Kinetics of photocatalytic degradation of diuron in aqueous colloidal solutions of Q-TiO2 particles

Kinetics of the photocatalytic degradation of a phenylurea herbicide diuron in aqueous colloidal solutions of Q-TiO2 nanoparticles was analyzed in detail applying a model of parallel consecutive reactions of the first-order. The found mechanism was compared with the reaction pathways of electrochemically assisted photoprocesses on illuminated TiO2 layers, polarized by external voltage, in various solvents. While a reductive dechlorination on benzene ring of diuron represented the major pathway in acetonitrile, a consecutive oxidative demethylation on the aliphatic side chain was mainly observed in water.