Electrochemical Characterization of Nanostructured Polyaniline-PbO2 Composite Prepared by Cyclic Voltammetry

Abstract

PANi-PbO₂ composites were prepared onto stainless steel substrate by cyclic voltammetry from acidic medium (potential range: 1.2-1.7 V; scan rates: 50-150 mV/s). The electrochemical properties of those materials were evaluated by cyclic potentiodynamic polarization (±150 mV to zero potential), cyclic voltammetry (potential range from 0.7 V to 1.8 V at scan rate of 100 mV/s) and impedance spectroscopy following potential from 1.5 V to 1.8 V (frequences: 100 kHz-10 mHz; amplitude: 5mV). There were found two electrical equivalent schemas by simulation that containing Warburg diffusion for potential area from 1.5 V to 1.6 V and without it for potential from 1.7 V to 1.8 V, respectively. The results showed that the formation of both a and b-modifications of lead dioxide in composite depended on scan rate at which samples synthesized and their electrochemical redoxidation peaks increased following cycle number of cyclic voltammetry due to the presence of polyaniline in composite matrix. The material that performanced at 100 mV/s had the best corrosion stability among regarded samples because of having the smallest corrosion current and the positive corrosion potential.