Photocatalytic Decolorization of Cobalamin in Aqueous Suspensions of TiO2 and ZnO Under Solar Irradiation

摘要： Photolysis and photocatalysts treatments of aqueous solution of cobalamin were carried out over a suspension of titanium dioxide and zinc oxide. Heterogeneous photocatalytic processes applied under natural weathering conditions, in the presence of solar radiation show a promising degradation capability. Under solar radiation a complete removal of color was achieved in a relatively short time of about 10 minutes, when ZnO was used and in 45 min when TiO2 was used. However, in the presence of artificial UV-light, complete decolorization of cobalamin was obtained in 20 min of irradiation when ZnO was used and in 60 min, when TiO2 was used at the same temperature. The results indicate that the degree of photocatalytic decolorization of cobalamin was obviously affected by different parameters such as, catalyst mass, type of catalyst and addition of H2O2.