Effect of Anodization Parameters on Morphology and Photocatalysis Properties of TiO2 Nanotube Arrays

Highly ordered TiO2 nanotube arrays were fabricated via electrochemical anodization of high purity Ti foil in fluoride-containing electrolyte. The effects of applied anodization potential, anodization time on the formation of TiO2 nanotube arrays and the photocatalytic degradation of methylene blue (MB) were discussed. The TiO2 nanotube arrays calcined at 500 °C for 2 h show pure anatase phase. The pore diameters of TiO2 nanotube arrays can be adjusted from 30 to 90 nm using a different anodization voltage. Anodization time mainly influenced TiO2 tube length, and by increasing the anodization time, the nanotube length became longer gradually. When the anodization potential was 40 V, the average growth rate of TiO2 nanotube was about 4.17 µm/h. Both anodization potential and time had important effects on the photocatalytic efficiency. The TiO2 nanotube arrays obtained at anodization potential of 40 V for 1 h showed the best photocatalytic degradation ratio of MB.