Electrochemical fabrication of novel Pt/poly (m-toluidine)/Triton X-100 composite catalyst at the surface of carbon nanotube paste electrode and its application for methanol oxidation

摘要

In this work, for the first time an aqueous solution of Triton X-100 (TX-100) non-ionic surfactant is used as an additive for electropolymerization of m-toluidine (MT) onto multi-walled carbon nanotube paste electrode (CNTPE), which is investigated as a novel matrix for dispersion of platinum particles. Electrochemical response of the poly (m-toluidine) film prepared in the presence of TX-100 (PMT/TX-100) is, at least, 20 times higher than that obtained in the absence of the surfactant. The as-prepared substrate is used as porous matrix for dispersion of platinum particles by potentiodynamic method. As-formed novel support and composite catalyst are characterized by scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and electrochemical methods. The SEM images reveal that the deposits are composed of spherical Pt particles. The EDS confirms the presence of Pt on the modified electrode. The electrochemical methanol oxidation reaction (MOR) is studied at the surface of this modified electrode. It has been shown that the PMT/TX-100 at the surface of CNTPE improves the catalytic efficiency of the deposited platinum particles toward MOR. Then, the influence of scan rates of potential and switching potential on the MOR as well as long-term stability of this modified electrode have been investigated by chronoampero-metric and cyclic voltammetric methods.