Electrocatalytic oxidation of methanol on carbon paste electrode modified by nickel ions dispersed into poly (1,5-diaminonaphthalene) film

Poly (1,5-diaminonaphthalene) film was prepared by using the repeated potential cycling technique in an acidic solution at the surface of carbon paste electrode. Then transition metal ions of Ni(II) were incorporated to the polymer by immersion of the modified electrode in a 1.0 M nickel chloride solution. The electrochemical characterization of this modified electrode exhibits stable redox behavior of the Ni(III)/Ni(II) couple. Also, cyclic voltammetric experiments showed that methanol electrooxidized at the surface of this Ni(II) dispersed polymeric modified carbon paste electrode [Ni/P-1,5-DAN/MCPE]. The mechanism of methanol oxidation changes from diffusion control at low concentration to a catalytic reaction at higher methanol concentration. The effects of both scan rate and methanol concentration on the anodic peak height of the methanol oxidation were discussed.