Abstract
Polyaniline (PANI) nanostructures encapsulated in highly ordered TiO2 nanotubes (NTs) array was obtained by formation of TiO2 NTs array in HF-H3PO4 solution using constant potential anodization method; followed by electropolymerization of aniline to be encapsulated in the TiO2 NTs array, The electrochemical, morphological and structural characteristics of PANI/TiO2 nanocomposite electrode were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), X-ray diffraction (XRD) and infrared (IR) spectroscopy. Thermal behavior of PANI film was studied by thermogravimetric analysis (TGA). Studies showed that anatase phase of TiO2 prevailed and PANI-modified TiO2 composite did not change the crystalline structure of neat TiO2. Dye sensitized photogalvanic cell based on PANI/TiO2 nanocomposite electrode was also examined. Different metal phthalocyanine dyes were examined as the photosensitizer for composites formed of PANI nanostructures encapsulated in TiO2 NTs array. The Photoelectrochemical properties and the conversion efficiency of the modified CoPC dye sensitized PANI/TiO2 nanocomposite were enhanced compared to "neat" TiO2 NTs. The photogalvanic cell showed good stability for many turnovers.