ELECTROCHEMICALLY ASSISTED PHOTOCATALYSIS USING NANOCRYSTALLINE SEMICONDUCTOR THIN-FILMS

The principle and usefulness of electrochemically assisted photocataly sis has been illustrated with the examples of 4-chlorophenol and Acid Orange 7 degradation in aqueous solutions. Thin nanocrystalline semico nductor films coated on a conducting glass surface when employed as a photoelectrode in an electrochemical cell are effective for degradatio n of organic contaminants. The degradation rate can be greatly improve d even in the absence of oxygen by applying an anodic bias to the TiO2 film electrodes. A ten-fold enhancement in the degradation rate was o bserved when TiO2 particles were coupled with SnO2 nanocrystallites at an applied bias potential of 0.83 V versus SCE.