Fabrication of a magnetite/diazonium functionalized-reduced graphene oxide hybrid as an easily regenerated adsorbent for efficient removal of chlorophenols from aqueous solution. Issue 14 (15th February 2018)

• Record Type: Journal Article
• Authors: Shen, Xiaoqin; Chen, Xiaolei; Sun, Dejun; Wu, Tao; Li, Yujiang
• Is Part Of: RSC advances. Volume 8:Issue 14(2018)
• Page Start: 7351
• Page End: 7360
• Publication Date: 2018-02-15
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra00503f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A magnetite/diazonium functionalized-reduced graphene oxide hybrid is an easily regenerated and recyclable adsorbent for removal of chlorophenols from aqueous solution. Abstract : A magnetic hybrid nanomaterial, which contains magnetite (Fe3 O4 ) particles and diazonium functionalized-reduced graphene oxide (DF-RGO), was fabricated via a three-pot reaction. First, the reduced graphene oxide (RGO) was synthesized via a redox reaction. Second, diazonium functionalized-RGO was prepared via a feasible chemical reaction. Third, Fe3 O4 particles were loaded onto the surface of DF-RGO by covalent bonding, fabricating the M-DF-RGO hybrid. The fabricated hybrid was characterized by SEM, TEM, AFM, XRD, XPS, FT-IR, TGA, Raman spectroscopy, and magnetometry. The resulting M-DF-RGO hybrid possessed unique magnetic properties and was applied to remove 4-chlorophenol (4-CP) and 2, 4-dichlorophenol (2, 4-DCP) from aqueous solution. The adsorption of 4-CP and 2, 4-DCP on the M-DF-RGO hybrid was performed under various conditions, with respect to initial chlorophenol concentration, pH, and contact time. The results suggest that the adsorption of 4-CP and 2, 4-DCP onto the M-DF-RGO hybrid is strongly dependent on pH and weakly dependent on contact time. In addition, the adsorption isotherm of 4-CP and 2, 4-DCP on the M-DF-RGO hybrid fits the Freundlich model well and the adsorption capacities of 4-CP and 2, 4-DCP on M-DF-RGO reached 55.09 and 127.33 mg g −1, respectively, at pH 6 and 25 °C. In this situation, intermolecular interactions including π–π interactions and hydrogen bonding are operative. The calculated results of density functional theory further demonstrate that 2, 4-DCP molecules could be more easily absorbed than 4-CP molecules by the M-DF-RGO hybrid. Moreover, the M-DF-RGO hybrid could be easily separated by a magnetic separation process, and showed good recyclability of more than five cycles.