Magnetic separable zeolite-type ZSM-5/CdS nanorods/MoS2 nanoflowers/MnFe2O4 quaternary nanocomposites: synthesis and application of sonocatalytic activities

Abstract

In this current research, the novel zeolite ZSM-5/CdS nanorods (NRs)/MoS₂ nanoflowers (NFs)/MnFe₂O₄ as a magnetically separable nanocomposite catalyst was obtained by an ultrasonic-assisted hydrothermal route. The as-fabricated nanocomposite was further investigated by FE-SEM-EDX, FTIR, XRD, TEM, VSM, N₂-BET, UV-Vis DRS, and PL. This nanocomposite was then proposed for the sonodegradation of organic pollutants in aqueous solutions. The reactions were all performed under optimized conditions and the pursuant monitoring was accomplished by operating UV-Vis analysis. The sonocatalytic capability of this nanocomposite was surveyed against the H₂O₂-assisted degradation of organic pollutants, namely methylene blue (MB), eriochrome black T (EBT), methyl orange (MO), rhodamine B (RhB), and chlorpyrifos (CP), under ultrasonic irradiation. Moreover, the influence of several operational factors, namely contact time, catalyst amount, initial concentration of MB, H₂O₂ concentration, organic pollutant type, US power and process type, on the outcomes of the degradation processes for MB, RhB, EBT, MO, and CP were precisely considered. The sonodegradation reactions rate was also verified via a first-order kinetic model. The achieved results illustrated that the half-life (t_1/2) and apparent rate constant (k_app) values of the sonocatalytic degradation of MB dye (25 mg L⁻¹) using ZSM-5/CdS NRs/MoS₂ NFs/MnFe₂O₄ (10 mg) and H₂O₂ (4 mM) within 10 min were 2.547 min and 0.272 min⁻¹, respectively. Moreover, the noteworthy role of ˙OH radicals as oxidizing species in the sonodegradation processes was unambiguously proved. Additionally, the recyclability of the sonocatalyst was investigated, which confirmed that it can be recycled up to four times with almost trivial loss of catalytic performance.