The photocatalytic process employing semiconductor photocatalysts are the most powerful technology for the mineralization and decoloration of organic pollutants such as dyes, phenols, etc. The photocatalytic decoloration of an azonium dye namely, Saffranin O dye by TiO₂ and ZnO was investigated under UV light illumination. The effects of initial concentration of dye, pH, TiO₂ and ZnO and the illumination time were experimented and the optimized conditions for maximum removal of the dye were determined and compared. The kinetic was studied with Langmuir- Hinshelwood mechanism. Among the two catalysts, TiO₂ exhibited more removal efficiency than ZnO in this study.

Keywords: Photocatalysis; Saffranin O; Mineralization; Photoluminescence;