Sonochemical synthesis and characterization of barium fluoride–titanium dioxide nanocomposites and activity for photodegradation of Trypan Blue dye

The Barium fluoride loaded titanium dioxide (BaF2–TiO2), synthesized by a sonochemical method, was characterized for morphological and optical characteristics. DRS spectra reveal a slight increase in absorbance from 400 nm to entire visible region in BaF2 loaded TiO2. Presence of BaF2 was confirmed by X-ray photoelectron spectroscopy analysis. BaF2–TiO2 is found to be more efficient than prepared TiO2 and commercial TiO2-P25 at pH 5 in the degradation of Trypan Blue under solar light. The effects of operational parameters such as the amount of photocatalyst, initial pH on photomineralization by BaF2–TiO2 have been analyzed. The degradation intermediates identified by gas chromatography-mass spectrometry analysis are Naphthalen-1-ol, 2-aminobenzaldehyde and 5-aminobenzene-1,3-diol. A dual mechanism involving electron–hole separation by BaF2–TiO2 and dye sensitization is proposed for the degradation under solar light. The mineralization of TB was confirmed by FT-IR, COD and CV measurements. The catalyst was found to be reusable.