Synthesis, characterization and investigation of photocatalytic activity ofZnMnO ۳/Fe۳O۴ nanocomposite for degradation of dye Congo red under visible light irradiation

ZnMnO۳/Fe۳O۴ magnetic nanocomposites were fabricated via facile co-precipitation route and were calcined at ۴۰۰ °C for ۳ h. Synthesis of ZnMnO۳/Fe۳O۴ magnetic nanocomposites were optimized by different weight percentages. Then, the as-syn-thesized sample was characterized by X- ray diffraction (XRD), Fourier transform infrared (FT-IR), photoluminescence(PL), vibrating Sample Magnetometer (VSM), EDAX (Energy dispersive X-ray analysis), diffuse reflectance UV–Vis spectroscopy (DRS),ultraviolet–visible (UV–Vis) spectrometry, Bruner-Emmett-Teller (BET), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Based on the results, elemental analyses of the samples were similar to those expected from the initial concentrations of the solutions used during synthesis. The x -ray diffraction pattern revealed that ZnMnO۳/Fe۳O۴ has a cubic structure and average particle size of the catalyst was found ۲۷.۴۳ nm. In addition, Fourier transform infrared spectra could confirm the presence of hydroxyl group and Fe–O bond vibration in the catalyst. Further, the superparamagnetic behavior of the synthesized nanocomposite at room temperature was confirmed by VSM studies. Furthermore, the photocatalytic performance of ZnMnO۳/Fe۳O۴ samples were evaluated based on the removal of Congo red (CR) in aqueous solution in ۶۰ min of under visible light irradiation. The experiment demonstrated that ۰.۱۰ g of ZnMnO۳/Fe۳O۴ nanocomposites can degrade (۹۸.۱۷%) ۵۰ mg l−۱ of Congo red (CR) solution. The mechanistic study using scavengers propose that the superoxide (O۲·− ) is the most reactive species involved in the photodegradation of organic dyes. The photocatalytic degradation of Congo red conformed the pseudo-first-order kinetic model and the rate constant achievedfor ۰.۱۰ g l−۱ of ZnMnO۳/Fe۳O ۴ was (k = ۰.۰۳۸۴ min−۱). Finally, the effect of reaction time, pH, and loading of ZnMnO۳/ Fe۳O۴ on degrading Congo red was studied. The synthesized ZnMnO۳/Fe۳O۴ nanocomposite can be potentially applied as a magnetically separable photocatalyst to deal with water pollution problems