Fabrication of polypyrrole/TiO2 nanocomposite via electrochemical process and its photoconductivity

Size-controllable and vertically-oriented TiO2 nanotube (TNT) arrays were fabricated using anodic oxidation method from pure titanium sheets in electrolyte solutions. Then with the TNT arrays as the working electrode, a thin film of polypyrrole (Ppy) was synthesized into the TNT arrays via the electrochemical polymerization. During the process, the appearance of redox peaks in cyclic voltammetry curves of the resulting films indicates the occurrence of polymerization. The morphology, the molecular structure, crystallization and optical properties of the TNT arrays and the resulting polymer were investigated by field-emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-vis spectrum analysis, respectively. A dual-layered photoreceptor containing the nanocomposite film as the charge generation layer (CGL) was designed and fabricated. It is found that the photoreceptor based on Ppy/TiO2 nanotubes as CGL exhibits remarkable photoconductive performance.