Electrochemical synthesis of polyaniline films on zinc-cobalt alloy deposited carbon steel surface in sodium oxalate

• ZnCo alloy plating was obtained on the carbon steel by electrochemical deposition.
• PANI films were synthesized electrochemically on thin zinc-cobalt plated carbon steel in sodium oxalate (NaOX) medium.
• PANI films on the ZnCo plated carbon steel enhanced corrosion performance.
• The relationship between scan rate and corrosion performances was investigated.
• PANI films were achieved on the ZnCo plating to provide the anodic protection.

Polyaniline (PANI) coatings were electropolymerized on zinc-cobalt alloy deposited carbon steel (CS/ZnCo) electrode from an aqueous sodium oxalate solution using three different scan rates in cyclic voltammetric technique. Scanning electron microscopy (SEM) was used to analyze the surface morphology of the polymer film. The SEM images showed that the increase in scan rate induced an increase in grain size of the PANI film. The corrosion behavior of CS/ZnCo electrodes with and without PANI film in 3.5% NaCl solution were investigated through electrochemical impedance spectroscopy (EIS) and anodic polarization studies. The results of the study showed that the PANI coatings provided significant and effective protection for the CS/ZnCo electrode, in preventing corrosion. In addition, the PANI film that was synthesized at a high scan rate, exhibited the best anti-corrosive performance due to the formation of protective oxide layers through its catalytic efficiency.