AgFe2O4/MWCNT nanoparticles as novel catalyst combined adsorption-sonocatalytic for the degradation of methylene blue under ultrasonic irradiation

Abstract

AgFe2O4@MWCNT nanocatalysts were successfully synthesized by following a series of physicochemical hydrothermal processes and characterized by various instruments such as XRD, TEM, Raman, UV-Vis spectroscopy, and XPS techniques. The activity of the nanocatalyst was assessed by examining the degradation of methylene blue (MB) through combined adsorption and heterogeneous sonocatalysis. AgFe2O4@MWCNT nanocatalysts exhibited better removal efficiency in the case of pre-adsorption followed by sonocatalytic reaction as compared to the simultaneous adsorption and sonocatalysis system. The effects the AgFe2O4@MWCNT nanocatalysts on the sonocatalytic activity were investigated in details by various experimental parameters such as solution pH (5.5–10), catalyst dosage (8–20 mg L−1), hydrogen peroxide (H2O2) dosage (5–20 mM), temperature (298–328 K), and dye concentration (12–40 mg L−1). The results revealed that the efficiency of AgFe2O4@MWCNT in MB degradation after sonocatalytic activity under optimum conditions was found to be about 98.5% in 75 min. Furthermore, OH• and O2• radicals exhibited the crucial molecular functions in the degradation of MB under sonocatalytic conditions in the presence of AgFe2O4@MWCNT nanocatalysts.The intermediate products after the degradation of MB were characterized by the GC-MS technique Based on the results, the adsorption followed by sonocatalytic degradation in the presence of AgFe2O4@MWCNT nanocatalysts showed great potential for the efficient treatment of wastewater.