Potentiodynamic and electrochemical impedance spectroscopy study of anticorrosive properties of p-type conductive polymer/TiO2 nanoparticles

Abstract

We introduce a simple and facile strategy for dispersing of nanoparticles within a p-type conducting polymer matrix by in situ electropolymerization using oxalic acid as the supporting electrolyte. Coatings prepared from polypyrrole–nano-metal oxide particles synthesized by in situ polymerization were found to exhibit excellent corrosion resistance much superior to polypyrrole (PPy) in an aggressive environment. The anti-corrosion behavior of polypyrrole films in different states and the presence of TiO2 nanoparticles synthesized by electropolymerization on copper electrodes have been investigated in a corrosive solution using potentiodynamic polarization and electrochemical impedance spectroscopy. The electrochemical response of the coated electrodes in polymer and nanocomposite state was compared with bare electrodes. The use of TiO2 nanoparticles has proved to be a great improvement in the performances of polypyrrole films for corrosion protection of copper samples. The polypyrrole synthesized in the presence of TiO2 nanoparticles coated electrodes offered a noticeable enhancement of protection against corrosion processes. The exceptional improvement of performance of these coatings has been associated with the increase in barrier to diffusion, prevention of charge transport by the nanosize TiO2, redox properties of polypyrrole as well as very large surface area available for the liberation of dopant due to nano-size additive.