Electrostatic capacitance of TiO_2 nanowires in a porous alumina template

Abstract

Titanium oxide (TiO_2) nanowires were prepared for an electrolytic capacitor application by the automatic dipping technique using a porous alumina template. The automatic dipping technique allows us to exactly control the dipping rate so that we can obtain homogenous infiltration of nanowires in the porous alumina membrane, even though the solution is very acidic. From the TEM, SEM and XRD measurements, we confirmed that anatase phase TiO2 nanowires are highly infiltrated into the porous alumina template. In addition, the electrostatic capacitance of nanowires was measured and compared with a theoretical calculation using an effective thickness (delta e). We found that the effective thickness corresponds to the mean radius of nanowires and the experimental measurements were in good agreement with the calculations.