In situ growth of monodispersed Fe₃O₄ nanoparticles on graphene for the removal of heavy metals and aromatic compounds

We report on the efficient removal of heavy metal ions and aromatic compounds from simulated wastewater with a nanocomposite. The nanocomposite was obtained via thermal decomposition of the precursor Fe(acac)₃ onto the surface of graphene, modified by diethylenetriamine pentaacetic anhydride through dopamine. It was found that the maximum adsorption capacity of the nanocomposite toward Cu²⁺ and naphthalene was 207.9 and 72.2 mg g⁻¹ respectively, displaying a high efficiency for the removal of heavy metal ions as well as aromatic compounds at pH 7.0 and 293 K. The Langmuir for naphthalene and the Freundlich for the Cu²⁺ adsorption isotherms were applicable for describing the removal processes. Furthermore, the nanocomposite was carefully examined by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectra, and UV-vis spectroscopy. This work provides a very efficient, fast and convenient approach to exploring a promising nanocomposite for water treatment.