Electrochemical and spectroscopical studies of polypyrrole synthesized on carbon steel from aqueous medium

•Polypyrrole is deposited on carbon steel using different electrochemical techniques.•Surface nucleation and PPy growth constitute the mechanism of electrodeposition.•Microscopic and spectroscopic techniques are used for characterization.•The behavior of CS is investigated by EIS, OCP, cyclic and linear voltammetry.•PPy coatings act as a protective layer of carbon steel. Polypyrrole films were deposited electrochemically on carbon steel from sodium saccharinate aqueous medium using cyclic voltammetry, potentiostatic and galvanostatic techniques. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and normalized tape test show that the polypyrrole coating is homogeneous and adherent to carbon steel surface with globular structure. The adherence rate depends closely on the applied current densities. The corrosion protection performance of the coating was investigated by potentiodynamic polarization technique, open circuit potential over time, and electrochemical impedance spectroscopy (EIS) in 3% sodium chloride solution.