Hydrothermal synthesis, characterization and photocatalytic activity of nanosized $TiO_2$ based catalysts for rhodamine B degradation

Abstract

Nanosize crystalline TiO2 and SiO2/TiO2 mixed oxide particles as a photocatalyst for rhodamine B dye (RB) degradation in aqueous media were synthesized by a hydrothermal process at 200 °C. They were characterized using XRD, SEM, FT-IR, UV/VIS and BET analysis. The effects of silica content on the crystallinity and photocatalytic activity of TiO2 were investigated. Photocatalytic activity of the nano-TiO2 was compared with that of SiO2/TiO2 mixed oxides at the same conditions for degradation of RB, and mixed oxide catalysts showed more effective catalytic activity than the TiO2- The results revealed that photodegradation of RB proceeds by pseudo-first-order reaction kinetics where the rate constant, k, for degradation of 30 mg/L RB using the catalyst with 0.05 SiO2/TiO2 mole ratio is 0.133 $min^{-1}$