Feasible One-Pot Sequential Synthesis of Aminopyridine Functionalized Magnetic Fe3O4 Hybrids for Robust Capture of Aqueous Hg(II) and Ag(I)

Heavy metal pollution to aqueous media is an important issue for environmental sustainability. A simple strategy for the synthesis of an efficient adsorbent is strongly desired for water remediation. Herein, aminopyridine functionalized magnetic Fe3O4 (HO–Fe3O4@ SiO2–AP) with excellent adsorption capacity and selectivity was synthesized by a feasible one-pot sequential reaction. As a comparison, the same adsorbent was also prepared by the general step-by-step surface modification method. The structure characterization and adsorption performance prove the efficiency of this strategy. The factors that affect the adsorption were determined. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Density Functional Theory calculation were used to demonstrate the adsorption mechanism. As HO–Fe3O4@SiO2–AP exhibits competitive adsorption capacity and excellent adsorption selectivity, it can be used potentially for robust removal, preconcentration, and recovery of aqueous Hg­(II) and Ag­(I).