Comparative Studies of Electrochemical Behaviors of Benzenediols at a Gold Nanoparticle/carbon Nanotube Composite Modified Glassy Carbon Electrode

Abstract

A gold nanoparticle/carbon nanotube composite modified glassy carbon electrode was fabricated and used to investigate electrochemical characteristics of hydroquinone, catechol, and resorcinol via cyclic voltammetric analysis under neutral pH conditions. The results imply that the gold nanoparticle/carbon nanotbue modified electrode exhibited a synergistic and excellent electrocatalytic effect of gold nanoparticles and carbon nanotube on the redox behaviors of benzenediols. The reversibility of electrochemical reaction was improved greatly and the peak currents were increased significantly compared with a bare electrode. Good linear relationships were obtained between the oxidation peak currents and the concentrations of catechol and resorcinol. The electrochemical process of catechol was controlled by surface adsorption process, while that of resorcinol was controlled by diffusion process. However, the peak current and the concentration of hydroquinone were not proportional in the whole concentration range, which is because the controlling process of electrochemical reactions was different in the different hydroquinone concentration. Benzenediols could be detected simultaneously at the modified electrode but not at the bare electrode. The stability of the modified electrode was excellent in the benzenediols solutions, which made it possible for the practical application of the modified electrode.