Photocatalytic Degradation of Reactive Dyes in Effluents Employing Copper Doped Titanium Dioxide Nanocrystals and Direct Sunlight

Abstract

Nanosized photocatalyst samples of TiO 2 and Cu-doped TiO 2 were synthesized employing sol-gel method. The photocatalysts were characterized by powder XRD, SEM, EDAX and diffused reflectance spectral studies. Model effluents of reactive dyes were subjected to degradation employing the Cu-doped TiO 2 catalysts with direct sunlight irradiation and liberal aeration. The heterogeneous Advanced Oxidation Process (AOP) involves photolytic generation of very reactive hydroxyl radicals. The photocatalytic degradation activity of the nanocatalysts has been evaluated on the basis of Langmuir-Hinshelwood kinetic model. The effects of pH, concentration of H 2O2 added, initial dye concentration and dosage of the catalyst have also been investigated. The degrees of degradation/mineralization of the organic dyes have also been estimated by measuring the CODs of the photocatalytically degraded dye solutions. The results show that the Cu-doped TiO 2 nanoparticles are very effective in degrading the dye pollutants.