Synthesis of Fe3O4@SiO2 core-shell nanocomposite for fast removal of methylene blue from water

Abstract

In this work, Fe₃O₄@SiO₂ core-shell nanocomposites were successfully synthesised via a simple co-precipitation method. X-ray diffraction pattern of Fe₃O₄@SiO₂ clearly shows the existence of a main phase of Fe₃O₄, beside an amorphous structure of SiO₂. The core-shell Fe₃O₄@SiO₂ with an average particle size in the range of 10-20 nm is observed by SEM and TEM images. FTIR spectrum illustrates the Fe-O and Si-O-Si bonds in the sample, indicating the formed nanocomposite of Fe₃O₄@SiO₂. The brunauer, emmett and teller surface area analysis of the Fe₃O₄@SiO₂ sample is 4 times higher than that of Fe₃O₄. The vibrating sample magnetometer data indicated that the saturation of Fe₃O₄@SiO₂ (23.1 emu/g) is strongly decreased in comparison with Fe₃O₄ nanoparticles (58.1 emu/g), explained by the shielding of the SiO₂ nonmagnetic materials. The methylene blue adsorption efficiency in the saturation adsorption time of 60 min for Fe₃O₄@SiO₂
nanocomposite is 88.8%, which is 3 times higher than that of Fe₃O₄ nanoparticles. A model explaining the enhanced mechanism in methylene blue adsorption efficiency of Fe₃O₄@SiO₂ nanocomposite is proposed. The obtained results show that the synthesised Fe₃O₄@SiO₂ nanocomposite has great potential in dye removal applications from water.