Single step synthesis of amine-functionalized mesoporous magnetite nanoparticles and their application for copper ions removal from aqueous solution.

Amine-functionalized mesoporous superparamagnetic Fe3O4 nanoparticles with an average size of 70nm have been synthesized using a single step solvothermal method by the introduction of triethylenetetramine (TETA), a chelating agent recommended for the removal of excess copper in patients with Wilson's disease. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption/desorption isotherm, vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR). It is confirmed that the magnetic nanoparticles have been functionalized with TETA during the synthetic process, and the concentration of TETA is crucial for the formation of monodisperse mesoporous nanoparticles. The obtained single-crystal magnetic nanoparticles have a high magnetization, which enhances their response to external magnetic field and therefore should greatly facilitate the manipulation of the particles in practical uses. Reaction parameters affecting the formation of mesoporous structure were explored, and a possible formation mechanism involving templated aggregation and recrystallization processes was proposed. The capacity of the synthesized amine-functionalized Fe3O4 nanoparticles toward Cu(II) removal from aqueous solution was investigated. The adsorption rate of Cu(II) on amine-functionalized Fe3O4 nanoparticles followed a pseudo-second order kinetic model. The results of this study demonstrated that the amine-functionalized mesoporous superparamagnetic Fe3O4 nanoparticles could be used as an efficient adsorbent in water treatment and would also find potential application for Cu(II) removal in vivo.