Photocatalysed degradation of two selected dyes in UV-irradiated aqueous suspensions of titania

The photocatalysed degradation of two selected dyes, such as Acridine Orange (1) and Ethidium Bromide (2) has been investigated in aqueous suspensions of titanium dioxide (TiO2) under a variety of conditions, which is essential from application point of view. The degradation was monitored by measuring the change in substrate concentration as a function of irradiation time employing UV Spectroscopic analysis technique. The degradation was studied using different parameters such as types of TiO2, reaction pH, catalyst concentration, substrate concentration and in the presence of different electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate ((NH4)(2)S2O8) besides air. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst, Degussa P25, was found to be more efficient for the photocatalytic degradation of dye derivatives 1 and 2. The dye derivative I was found to degrade faster as compared to the dye derivative 2. (c) 2005 Elsevier Ltd. All rights reserved.