Synthesis of Magnetic Fe_3O_4@C Nanoparticles Modified with -SO_3H and -COOH Groups for Fast Removal of Pb~(2+), Hg~(2+), and Cd~(2+) Ions

摘要

Core-shell magnetic Fe_3O_4@C nanoparticles functionalized with sulfonic and carboxylic acid groups were synthesized and employed to capture heavy metal ions in aqueous media. The Fe_3O_4 cores possess unique magnetic properties for adsorbent separation, and the -SO_3H and -COOH groups attached to the surface of the carbon shells determine the efficiency of heavy metal ion removal. Batch adsorption experiments showed that Pb~(2+), Hg~(2+), and Cd~(2+) ions can be com-pletely and quickly removed by the Fe_3O_4@C nanoparticles. The equilibrium was established within 5 min, and the maximum adsorption capacities of the Fe_3O_4@C nanoparticles toward Pb~(2+), Hg~(2+), and Cd~(2+) ions were 90.7, 83.1, and 39.7 mg/g, respectively. The removal efficiencies were 96.3, 98.1, and 93.8% for Pb~(2+), Hg~(2+), and Cd~(2+) ions, respectively. This work provides a facile and general approach to synthesize magnetic functional nanocomposites for wastewater treatment.