ZnO/Polytyramine nanocomposite film: Facile electrosynthesis and high performance electrocatalytic activity toward methanol oxidation

Abstract

In the present study, the methanol oxidation reaction was investigated on a nickel ion incorporated to the zinc oxide-sodium dodecyl sulfate-polytyramine (ZnO-SDS-Pty) nanocomposite film by cyclic voltammetry and chronoamperometry. ZnO-SDS-Pty nanocomposite was prepared by using the repeated potential cyclic voltammetry in a solution containing ZnO nanoparticles and tyramine in an acidic solution of SDS by cycling the potential. The electrochemical oxidation of methanol was investigated by a stable redox behavior of the Ni(III)/Ni(II) couple at the potential of 0.4 V, after the immersion of the modified electrode (ZnO-SDS-Pty/G) in an alkaline media (i.e. NaOH 0.1 molL−1) of nickel chloride solution. The electrochemical characterization of the modified electrode exhibited that the ZnO-SDS-Pty nanocomposite, electrodeposited on the electrode surface, improved the catalytic efficiency of the dispersed nickel ions toward methanol oxidation. The catalytic rate constant and diffusion coefficient of the methanol oxidation reaction were calculated by chronoamperometry. The Ni-ZnO-SDS-Pty nanocomposite displayed a highly stable response during the oxidation of methanol, proving to be a suitable electrode material in methanol fuel cells.