Adsorption of Eu(III) on titanate nanotubes studied by a combination of batch and EXAFS technique

The effects of pH,contact time and natural organic ligands on radionuclide Eu(Ⅲ) adsorption and mechanism on titanate nanotubes(TNTs) are studied by a combination of batch and extended X-ray absorption fine structure(EXAFS) techniques.Macroscopic measurements show that the adsorption is ionic strength dependent at pH < 6.0,but ionic strength independent at pH > 6.0.The presence of humic acid(HA) /fulvic acid(FA) increases Eu(Ⅲ) adsorption on TNTs at low pH,but reduces Eu(Ⅲ) adsorption at high pH.The results of EXAFS analysis indicate that Eu(Ⅲ) adsorption on TNTs is dominated by outer-sphere surface complexation at pH < 6.0,whereas by inner-sphere surface complexation at pH > 6.0.At pH < 6.0,Eu(Ⅲ) consists of ～ 9 O atoms at REu?O ≈ 2.40  in the first coordination sphere,and a decrease in NEu-O with increasing pH indicates the introduction of more asymmetry in the first sphere of adsorbed Eu(Ⅲ).At long contact time or high pH values,the Eu(Ⅲ) consists of ～2 Eu at REu-Eu ≈ 3.60  and ～ 1 Ti at REu-Ti ≈ 4.40 ,indicating the formation of inner-sphere surface complexation,surface precipitation or surface polymers.Surface adsorbed HA/FA on TNTs modifies the species of adsorbed Eu(Ⅲ) as well as the local atomic structures of adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids.Adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids forms both ligand-bridging ternary surface complexes(Eu-HA/FA-TNTs) as well as surface complexes in which Eu(Ⅲ) remains directly bound to TNT surface hydroxyl groups(i.e.,binary Eu-TNTs or Eu-bridging ternary surface complexes(HA/FA-Eu-TNTs)).The findings in this work are important to describe Eu(Ⅲ) interaction with nanomaterials at molecular level and will help to improve the understanding of Eu(Ⅲ) physicochemical behavior in the natural environment.     

Mechanism and microstructure of Eu(Ⅲ) interaction with γ-MnOOH by a combination of batch and high resolution EXAFS investigation

In this paper,the macroscopic interaction method and high resolution EXAFS technique with a bent crystal analyzer were combined to study Eu(Ⅲ)interaction mechanism and microstructure withγ-MnOOH as a function of pH.The results indicated that Eu(Ⅲ)interaction withγ-MnOOH was apparently dependent on pH but independent of ionic strength,suggesting the formation of inner-sphere surface complexation for Eu(Ⅲ)ontoγ-MnOOH.Results of EXAFS analysis indicated that Eu was surrounded by~9.0 O atoms in first coordination shell at REu–O≈2.40,and second shell of Mn atoms at REu–Mn≈3.60 was observed for the three adsorption samples.These findings suggested formation of a bidentate surface complex with Eu(Ⅲ)bonding by edge sharing to MnO6-octahedron on γ-MnOOH surface.Both the macroscopic interaction data and the molecular level evidence of Eu(Ⅲ)microstructure at the γ-MnOOH-water interface should be factored into better understanding the fate and mobility of Eu(Ⅲ)and related radionuclides in the natural soil and water environment.     

Preparation,Characterization and Properties of Two New Lanthanide(Ⅲ)-5-(2-pyridyl)tetrazolate Complexes

Two new mononuclear lanthanide(Ⅲ) complexes Ln(pytz)3(H2O)3·(H2O)3.5[Ln=Tb(1);Eu(2);Hpytz=5-(2-pyridyl)tetrazole] were synthesized by reacting Hpytz with the corresponding lanthanide(Ⅲ) ions and characterized.The single crystal X-ray diffraction analysis reveals that complexes 1 and 2 are isostructural and the lanthanide(Ⅲ) ions in both complexes 1 and 2 are nine-coordinated,with three oxygen atoms of three coordination water molecules and six nitrogen atoms of three pytz ligands,forming a monocapped square antiprism.Extensive hydrogen bonds exist,resulting in a three-dimensional supramolecular network structure by hydrogen-bonds in both complexes 1 and 2,respectively.Complex 1 exhibits typical green fluorescence of Tb(Ⅲ) ion and complex 2 red fluorescence of Eu(Ⅲ) ion,in solid state at room temperature.     

Structures and Photoluminescent Properties of 3D Ho(Ⅲ) and Y(Ⅲ) Complexes with 2,4,6-Pyridinetricarboxylate

Two 3D rare earth coordination polymers {[Ho(ptc)(H_2O)_(2.5)]·0.5 H_2O}n(1) and {[Y2(ptc)2(H_2O)_5]·H_2O}n(2)(H_3ptc = 2,4,6-pyridinetricarboxylic acid) have been synthesized with Ho(Ⅲ) or Y(Ⅲ) chloride and H_3ptc by hydrothermal method. The X-ray structure analyses display the two complexes are isomorphic and crystallize in monoclinic crystal system with P21/n space group for 1 and P21/c space group for 2. Ho(Ⅲ) and Y(Ⅲ) both show two different coordination modes. One is nine-coordinated and forms a distorted tricapped trigonal prism and the other is eight-coordinated to get a distorted bicapped trigonal prism. The ptc3-also shows two different coordination modes by connecting four or three rare earth ions. The photoluminescent properties of 2 show that it can emit blue fluorescence at 440 nm with excitation at 335 nm. The fluorescence lifetime of 2 is 1.64 μs and the absolute fluorescence quantum yield is 10.2%.     

Surface chemistry of polymer-supported nano-hydrated ferric oxide for arsenic removal: effect of host pore structure

Immobilization of hydrous ferric oxide(HFO) particles inside solid hosts of porous structure is an important approach to improve their applicability in advanced water treatment such as arsenic and heavy metal removal. Here, we fabricated three polystyrene(PS)-based nano-HFOs and explored the effect of host pore structure on the surface chemistry of the immobilized HFOs. Potentiometric titration of the hybrids and surface complexation modeling of their adsorption towards arsenite and arsenate were performed to evaluate the surface chemistry variation of the loaded HFOs. Polymer hosts of higher surface area and narrower pore size would result in smaller particle size of HFOs and lower the value of the point of zero charge. Also, the site density(normalized by Fe mass) and the deprotonation constants of the loaded HFOs increased with the decreasing host pore size. Arsenite adsorption did not change the surface charge of the loaded HFOs, whereas arsenate adsorption accompanied more of the negative surface charges. Adsorption affinity of both arsenic species with three HFO hybrids were compared in terms of the intrinsic surface complexation constants optimized based on the adsorption edges. HFO loaded in polystyrene host of smaller pore size exhibits stronger affinity with arsenic species.     

Theoretical studies on the complexation of Eu(Ⅲ) and Am(Ⅲ) with HDEHP: structure,bonding nature and stability

Separation of trivalent lanthanides(Ln(Ⅲ)) and actinides(An(Ⅲ)) is a key issue in the advanced spent nuclear fuel reprocessing. In the well-known trivalent actinide lanthanide separation by phosphorus reagent extraction from aqueous komplexes(TALSPEAK) process, the organophosphorus ligand HDEHP(di-(2-ethylhexyl) phosphoric acid) has been used as an efficient reagent for the partitioning of Ln(Ⅲ) from An(Ⅲ) with the combination of a holdback reagent in aqueous lactate buffer solution. In this work, the structural and electronic properties of Eu~(3+) and Am~(3+) complexes with HDEHP in nitric acid solution have been systematically explored by using scalar-relativistic density functional theory(DFT). It was found that HDEHP can coordinate with M(Ⅲ)(M=Eu, Am) cations in the form of hydrogen-bonded dimers HL_2~-(L=DEHP), and the metal ions prefer to coordinate with the phosphoryl oxygen atom of the ligand. For all the extraction complexes, the metal-ligand bonds are mainly ionic in nature. Although Eu(Ⅲ) complexes have higher interaction energies, the HL_2~- dimer shows comparable affinity for Eu(Ⅲ) and Am(Ⅲ) according to thermodynamic analysis, which may be attributed to the higher stabilities of Eu(Ⅲ) nonahydrate. It is expected that this work could provide insightful information on the complexation of An(Ⅲ) and Ln(Ⅲ) with HDEHP at the molecular level.     

Two Cu(Ⅱ) Complexes with Hydrolyzed Nicotinamide Ligand: Crystal Structures and Bioactivities

Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H_2O)]·H_2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu_2(2,4-D)_4(Hnta)_2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes' cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.     

Investigation of radionuclide 60Co(II) binding to TiO2 by batch technique, surface complexation model and DFT calculations

The interaction between radionuclides and solid/water interfaces is important to understand the physicochemical processes of radionuclides in the natural environment.Herein,the interaction of 60Co(Ⅱ) with TiO 2 in aqueous solution as a function of pH and ionic strength was studied by using batch technique combined with surface complexation model and density functional theory(DFT) calculations.The batch experimental results showed that the adsorption of 60Co(Ⅱ) was dependent on pH and independent of ionic strength,indicating the formation of inner-sphere surface complexes on TiO 2 surfaces.The results of surface complexation models and DFT calculations indicated that the surface species of 60Co(Ⅱ) adsorbed on TiO 2 followed the trend:B structure(i.e.,60Co(Ⅱ) was linked to one bridge oxygen site) was the dominant surface species at low pH,and TT structure(i.e.,60Co(Ⅱ) was linked to two terminal oxygen sites) became the important surface complex at neutral and alkaline pH values.These results demonstrated that a multi-technique approach could lead to definitive information on the structures of adsorbed 60Co(Ⅱ) at the molecular level at the TiO 2 /water interfaces,as well as realistic models to rationalize and accurately evaluate the macroscopic manifestations of radionuclide adsorption phenomena.     

Synthesis and Fluorescent and Magnetic Properties of a New Europium Complex Eu(C_(20)H_(14)O_3N)_3(2,2'-bipy)(H_2O)·H_2O

A new europium(Ⅲ) complex Eu(C_(20)H_(14)O_3N)_3(2,2?-bipy)(H_2O)·H_2O has been synthesized with2-diphenylanine carbonyl benzoic acid and 2,2?-bipyridine as ligands.Crystal data for the complex are as follows:triclinic,space group ■,a=11.3334(5),b=16.0883(7),c=17.0116(8)?,α=70.411(4)o,β=82.435(4)o,γ=85.095(4)o,V=2894.0(2)?~3,D_c=1.484 g/cm~3,Z=2,μ=1.15 mm~(-1),F(000)=1320 and the final R=0.0447 and w R=0.0578.The Eu(Ⅲ) ion is coordinated by nine atoms to give a monocapped square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu~(3+):~5D_0→~7F_1 (592 nm) and ~5D_0→~7F_2 (616 nm),respectively.Also reported is the magnetic property of the complex.The complex exhibits antiferromagnetism in the temperature range of 300～2 K.     

Heterometal–organic frameworks: Three novel copper(Ⅱ)–lanthanide(Ⅲ) 15-metallacrown-5 complexes based on pyrazinohydroxamic acid as new multiple-binding pentagonal platform

Reactions of copper(Ⅱ) sulfate or copper(Ⅱ) perchlorate,samarium(Ⅲ),erbium(Ⅲ) or neodymium(Ⅲ)nitrate(5/1 equiv.) with pyrazinohydroxamic acid(H_2Pyzha) in H_2O/Me0 H led to three new heterobimetallic 15-metallacrown-5 complexes.In a MeOH/H_2O solution,when adding inorganic salts,the ligands exist as protonated metallacrowns.In the solid state,their structures are more complicated as confirmed by X-ray analysis:metallacrown[Sm(H_2O)_3 {Cu(pyzha)}_5(H_2O)_2(MeOH)(HSO_4)_2]·(H_2O)_2(HSO_4)(1);[Nd(H_2O)_2(MeOH) {Cu(pyzha)}_5(ClO_4)_2(H_2O)_5(NO_3)](2);[Eu(H_2O)_2(MeOH) {Cu(pyzha)}_5(ClO_4)_2(H_2O)_5(NO_3)](3).The differentiation of atomic and ionic radii between the encapsulated lanthanide(Ⅲ) could be used to control the bowl-shape distortion of the metallacrowns from the planar geometry.The complex 1 clearly exhibits fluorescence behavior of samarium(Ⅲ),while 2and 3 show that of copper(Ⅱ) and ligand.     

Synthesis of La(Ⅲ), Y(Ⅲ) complexes with polyglycol aldehyde-amino acid Schiff base and their high resolution solid state ~(13)C NMR spectra

La(Ⅲ), Y(Ⅲ) complexes with diglycol aldehyde bis-arginine (H_2DAAR) and tetraglycol aldehyde bislysine (H_2TALY) Schiff bases were synthesized. They were characterized and formulated as La(H_2DAAR) (NO_3)_3·6H_2O and Y (H_2TALY)(NO_3)_3·5H_2O separately by elemental analyses. The obtained complexes were investigated in detail by high resolution solid state (HRSS) ~(13)C NMR using cross polarization, magic angle spinning (CPMAS), and total suppression of sidebands (TOSS)techniques. The results are supported by the liquid state 2D-~1H-~(13)C COSY NMR spectra. Some new information about the splitting peaks of ~(13)C for—CH=N—group and alkene carbon bands, etc. in HRSS ~(13)C NMR spectra are given.     

STUDIES ON RARE EARTH COMPLEXES OF QUARTERNARY AMMONIUM SALT——SYNTHESIS AND CRYSTAL STRUCTURE OF TETRAKIS-(TRIMETHYL-HEXADECYL AMMONIUM)DECANITRATO DINEODYMATE,((CH_3)_3C_(16)H_(33)N)_4Nd_2(NO_3)_(10)

A series of binuclear eleven-coordinated rare earth complexes with long chain quarternary ammonium salt have been synthesized. The general formula of the complexes may be represented by((CH_3)_3 C_(16)H_(33)N)_4Ln_2(NO_3)_(10) where Ln is La, Ce, Pr, Nd, Sm, Eu, Ga, Ho, Er or Y. The TG curve, the magnetic moment and the dissociation degree of the Nd complexes in alcoholic solution have been determined.((CH_3)_3C_(16)H_(33)N)_4 Nd,_2NO_3)_(10) was chosen as a representative of the complexes for the crystal structure determination. The crystal is monoclinic with space group P. Each Nd atom is coordinated by four terminal nitrate groups bidentately, and two Nd atoms are connected through two O atoms of the nitrate groups forming binuclear complex. Therefore, each Nd atom is surrounded by eleven oxygen atoms. The average bond length of the eleven Nd-O bond is 2.57, while the Nd-O bond length on the oxygen-bridge is 2.62.     

One Novel Mn(Ⅱ) Complex with 1-Substituted-1H-1,2,3-triazole-4-carboxylic Acid:Crystal Structure,Fluorescence and Hirshfeld Surface Analysis

The crystal structure of one novel Mn(II) complex, [Mn(pmta)_3]_2[Mn(H_2O)_6]·4H_2O(1), is reported(Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid). In the title compound, the asymmetric unit consists of a [Mn(pmta_)3]ˉ anion, half [Mn(H_2O)_6]~(2+) counter cation and two lattice H_2O molecules, and the intra- and intermolecular hydrogen bonds connect the complex into a supramolecular structure. The liquid-state fluorescence spectra of complex 1 have been determined. Hirshfeld surface analysis was also studied. The main intermolecular interactions in the complex are O···H and H···H contacts.     

Simultaneous assembly of mononuclear and dinuclear dysprosium(Ⅲ) complexes behaving as single-molecule magnets in a one-pot hydrothermal synthesis

Two dysprosium(Ⅲ) complexes derived from 2,2'-bipyridine-6,6'-dicarboxylic acid(H_2bpdc),[Dy(bpdc)(Hbpdc)]-3H_2O(1) and[Dy_2(bpdc)_3(H_2O)_3]·2.125H_2O(2),were isolated from the same hydrothermal reaction container as different phases.Compound1 is a mononuclear complex with a DyN_4O_4 coordination polyhedron;whereas compound 2 is a dinuclear complex with two types of eight coordinated dy sprosium(Ⅲ) ions,showing DyN_4O_4 and DyN_2O_6 coordination polyhedra,respectively.Remarkably,a new type of(H_2O)_6 supramolecular aggregate exists in the crystal structure of 2.Magnetic investigations revealed that 1 is a field-induced single-ion magnet with an effective energy barrier of 45.6 K,exhibiting two-step magnetic relaxation;while an intramolecular ferromagnetic interaction exists in 2,which is a field-induced single-molecule magnet,displaying two-step magnetic relaxation too,with effective energy barriers of 53.4 and 92.1 K,respectively.     

In-situ reduction synthesis of manganese dioxide@polypyrrole core/shell nanomaterial for highly efficient enrichment of U(Ⅵ) and Eu(Ⅲ)

Radionuclides with long half-life are toxic,and thereby result in serious threat to human beings and ecological balance.Herein,a simple two-step synthesis method was used to prepare manganese dioxide@polypyrrole(Mn O_2@PPy)core/shell structures for efficient removal of U(Ⅵ)and Eu(Ⅲ)from aqueous solutions.The adsorption of U(Ⅵ)and Eu(Ⅲ)were investigated under different kinds of experimental conditions.The experimental results suggested that the adsorption of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy were greatly affected by p H.U(Ⅵ)adsorption on Mn O_2@PPy was independent of ionic strength at p H6.0,and dependent on ionic strength at p H6.0.However,Eu(Ⅲ)adsorption on Mn O_2@PPy was independent of ionic strength at the whole p H range of experimental conditions.The maximum adsorption capacities(q_(max))of U(Ⅵ)and Eu(Ⅲ)were 63.04 and54.74 mg g~(-1)at T=298 K,respectively.The BET,XRD,FTIR and XPS analysis evidenced that high adsorption capacities of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy were mainly due to high surface area and rich metal oxygen-containing group(i.e.,Mn–OH and Mn–O),and the interaction was mainly attributed to strong surface complexation and electrostatic interaction.This study highlighted the excellent adsorption performance of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy and could provide the reference for the elimination of radionuclides in real wastewater management.     

SYNTHFSIS AND CHARACTERIZATION OF LANTHANIDE COMPARTMENTATL COMPLEXES, ln_2 [h_2 (BAA)_2 en]_2·pH_2O

A series of new complexes of formula Ln_2[H_2(BAA)_2en]_3nH_2 Otwhere Ln- La,Pr, Eu, Cd, Dy, Er, Yb, n-1-4) have been prepared by the reaccLon of lanthanideions with acycllc compartmental ligand X, N'-bis(benzoylacetylacetone)ethylenediamine(H_4(BAA)_2 en) in methanol. IR and UV spectra, as well as TC DAT analysis prove thatthe ligand and the Lanthanide ions have coordinated. The coordination number is 12and the complexes may be of double sandwiched structure.     

三元稀土配合物RE(NTA)2AA的合成、共聚反应性及荧光性能研究

Four new ternary rare earth complexes RE(NTA)₂AA (RE=Sm³⁺， Eu³⁺， Tb³⁺， Dy³⁺) have been synthesized by the reaction of rare earth chloride(RECl₃·6H₂O) with Acrylic Acid (HAA) and 4，4，4-trifluoro-1-(3-pyridyl)-1，3-butanedione(NTA) in alcohol. The copolymerization of the complexes RE(NTA)₂AA (RE=Sm³⁺， Eu³⁺) with methyl methacrylate (MMA) has been studied by 2， 2-azobis-isobutyronitrile as an initiator. Influence of adding Eu(Ⅲ) and 2，2′-bipyridine(bipy) into copolymer Eu(NTA)₂AA-co-MMA on fluorescence property of the Eu copolymer was investigated. The compositions of the complexes and copolymer were characterized by means of elemental analysis and FTIR. The heat decomposing behaviors of the complexes were determined by TG-DTA. The glass transition temperature and molecular weight were obtained by DSC and GPC. The results of fluorescence properties show that the Eu， Sm complexes and Eu copolymer can efficiently emit fluorescence， but the Tb and Dy complexes only emit the fluorescence of β-diketone ligand.     

Design criteria for tetradentate phenanthroline-derived heterocyclic ligands to separate Am(Ⅲ) from Eu(Ⅲ)

To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) were constructed and their complexation behaviors with Am(ⅡI) and Eu(ⅡI) were systematically investigated by density functional theory(DFT) coupled with relativistic small-core pseudopotential. In all the 1:1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms(N1 and N1′) of the phenanthroline skeleton and the other two nitrogen atoms(N2 and N2′) of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am(ⅡI) are larger than those of Eu(ⅡI). Additionally, the negative ΔΔGAm/Eu value for the reaction of [M(H2O)4-(NO3)3] + L → ML(NO3)3 + 4H2 O indicates that the complexation reaction of Am(ⅡI) is more energetically favorable than that of Eu(ⅡI); this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA(ⅡI) extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am(ⅡI) over Eu(ⅡI) follows the order of BTPhen BBizPhen BPyPhen BPzPhen.     

Synthesis and catalytic activity of novel heteronuclear Ln(Ⅲ)-Cu(Ⅱ) complexes with noncyclic polyether-amino acid Schiff base

A series of novel heteronuclear Ln(Ⅲ)-Cu(Ⅱ) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is [LnCu_2(H_2TALY)(NO_3)_5](NO_3)_2' nH_2O(Ln=La, Nd, Sm, Gd, n= 4; Ln=Yb, Y, n=3), where H_2TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(Ⅱ) complexes and Ln(Ⅲ)-Cu(Ⅱ) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra, TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst, which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bas     

Understanding the adsorption mechanism of Ni(II) on graphene oxides by batch experiments and density functional theory studies

The graphene oxides(GOs) have attracted multidisciplinary study because of their special physicochemical properties. The high surface area and large amounts of oxygen-containing functional groups make GOs suitable materials for the efficient elimination of heavy metal ions from aqueous solutions. Herein the sorption of Ni(II) on GOs was studied using batch experiments, and the results showed that the sorption of Ni(II) is strongly dependent on p H and ionic strength at pH8, and independent of ionic strength at pH8. The sorption of Ni(II) is mainly dominated by outer-sphere surface complexation and ion exchange at low p H, and by inner-sphere surface complexation at high p H. The interaction of Ni(II) with GOs was also investigated by theoretical density functional theory(DFT) calculations, and the results show that the sorption of Ni(II) on GOs is mainly attributed to the –COH and –COC groups and the DFT calculations show that Ni(II) forms stable GO_Ni_triplet structure with the binding energy of -39.44 kcal/mol, which is in good agreement with the batch sorption experimental results. The results are important for the application of GOs as adsorbents in the efficient removal of Ni(II) from wastewater in environmental pollution cleanup.