Heterogeneous photocatalyzed degradation of uracil and 5-bromouracil in aqueous suspensions of titanium dioxide

摘要

Photocatalyzed degradation of uracil (1) and 5-bromouracil (2) has been investigated in aqueous suspensions of titanium dioxide under a variety of conditions. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic analysis technique and depletion in total organic carbon (TOC) content as a function of irradiation time. The degradation of the compounds under investigation was studied using various parameters such as, different types of TiO_2 powders, pH, catalyst concentration, substrate concentrations, and in the presence of electron acceptors like hydrogen peroxide (H_2O_2) and potassium bromate (KBrO_3) besides molecular oxygen. Photocatalyst Degussa P25 was found to be more efficient for the degradation of both compounds as compared with other TiO_2 powders such as UV100, PC500 and TTP.