Electrosynthesis of polypyrrole-nanodiamond composite film under ultrasound irradiation: Promotion for methanol electrooxidation by gold and Cu2O nanostructures

This work presents the preparation of the modified electrode based on polypyrrole which is electro-chemically doped by nanodiamond (ND), gold nanoparticles and cuprous oxide and the corresponding electrocatalytic performance for the methanol oxidation reaction was studied. Herein, decorated PPy-nanodiamond composite films on St-12 steel electrodes were electro-synthesized using in situ polymerization process under ultrasonic irradiation. Afterward, the potentiostatic and galvanostatic techniques were used to synthesize the Au nanoparticles and cuprous oxide on the PPy/ND coated electrode, respectively. The results of cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy measurements showed significantly enhanced catalytic performance of the prepared electrode. It was observed that the modified electrodes prepared from PPy(ND) decorated with Au and Cu2O yielded a slightly higher current and lower onset potential for the oxidation of methanol. Besides, the mechanism based on the electrochemical synthesis of Cu2O active sites and the effects of nanodiamond along with gold nanoparticles have been discussed. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.