Synthesis of pumice-TiO₂ nanoflakes for sonocatalytic degradation of famotidine

Pumice-TiO₂ was synthesized through simple sol-gel method. The successful synthesis of the catalyst was verified by SEM, EDS, XRF, FT-IR and BET techniques. Then, a sonocatalytic process was performed to degrade famotidine in the presence of the synthesized catalyst and under ultrasonic irradiation. The removal efficiency of the sonocatalytic process with pumice‒TiO₂, TiO₂, pumice and sonolysis within 70 min was 71.1%, 33.9%, 31.1% and 8.9%, respectively. The main operational parameters which were examined in this study were catalyst dosage, pH, famotidine concentration and ultrasonic power which were optimized as 1.5 g/L, 5, 20 mg/L and 150 W, respectively. Moreover, the addition of radical scavengers (EDTA, Na₂SO₄ and 1, 4–benzoquinone) and enhancers (H₂O₂ and K₂S₂O₈) which can affect the removal efficiency were investigated. Diverse degradation by-products were identified using GC‒MS analysis. Eventually, the reusability tests confirmed that the synthesized pumice‒TiO₂ catalyst had significant stability after 5 consecutive runs.