Electrocatalytic Degradation of Methyl Orange on PbO2-TiO2 Nanocomposite Electrodes

The electrocatalytic degradation of methyl orange (MO) on PbO2-TiO2 nanocomposite electrodes was studied by cyclic voltammetry and bulk electrolysis. The results reveal that PbO2-TiO2 nanocomposite electrodes possess higher oxygen evolution overpotential than PbO2 electrodes and the electrocatalytic degradation of MO on the electrodes is direct oxidation process. The influence of experimental parameters, such as current density, initial MO concentration, initial pH value and Na2SO4 concentration, on the MO removal efficiency was studied in order to optimize the electrochemical oxidation process. The results show that the MO and COD removal efficiency in 0.1 mol/L Na2SO4 solution containing 30 mg/L MO could reach 95.5 % and 77.2% with current density 30 mA/cm2 after 240 min. Compared with PbO2 electrodes, the PbO2-TiO2 nanocomposite electrodes show higher COD removal efficiency and instantaneous current efficiency with MO degradation. The experimental results demonstrate that electrochemical oxidation on PbO2-TiO2 nanocomposite electrodes is a suitable method for treatment of water polluted with organic pollutants.