Effect of applied potential on the formation of self-organized TiO 2 nanotube arrays and its photoelectrochemical response

Abstract

Self-organized TiO2 nanotube arrays have been fabricated by anodization of Ti foil in an electrochemical bath consisting of 1M of glycerol with 0.5wt of NH4F. The effects of applied potential on the resulting nanotubes were illustrated. Among all of the applied potentials, 30V resulted in the highest uniformity and aspect ratio TiO2 nanotube arrays with the tube's length approximately 1 m and pore's size of 85nm. TiO2 nanotube arrays were amorphous in as-anodized condition. The anatase phase was observed after annealing at 400 °C in air atmosphere. The effect of crystallization and effective surface area of TiO2 nanotube arrays in connection with the photoelectrochemical response was reported. Photoelectrochemical response under illumination was enhanced by using the annealed TiO2 nanotube arrays which have larger effective surface area to promote more photoinduced electrons. Copyright © 2011 Chin Wei Lai and Srimala Sreekantan.