Photoelectrocatalytic Degradation of Methyl Orange in TiO2 Suspension-Ti Electrode System

Photoelectrochemical (PEC) degradation and electrodegradation (ED) of methyl orange were investigated in aqueous NaCl and Na₂SO₄ solutions. Photocatalytic degradation(PCD) was also performed in TiO₂(P25) suspension under UV-irradiation for comparison. Electrodegradation efficiencies showed enhanced decolorization performance at higher concentrations of electrolyte solutions and applied potentials. There is synergetic effect between electrolysis and photocatalysis treatments. Photocatalytic degradation process alone could result in 50.7% decolorization of methyl orange solution after 60 minutes of irradiation while the degradation rate were 82.1% in 0.5 mol/l Na₂SO₄ solution and 98.9% in 0.5M NaCl solution when 10 V bias was applied in photoelectrochemical degradation processes.