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.