Studies on photo-degradation of thionine in the presence of uranyl ion and H2O2

Highly oxidizing nature of electronically excited uranyl ion has been utilized to degrade thionine dye with the aim of developing a new methodology for degradation of organic pollutants/waste. In this connection, photo-degradation of thionine has been studied under different conditions. It was found that in HClO4 medium photo-degradation is faster than in H2SO4 medium on photolysis with 254 nm light. Experiments with visible light irradiation of the same system were studied in the presence of H2O2. In the presence of H2O2, hydroxyl radicals formed during oxidation of U(IV)/U(V) were found to enhance the rate of photo-degradation.