Enhancement of the electrochemical capacitance of TiO2nanotube arrays through controlled phase transformation of anatase to rutile

Abstract

Here, we report the fabrication of self-organized titania (TiO₂) nanotube array supercapacitor electrodes through controlled phase transformation of TiO₂, with aerial capacitances as high as 2.6 mF cm⁻², which far exceeds the values so far reported in the literature. The role of phase transformation in the electrochemical charge–discharge behaviour of nanocrystalline TiO₂ nanotubes is investigated and discussed in detail. The ease of synthesis and the exceptional electrochemical properties make these nanotube arrays an alternative candidate for use in energy storage devices.