Synthesis and Characterization of Fe3O4@SiO2@mesoporous-SiO2 Materials

Abstract

In this work, a magnetic Fe₃O₄@SiO₂@mesoporous-SiO₂ (F@S@m-S) material was successfully prepared by a three-step method: firstly, Fe₃O₄ particles were synthesized through hydro-thermal synthesis process; secondly, Fe₃O₄@SiO₂ materials were fabricated via a template method using tetraethyl orthosilicate (TEOS) as silicon sources and cetyltrimethylammonium chloride (CTAC) as templates; lastly, F@S@m-S materials were prepared through a template method as well. The influence of TEOS/CTAC molar ratio on the morphology and mesostructure was investigated. The product was characterized by Fourier-transform Infrared Spectroscopy (FT-IR), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), transmission electron microscope (TEM), and N₂ adsorption-desorption. The results demonstrated that F@S@m-S materials have a well spherical morphology and a typical mesostructure. The increase of TEOS/CTAC molar ratio can improve the mesostructure and crystal form of F@S@m-S materials. The average particle size, specific surface area, average pore size and pore volume of F@S@m-S-4.78 materials are 130 nm, 77.1 m²/g, 9.2 nm and 0.1668 cm²/g, respectively.