Adsorption of organic dyes by Fe₃O₄@C, Fe₃O₄@C@C, Fe₃O₄@SiO₂ magnetic nanoparticles

Abstract

The Fe3O4@C, Fe3O4@C@C, and Fe3O4@SiO2 core-shell nanoparticles were synthesized using thermal decomposition and co-precipitation techniques and characterized by X-ray spectroscopy, transmission electron microscopy and magnetometry. It is shown that the magnetic core of all nanoparticles is nanocrystalline with crystal parameters corresponding to only one Fe3O4 phase, which is covered with a uniform shell of amorphous carbon or silicon oxide about 8 nm thick. The main attention was paid to the adsorption properties of nanoparticles with respect to four dyes: methylene blue, Congo red, eosin Y, and rhodamine C. The high selectivity of Fe3O4@C nanoparticles with respect to various dyes was revealed.