Mesoporous ITO/NiO with a core/shell structure for supercapacitors

In this study, a novel mesoporous NiO/ITO NW with a shell/core structure has been successfully synthesized by combining chemical vapor deposition (CVD) on titanium substrate and electrodeposition of H_I-e (hexagonal lyotropic) nickel hydroxide through a lyotropic liquid crystalline (LLC) template, followed by calcination in air at 270°C. The electrode material is characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Both cyclic voltammetry (CV) and chronopotentiometry demonstrate enhanced electrochemical properties of NiO/ITO NWs composite electrode and improved supercapacitive behaviors as compared to bulk mesoporous nickel oxide film. Maximum specific capacitance of 1025Fg^-1 at a discharge current density of 1Ag^-1 in the potential ranges from 0V to 0.5V is determined by galvanostatic charge-discharge measurement in 1M KOH solution. The newly synthesized heterostructure also possesses high capacitance retention ratio at high discharge current densities and long-term electrochemical stability in an alkaline solution. Therefore, this study provides a promising electrode engineering technique for various applications.