PEDOT/Nafion composite thin films supported on Pt electrodes: Facile fabrication and electrochemical activities

Poly-3,4-ethylenedioxythiophene(PEDOT)/Nafion composite thin films were prepared by a facile electrochemical polymerization approach. These films were characterized by wavelength dispersive spectroscopy (WDS), scanning electron microscopy (SEM), atomic/electric force microscopy (AFM/EFM), cyclic voltammetry (CV), potential step chronoamperometry (PSC), and electrochemical impedance spectroscopy (EIS). The as-prepared film was dense and smooth and had nearly uniform PEDOT and Nafion distribution on the nanometer scale with slight localized phase segregation. Electrochemical experiments revealed a PEDOT/Nafion stable potential window and a PEDOT/Nafion overoxidation potential window. Hole mobility in the film was quantified by PSC technique and charge transport theory, and was verified independently by EIS technique.