The photocatalytic oxidation of reactive blue 2 and reactive red 120 has been studied by using TiO2 Degussa P25 as catalyst and UV-light. The formation of intermediate molecules could be predicted on the basic of point charge calculations on all the individual atoms of the dyes. The agreement between calculations from quantum theory and the results of experiments was the background to establish a pathway for degradation of reactive dyes. A plausible mechanism of dye photodegradations is discussed.
