Efficiency of various semiconductor catalysts for photodegradation of Safranin-T

Semiconductor photocatalysis often leads to partial or complete mineralization of organic pollutants. In this study, photocatalytic degradation of Safranin-T, a hazardous textile dye, has been investigated using various semiconductors such as titanium dioxide (TiO2), zinc oxide (ZnO), bismuth oxide (Bi2O3), cerium oxide (CeO2), yttrium oxide (Y2O3), and zirconium oxide (ZrO2). The experiments were carried out by irradiating the aqueous solution of Safranin-T containing photocatalysts with UV and air. Maximum decolorization of Safranin-T occurred with TiO2 (99.8%), followed by ZnO (80.3%), Bi2O3 (57.1%), CeO2 (13.1%), Y2O3 (12.2%), and ZrO2 (10.2%). The rate of photocatalytic degradation varied with increasing concentration of Safranin-T. The equilibrium degradation data of Safranin-T by TiO2 and ZnO were fitted to the Langmuir and Freundlich isotherm models. The Freundlich and Langmuir model showed satisfactory fit to the equilibrium degradation data for TiO2 and ZnO, respectively. Photocatalytic degradation of Safranin-T followed pseudo second-order kinetics.