Effective removal of Hg(II) ion from aqueous solutions by thiol functionalized cobalt ferrite magnetic mesoporous silica composite

The preparation and testing of thiol-functionalized cobalt ferrite magnetic mesoporous silica composite (SH-mSiO(2)@CoFe2O4) is described. It was investigated by means of Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), N-2 adsorption-desorption and transmission electron microscopy (TEM). SH-mSiO(2)@CoFe2O4 was very sensitive to external magnetic fields and can be separated from aqueous solution in less than 1 min. The adsorption properties of SH-mSiO(2)@CoFe2O4 toward Hg2+ ions were evaluated. Various factors affecting Hg2+ adsorption were discussed, such as adsorption time, pH and temperature. The pseudo-first-order and pseudo-second-order models was used to evaluate adsorption kinetics. The SH-mSiO(2)@CoFe2O4 showed excellent adsorption capability for Hg2+ and the maximum adsorption was 258 mg g(-1) at room temperature when the initial concentration of Hg2+ is 8 mg L-1. Based on current experimental data, SH-mSiO(2)@CoFe2O4 is a very promising material for effectively adsorbing Hg2+ in aqueous solution. [GRAPHICS]