Study of the dimensions and photoelectric properties of TiO2 NTs prepared by the double Ti-Electrode oxidation method

In this paper, TiO2 nanotube (TiO2 NT) arraies are produced by a modified anodization method referred to as double titanium-electrode oxidation (DTEO). The effects of anodizing factors (e.g., anodizing voltage, time and the NH4F mass fraction of the electrolyte) on the dimensions of the TiO2 NTs are studied by a central composite design (CCD) experiment. From the results, it can be seen that within the scope of tests, the NT length (l) is strongly influenced by the interaction of the anodizing voltage and time. The tube pitch of the NTs (c) only depends on the anodizing voltage and has a positive correlation with it. Moreover, the photoelectric properties of the TiO2 NTs is analysed by using the photocurrent density (Jp) and dimensional parameters, such as the diameter-to-thickness ratio (di/w) of the NTs. In addition, there is a correlation between the di/w and the Jp values. The dimensions and photoelectric conversion properties of the TiO2 NTs can be controlled by the anodizing parameters used for the DTEO method.