Evaluation of sodium dodecyl sulfate effect on electrocatalytic properties of poly (4-aminoacetanilide)/nickel modified carbon paste electrode as an efficient electrode toward oxidation of ethylene glycol

Abstract

Poly (p-aminoacetanilide) (PPAA) was prepared by oxidation of PAA in acidic aqueous solution in the presence of sodium dodecyl sulfate (SDS) at the surface of carbon paste electrode (CPE). Then Ni (II) ions were incorporated to the polymer by immersion of the modified electrode in a 0.1 M Ni (II) ions solution. The electrochemical behavior of this modified electrode (Ni/SDS–PPAA/CPE) was investigated by using cyclic voltammetry and chronoamperometry techniques. The experimental results exhibited the stable redox behavior of the Ni (III)/Ni (II) couple immobilized at the polymeric electrode. This polymeric modified electrode has a very good activity toward the ethylene glycol (EG) electrooxidation in a 0.1 M NaOH solution. By comparison of the different responses to EG oxidation using electrodes Ni/SDS–PPAA/CPE, Ni/PPAA/CPE and Ni/CPE, we observed that Ni/SDS–PPAA/CPE is a more effective catalyst for the electrooxidation of ethylene glycol. The anodic peak current of EG increases with increasing ethylene glycol concentration up to 0.08 M. A diffusion-controlled process at low EG concentrations and a kinetic-controlled process at high EG concentrations are predominant. Finally, the catalytic rate constant ( k) for the ethylene glycol oxidation reaction was calculated 1.1 × 10 4 cm 3 mol −1 s −1 by using a chronoamperometric technique.