LAUSR

Abstract In order to improve the degradation of the methylene blue and to overcome the problem of the incapability of recyclability of the catalysts, we use in this work a thin film of tin oxide (SnO2) synthesized via ultrasonic spray pyrolysis technique in the inner wall of glass tube. The catalysts are characterized by XRD patterns, FTIR spectra, Raman spectra, UV–Visible spectra, XPS analysis, AFM images and SEM images with EDX analysis. The initial and degraded solutions of the methylene blue are analysed by UV–Vis absorption spectroscopy. Adsorption, photocatalysis, photolysis, sonocatalysis, sonolysis, sonophotocatalysis and sonophotolysis degradation of methylene blue in presence of tin oxide are studied. The results showed that the sonocatalysis process using the SnO2 thin film as a catalyst presents the best degradation efficiency compared to the other processes. A possible sonophotodegradation mechanism is proposed.