Co-reporter:Lijiao Ma, Saiful M. Islam, Chengliang Xiao, Jing Zhao, Hongyun Liu, Mengwei Yuan, Genban Sun, Huifeng Li, Shulan Ma, and Mercouri G. Kanatzidis
Journal of the American Chemical Society September 13, 2017 Volume 139(Issue 36) pp:12745-12745
Publication Date(Web):August 7, 2017
DOI:10.1021/jacs.7b07123
We demonstrate fast, highly efficient concurrent removal of toxic oxoanions of Se(VI) (SeO42–) and Se(IV) (SeO32–/HSeO3–) and heavy metal ions of Hg2+, Cu2+, and Cd2+ by the MoS42– intercalated Mg/Al layered double hydroxide (MgAl-MoS4-LDH, abbr. MoS4-LDH). Using the MoS4-LDH as a sorbent, we observe that the presence of Hg2+ ions greatly promotes the capture of SeO42–, while the three metal ions (Hg2+, Cu2+, Cd2+) enable a remarkable improvement in the removal of SeO32–/HSeO3–. For the pair Se(VI)+Hg2+, the MoS4-LDH exhibits outstanding removal rates (>99.9%) for both Hg2+ and Se(VI), compared to 81% removal for SeO42– alone. For individual SeO32– (without metal ions), 99.1% Se(IV) removal is achieved, while ≥99.9% removals are reached in the presence of Hg2+, Cu2+, and Cd2+. Simultaneously, the removal rates for these metal ions are also >99.9%, and nearly all concentrations of the elements can be reduced to <10 ppb, a limit acceptable for drinking water. The maximum sorption capacities for individual Se(VI) and Se(IV) are 85 and 294 mg/g, respectively. The 294 mg/g capacity for Se(IV) reaches a record value, placing the MoS4-LDH among the highest-capacity selenite adsorbing materials described to date. More interestingly, the presence of metal ions extremely accelerates the capture of the selenium oxoanions because of the reactions of the metal ions with the interlayer MoS42– anions. The sorptions of Se(VI)+Hg and Se(IV)+M (M = Hg2+, Cu2+, Cd2+) are exceptionally rapid, showing >99.5% removals for Hg2+ within 1 min and ∼99.0% removal for Se(VI) within 30 min, as well as >99.5% removals for pairs Cu2+ and Se(IV) within 10 min, and Cd2+ and Se(IV) within 30 min. During the sorption of SeO32–/HSeO3–, reduction of Se(IV) occurs to Se0 caused by the S2– sites in MoS42–. Sorption kinetics for the oxoanions follows a pseudo-second-order model consistent with chemisorption. The intercalated material of MoS4-LDH is very promising as a highly effective filter for decontamination of water with toxic Se(IV)/Se(VI) oxoanions along with heavy metals such as Hg2+, Cd2+, and Cu2+.
Co-reporter:Mengwei Yuan, Caiyun Nan, Yan Yang, Genban Sun, Huifeng Li, and Shulan Ma
ACS Omega August 2017? Volume 2(Issue 8) pp:4269-4269
Publication Date(Web):August 7, 2017
DOI:10.1021/acsomega.7b00497
Uniform FexNiy nanospheres were synthesized via a simple solvothermal method and used as electrocatalysts for Li–O2 batteries. Fe7Ni3 nanospheres exhibited relatively high catalytic activities in the electrochemical tests. They delivered a reversible capacity of more than 7000 mAh/gKB and gave a discharge–charge voltage gap reduction of 250 mV compared with Ketjen Black.Topics: Batteries; Catalysts; Electric transport processes and properties; Electrochemical analysis; Nanostructures; Phase; Spectra;
Co-reporter:Feifei Su, Chenyu Liu, Yan Yang, Shulan Ma, Genban Sun, Xiaojing Yang
Materials Research Bulletin 2017 Volume 88(Volume 88) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.materresbull.2017.01.008
•The intercalation of three benzenepolycarboxylic species into LTbH is reported.•Intercalation structure and arrangement of the interlayer guests are studied.•The organic anions can markedly enhance the luminescence of layer Tb3+ ions.•Energy transfer between organics and Tb3+ contributes to sensitized luminescence.We herein demonstrate the intercalation of several organic benzenepolycarboxylic compounds, terephthalic acid (TC), 1,3,5-benzenetricarboxylic acid (BTC) and 1,2,4,5-benzenetetracarboxylic acid (BTCC), into the layered terbium hydroxide (LTbH) and the sensitized luminescence of these organic species for the layer Tb3+. All of the as-prepared products demonstrated characteristic XRD diffractions attributed to layered materials. Compared with the NO3–LTbH precursor, efficient energy transfer from intercalated organic anions to Tb3+ centers in LTbH layers took place, thus markedly enhancing the Tb3+ luminescence. The relationship between the triplet energy levels of the organic guests and the energy level of Tb3+ was analyzed to explain the sensitization effect and energy transfer from the gallery sensitizers to the layer Tb3+ ions. The fluorescence lifetimes of NO3-LTbH, TC-LTbH, BTC-LTbH and BTCC-LTbH were determined to be 0.131, 0.315, 0.579 and 0.642 ms, respectively, indicating significantly increased lifetimes of the LTbH composites intercalated with the organic species.Download high-res image (126KB)Download full-size image
Co-reporter:Lijiao Ma;Mengwei Yuan;Chenyu Liu;Linxia Xie;Feifei Su;Genban Sun;Huifeng Li
Dalton Transactions 2017 vol. 46(Issue 37) pp:12724-12731
Publication Date(Web):2017/09/25
DOI:10.1039/C7DT02662E
The organic compound of coumarin-3-carboxylic acid (CCA), deprotonated beforehand by NaOH, and the 1-octane sulfonic acid anion (OS) were co-intercalated into the gallery of the layered europium hydroxide (LEuH) via an ion exchange method. Different molar ratios of CCA/OS and NaOH/CCA gave rise to the composites of CCA1−xOSx-LEuH (x = 0.8–1.0) showing different emission intensities. In formamide (FM), all composites were delaminated and the formed colloidal suspensions exhibited enhanced red luminescence of Eu3+ in comparison with the OS-LEuH without CCA. Also, the red emissions of the composites were different from the violet emission (421 nm) of free CCA− and blue emission (471 nm) of CCA2− anions in different deprotonation states. The energy levels of CCA and Eu3+ were analyzed to explain the sensitization effect for Eu3+ luminescence. The fluorescence lifetimes of CCA0.2OS0.8-LEuH-1 : 1, CCA0.02OS0.98-LEuH-1 : 1, CCA0.2OS0.8-LEuH-1 : 2, and CCA0.02OS0.98-LEuH-1 : 2 were determined to be 0.705, 0.704, 0.699 and 0.638 ms, respectively, indicating significantly longer lifetimes. The PL quantum yields of ∼10% demonstrate the excellent luminescence properties of the as-prepared CCA1−xOSx-LEuH composites. This is the first report on the sensitized luminescence properties of layer Eu3+ ions in LRH composites in the delaminated state. The intriguing red luminescence of delaminated LEuH composites offers a promising approach to achieve efficient luminescent film materials.
Co-reporter:Linxia Xie;Chenyu Liu;Lijiao Ma;Chengliang Xiao;Genban Sun;Huifeng Li;Xiaojing Yang
Dalton Transactions 2017 vol. 46(Issue 10) pp:3110-3114
Publication Date(Web):2017/03/07
DOI:10.1039/C6DT04870F
We demonstrate a novel example of a delaminated MoS4/OS-LEuH composite (LEuH is layered europium hydroxide, OS is 1-octane sulfonate), which exhibits quenched luminescence in formamide and highly enhanced red emission in the water-present case. The turn-on luminescence sensing capability of the material is promising for feasible detection of a trace amount of water in formamide (FM) and N,N-dimethylformamide (DMF).
Co-reporter:Lijiao Ma; Qing Wang; Saiful M. Islam; Yingchun Liu; Shulan Ma;Mercouri G. Kanatzidis
Journal of the American Chemical Society 2016 Volume 138(Issue 8) pp:2858-2866
Publication Date(Web):January 31, 2016
DOI:10.1021/jacs.6b00110
The MoS42– ion was intercalated into magnesium–aluminum layered double hydroxide (MgAl—NO3-LDH) to produce a single phase material of Mg0.66Al0.34(OH)2(MoS4)0.17·nH2O (MgAl—MoS4-LDH), which demonstrates highly selective binding and extremely efficient removal of heavy metal ions such as Cu2+, Pb2+, Ag+, and Hg2+. The MoS4-LDH displays a selectivity order of Co2+, Ni2+, Zn2+ < Cd2+ ≪ Pb2+ < Cu2+ < Hg2+ < Ag+ for the metal ions. The enormous capacities for Hg2+ (∼500 mg/g) and Ag+ (450 mg/g) and very high distribution coefficients (Kd) of ∼107 mL/g place the MoS4-LDH at the top of materials known for such removal. Sorption isotherm for Ag+ agrees with the Langmuir model suggesting a monolayer adsorption. It can rapidly lower the concentrations of Cu2+, Pb2+, Hg2+, and Ag+ from ppm levels to trace levels of ≤1 ppb. For the highly toxic Hg2+ (at ∼30 ppm concentration), the adsorption is exceptionally rapid and highly selective, showing a 97.3% removal within 5 min, 99.7% removal within 30 min, and ∼100% removal within 1 h. The sorption kinetics for Cu2+, Ag+, Pb2+, and Hg2+ follows a pseudo-second-order model suggesting a chemisorption with the adsorption mechanism via M—S bonding. X-ray diffraction patterns of the samples after adsorption demonstrate the coordination and intercalation structures depending on the metal ions and their concentration. After the capture of heavy metals, the crystallites of the MoS4-LDH material retain the original hexagonal prismatic shape and are stable at pH ≈ 2–10. The MoS4-LDH material is thus promising for the remediation of heavy metal polluted water.
Co-reporter:Teng Ma, Mengwei Yuan, Saiful M. Islam, Huifeng Li, Shulan Ma, Genban Sun, Xiaojing Yang
Journal of Alloys and Compounds 2016 Volume 678() pp:468-477
Publication Date(Web):5 September 2016
DOI:10.1016/j.jallcom.2016.03.243
•Monodispersed FeNi3 alloy nanocrystals have been successfully assembled on 2D graphene via a one-pot strategy.•The process ensures different crystal phase and controlled morphology and size in the monodispersed particles.•The nanocomposites exhibit excellent microwave absorbability, which is stronger than the corresponding alloy monomer.FeNi3 nanocrystals as an ideal candidate for EM-wave-absorption material have a great advantage due to their excellent magnetic properties. However, its large permittivity and poor chemical stability confine its application. A strategy to improve electromagnetic performance of FeNi3via phase-controlled synthesis of FeNi3 nanostructures grown on graphene networks has been employed in this work. The phases, structures, sizes and morphologies of FeNi3 nanocomposites were in-depth characterized by using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), and Raman spectroscopy. The results of electromagnetic performance tests for the as-synthesized FeNi3 nanocomposites showed excellent microwave absorbability in comparison with the corresponding FeNi3 nanocrystals, especially in the low (2–6 GHz) and middle (6–12 GHz) frequencies. The one-pot method we utilized is simple and effective, and because of its versatility, it may be extended to prepare some magnetic metal or alloy materials via this route.
Co-reporter:Qingyang Gu, Feifei Su, Lijiao Ma, Shulan Ma, Genban Sun and Xiaojing Yang
Journal of Materials Chemistry A 2015 vol. 3(Issue 18) pp:4742-4750
Publication Date(Web):02 Apr 2015
DOI:10.1039/C5TC00441A
Organic compounds of ortho-coumaric acid (abbr. o-CMA) and para-coumaric acid (abbr. p-CMA) are intercalated into the layered rare-earth hydroxides (LRHs, R = Eu, Gd) via the ion exchange method. The two organics having the same phenolic hydroxyl and carboxyl groups located at different positions demonstrate variant intercalation structures. The CMA anion guests within the LRH gallery indicate monolayered or bi-layered arrangements depending on their own characteristic features and deprotonation degrees. The combination of o-/p-CMA molecules with LEuH/LGdH layers generates hybrid materials exhibiting versatile luminescence properties. In the solid state, for LEuH layers, the luminescence of layer Eu3+ and interlayer o-CMA is co-quenched; however, for LGdH layers, green emissions (∼520 nm) are observed, both of which are different from the cyan emission (475 nm) of free o-CMA anions. When dispersed in formamide (FM), o-CMA–LEuH composites exhibit weak luminescence, in sharp contrast to o-CMA–LGdH composites displaying green emissions (495–520 nm) with markedly enhanced intensity. The p-CMA–LGdH composites display blue emission (457 nm) quite different from the green emission (499 nm) for free p-CMA in FM, compared with the unobservable emission within LEuH layers. In addition, co-intercalation of the surfactant OS (1-octane sulfonic acid sodium) with o-CMA anions into LEuH produces composites showing desirable blue emission or violet emission, due to the change of the microenvironment of organic guests. The energy transfer between layer Eu3+ and interlayer CMA was proposed to account for the co-quenching or blue shift. This work offers a beneficial approach to fabricate organic–inorganic photofunctional materials with a controllable structure and tunable fluorescence properties.
Co-reporter:Feifei Su, Qingyang Gu, Shulan Ma, Genban Sun, Xiaojing Yang and Li-Dong Zhao
Journal of Materials Chemistry A 2015 vol. 3(Issue 27) pp:7143-7152
Publication Date(Web):03 Jun 2015
DOI:10.1039/C5TC01045D
We demonstrate a novel example of delaminated layered rare-earth hydroxide (LRH, R = Tb, Y) composites with ortho-coumaric acid (CMA) and surfactant 1-octane sulfonic (OS) anions that exhibit tunable photoluminescence, especially blue emission due to energy transfer via the layer Tb3+. Different molar ratios of organic guests (OS/CMA) and layer ions (Tb/Y) give rise to versatile composites of OSxCMA1−x–LTbyY1−yH (x = 0.9, 0.8, 0.7, 0.6, 0.5, y = 1, 0.9, 0.7, 0.5, 0.3, 0.1, 0). In the solid state, for LTbH composites, co-quenching for emissions of CMA and the layer Tb3+ is found, while for LYH composites, green emission (502 nm) is observed. In formamide (FM), all of the composites are found to be facilely delaminated, and the colloidal suspensions of LTbH composites with varied OSxCMA1−x interlayer guests exhibit color-tuning within the blue-light region (430–465 nm), with blue-shift of emissions and enhanced luminescence intensity following increased OS content. LTbyY1−yH composites (with a fixed OS/CMA ratio of 0.7:0.3), however, present emissions from blue to green with increased Y3+ content. A new concept of ‘host-energy transfer-induced-emission (HETIE)’ is proposed to explain the blue luminescence via energy transfer of the host Tb3+. The intriguing energy transfer between a photoactive host matrix and interlayer guests in the delaminated state offers a promising approach to achieve efficient tuning of luminescence, thus meeting the high demand of applications on multicolor optical and display devices; especially blue emission.
Co-reporter:Qingyang Gu, Feifei Su, Shulan Ma, Genban Sun and Xiaojing Yang
Chemical Communications 2015 vol. 51(Issue 13) pp:2514-2517
Publication Date(Web):02 Dec 2014
DOI:10.1039/C4CC08380F
We demonstrate the first example of exfoliated layered europium hydroxide (LEuH) composites with a fluorescent molecule that exhibit blue luminescence. Co-quenching in the solid state, blue emission (440 nm) in formamide, and green emission (514 nm) in water–formamide were found, for which delamination and swollen states account for the versatile luminescence behaviors.
Co-reporter:Gailing Huang, Dong Wang, Shulan Ma, Junli Chen, Ling Jiang, Peiyuan Wang
Journal of Colloid and Interface Science 2015 Volume 445() pp:294-302
Publication Date(Web):1 May 2015
DOI:10.1016/j.jcis.2014.12.099
This work aimed to develop waste (i.e., sulfonated lignin) application in simulated wastewater treatment. Sulfonated lignin (LS), a byproduct of the paper industry, was intercalated into a parent host of layered double hydroxides (LDH) by swelling–restacking method. X-ray diffraction patterns of the composite confirmed that long-chain LS anions exited in the interlayer of Mg2Al–LDH in two forms: (1) a “flat” form with d003 = 0.88 nm; and (2) a “vertical” form with d003 = 9.08 nm. Results showed that the obtained Mg2Al–LS–LDH composite was highly selective and efficient for the removal of Pb2+ and Cu2+, especially Pb2+, compared with the NO3–LDH precursor. The coexisting cations decreased the removal efficiency of Pb2+ or Cu2+ on Mg2Al–LS–LDH composite, which could be ascribed to outer-sphere sorption style, and the effect order of cations is Li+ > Ca2+ > K+ > Na+. The pseudo-second-order model appropriately described the sorption kinetics of Mg2Al–LS–LDH composite for Pb2+ and Cu2+. Sorption isotherms for Pb2+ and Cu2+ by the Mg2Al–LS–LDH composite were found to be more satisfactorily fitted by the Langmuir model than by the Freundlich one. With increased Pb2+ or Cu2+ concentration from 2 ppm to 200 ppm, the maximum absorption capacity of the composite toward Pb2+ was ∼123 mg/g and that toward Cu2+ was ∼64 mg/g. Therefore, a new, low-cost adsorbent was synthesized by utilizing the byproduct LS, which may be a potential remedy for Pb2+ or Cu2+ in contaminated water.
Co-reporter:Feifei Su, Junjun Pan, Yanpeng Wei, Lin Fan, Yingchun Liu, Shulan Ma
Inorganic Chemistry Communications 2015 Volume 58() pp:103-107
Publication Date(Web):August 2015
DOI:10.1016/j.inoche.2015.06.017
•2D complexes of azacrown ether carboxylic acid with Ln3 + and Na+ were reported.•Coordination network was built up by Ln–L coordinating subunits and 1D Na–O bridging chains.•A novel example of hetero-bimetallic sandwich structure was found.•Four versatile coordination modes of carboxyl groups were observed.Two lanthanide-based coordination polymers [Na3La(L)Cl·(H2O)6]·NO3 (La-L) and [Na3Eu(L)Cl·(H2O)6]·NO3 (Eu-L) were newly synthesized by reaction of an azacrown ether carboxylic acid ligand H4L (4,7,13,16-tetracarboxymethyl-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane) with La(III)/Eu(III). Complexes La-L and Eu-L exhibited two-dimensional (2D) coordination architectures built up by Ln–L coordinating subunits and one-dimensional (1D) Na–O bridging chains. Four versatile coordination modes of carboxyl groups and Na–O coordination bi-chains linked by novel μ-O bridges (μ2-O and μ3-O) were demonstrated in the structure. Photoluminescence spectra of Eu-L were investigated to reveal characteristic emissions of Eu(III). This is the first example of hetero-bimetallic complex of the tetraazacrown ether ligand with lanthanide and sodium ions.Reaction of carboxyethyl substituted azacrown ether ligand (L) with La(III)/Eu(III) ions produces novel hetero-bimetallic 2D networks which were built up by Ln–L coordinating subunits and 1D Na–O bridging chains.
Co-reporter:Xiangyu Xue, Qingyang Gu, Guohua Pan, Jie Liang, Gailing Huang, Genban Sun, Shulan Ma, and Xiaojing Yang
Inorganic Chemistry 2014 Volume 53(Issue 3) pp:1521-1529
Publication Date(Web):January 14, 2014
DOI:10.1021/ic402494m
Nanocage structures derived from decasulfonated β-cyclodextrin (SCD) intercalated ZnAl- and MgAl- layered double hydroxides (LDHs) were prepared through calcination-rehydration reactions. The ZnAl- and MgAl-LDH layers revealed different basal spacings (1.51 nm for SCD-ZnAl-LDH and 1.61 nm for SCD-MgAl-LDH) when contacting SCD, while producing similar monolayer and vertical SCD orientations with cavity axis perpendicular to the LDH layer. The structures of the SCD-LDH and carboxymethyl-β-cyclodextrin (CMCD)-LDH intercalates were fully analyzed and compared, and a structural model for the SCD-LDH was proposed. The thermal stability of SCD after intercalation was remarkably enhanced, with decomposition temperature increased by 230 °C. The adsorption property of the SCD-LDH composites for phenol compounds (the effects of adsorption time and phenol concentration on adsorption) was investigated completely. The monolayer arrangement of the interlayer SCD did not affect the adsorption efficiency toward organic compounds, which verified the highly swelling ability of the layered compounds in solvents. Both composites illustrated preferential adsorptive efficiency for 2,3-dimethylphenol (DMP) in comparison with other two phenols of hydroquinone (HQ) and tert-butyl-phenol (TBP), resulting from appropriate hydrophobicity and steric hindrance of DMP. For the two phenols of HQ and TBP, SCD-MgAl-LDH gave better adsorption capacity compared with SCD-ZnAl-LDH. The double-confinement effect due to the combination of the parent LDH host and intercalated secondary host may impose high selectivity for guests. This kind of nanocage structure may have potential applications as adsorbents, synergistic agents, and storage vessels for particular guests.
Co-reporter:Qingyang Gu;Nankai Chu;Guohua Pan;Genban Sun, ;Xiaojing Yang
European Journal of Inorganic Chemistry 2014 Volume 2014( Issue 3) pp:559-566
Publication Date(Web):
DOI:10.1002/ejic.201301181
Abstract
Organic anions of two benzenepolycarboxylic acids [1,3,5-benzenetricarboxylic acid (BTA) and 2,2′-biphenyldicarboxylic acid (BDA)], two pyridinecarboxylic acids [quinolinic acid (QA) and 2,5-pyridinedicarboxylic acid (PDA)], and two amino acids [phenylalanine (Phe) and tyrosine (Tyr)] were intercalated into the galleries of NO3–-type layered europium hydroxide (NO3–LEuH). All the prepared products displayed XRD patterns with series of diffractions due to layered materials. The composite structures and the arrangement of the guests in the galleries were investigated in detail. The structure of the organic guests (such as the number and position of carboxyl groups) affects the arrangement in the interlayer. SEM observations showed that the NO3–LEuH precursor and its intercalates crystallize in a columnar or layered stacking structure composed of hexagonal thin platelets. The luminescence study indicated that all samples display the typical red emission of Eu3+. Efficient energy transfer between intercalated BTA/BDA anions and Eu3+ centers takes place, markedly enhancing the Eu3+ luminescence, whereas QA–LEuH and PDA–LEuH with pyridinedicarboxylic acid anions show no obvious change in luminescence intensity. When amino acid anions such as Phe and Tyr were introduced into the interlayer, the Eu3+ emission was strongly quenched. The simple soft chemical method can open great opportunities for developing organic–inorganic multifunctional luminescent materials or biological probes for detecting certain amino acids.
Co-reporter:Qingyang Gu, Guohua Pan, Teng Ma, Gailing Huang, Genban Sun, Shulan Ma, Xiaojing Yang
Materials Research Bulletin 2014 53() pp: 234-239
Publication Date(Web):
DOI:10.1016/j.materresbull.2014.01.033
Co-reporter:Guohua Pan, Jia Zhu, Shulan Ma, Genban Sun, and Xiaojing Yang
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 23) pp:12716
Publication Date(Web):November 18, 2013
DOI:10.1021/am404117v
Cobalt is a promising soft metallic magnetic material used for important applications in the field of absorbing stealth technology, especially for absorbing centimeter waves. However, it frequently presents a weak dielectric property because of its instability, aggregation, and crystallographic form. A method for enhancing the electromagnetic property of metal Co via phase-controlled synthesis of Co nanostructures grown on graphene (GN) networks has been developed. Hexagonal close-packed cobalt (α-Co) nanocrystals and face-centered cubic cobalt (β-Co) nanospheres with uniform size and high dispersion have been successfully assembled on GN nanosheets via a facile one-step solution-phase strategy under different reaction conditions in which the exfoliated graphite oxide (graphene oxide, GO) nanosheets were reduced along with the formation of Co nanocrystals. The as-synthesized Co/GN nanocomposites showed excellent microwave absorbability in comparison with the corresponding Co nanocrystals or GN, especially for the nanocomposites of GN and α-Co nanocrystals (the reflection loss is −47.5 dB at 11.9 GHz), which was probably because of the special electrical properties of the cross-linked GN nanosheets and the perfect electromagnetic match in their microstructure as well as the small particle size of Co nanocrystals. The approach is convenient and effective. Some magnetic metal or alloy materials can also be prepared via this route because of its versatility.Keywords: cobalt; electromagnetic performance; graphene; microwave absorbability; nanostructures;
Co-reporter:Weili Li ; Qingyang Gu ; Feifei Su ; Yahong Sun ; Genban Sun ; Shulan Ma ;Xiaojing Yang
Inorganic Chemistry 2013 Volume 52(Issue 24) pp:14010-14017
Publication Date(Web):December 3, 2013
DOI:10.1021/ic4017307
A carboxyethyl substituted azacrown ether (CSAE) derivative was intercalated as a second host into a parent host of layered gadolinium hydroxides (LGdH) by an anion-exchange reaction. The influence of intercalation temperature and starting material ratios of CSAE/LRH on the structures and compositions of CSAE-LRH nanocomposites were investigated. Higher temperature and larger initial CSAE-LGdH weight ratios favor of higher degree of ion exchange at a certain range, while lower temperature gives good morphology for the composites. The adsorptive properties for transition and heavy metal ions were studied using the 20 °C-reacted composite, which showed higher adsorptivity toward transition and heavy metal ions, accompanied by the introduction of nitrate anions. The adsorptive capacity for transition metal ions was in the sequence of Cu2+ > Zn2+∼Ni2+∼Co2+ with a high selectivity to Cu2+. For the heavy metal ions Ag+, Hg2+, Pb2+, and Cd2+, the composite showed markedly high selectivity for Ag+ and Hg2+. When putting Cu2+, Ag+, Hg2+, Pb2+, and Cd2+ together, Ag+ and Hg2+ still have higher adsorptive selectivity over Pb2+ and Cd2+, and Cu2+ has also relatively high selectivity but not as high as Ag+ and Hg2+. The nanocomposites with a second host in the interlayer are one promising kind of material because of the synergy of the steric effect of the parent host (LRH layer) and the particular characteristics of the secondary host (interlayer crown ether anions).
Co-reporter:Yahong Sun;Nankai Chu;Qingyang Gu;Guohua Pan;Genban Sun, ;Xiaojing Yang
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 1) pp:32-38
Publication Date(Web):
DOI:10.1002/ejic.201201048
Abstract
The organic sensitizer terephthalic acid and its anion terephthalate (TA) were introduced into the galleries of europium-doped layered yttrium hydroxide (LYH:Eu). In contrast to using water as solvent, the use of formamide resulted in the introduction of more organic guests and markedly enhanced the Eu3+ luminescence. Formamide prevented water from entering the system, leading to an excess of terephthalic acid molecules, and more efficient coordination of the TA guest with the Eu3+ in the layers of the composite, all of which may have contributed to the enhanced Eu3+ luminescence.
Co-reporter:Shulan Ma;Juan Wang;Li Du;Cuihong Fan;Yahong Sun;Genban Sun ;Xiaojing Yang
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 8) pp:1363-1370
Publication Date(Web):
DOI:10.1002/ejic.201200847
Abstract
Co-assembly of inorganic LDH nanosheets with an organic azacrown ether carboxylic acid derivative was studied by a flocculation method. The homogeneous structure seen in the wet state changed markedly after drying: a staging structure transformed into a homogeneous one after increased assembly times. The experimental observations, changeover from homogeneous to staging and unequal charges of organic and inorganic guests in gallery, might suggest the Daumas–Hérold model applicable in LDH system. The composites with staging could function as powerful water adsorption materials with facile reversibility.
Co-reporter:Yahong Sun, Guohua Pan, Qingyang Gu, Xinxin Li, Genban Sun, Shulan Ma, Xiaojing Yang
Materials Research Bulletin 2013 48(11) pp: 4460-4468
Publication Date(Web):
DOI:10.1016/j.materresbull.2013.07.053
Co-reporter:Nankai Chu, Yahong Sun, Yushuang Zhao, Xinxin Li, Genban Sun, Shulan Ma and Xiaojing Yang
Dalton Transactions 2012 vol. 41(Issue 24) pp:7409-7414
Publication Date(Web):24 Apr 2012
DOI:10.1039/C2DT30678F
Two organic sensitisers 4-biphenylcarboxylate (BPC) and terephthalate (TA) were intercalated into the gallery of layered europium hydroxide (LEuH). PL spectra tests indicated that BPC markedly enhanced the red luminescence of Eu3+ due to efficient energy transfer between BPC and Eu3+, forming a contrast to intercalated TA and the starting NO3− anions in the gallery. The energy level matching of the organic guests and Eu3+ was also discussed to explain the energy transfer from sensitiser to Eu3+.
Co-reporter:Qingyang Gu;Yahong Sun;Nankai Chu, ;Zhiqian Jia ;Xiaojing Yang
European Journal of Inorganic Chemistry 2012 Volume 2012( Issue 28) pp:4407-4412
Publication Date(Web):
DOI:10.1002/ejic.201200662
Abstract
The NO3–-type Eu3+-doped layered gadolinium hydroxide (NO3–LGdH:Eu) was prepared by a developed homogeneous precipitation method through hexamethylenetetramine (HMT) hydrolysis with hydrothermal treatment. Two amino acid anions, phenylalanine (Phe) and tyrosine (Tyr), were intercalated into LGdH:Eu to form composites Phe–LGdH:Eu and Tyr–LGdH:Eu. Photoluminescence studies show that the incorporation of Phe and Tyr into the host layer can sharply quench the Eu3+ luminescence. This simple method is expected to be applied in biological systems for detecting amino acids.
Co-reporter:Shulan Ma, Li Du, Juan Wang, Nankai Chu, Yahong Sun, Genban Sun, Xiaojing Yang and Kenta Ooi
Dalton Transactions 2011 vol. 40(Issue 38) pp:9835-9843
Publication Date(Web):23 Aug 2011
DOI:10.1039/C1DT10982K
The structural control involving staging formation was studied in the nanocomposites of macrocyclic tetraazacrown ether carboxylic acid derivative (TECA) and layered double hydroxide (LDH) obtained by an osmotic swelling/restoration process. After NO3-type MgAl–LDH was osmotically swollen in formamide, TECA was added, leading to a restoration of the LDH sheets and formation of TECA–LDH nanocomposites. In the wet state, the structure of the composites was homogenous, and the basal spacings of ∼2.0 or 1.8 nm were not changed by the water-washing process that removed formamide and caused the replacement of NO3− by CO32−. However, in the drying process, both the orientation of TECA in the interlayer and the formed staging structure varied with the TECA content. The TECA orientation changed from horizontal to tilted/twisted and finally to vertical with interlayer TECA density. The staging structure occurred for samples with both TECA and small inorganic guests coexisting in the interlayer. Third-staging, second-staging, and homogenous structures were observed at TECA/LDH weight ratios of low (0.125 and 0.25), medium (0.5) and large (1 and 2) values, respectively. The decrease of negative charge of TECA ions from −4 to −1 led to the co-existence of small ions (NO3−) with TECA in the gallery and the formation of a NO3−-containing staging structure, even at a high TECA/LDH ratio of 2. The study of the influence of CO32− on the composite structure indicates that a TECA/CO32− ion exchange progressed reversibly and the staging structure formed is thermodynamically stable, depending mainly on the chemical composition of the interlayer guests. The staging formation could be explained by the Daumas–Hérold model, which differs markedly from the Rüdorff model previously proposed for the LDH system. The treatment in formamide of the composite such as T2L+Na2CO3 with staging structure shows that the transformation process is reversible, and these kinds of composites may be used as an adsorbent for some harmful organic solvents.
Co-reporter:Shulan Ma;Cuihong Fan;Gailing Huang;Yumei Li;Xiaojing Yang;Kenta Ooi
European Journal of Inorganic Chemistry 2010 Volume 2010( Issue 14) pp:2079-2083
Publication Date(Web):
DOI:10.1002/ejic.201000010
Abstract
A carbonate shortage phenomenon (CO32–/Al < 0.5) was found in MgAl layered double hydroxides (LDHs) withMg/Al < 2 synthesized by the homogeneous precipitation (urea hydrolysis) method. To explain the phenomenon, a “gibbsite-layer based substitution–filling” model containing octahedral vacancies with formula [Mgy□0.5–y][MgxAl1–x](OH)3(CO32–)y–x/2·mH2O is proposed on the basis of the detailed composition analysis and ordered distribution of Mg and Al in the layer.
Co-reporter:Shulan Ma;Die Zhang;Song Gao;Yong He;Hui Ma;Chuanmin Qi;Cuihong Fan;Yufeng Chen;Xiaojing Yang
European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 24) pp:3776-3785
Publication Date(Web):
DOI:10.1002/ejic.200800375
Abstract
Two new 2D supramolecular architectures [{Mn2(L1)2(H2O)2}·2CH3OH]n (1) and [{Mn2(L2)2(CH3OH)4}·2CH3OH·4(H2O)]n (2) were assembled from the newly synthesised semi-rigid ligands H2L1 {2,6-bis[(6-carboxy-2,4-dimethylbenzimidazol-1-yl)methyl]pyridine} and H2L2 {2,6-bis[(6-carboxy-4-methyl-2-propylbenzimidazol-1-yl)methyl]pyridine} by reaction with MnII ions. They both contain novel 1D double-stranded coordinating chains with metallomacrocyclic subunits and dinuclear MnII subrings bridged by benzimidazolecarboxylato ions, the latter derived from the ligands. The differences in the steric hindrance of the methyl and propyl groups attached to the benzimidazole rings in H2L1 and H2L2 led to different coordinating modes of the carboxylato groups and, thus, aesthetically fascinating extended structures with useful magnetic properties. Variable-temperature susceptibility measurements (2–300 K) revealed antiferromagnetic coupling interactions (J = –0.23 cm–1 for 1 and –0.92 cm–1 for 2) with values being within the reported range but differing from each other due to the distinct bridging modes of the carboxylato ions. The different crystal structures and magnetic properties of 1 and 2 are discussed in detail.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Co-reporter:Chuanmin Qi, Die Zhang, Song Gao, Hui Ma, Yong He, Shulan Ma, Yufeng Chen, Xiaojing Yang
Journal of Molecular Structure 2008 Volume 891(1–3) pp:357-363
Publication Date(Web):26 November 2008
DOI:10.1016/j.molstruc.2008.04.008
One new metal-organic framework (MOF) {[Mn2L2(CH3OH)2.5H2O]·2.5CH3OH·5.5H2O}n1 was prepared by assembling from the newly synthesized semirigid benzimidazole carboxylate ligand 2,6-bis(6-carboxy-4-methyl-2-propyl-benzimidazol-1-ylmethyl)benzene (H2L) with Mn(II) ion. It contained novel 1D double-stranded coordinating chain with metallomacrocycle and dinuclear Mn(II) subunit bridged by carboxylate ions. Variable temperature susceptibility measurements (2–300 K) revealed an antiferromagnetic coupling interaction (J = −0.97 cm−1). The crystal structure and the magnetic behavior of 1 were discussed in detail.
Co-reporter:Feifei Su, Chenyu Liu, Yan Yang, Shulan Ma, Genban Sun, Xiaojing Yang
Journal of Colloid and Interface Science (15 June 2017) Volume 496() pp:
Publication Date(Web):15 June 2017
DOI:10.1016/j.jcis.2017.02.039
This work demonstrates tunable and purified luminescence via one-step delamination of HPTS/OS-LRH composites (HPTS is trisodium 8-hydroxy-pyrene-1,3,6-trisulphonate, OS is sodium salt of 1-octane sulfonic acid, LRH is layered rare-earth hydroxide, R = Tb, Y) along with energy transfer. The HPTSxOS1−x-LTbyY1−yH composites presented varied luminescence behavior depending on their physical state. In solid state, dual-color luminescence was observed: blue-dominant emissions (437 nm) for HPTSxOS1−x-LTbH, and blue- (437 nm) to green-dominant (516 nm) luminescence for HPTS0.02OS0.98-LTbyY1−yH. In delaminated state in famamide, purified luminescence was present: pure blue emission (440 nm) for HPTSxOS1−x-LTbH and HPTS0.02OS0.98-LTbyY1−yH (y ≥ 0.5), while pure bluish-green emission (498 nm) for HPTS0.02OS0.98-LTbyY1−yH (y ≤ 0.3). Both the delamination of the composites and energy transfer from layer Tb3+ to HPTS contributed to the blue luminescence. The intriguing energy transfer process between photoactive inorganic hosts and organic guests can be utilized to fabricate hybrid materials with superior luminescence property.Energy transfer from layer Tb3+ to HPTS guest in delaminated HPTS/OS-LRH composites contributes to purified blue luminescence.
Co-reporter:Qingyang Gu, Feifei Su, Lijiao Ma, Shulan Ma, Genban Sun and Xiaojing Yang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 18) pp:NaN4750-4750
Publication Date(Web):2015/04/02
DOI:10.1039/C5TC00441A
Organic compounds of ortho-coumaric acid (abbr. o-CMA) and para-coumaric acid (abbr. p-CMA) are intercalated into the layered rare-earth hydroxides (LRHs, R = Eu, Gd) via the ion exchange method. The two organics having the same phenolic hydroxyl and carboxyl groups located at different positions demonstrate variant intercalation structures. The CMA anion guests within the LRH gallery indicate monolayered or bi-layered arrangements depending on their own characteristic features and deprotonation degrees. The combination of o-/p-CMA molecules with LEuH/LGdH layers generates hybrid materials exhibiting versatile luminescence properties. In the solid state, for LEuH layers, the luminescence of layer Eu3+ and interlayer o-CMA is co-quenched; however, for LGdH layers, green emissions (∼520 nm) are observed, both of which are different from the cyan emission (475 nm) of free o-CMA anions. When dispersed in formamide (FM), o-CMA–LEuH composites exhibit weak luminescence, in sharp contrast to o-CMA–LGdH composites displaying green emissions (495–520 nm) with markedly enhanced intensity. The p-CMA–LGdH composites display blue emission (457 nm) quite different from the green emission (499 nm) for free p-CMA in FM, compared with the unobservable emission within LEuH layers. In addition, co-intercalation of the surfactant OS (1-octane sulfonic acid sodium) with o-CMA anions into LEuH produces composites showing desirable blue emission or violet emission, due to the change of the microenvironment of organic guests. The energy transfer between layer Eu3+ and interlayer CMA was proposed to account for the co-quenching or blue shift. This work offers a beneficial approach to fabricate organic–inorganic photofunctional materials with a controllable structure and tunable fluorescence properties.
Co-reporter:Linxia Xie, Chenyu Liu, Lijiao Ma, Chengliang Xiao, Shulan Ma, Genban Sun, Huifeng Li and Xiaojing Yang
Dalton Transactions 2017 - vol. 46(Issue 10) pp:NaN3114-3114
Publication Date(Web):2017/01/30
DOI:10.1039/C6DT04870F
We demonstrate a novel example of a delaminated MoS4/OS-LEuH composite (LEuH is layered europium hydroxide, OS is 1-octane sulfonate), which exhibits quenched luminescence in formamide and highly enhanced red emission in the water-present case. The turn-on luminescence sensing capability of the material is promising for feasible detection of a trace amount of water in formamide (FM) and N,N-dimethylformamide (DMF).
Co-reporter:Shulan Ma, Li Du, Juan Wang, Nankai Chu, Yahong Sun, Genban Sun, Xiaojing Yang and Kenta Ooi
Dalton Transactions 2011 - vol. 40(Issue 38) pp:NaN9843-9843
Publication Date(Web):2011/08/23
DOI:10.1039/C1DT10982K
The structural control involving staging formation was studied in the nanocomposites of macrocyclic tetraazacrown ether carboxylic acid derivative (TECA) and layered double hydroxide (LDH) obtained by an osmotic swelling/restoration process. After NO3-type MgAl–LDH was osmotically swollen in formamide, TECA was added, leading to a restoration of the LDH sheets and formation of TECA–LDH nanocomposites. In the wet state, the structure of the composites was homogenous, and the basal spacings of ∼2.0 or 1.8 nm were not changed by the water-washing process that removed formamide and caused the replacement of NO3− by CO32−. However, in the drying process, both the orientation of TECA in the interlayer and the formed staging structure varied with the TECA content. The TECA orientation changed from horizontal to tilted/twisted and finally to vertical with interlayer TECA density. The staging structure occurred for samples with both TECA and small inorganic guests coexisting in the interlayer. Third-staging, second-staging, and homogenous structures were observed at TECA/LDH weight ratios of low (0.125 and 0.25), medium (0.5) and large (1 and 2) values, respectively. The decrease of negative charge of TECA ions from −4 to −1 led to the co-existence of small ions (NO3−) with TECA in the gallery and the formation of a NO3−-containing staging structure, even at a high TECA/LDH ratio of 2. The study of the influence of CO32− on the composite structure indicates that a TECA/CO32− ion exchange progressed reversibly and the staging structure formed is thermodynamically stable, depending mainly on the chemical composition of the interlayer guests. The staging formation could be explained by the Daumas–Hérold model, which differs markedly from the Rüdorff model previously proposed for the LDH system. The treatment in formamide of the composite such as T2L+Na2CO3 with staging structure shows that the transformation process is reversible, and these kinds of composites may be used as an adsorbent for some harmful organic solvents.
Co-reporter:Nankai Chu, Yahong Sun, Yushuang Zhao, Xinxin Li, Genban Sun, Shulan Ma and Xiaojing Yang
Dalton Transactions 2012 - vol. 41(Issue 24) pp:NaN7414-7414
Publication Date(Web):2012/04/24
DOI:10.1039/C2DT30678F
Two organic sensitisers 4-biphenylcarboxylate (BPC) and terephthalate (TA) were intercalated into the gallery of layered europium hydroxide (LEuH). PL spectra tests indicated that BPC markedly enhanced the red luminescence of Eu3+ due to efficient energy transfer between BPC and Eu3+, forming a contrast to intercalated TA and the starting NO3− anions in the gallery. The energy level matching of the organic guests and Eu3+ was also discussed to explain the energy transfer from sensitiser to Eu3+.
Co-reporter:Qingyang Gu, Feifei Su, Shulan Ma, Genban Sun and Xiaojing Yang
Chemical Communications 2015 - vol. 51(Issue 13) pp:NaN2517-2517
Publication Date(Web):2014/12/02
DOI:10.1039/C4CC08380F
We demonstrate the first example of exfoliated layered europium hydroxide (LEuH) composites with a fluorescent molecule that exhibit blue luminescence. Co-quenching in the solid state, blue emission (440 nm) in formamide, and green emission (514 nm) in water–formamide were found, for which delamination and swollen states account for the versatile luminescence behaviors.
Co-reporter:Feifei Su, Qingyang Gu, Shulan Ma, Genban Sun, Xiaojing Yang and Li-Dong Zhao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 27) pp:NaN7152-7152
Publication Date(Web):2015/06/03
DOI:10.1039/C5TC01045D
We demonstrate a novel example of delaminated layered rare-earth hydroxide (LRH, R = Tb, Y) composites with ortho-coumaric acid (CMA) and surfactant 1-octane sulfonic (OS) anions that exhibit tunable photoluminescence, especially blue emission due to energy transfer via the layer Tb3+. Different molar ratios of organic guests (OS/CMA) and layer ions (Tb/Y) give rise to versatile composites of OSxCMA1−x–LTbyY1−yH (x = 0.9, 0.8, 0.7, 0.6, 0.5, y = 1, 0.9, 0.7, 0.5, 0.3, 0.1, 0). In the solid state, for LTbH composites, co-quenching for emissions of CMA and the layer Tb3+ is found, while for LYH composites, green emission (502 nm) is observed. In formamide (FM), all of the composites are found to be facilely delaminated, and the colloidal suspensions of LTbH composites with varied OSxCMA1−x interlayer guests exhibit color-tuning within the blue-light region (430–465 nm), with blue-shift of emissions and enhanced luminescence intensity following increased OS content. LTbyY1−yH composites (with a fixed OS/CMA ratio of 0.7:0.3), however, present emissions from blue to green with increased Y3+ content. A new concept of ‘host-energy transfer-induced-emission (HETIE)’ is proposed to explain the blue luminescence via energy transfer of the host Tb3+. The intriguing energy transfer between a photoactive host matrix and interlayer guests in the delaminated state offers a promising approach to achieve efficient tuning of luminescence, thus meeting the high demand of applications on multicolor optical and display devices; especially blue emission.
