title: One-pot synthesis of magnetic graphene nanocomposites decorated with core@double-shell nanoparticles for fast chromium removal.
abstract: A facile thermodecomposition process to synthesize magnetic graphene nanocomposites (MGNCs) is reported. High-resolution transmission electron microscopy and energy filtered elemental mapping revealed a core@double-shell structure of the nanoparticles with crystalline iron as the core, iron oxide as the inner shell and amorphous Si-S-O compound as the outer shell. The MGNCs demonstrate an extremely fast Cr(VI) removal from the wastewater with a high removal efficiency and with an almost complete removal of Cr(VI) within 5 min. The adsorption kinetics follows the pseudo-second-order model and the novel MGNC adsorbent exhibits better Cr(VI) removal efficiency in solutions with low pH. The large saturation magnetization (96.3 emu/g) of the synthesized nanoparticles allows fast separation of the MGNCs from liquid suspension. By using a permanent magnet, the recycling process of both the MGNC adsorbents and the adsorbed Cr(VI) is more energetically and economically sustainable. The significantly reduced treatment time required to remove the Cr(VI) and the applicability in treating the solutions with low pH make MGNCs promising for the efficient removal of heavy metals from the wastewater.
authors: Integrated Composites Laboratory (ICL), Dan F Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710, United States.
authors: Jiahua
authors: J
authors: Zhu
authors: Suying
authors: S
authors: Wei
authors: Hongbo
authors: H
authors: Gu
authors: Sowjanya B
authors: SB
authors: Rapole
authors: Qiang
authors: Q
authors: Wang
authors: Zhiping
authors: Z
authors: Luo
authors: Neel
authors: N
authors: Haldolaarachchige
authors: David P
authors: DP
authors: Young
authors: Zhanhu
authors: Z
authors: Guo
mesh_terms: D000327:Adsorption; D001557:Benzenesulfonates / Q000737:chemistry; D002857:Chromium / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007501:Iron; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D001557:Benzenesulfonates; D014874:Water Pollutants, Chemical; D002857:Chromium; C001114:dodecylbenzenesulfonic acid; D006108:Graphite; D007501:Iron