Sonoelectrosynthesized polypyrrole-graphene oxide nanocomposite modified by carbon nanotube and Cu2O nanoparticles on copper electrode for electrocatalytic oxidation of methanol

Herein, the role of modified electrode comprised of polypyrrole (PPy), graphene oxide (GO), multi walled carbon nanotubes (MWCNTs) and copper (I) oxide nanoparticles in the electrochemical methanol oxidation is considered. The modified electrodes prepared through the successive Layer by Layer (LBL) electrochemical and sonoelectrochemical deposition processes. As-fabricated electrodes were characterized by FT-IR spectroscopy and scanning electron microscopy (SEM), which confirmed the incorporation of GO into the PPy matrix. Afterward, the electrocatalytic performance of as-prepared electrodes was evaluated for methanol oxidation reaction by cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). It was found that the Pd sub-layer has a vital role in synthesis of Cu2O nanostrucures, because this noble nano-layer can protect the copper substrate and consequently lead to synthesis of Cu2O nanostrucures. CV measurements indicated that the simultaneous presence of GO with PPy and MWCNTs in the structure of electrode enhances the overall electrocatalytic performance of the LBL electrodes for methanol oxidation. So, a strong synergistic interaction is expected to be between these components. Moreover, the results from chronoamperometry confirmed that the modified electrode had a good stability and repeatability as electrocatalyst. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.