Capacitance characteristics and corrosion resistance of polyaniline/polypyrrole composite film prepared by electrochemical method

Polyaniline/polypyrrole (PANI/PPy) composite films were synthesized on a stainless steel substrate by cyclic voltammetry (CV) in the corresponding monomer solution. The structure of the composite film were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD). The electrochemical supercapacitor properties of the composite film were investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) in 0.5 mol/L H2SO4 electrolyte, and the corrosion resistance of the composite film was researched simply by Tafel curves. The results suggest that the specific capacitance of the composite film is up to 747.5 F/g at a current density of 5 mA/cm2, and the corrosion potential of the composite film shift positively by 0.064 V, 0.117 V compared with that of the pure PANI, PPy film, respectively, which suggest that the composite films turn out to be a promising material for supercapacitor.