Cerium-substituted magnetite: Fabrication, characterization and sonocatalytic activity assessment

The present paper reports the sonocatalytic activity of cerium-substituted-magnetite for removal of oxytetracycline (OTC). The catalyst was prepared through a chemical route (co-precipitation, Fe_3-xCe_xO₄) and a mechanical procedure (CeO₂/Fe₃O₄). Subsequently, the physico-chemical characteristics of both samples were determined using XRD, BET, SEM, EDX, TEM, Dot-mapping, FT-IR, DRS, and VSM analysis and compared to pristine magnetite and ceria. Afterwards, the effects of various operational conditions were assessed on sonocatalytic performance of Fe_2.8Ce_0.2O₄ for OTC removal and the obtained optimal conditions were applied to compare the resulted DE with so-synthesized Fe₃O₄, CeO₂, and CeO₂/Fe₃O₄ samples. Fe_2.8Ce_0.2O₄ (0.75 g/L) exhibited great catalytic performance for sono-degradation of OTC under its unchanged pH and US power of 300 W, wherein about 88% and 64% of OTC was removed at its initial concentrations of 20 and 50 mg/L. Moreover, the effects of the addition of a number of oxidants, organic and inorganic compounds and gases on the sonocatalytic degradation of OTC were evaluated under the identical condition. The obtained results presented an effective sonocatalytic system based on the synergistic action of Fe_2.8Ce_0.2O₄ under ultrasonic irradiation.