Synthesis and Characterization of Sulfydryl-Functionalized Core-Shell Magnetic Fe₃O₄@SiO₂ Nanoparticles Based on a Branched Polyethylenimine for Enhanced Removal of Heavy Metal Ions

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.

Keywords:

• Fe₃O₄@SiO₂ nanoparticles
• sulfydryl
• PEI
• removal
• heavy metal ion

Additional information

Funding

This work was supported by the Leshan Normal University Research Program of China (Z16024); Leshan Normal University Research Program of China (Z16023); and Science and Technology Bureau of Leshan city of China (17GZD051).