Anatase TiO2 nanotube by electrochemical anodization method: effect of tubes dimension on the supercapacitor application

This study investigates the suitability of titanium dioxide (TiO2) nanotubes for supercapacitor application. For this purpose, electrochemical anodization technique has been employed. In order to obtain the nanotubes with different dimensions, the quantity of ethylene glycol (Eg) and glycerol (Gy) were varied in the concentration ratio 70:30 (E7G3) and 50:50 (E5G5), respectively. The tube length and pore diameter of the nanotubes are found to be 7.6 μm and 96 nm for E5G5 and 9.1 μm and 110 nm for E7G3 samples. Nanostructured materials with high surface area show strong influence in modifying their specific capacitance. Hence, both samples exhibit good charge storage and electrochemical double-layer capacitor (EDLC) behavior which was confirmed by cyclic voltammetry studies. But, E7G3 samples have shown maximum areal specific capacitance of 1300 μF/cm2 at a scanning rate of 20 mV/s, which was mainly due to its availability of more active sites for ions adsorption on the nanotube surface.