Degradation of pararosaniline dye photoassisted by visible light

The photoassisted degradation of pararosaniline dye has been investigated in aqueous solutions under illumination by visible light. Illumination of the dye solution in the presence of oxygen or argon does not degrade the dye molecule. Degradation occurs in the presence of H2O2. Pararosaniline dye can be easily decomposed in the TiO2 suspensions using oxygen and hydrogen peroxide as electron acceptors. The degradation kinetics followed first-order type equation in all cases. Based on the data obtained the reaction mechanism was proposed. (C) 2002 Elsevier Science B.V. All rights reserved.