Photo-Catalytic Degradation of Rhodamine-B by using UV/TiO2 and Nb2O5 Process: A Kinetic Study

Abstract

The photo-catalytic degradation of Rhodamine-B (RB) in aqueous solution with titanium dioxide (TiO₂) and niobium pentaoxide (Nb₂O₅) as photocatalyst in slurry form has been carried out using UV-A light (254 nm). The effect of various parameters such as catalyst loading, pH and initial concentration of the RB dye on degradation have been determined. An attempt has been made to study the effect of process parameters through concentration of dye, amount of catalyst, and operating pH on photocatalytic degradation of RB. The experiments were carried out by varying initial concentration of dye
(10–50 ppm), amount of catalyst (0.25–1.5 g/l) and pH (2–11). The optimum catalyst dose was found to be 1.25 g/l of Nb₂O₅ and1 g/l of TiO₂ for RB at 30 ppm respectively. The maximum degradation rate was observed in acidic medium at pH 3 for catalyst Nb₂O₅ andTiO₂ respectively. Photo catalytic activity of TiO₂ was found to be greater than Nb₂O₅. Finally, the photo-degradation kinetics was fitted in terms of Langmuir-Hinshelwood kinetic model.