Corrosion of conductive polypyrrole: Effects of environmental factors, electrochemical stimulation, and doping anions

The effects of environmental factors, electrochemical stimulation, and doping anions on the corrosion behaviour of conductive polypyrrole (PPy) films in alkaline aqueous media were studied with cyclic voltammetry, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. High concentrations of electrolyte, low dissolved oxygen and low temperatures enhance the stability of PPy. Polarising PPy at a negative potential inhibits its corrosion obviously. PPy doped with large counter anions shows better corrosion resistance than PPy doped with small counter ions. The possible mechanism involved in PPy corrosion process is discussed.

► Corrosive galvanic cells form on PPy film with the electrochemical reduction of O2.
► Suitable electrochemical stimulation can inhibit the PPy’s corrosion.
► PPy film doped with larger sized anions has better corrosion resistance performance.