Evaluation of sodium dodecyl sulfate effect on electrocatalytic properties of poly(1-naphtylamine)/nickel-modified carbon paste electrode as an efficient electrode toward electrooxidation of methanol

Abstract

In this work, 1-naphtylamine is electropolymerized at the surface of carbon paste electrode (CPE) using consecutive cyclic voltammetry in 15 mM monomer aqueous solution in the presence of 15 mM sodium dodecyl sulfate (SDS) as surfactant. Then, transition metal of nickel is incorporated into the polymeric electrode placing in 1.2 M NiCl2 solution without applying any potential to the electrode for 7 min. In alkaline medium (i.e., NaOH 0.1 M), a good redox behavior of Ni(III)/Ni(II) couple at the surface of Ni/poly (1-naphtylamine) modified carbon paste electrode (Ni/PNAM/MCPE) in the absence and presence of SDS (Ni/SDS-PNA/MCPE) can be observed. Electrocatalytic oxidation of methanol has been studied on Ni/PNA/MCPE and Ni/SDS-PNAM/MCPE. The results show that SDS significantly enhances the catalytic efficiency of nickel particles on the oxidation of methanol in aqueous alkaline media. Moreover, the effects of various parameters such as concentration of SDS, concentration of methanol, film thickness, and monomer concentration on the electrooxidation of methanol as well as long-term stability of the Ni/SDS-PNAM/MCPE have also been investigated. This polymeric modified electrode can oxidize the methanol with high current density (over 3 mA).