The photooxidative degradation of an anionic surfactant, sodium dodecylbenzene sulfonate (DBS), has been examined on a TiO2 thin film immobilized onto a transparent semiconducting oxide (TCO support) electrode assembly. Some of the characteristics of this assembly have been explored. Changes in the rates of decomposition as a function of applied bias and as a function of the nature of the supporting electrolyte were surveyed. The efficiency of the photodegradation was governed by the electrode potential.