Study on electrochemical oxidation of 4-Chlorophenol on a vitreous carbon electrode using cyclic voltammetry

Abstract

The electrochemical oxidation behavior of 4-Chlorophenol (4-CP) on a vitreous carbon electrode was investigated in acidic (1M H2SO4, pH 0.4), neutral (1M Na2SO4, pH 6.9), and alkaline (1M NaOH, pH 12.0) mediums containing 1–5mM of 4-CP, at different temperatures between 25 and 85°C, by cyclic voltammetry technique. The results indicate that the 4-CP was oxidized more easily in alkaline medium than acidic and neutral mediums, and the oxidation peaks of 4-CP shifted toward lower potential values by increasing temperature and 4-CP concentration. Successive scans led to the inactivation of vitreous carbon electrode as a result of the forming of polymeric films whatever the pH, the temperature and the 4-CP concentration used, but the inactivation of electrode surface was more easily induced in neutral and acidic mediums rather than alkaline medium and was retarded significantly when performed at the temperatures higher than 45°C. Additionally, the 4-CP oxidation process at vitreous carbon electrode was controlled by diffusion except at higher concentration (50, 100mM) where it is limited by adsorption.