Fabrication of magnetic mesoporous manganese ferrite nanocomposites as efficient catalyst for degradation of dye pollutants

Abstract

In this study, mesoporous silica encapsulated with magnetic MnFe₂O₄ nanoparticles is synthesized by a solvothermal method. The synthetic route is feasible and widely applicable. The obtained products have been characterized by an X-ray powder diffraction (XRD) pattern, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and nitrogen adsorption–desorption isotherm measurements. The synthesized magnetic mesoporous MnFe₂O₄ nanoparticles are monodispersed with a mean diameter of 200 nm, and have an obvious mesoporous silica shell of ∼20 nm. The surface area of magnetic mesoporous MnFe₂O₄ nanocomposites is 423 m² g⁻¹. The nanoparticles are superparamagnetic in nature at room temperature and can be separated by an external magnetic field. This magnetic mesoporous material is used as a catalyst for the degradation of methyl orange dye. The merits of the effect under different conditions like pH, temperature, light and sonolysis have been evaluated by investigating the degradation of azo dye. The mesoporous MnFe₂O₄ nanocomposites have effective adsorption of dyes inside the porous network followed by degradation with the central magnetite core and regeneration of the catalyst with the help of a simple magnet for successive uses.