title: Removal of Pb(II) ions from aqueous solutions on few-layered graphene oxide nanosheets.
abstract: Few-layered graphene oxide (FGO) was synthesized from graphite by using the modified Hummers method, and was characterized by scanning electron microscopy, atomic force microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. The prepared FGO was used to adsorb Pb(II) ions from aqueous solutions. The abundant oxygen-containing groups on the surfaces of FGO played an important role in Pb(II) ion adsorption on FGO. The adsorption of Pb(II) ions on FGO was dependent on pH values and independent of ionic strength. The adsorption of Pb(II) ions on FGO was mainly dominated by strong surface complexation. From the adsorption isotherms, the maximum adsorption capacities (C(smax)) of Pb(II) ions on FGO calculated from the Langmuir model were about 842, 1150, and 1850 mg g(-1) at 293, 313, and 333 K, respectively, higher than any currently reported. The FGO had the highest adsorption capacities of today's nanomaterials. The thermodynamic parameters calculated from the temperature dependent adsorption isotherms indicated that the adsorption of Pb(II) ions on FGO was a spontaneous and endothermic process.
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei, 230031, PR China.
authors.forename: Guixia
authors.initials: G
authors.lastname: Zhao
authors.forename: Xuemei
authors.initials: X
authors.lastname: Ren
authors.forename: Xing
authors.initials: X
authors.lastname: Gao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Tan
authors.forename: Jiaxing
authors.initials: J
authors.lastname: Li
authors.forename: Changlun
authors.initials: C
authors.lastname: Chen
authors.forename: Yuying
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiangke
authors.initials: X
authors.lastname: Wang