Hydrothermal Synthesis, Characterization and Photocatalytic Activity of Nanosized TiO_2 Based Catalysts for Rhodamine B Degradation

Authors: FUNDA SAYILKAN, MELTEM ASİLTÜRK, ŞADİYE ŞENER, SEMA ERDEMOĞLU, MURAT ERDEMOĞLU, HİKMET SAYILKAN

Abstract: Nanosize crystalline TiO_2 and SiO_2/TiO_2 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 TiO_2 were investigated. Photocatalytic activity of the nano-TiO_2 was compared with that of SiO_2/TiO_2 mixed oxides at the same conditions for degradation of RB, and mixed oxide catalysts showed more effective catalytic activity than the TiO_2. 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 SiO_2/TiO_2 mole ratio is 0.133 min^{-1}.

Keywords: SiO_2/TiO_2 mixed oxides, hydrothermal process, photocatalyst, rhodamine B, photodegradation

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