Silica-coated Magnetic Nanocomposites as an Adsorbent for the Removal of Methylene Blue Dyes from Water: Preparation and Characterization

A novel magnetic nanocomposites (MNCs) adsorbent was synthesized for the removal of methylene blue (MB) dyes from wastewater. The inner core Mn0.6Zn0.4Fe2O4 magnetic nanoparticles (MNPs) were coated with an outer shell of silica based on a facile method using tetraethylorthosilicate (TEOS) as a precursor material. The optimum conditions of preparation were gotten. The observed BET surface area and pore volume of MNCs all increased, which makes it useful for adsorption of MB dyes. It was confirmed that the MNCs adsorbent was synthesized with large surface area, suitable pore size, and uniform pore size distribution, but the material possessed irregular pore structures by HRTEM. The synthesized silica-coated Mn-Zn ferrite MNCs were nanosized microspheres with a special "core/shell" structure. The Mn-Zn ferrite MNCs exhibited a good dispersibility and magnetic separability in water. The nanosize and fast separation from water make silica coated Mn-Zn ferrite MCPs adsorbent a potential claimant for environmental applications.