Facile preparation of mercapto modified magnetic iron oxide nanoparticle for removal of mercury(II) from aqueous solutions

Abstract

A simple ultrasound-assisted co-precipitation method was developed to prepare lipophilic thiol-functionalized Fe 3 O 4 magnetic nanoparticles (EDT-Fe 3 O 4 MNPs) with sodium dodecyl sulfonate (SDS) as dispersant and 1,2-ethanedithiol (EDT) as functionalization reagent. The property of EDT-Fe 3 O 4 MNPs was characterized by Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). It was found that EDT-Fe 3 O 4 MNPs dispersed well in the system of ethanol/water (1:1) and had an average diameter of 15 nm. The hysteresis loop of EDT-Fe 3 O 4 MNPs demonstrated that these MNPs expressed high magnetic responsiveness. The EDT-Fe 3 O 4 MNPs were further used as an adsorbent for removal of Hg 2+ . The effects of the dosage of adsorbent, initial pH of the solution and contact time were investigated. The adsorption equilibrium and kinetics data could be well fitted with the Freundlich isotherm and the pseudo-first-order kinetic model respectively. Furthermore, the adsorbent could be effectively separated using an external magnetic field and regenerated.