Electrochemical properties of TiO2 nanotube arrays prepared by anodic oxidation

Abstract

TiO2 nanotube arrays were fabricated by anodic oxidation at different applied voltages, and the electrochemical properties of the TiO2 nanotube arrays were investigated. At higher applied voltage, the average pore size and the length of the tubes were increased due to an increase in the rate of TiO2 formation and dissolution during the anodic oxidation. The TiO2 nanotube electrodes fabricated at an applied voltage of 30 V delivered a first discharge capacity of similar to 235 mu Ah cm(-2). Although the electrode showed a large irreversible capacity during the initial charge/discharge process, it exhibited excellent cycle performance until the fortieth cycle because the larger pore size allowed homogeneous contact between the tubes and the liquid electrolyte by easy penetration of the liquid electrolyte into the tubes.