Electrosynthesis of Silane-Modified Magnetic Nanoparticles for Efficient Lead Ion Removal

The removal of heavy metal ions, such as lead (Pb²⁺), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb²⁺ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe₂O₃) phase. IONPs were characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). A novel electrochemical method was developed for the silanization of IONPs using tetraethoxysilane (TEOS), (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES). The resulting silane-modified IONPs were evaluated for the magnetic removal of Pb²⁺ ions, with TEOS-modified IONPs demonstrating superior performance. This material exhibited a high adsorption capacity of 519 mg/g at a Pb²⁺ ion concentration of 300 ppm, and high removal efficiency across a range of Pb²⁺ ion concentrations, attributed to its Fe₂O₃@SiO₂ core-shell structure. This study highlights the potential of the electrochemical synthesis and silanization of nanoparticles for heavy metal remediation in water.