Potential efficiency of magnetic mesoporous silica nanoparticles modified with aspartic acid to cationic dye removal from aqueous solution

This work includes the preparation of Fe3O4 NPs coated with mesoporous silica nanoparticles (MSNs). The combination between two different materials could improve the removal efficiency of pollutants from wastewater. The surface modification of magnetic nanoparticles could reduce the agglomeration. The Fe3O4-MSNs surface was modified with aspartic acid liked with the adsorbent surface via hydrophobic linker (1,4-phenylene diisothiocyanate, PDITC) to effectively remove the methylene blue (MB) dye from the contaminated water. The particles size was ranged between 110 and 160 nm, as estimated by SEM and TEM. The surface zeta potential of the surface was found to be negatively at pH above 2.5. The nanosorbent efficiency was evaluated at different conditions such as pH, contact time and initial MB concentration. The maximum adsorbed amount of the MB was estimated to be 135 mg/g at 200 mg/L MB concentration and 80 min contact time. The adsorption isotherm fits with the Langmuir model and pseudo-second-order kinetics.