Electrodeposition of Ni(II)–alizarin red complex on graphene-modified carbon paste electrode for formamide oxidation

Abstract

A modified electrode Ni(II)–ARS/GR/CPE has been fabricated by electrodepositing nickel(II)–alizarin red complex on the surface of graphene-modified carbon paste electrode (GR/CPE) in alkaline solution. The modified electrode is characterized by scanning electron microscopy, Fourier transform infrared spectrometry, x-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. It exhibits the characteristic of improved reversibility and enhanced current responses of the Ni(III)/Ni(II) couple compared with Ni(II)–ARS/CPE. It also shows enhanced electrocatalytic activity toward the oxidation of formamide, which is due to the high surface area and facile charge–transfer ability of graphene and Ni(II)–ARS complex. The mechanisms of film formation and the catalytic process are also discussed. Moreover, the catalytic currents present linear dependence on the concentration of formamide from 0.5 mM to 0.21 M by amperometry; the detection limit is 0.15 mM. The modified electrode for formamide determination is of the property of simple preparation, good stability, fast response, and acceptable sensitivity.