Electrodeposition and characterization of polypyrrole films on copper

In the present study, citric acid (CA), sodium acetate (SA) and sodium benzoate (SB) are used as electrolytes and compared in terms of easiness for polypyrrole deposition and film characteristics. Electrochemical measurements in the solution having these electrolytes with and without pyrrole demonstrate that copper can be efficiently passivated before PPy electrodeposition. This layer was sufficiently protective to inhibit further dissolution of the copper electrode and adequately conductive to enable the electropolymerization of pyrrole at the interface leading to the generation of an adherent polypyrrole film. The characterization of these coatings is carried out by cyclic voltammetry, UV–visible absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies. The performance of polypyrrole as protective coating against corrosion of Cu in both acidic and basic solutions is assessed by the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS).