Interaction between Eu(III) and Graphene Oxide Nanosheets Investigated by Batch and Extended X-ray Absorption Fine Structure Spectroscopy and by Modeling Techniques

Abstract

The interaction mechanism between Eu(III) and graphene oxide nanosheets (GONS) was investigated by batch and extended X-ray absorption fine structure (EXAFS) spectroscopy and by modeling techniques. The effects of pH, ionic strength, and temperature on Eu(III) adsorption on GONS were evaluated. The results indicated that ionic strength had no effect on Eu(III) adsorption on GONS. The maximum adsorption capacity of Eu(III) on GONS at pH 6.0 and T = 298 K was calculated to be 175.44 mg·g(-1), much higher than any currently reported. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggested that Eu(III) adsorption on GONS was an endothermic and spontaneous process. Results of EXAFS spectral analysis indicated that Eu(III) was bound to ∼6-7 O atoms at a bond distance of ∼2.44 Å in the first coordination shell. The value of Eu-C bond distance confirmed the formation of inner-sphere surface complexes on GONS. Surface complexation modeling gave an excellent fit with the predominant mononuclear monodentate >SOEu(2+) and binuclear bidentate (>SO)(2)Eu(2)(OH)(2)(2+) complexes. This paper highlights the application of GONS as a suitable material for the preconcentration and removal of trivalent lanthanides and actinides from aqueous solutions in environmental pollution management.

Adsorption kinetics, isotherms and thermodynamics of Cr(III) on graphene oxide

“…Thus, the lack of an ionic strength effect on Cr(III) adsorption suggested that Cr(III) is adsorbed on GO mainly through the coordination with the O-containing functional groups of GO to form inner-sphere complexes. In previous studies, the adsorption of Eu(III) and Pb(II) on GO were also independence of ionic strength [13,31], which was consistent with the result in this paper. Fig.…”

“…[9][10][11]. Among these approaches, adsorption has been found to be superior to other techniques due to its low-cost, high efficiency and easy operation [12,13].…”

Effects of humic acid on copper adsorption onto few-layer reduced graphene oxide and few-layer graphene oxide

“…As for GBNs, little information is available regarding the interactions between GBNs and HA, and their subsequent effects on the adsorption of coexisting contaminants. Previous studies usually examined the adsorption of contaminants by GBNs in single solute system [17][18][19][20][21][22]. Results showed that graphene oxide was an effective adsorbent for the removal of heavy metal from water due to the coordination between metal ion and O-containing functional groups of graphene oxide [17][18][19].…”

Effect of Microbes on the Adsorption of Naphthalene by Graphene Oxide

“…Figure 5 showed the FTIR spectra of GO and GO + P. catenlannulatus after naphthalene adsorption. For GO, the peaks at approximately 1725, 1620, 1390, and 1085 cm −1 corresponded to the stretching vibration of the C=O, skeletal C=C, carboxyl O=C-O, and alkoxy C-O bond, respectively [2,25,39,40]. The widen peaks at 3450 cm −1 (data not shown) were assigned to the -OH stretching vibration of adsorbed water [41].…”

“…Graphene oxide (GO), as the precursor of graphene, exhibits the large number of hydroxyl and epoxy groups in the plane and a small amount of carboxyl and carbonyl group at the edge [1][2][3]. Recently, it has been reported that GO displays the excellent adsorption performance for many organic contaminants, such as dyes [4][5][6][7], polychlorinated biphenyls (PCBs) [8][9][10], and polycyclic aromatic hydrocarbons (PAHs) [11][12][13].…”