Electrolyte and solvent effects on voltammetry behavior and surface morphology of Polypyrrole films deposited on glassy carbon electrode in the redox process

Abstract

Polypyrrole (PPy) films were electrochemically synthesized on glassy carbon electrode in different electrolytes and solvent media. Voltammetry studies of PPy films doped with Cl⁻, ClO₄⁻, NO₃⁻ anions showed that the redox activity of the polymer is affected by the nature of the anions and solvent used in the electrochemical synthesis. The mobilities of the anions exhibited a well-defined order: ClO₄⁻ < Cl⁻ < NO₃⁻. The electrodeposited PPy films were characterized ex situ independently by atomic force microscopy (AFM) technique. The effect of solvent on the surface morphology of PPy films was clarified by AFM imaging. Our results showed that the level of doping will depend on the polarity of the solvent used. In polar solvent like DMSO, the doping of Cl⁻ anion is predominant. The results obtained suggested the presence of chemisorbed anions on the surface of PPy films.