Fabrication of a novel magnetic CdS nanorod/NiFe2O4/NaX zeolite nanocomposite with enhanced sonocatalytic performance in the degradation of organic dyes

Abstract

In the present study, a novel magnetic CdS nanorods (NRs)/NiFe₂O₄/NaX zeolite sonocatalyst nanocomposite was successfully synthesized for the first time by a simple ultrasound-assisted solvothermal method. Several techniques, including FTIR, FE-SEM, EDAX, EDAX elemental dot-mapping, TEM, AFM, XRD, VSM, UV-Vis DRS, and N₂-BET, were utilized to characterize the as-fabricated catalyst. Then, the CdS nanorods/NiFe₂O₄/NaX catalyst nanocomposite was used for the degradation of various organic dyes, such as methylene blue (MB), eriochrome black T (EBT), rhodamine B (RhB), and methyl orange (MO), in aqueous solutions under ultrasound irradiation, and the results were obtained via UV-Vis absorption analysis. The sonodegradation processes of the dye contaminants were carried out in the presence of H₂O₂ as an oxidizing agent. Moreover, the effects of different experimental parameters, namely irradiation time, process type, catalyst dosage, initial dye concentration, H₂O₂ concentration, scavenger type, and catalyst reusability, on the degradation reactions of MB, EBT, RhB, and MO were investigated. Furthermore, to study the sonodegradation reactions of dyes, the first-order kinetic model was employed. Subsequently, the rate constant (k_app) and half-life (t_1/2) for the degradation of MB in the US/H₂O₂/CdS NRs/NiFe₂O₄/NaX system were measured as 0.0538 min⁻¹ and 12.881 min, respectively. In addition, the acquired information reveals the prominent role of ˙OH, known as a radical scavenger, derived from H₂O₂ in the entire sonodegradation reaction.