Synthesis of Fe3O4/SiO2/TiO2-Ag Core Shell Nanocomposites and Investigation of its Magnetic Properties

In this study, core–shell structure Fe3O4/SiO2/TiO2-Ag nanocomposites were synthesized in several stages. At first the Fe3O4 magnetic particles were obtained using the carbon reduction method. Then the Fe3O4/SiO2 composite was synthesized using Tetraethyl orthosilicate (TEOS) precursor via sol-gel method. In the following a shell of TiO2 was coated directly on it. Finally, Ag particle was deposited on the surface of TiO2 nano-shell by an in situ wet chemistry route. Prepared nanocomposites were characterized by environmental scanning electron microscopy analysis (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM). The results revealed Fe3O4/SiO2/TiO2–Ag nanocomposites have been successfully synthesized. The average size of Fe3O4 particles was about 300-400 nm and the size of Fe3O4/SiO2 particles is averagely between 400-450 nm and the average size of Fe3O4/SiO2/TiO2-Ag particles was calculated between 450-480 nm. Saturation magnetization (Ms) of nanocomposite showed a decreasing from 80emu/g to 37emu/g. Further coating of SiO2 and TiO2 decreases the saturation magnetization.