ELECTROCHEMICALLY ASSISTED PHOTOCATALYSIS USING NANOCRYSTALLINE SEMICONDUCTOR THIN-FILMS

The principle and usefulness of electrochemically assisted photocatalysis has been illustrated with the examples of 4-chlorophenol and Acid Orange 7 degradation in aqueous solutions. Thin nanocrystalline semiconductor films coated on a conducting glass surface when employed as a photoelectrode in an electrochemical cell are effective for degradation of organic contaminants. The degradation rate can be greatly improved 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 observed when TiO2 particles were coupled with SnO2 nanocrystallites at an applied bias potential of 0.83 V versus SCE.