LIGHT-INDUCED DECOMPOSITION OF SATURATED CARBOXYLIC-ACIDS ON IRON-OXIDE INCORPORATED CLAY SUSPENDED IN AQUEOUS-SOLUTIONS

Iron oxide prepared in sodium montmorillonite clay supports exhibited remarkable activities as photocatalysts for the decomposition of acetic acid, propionic acid, and n-butyric acid, being in marked contrast to alpha-ferric oxide bulk powder. The activities were greatly dependent on solution pH, and the highest activity was observed at a specified pH. The charged conditions of the photocatalysts were analyzed as a function of pH, based on potentiometric titration data of photocatalyst suspensions, and adsorption of acetate was evaluated to discuss the observed pH dependence. Slight reduction of the photocatalyst surfaces was noticed during the course of the decarboxylation reactions as in the cases of other iron oxide photocatalysts.