Facile green synthesis, characterization and visible light photocatalytic activity of MgFe2O4@CoCr2O4 magnetic nanocomposite

Abstract

A new, facile, low-cost, and green sol–gel route for the synthesis of the MgFe2O4@CoCr2O4 magnetic nanocomposite is reported. The photocatalytic performances of the prepared magnetic nanocomposite was investigated for the degradation of organic dye under visible light irradiation. The synthesized magnetic photocatalyst depicted high degradation performance for Reactive Blue 222 dye under the optimized conditions. The nanocomposite dosage, initial dye concentration, dark and visible light, irradiation time, and reusability of photocatalysis had a notable influence on dye degradation performance. Fourier transforms infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM), UV–Vis diffuse reflectance spectroscopy (DRS), and elemental mapping (MAP) analysis were considered to thoroughly characterize the synthesized magnetic nanocomposite. The analysis confirmed that the MgFe2O4@CoCr2O4 had a spinel cubic structure, with a crystallite size of 11 nm, ferromagnetic activity, uniform spherical morphology, narrow bandgap, and spatial distribution of all elements that can be noticed as a merit of this method over other methods developed techniques. The fast and high-efficiency degradation for RB222 dye with 40 mg/L concentration under ambient conditions was 93% in only 10 min. Photodegradation mechanism of RB222 dye was specified in presence of radical scavenger agents and degradation pathway was verified by Gas chromatography–mass spectrometry (GC–MS) analysis. Furthermore, the as synthesized magnetic nanocomposite could be easily separated from the solution by an external magnet, structural integrity and stability of reused photocatalyst attested by FTIR, XRD, SEM, and EDX analysis and their photocatalysis performance was maintained even after four continuous runs in the same optimized condition.