Sonocatalytic degradation of an anthraquinone dye using TiO₂-biochar nanocomposite

TiO₂-biochar (TiO₂-BC) nanocomposite was synthesized by sol-gel method. The characteristics of the prepared nanocomposite were examined using X-ray fluorescence, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and N₂ adsorption-desorption analysis. The performance of synthesized TiO₂-BC nanocomposite as efficient sonocatalyst was studied for the degradation of Reactive Blue 69 (RB69). Sonocatalytic degradation of RB69 in the presence of TiO₂-BC nanocomposite could be explained by the mechanisms of hot spots and sonoluminescence. The optimized values for main operational parameters were determined as pH of 7, TiO₂-BC dosage of 1.5 g/L, RB69 initial concentration of 20 mg/L and ultrasonic power of 300 W. Furthermore, the effect of ^[rad]OH, h⁺ and O₂^[rad]− scavengers on the RB69 degradation efficiency was studied. Gas chromatography-mass spectroscopy analysis was used to identify intermediate compounds formed during the RB69 degradation. The results of repeated applications of TiO₂-BC in the sonocatalytic process verified its stability in long-term usage.