Abstract
The end sulfydryl group functionalized Fe3O4@SiO2 (Fe3O4@SiO2-SH) nanoparticles were synthesized with 3-mercaptopropionic acid as a sensitive and efficient chemosensor for the removal of heavy metal ions, in which branched polyethylenimine was used to provide numerous sites for the modification with 3-mercaptopropionic acid in order to increase the amount of sulfydryl group on the Fe3O4@SiO2 surface. The magnetic Fe3O4@SiO2-SH nanoparticles displayed the maximum adsorption efficiency for Pb2+ (257.1 mg/g) at room temperature without pH pre-adjustments. Moreover, Fe3O4@SiO2-SH nanoparticles also had desirable capturing abilities towards Cu2+ (90.3%), Hg2+ (89.8%), Ag+ (84.1%) and Cd2+ (78.6%) when their initial concentrations were 200 mg/L.