Preparation and photoelectric effect of Zn2+-TiO2 nanotube arrays

Zn2+- TiO2 nanotube arrays were prepared by anodic oxidation method. The current-time curves were used to investigate their growth mechanism. Scanning electron microscopy and X-ray diffractometry were applied to characterizing their structures and properties. The photoelectrochemical properties were studied by electrochemical impedance spectrum (EIS). The optimised working conditions for TiO2 nanotube arrays were found to be pH 1, 0.5% HF (mass fraction), 20 V oxidation voltage and for 2 h. The produced sample was in anatase form, with length of 70-100 nm, thickness of 10 nm, uniform diameter and structure that does not collapse under the preparation conditions. The EIS results show that TiO2 nanotube arrays prepared with 0.5% HF (mass fraction) present a low impedance and TiO2 nanotube arrays loaded by Zn2+ could have a decreased resistance. This decrease could likely accelerate the transfer of carriers and even increase photoelectric conversion.