Synthesis and Characterization of Fe₃O₄/SiO₂/AC Nanocomposite as a Heavy Metal Adsorbent

¹ Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Malang, Indonesia
² Laser Center, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, Malaysia

^* Corresponding author: ahmad.taufiq.fmipa@um.ac.id

Abstract

This research successfully synthesized Fe₃O₄/SiO₂/activated carbon (AC) nanocomposite as heavy metal adsorbent. This research aimed to determine nanocomposite characteristics, including crystal structure, morphology, functional groups, magnetic properties, and heavy metal adsorption performance. The X-ray diffraction (XRD) results showed that Fe₃O₄ has a crystal phase with an inverse cubic spinel structure and a crystallite size of 11.73 nm with lattice parameters a=b=c=8.346 Å. Scanning electron microscopy (SEM) image showed a porous morphology in the form of chunks of AC particles and spherical Fe₃O₄ and SiO₂ particles with a particle size of 23.11 nm. Fourier transform infrared (FTIR) spectrum showed the presence of octahedral and tetrahedral Fe-O bonds, which confirmed the existence of Fe₃O₄, Si-O and Si-O-Si bonds, which indicated the presence of SiO2, and C-C bonds, which confirmed the presence of AC. The magnetization curve showed superparamagnetic properties with a saturation magnetization value of 15.86 emu/g. According to the results of the adsorption test from atomic absorption spectroscopy (AAS) at room temperature with a concentration of 100 ppm and a contact time of 30 minutes, the Fe₃O₄/SiO₂/AC was able to adsorb heavy metal Pb(II) with an efficiency of 69.95% and an adsorption capacity of 5.534 mg/g.