Titanium dioxide (TiO2) has been widely used with UV light to degrade organic waste contaminants. Immobilised layers of TiO2 on electrode surfaces have shown enhanced activity when appropriate potentials have been applied. In this work, it is shown that a novel immobilised layer of TiO2 on an electrode, a TiO2/poly(vinylchloride) composite cast from THF, mineralises acetone or starch when exposed to a xenon arc light only if the electrode is connected to a Pt electrode where concomitant reduction of oxygen occurs. When an isolated electrode with an immobilised TiO2 layer is exposed to UV light in a solution of starch or acetone, no decrease in acetone or starch concentration is observed. (c) 2007 Elsevier B.V. All rights reserved.