Synthesis, crystal structure and magnetic properties of a new tri-nuclear iron (II, III) complex, a precursor for the preparation of superparamagnetic Fe3O4 nanoparticles applicable in the removal of Cd2+

摘要

This study reports the structural and spectroscopic characterization of a novel metal organic compound formulated as [Fe (bpy)(3)] [Fe (dipic)(2)](2).7H(2)O (1) (dipic = pyridine-2,6-dicarboxylate and bpy = 2,2(')-bipyridine). 1 was investigated by elemental analysis, FT-IR spectroscopy, powder X-ray diffraction and single crystal X-ray diffraction (SC-XRD), which revealed a triclinic structure of expected composition. Thermal degradation of 1 was also investigated. Complex 1 was used as a precursor to prepare superparamagnetic nanoparticles of Fe3O4 by thermal analysis. The obtained Fe3O4 was characterized by Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Fe3O4 nanoparticles were used as a nano-adsorbent to remove Cd2+ from water at room temperature. The results showed that this nano-adsorbent is effective in removing Cd2+ from contaminated water sources, and that the maximal effectivity of adsorption occurs at pH = 6. Magnetic measurements of complex 1 and Fe3O4 nanoparticles at room temperature revealed paramagnetic and superparamagnetic behavior, respectively.