Elaboration and characterization of polyaniline films electrodeposited on tin oxides

This paper presents the electrochemical synthesis of polyaniline films on fluorine tin oxide (FTO) and indium tin oxide (ITO) in acidic medium by both potentiodynamic and potentiostatic methods. The use of potentiodynamic deposition showed that conductive polyaniline films were synthesized by the same process than on noble metals and allowed the determination of the electrodeposition potential used for further potentiostatic electrodepositions. The electropolymerization was then performed by chronoamperometry and appeared easier on ITO than on FTO. The electrodeposited polyaniline films were extensively characterized in terms of chemical nature, electrochemical growth, thickness, roughness and morphology. The chemical nature of the films was identified through infrared spectroscopy and X-ray diffraction analyses. The roughness and the morphology of the polymer coatings, determined by profilometry, scanning electron microscopy and atomic force microscopy, were correlated to the calculated thickness of each polyaniline film and to the nature of the substrate.