Effect of Fe3O4 content and microwave reaction time on the properties of Fe3O4/ZnO magnetic nanoparticles

Abstract The effect of Fe 3 O 4 content and microwave reaction time on the properties of Fe 3 O 4 /ZnO magnetic nanoparticles (ZnO MNPs) was investigated. The corresponding structural properties of the ZnO MNPs were demonstrated by a series of characterization techniques including Brunauer–Emmett–Teller (BET), X–ray diffraction (XRD), field emission scanning electron microscopy (FE–SEM), high resolution transmission electron microscopic (HR–TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance (UV–vis DRS), Fourier transformed infra-red (FT–IR) spectroscopy and vibrating sample magnetometer (VSM). Photocatalytic activity of the ZnO MNPs was evaluated by choosing 4–Nitrophenol (4–NP) as the target pollutant. The Characterization and experimental results indicated that the ZnO MNPs containing 20% Fe 3 O 4 exhibited the largest specific surface area, pore volume and average pore diameter along with the strongest UV‒light absorption capacity. Moreover, diameters of the spherical ZnO MNPs decreased with the increase of Fe 3 O 4 contents. Furthermore, saturation magnetization of the ZnO MNPs increased with increasing Fe 3 O 4 contents, and the ZnO MNPS with 20% and 30% Fe 3 O 4 contents exhibited good superpara–magnetic behavior and coercivity, respectively. The best degradation of 4–NP was exhibited in ZnO MNPS with 30% Fe 3 O 4 content. On the other hand, the best photocatalytic activity was exhibited by ZnO MNPs prepared by 30 min microwave reaction time. The morphology was independent of microwave reaction time, while agglomerates of the ZnO MNPs were observed with increasing microwave reaction time up to 60 min. The study comprehensively discovered that the ZnO MNPs prepared with 20% Fe 3 O 4 content and 30 min microwave reaction time exhibited enhanced degradation of 4–NP up to 99% within 120 min. As a conclusion, Fe 3 O 4 content and microwave reaction time played an important role in the structural fabrication, photodegradation properties and reusability of ZnO MNPs. The current study could be deemed of great potential for the preparation and applications of ZnO MNPs in environmental remediation.