a promising electroactive material for supercapacitor.