Poly(o-aminophenol) film prepared in the presence of sodium dodecyl sulfate: Application for nickel ion dispersion and the electrocatalytic oxidation of methanol and ethylene glycol

Abstract

Poly(o-aminophenol) (POAP) was formed by successive cyclic voltammetry in monomer solution in the presence of sodium dodecyl sulfate (SDS) on the surface of a carbon paste electrode. The electrochemical behavior of the SDS–POAP carbon paste electrode has been investigated by cyclic voltammetry in 0.5 M HClO 4 and 5 mM K 4[Fe(CN) 6]/0.1 M KCl solutions as the supporting electrolyte and model system, respectively. Ni(II) ions were incorporated into the electrode by immersion of the polymeric modified electrode having amine groups in 0.1 M Ni(II) ion solution. Cyclic voltammetric and chronoamperometric experiments were used for the electrochemical study of this modified electrode. A good redox behavior of the Ni(III)/Ni(II) couple at the surface of electrode can be observed. The electrocatalytic oxidations of methanol and ethylene glycol (EG) at the surface of the Ni/SDS–POAP electrode were studied in a 0.1 M NaOH solution. Compared to bare carbon paste and POAP-modified carbon paste electrodes, the SDS–POAP electrode significantly enhanced the catalytic efficiency of Ni ions for methanol oxidation. Finally, using a chronoamperometric method, the catalytic rate constants ( k) for methanol and ethylene glycol were found to be 2.04 × 10 5 and 1.05 × 10 7 cm 3 mol −1 s −1, respectively.