Effects of potentiodynamic electropolymerization parameters on electrochemical properties and morphology of fabricated PANI nanofiber/graphite electrode

In this study, aniline nanofibers were fabricated through cyclic voltammetry electropolymerization on graphite electrode in the acidic solution of Aniline, in two different conditions. In the first condition aniline was electropolymerized in a potential range from -0.2 to 1 V and at different scan rates, while in the second condition; electropolymerization was done at a fixed scan rate of 25 mV s(-1) and with different switching potentials. The effect of scan rate and switching potential on electrochemical properties and the morphology of produced polyaniline film was investigated by different electrochemical tests such as cyclic voltammetry, electrochemical impedance spectroscopy, and also scanning electron microscopy. The electrochemical investigations indicated that an optimum condition of 25 mV s(-1) scan rate and a -0.2 to 1 V potential range can be reached where electropolymerized polyaniline could be at its peak of electroactivity, electrical and ionic conductivity and apparent diffusion coefficient (D), which is ideal for electrocatalytic applications. The SEM micrographs also confirm the formation of polyaniline with nanofibrous morphology at this optimum condition. (C) 2014 Elsevier B.V. All rights reserved.