Desalination, Vol.115, No.3, 295-302, 1998
Sol-gel film-preparation of novel electrodes for the electrocatalytic oxidation of organic pollutants in water
The electrochemical oxidation of phenol as a model contaminant, has been studied using different electrode materials (Ebonex, Ebonex/PbO2, Ti/SnO2) in water by means of cyclic voltammetry. Best results have been obtained with doped SnO2-films on titanium foils prepared by a sol-gel dip-coating technique. The cyclovoltammograms reveal a high overpotential for oxygen-evolution, resulting in a well separated peak for the oxidation of phenol. Improvements of the conductivities of the films and higher current densities for the oxidation were obtained by doping the film sol-gel solution with 10% Sb. Doping with fluoride increased the conductivity, but decreased the oxidation peaks. The PbO2-coated Ebonex-electrodes were obtained by the galvanostatic deposition in an acidic PbNO3-solution. Upon the addition of phenol to the electrolyte, however, the electrodes did not show a separated oxidation peak. The oxidation peak is partially hidden by oxygen evolution. The electrochemical characteristics of the electrode material Ebonex is not significantly changed by the addition of phenol to the electrolyte.