Co-reporter:Xin Gu, Liangjun Li, Ying Wang, Pengcheng Dai, Hongbo Wang, Xuebo Zhao
Electrochimica Acta 2016 Volume 211() pp:77-82
Publication Date(Web):1 September 2016
DOI:10.1016/j.electacta.2016.06.029
•Rutile TiO2 hierarchical nanotubes are prepared by a hard-template method.•Rutile TiO2 hierarchical nanotubes exhibit superior sodium storage properties.•Rutile TiO2 hierarchical nanotubes deliver a capacity of 221 mA h g−1 at 0.3 C.Hierarchical tubular structures constructed from rutile TiO2 nanorods are fabricated, using MnO2 nanorods as sacrificial templates. The resultant rutile TiO2 hierarchical nanotubes show unique structural features (hierarchical, hollow) and a large surface area (180 m2 g−1), which substantially improve their electrochemical performance. This type of hierarchical structures with high porosity produced by neighboring building blocks, are desirable for the development of sodium ion batteries, because the large amounts of pores can enhance the contact areas between electrode and electrolyte, and faciliate the ion diffusion during the charge/discharge process. As an anode material for sodium ion batteries, these hierarchical nanotubes deliver a high reversible capacity of 221 mA h g−1 at 0.3 C (100 mA g−1), superior rate capability with a stable capacity of 71 mA h g−1 at 15C, and good long-term cycling stability with a capacity of 79 mA h g−1 after 1000 cycles at 3 C. The superior sodium storage performances make this rutile TiO2 hierarchical nanotube a promising anode metarial for sodium ion batteries.
Co-reporter:Min Jiang, Liangjun Li, Dandan Zhu, Hongyu Zhang and Xuebo Zhao
Journal of Materials Chemistry A 2014 vol. 2(Issue 15) pp:5323-5329
Publication Date(Web):20 Jan 2014
DOI:10.1039/C3TA15319C
A highly porous metal–organic framework (MOF) containing copper metal centres and nanocages was modified onto a glassy carbon electrode as a noble-metal-free electrocatalyst for oxygen reduction reaction. The nanocages in the metal–organic framework were fully activated by the solvent-exchange method. Although both the as-prepared MOF and activated MOF samples showed electrochemical activity of Cu2+/Cu+ redox pairs by cyclic voltammetric studies, only the activated MOF samples could catalyze an oxygen reduction reaction. In order to avoid detachment of the activated sample from the glassy carbon electrodes surface owing to a low-effective electron-transfer pathway during electrochemical scanning in aqueous solution, reduced graphene oxide (RGO) was immobilized onto a glassy carbon electrode surface as a binder and electron transfer mediator under MOF active layer. The MOF layer on RGO immobilized glassy carbon electrode can catalyze the oxygen reduction reaction through a 2–4 electrons reduction pathway. Furthermore, the occurrence potential of ORR versus Ag/AgCl by MOF catalyst shifted to the positive near 100 mV in comparison with other MOF catalysts.
Co-reporter:Jinjun Cai, Jingbo Qi, Chunpeng Yang, and Xuebo Zhao
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 5) pp:3703
Publication Date(Web):February 18, 2014
DOI:10.1021/am500037b
Poly(vinylidene chloride)-based carbon (PC) with ultrahigh microporisity was prepared by simple carbonization and KOH activation, exhibiting great potential to be superior CO2, CH4, and H2 adsorbent at high pressures. The CO2 uptake for pristine PC is highly up to 3.97 mmol/g at 25 °C and 1 bar while the activated PC exhibits a slightly lower uptake at 1 bar. However, the activated PC has an outstanding CO2 uptake of up to 18.27 mmol/g at 25 °C and 20 bar. Gas uptakes at high pressures are proportional to the surface areas of carbons. The CH4 uptake for the activated PC is up to 10.25 mmol/g (16.4 wt % or 147 v/v) at 25 °C and 20 bar which is in a top-ranked uptake for large surface area carbons. Furthermore, H2 uptake on the activated PC reaches 4.85 wt % at −196 °C and 20 bar. Significantly, an exceptionally large H2 storage capacity of up to 2.43 wt % at 1 bar was obtained, which is among the largest value reported to date for any porous adsorbents, to the best of our knowledge. The ease of preparation and large capture capacities endow this kind of carbon attractive as promising adsorbent for CH4, H2, and CO2 storage.Keywords: activation; carbon capture; carbonization; hydrogen storage; porous carbons;
Co-reporter:Jinjun Cai, Liangjun Li, Xiaoxia Lv, Chunpeng Yang, and Xuebo Zhao
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 1) pp:167
Publication Date(Web):December 17, 2013
DOI:10.1021/am403810j
We report the preparation of ordered porous carbons for the first time via nanocasting zeolite 10X with an aim to evaluate their potential application for hydrogen storage. The synthesized carbons exhibit large Brunauer-Emmett-Teller surface areas in the 1300–3331 m2/g range and pore volumes up to 1.94 cm3/g with a pore size centered at 1.2 nm. The effects of different synthesis processes with pyrolysis temperature varied in the 600–800 °C range on the surface areas, and pore structures of carbons were explored. During the carbonization process, carbons derived from the liquid–gas two-step routes at around 700 °C are nongraphitic and retain the particle morphology of 10X zeolite, whereas the higher pyrolysis temperature results in some graphitic domains and hollow-shell morphologies. In contrast, carbons derived from the direct acetylene infiltration process have some incident nanoribbon or nanofiber morphologies. A considerable hydrogen storage capacity of 6.1 wt % at 77 K and 20 bar was attained for the carbon with the surface area up to 3331 m2/g, one of the top-ranked capacities ever observed for large surface area adsorbents, demonstrating their potential uses for compacting gaseous fuels of hydrogen. The hydrogen capacity is comparable to those of previously reported values on other kinds of carbon-based materials and highly dependent on the surface area and micropore volume of carbons related to the optimum pore size, therefore providing guidance for the further search of nanoporous materials for hydrogen storage.Keywords: adsorption; hydrogen storage; nanocasting; porous carbons; zeolite template;
Co-reporter:Xiaoxia Lv, Liangjun Li, Sifu Tang, Chao Wang and Xuebo Zhao
Chemical Communications 2014 vol. 50(Issue 52) pp:6886-6889
Publication Date(Web):02 Apr 2014
DOI:10.1039/C4CC00334A
A metal–organic framework with chiral pores and decorated imidazole and methyl groups was constructed. Upon activation, this MOF undergoes a pore contraction and shows very high selectivity for CO2/N2 and CO2/CH4, indicating a synergistic effect of dynamic pores and functional groups.
Co-reporter:Liangjun Li, Sifu Tang, Chao Wang, Xiaoxia Lv, Min Jiang, Huaizhi Wu and Xuebo Zhao
Chemical Communications 2014 vol. 50(Issue 18) pp:2304-2307
Publication Date(Web):10 Dec 2013
DOI:10.1039/C3CC48275H
A UiO type MOF with Lewis basic bipyridyl sites was synthesized and structurally characterized. After being activated by Soxhlet-extraction, this MOF exhibits high storage capacities for H2, CH4 and CO2, and shows unusual stepwise adsorption for liquid CO2 and solvents, indicating a sequential filling mechanism on different adsorption sites.
Co-reporter:Dandan Zhu, Liangjun Li, Jinjun Cai, Min Jiang, Jingbo Qi, Xuebo Zhao
Carbon 2014 Volume 79() pp:544-553
Publication Date(Web):November 2014
DOI:10.1016/j.carbon.2014.08.013
A novel pyridine-containing metal-organic framework (MOF), [Zn(bpdc)DMA]·DMF, was first constructed by solvothermal reaction of 2,2′-bipyridine-5,5′-dicarboxylate (bpdc) with zinc nitrate, and then it was converted to nitrogen-doped porous carbons (NPCs) by direct carbonization. The as-prepared porous carbon (NPC800) was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), N2 sorption isotherms, and X-ray photoelectron spectroscopy. NPC800 was modified onto glassy carbon electrode surface for investigating its electrochemical applications. Cyclic voltammetry (CV) and linear sweep voltammetry were performed to evaluate the electrocatalytic activity of NPC800 for oxygen reduction reaction (ORR) in alkaline solution. NPC800 exhibited better ORR activity than commercial Pt/C. Pt-catalyst supported on NPCs (Pt/NPC800) was prepared by means of electrodeposition and characterized by SEM, Energy dispersive spectrometry and XRD. The electrocatalytic activity and stability of Pt/NPC800 for methanol oxidation reaction (MOR) were estimated in acidic methanol solution by CV and chronoamperometric curves, respectively. Pt/NPC800 showed catalytic role for MOR, and also had better stability than Pt-catalyst supported on commercial Vulcan XC-72.
Co-reporter:Si-Fu Tang, Liang-Jun Li, Xiao-Xia Lv, Chao Wang and Xue-Bo Zhao
CrystEngComm 2014 vol. 16(Issue 30) pp:7043-7052
Publication Date(Web):20 May 2014
DOI:10.1039/C4CE00375F
Eight new transition metal diphosphonates, namely, [Mn(H2L)(H2O)2][(H2O)2] (1), [Co(H2O)6][H2L][(H2O)2] (2), [Co(H2O)6][(H3L)2][(H2O)2] (3), [Ni(H2O)6][H2L][(H2O)2] (4), [Cu(H2L)][(H2O)2] (5), [Zn(H2O)6][(H3L)2][(H2O)2] (6), [Zn(H2L)(H2O)2] (7) and [Cd(H2L)(H2O)2] (8), have been synthesized hydrothermally from 2,5-dimethyl-1,4-phenylenediphosphonic acid (H4L) and thoroughly characterized using EA, IR, TGA, powder and single-crystal XRD, luminescence and magnetism methods. The single-crystal X-ray diffraction measurements indicate that the diphosphonate ligands adopt three kinds of coordination modes which have a huge influence on the structure formation. Compounds 1 and 8 are isostructural and feature 3D framework structures which are constructed by the connectivity of MO6 (M = Mn and Cd) octahedrons and tetradentate organic linkers. Compounds 2 and 4, 3 and 6 are also isostructural, but have isolated mononuclear structures. Compound 5 exhibits 2D layered structure, in which four-connected copper(II) centers are bridged by tetradentate diphosphonate ligands. Compound 7 has a 1D infinite chain structure which is constructed from ZnO4 tetrahedrons and bidentate bridging diphosphonate ligands. It is also found that compounds 6–8 display interesting luminescent properties, whereas 1 shows an antiferromagnetic property.
Co-reporter:Si-Fu Tang, Jin-Jun Cai, Liang-Jun Li, Xiao-Xia Lv, Chao Wang and Xue-Bo Zhao
Dalton Transactions 2014 vol. 43(Issue 16) pp:5970-5973
Publication Date(Web):28 Nov 2013
DOI:10.1039/C3DT53167H
A 3D porous aluminum(III) trisphosphonate, constructed from 1D inorganic aluminum phosphate chains and tripodal organic linkers, contains large hexagonal channels (1.24 nm in diameter) and a highly accessible void (50.3%) which allow it to have a fast and relatively high uptake of H2, N2 and CO2.
Co-reporter:Min Jiang, Dandan Zhu, Hongyu Zhang and Xuebo Zhao
New Journal of Chemistry 2014 vol. 38(Issue 8) pp:3354-3357
Publication Date(Web):26 Mar 2014
DOI:10.1039/C4NJ00241E
A facile electrochemical approach for the synthesis of graphene is developed by highly effective electron transfer from electron-rich heteropoly blue to graphene oxide. Reduced graphene oxide immobilized on a glassy carbon electrode (GCE) shows more positive potential for hydrogen evolution owing to the presence of the polyoxometalate electrocatalyst.
Co-reporter:Chao Wang;Sifu Tang;Xiaoxia Lv;Liangjun Li
European Journal of Inorganic Chemistry 2014 Volume 2014( Issue 19) pp:3133-3139
Publication Date(Web):
DOI:10.1002/ejic.201402094
Abstract
Three new metal–organic frameworks (MOFs), [Zn2(L)(H2O)]·3DMF·1.5H2O (1), [Zn2(L)(4,4′-bpy)1.5(H2O)2]·2DMF·2H2O (2), and [Zn2(L)(2,2′-bpy)2(DMF)2]·2DMF·4H2O (3) [H4L = 5,5′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(azanediyl)diisophthalic acid, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine, DMF = N,N-dimethylformamide], were synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction analysis, elemental analysis, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). The L4– ligands in 1–3 display different coordination modes, and the introduction of bipyridine colinkers brings significant structural variation into the frameworks. Complex 1 is constructed from dinuclear carboxylate [Zn2O(COO)4] secondary building units (SBUs) and H4L ligands and exhibits a binodal (4,4)-connected pts net with 54.6 % solvent-accessible void. Complex 2 exhibits an unprecedented tetranodal (3,4,4,4)-connected net, which is constructed from two types of crystallographically independent ZnII ions, H4L ligands, and the 4,4′-bipyridine colinker. Complex 3 is constructed from parallel 1D molecular ladders stacked along the a axis that generate 1D channels (7.8 × 10.4 Å) and are hydrogen bonded to form 2D layers. The thermal stabilities and luminescence properties of 1–3 have also been studied in detail.
Co-reporter:Jinjun Cai, Xiaoxia Lv, Yanlong Xing, Xuebo Zhao
Materials Letters 2014 Volume 114() pp:37-39
Publication Date(Web):1 January 2014
DOI:10.1016/j.matlet.2013.10.004
•Carbons with ultrahigh microporosities were prepared via facile carbonization method.•The KOH activation can greatly enlarge surface area and pore volume of carbons.•Activation can widen pore size without wrecking the pristine smaller micropores.•The PVDC-based carbon shows excellent CO2 adsorption capacities and kinetics.Poly(vinylidene chloride) (PVDC)-based carbon with high microporosity was prepared via facile carbonization, and further moderate KOH activation can widen micropore size with higher surface area and larger pore volume. A superior CO2 capture uptake at 1 bar of up to 5.87 mmol/g at 0 °C and 3.98 mmol/g at 25 °C is obtained for pristine carbon and the isosteric heat of CO2 adsorption is in the range of 24–28 kJ/mol, along with fast kinetics. The KOH activated sample shows a slightly low CO2 uptake at 1 bar because activation produces some larger micropores in frameworks, resulting in the reduction of interactions between pores and CO2 molecules.
Co-reporter:Si-Fu Tang, Xiao-Xia Lv, Liang-Jun Li, Chao Wang, Xue-Bo Zhao
Inorganic Chemistry Communications 2014 Volume 39() pp:51-55
Publication Date(Web):January 2014
DOI:10.1016/j.inoche.2013.10.039
•Main group metal phosphonates are very interesting but less developed.•Two lead (II) compounds are synthesized from two trisphosphonate ligands.•They have different three-dimensional structures.•They both absorb below 325 nm and have similar thermal behaviors.Two lead (II) trisphosphonates, [Pb3(H3L1)2(H2O)] (1) and [Pb5(HL2)(H3L2)(H4L2)(H2O)2][(H2O)2] (2), have been synthesized from two trisphosphonate ligands and characterized by EA, IR, UV–vis, TGA, powder and single-crystal X-ray diffraction methods. The single-crystal X-ray diffraction analyses reveal that they both feature three-dimensional framework structures. The lead (II) ions are mainly five-coordinated, forming square pyramid coordination geometry. Although the two trisphosphonate ligands are very similar, different coordination modes and conformations are observed for them, suggesting that attachment of methyl groups to the central benzene ring has a major effect on the structure formation. They both absorb below 325 nm and are thermally robust.Two new lead (II) trisphosphonates, [Pb3(H3L1)2(H2O)] (1) and [Pb5(HL2)(H3L2)(H4L2)(H2O)2][(H2O)2] (2), have been synthesized and thoroughly characterized. They have different three-dimensional framework structures, suggesting that the attachment of methyl groups has a major effect on the structure formation. The TGA measurements reveal that they have similar thermal behaviors.
Co-reporter:Jinjun Cai, Menglong Yang, Yanlong Xing, Xuebo Zhao
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 444() pp:240-245
Publication Date(Web):5 March 2014
DOI:10.1016/j.colsurfa.2013.12.063
•Sucrose was selected as precursor to prepare carbons in the existence of USY zeolite.•We studied the influence of USY zeolite on the pore structure of carbons.•The specific surface area and pore width of these carbons can be easily adjusted.•Hydrogen storage properties on these carbons were correlated with their pore structure.We report the preparation of sucrose-based nanoporous carbons via template-assisted routes using zeolite USY as the hard-template. Sulfuric acid-pretreated sucrose solution is polymerized and carbonized via adjusting the mass ratios of zeolite over sucrose and temperatures. Large surface area carbons with wide micropore size, developed mesoporosity and moderate storage capacity were obtained. We find that preparation parameters have great effects on the pore structure of carbons. Total pore volume of carbons develops with an increase of carbonization temperature and the presence of zeolite in carbonization processes can effectively enlarge the surface area and pore volume. However, the morphology of carbons is not transferred from zeolites, and micropore in the carbons is almost wholly from the sucrose precursor itself. The hydrogen adsorption properties of carbons at 77 K and 20 bar are further investigated in this work. Carbon with a surface area of 1200 m2/g exhibits a hydrogen storage capacity of up to 3.65 wt% at 77 K and 20 bar, and the hydrogen capacities at higher pressures are found to be much more correlated with surface area and micropore volume of carbons.Sucrose-based porous carbons were prepared via template-assisted method. The presence of zeolite in carbonization will inhibit graphitic degrees to some extent and enlarge surface area and pore volume of carbons, and then improve hydrogen storage capacities.
Co-reporter:Min Jiang ; Dandan Zhu ; Jinjun Cai ; Hongyu Zhang
The Journal of Physical Chemistry C 2014 Volume 118(Issue 26) pp:14371-14378
Publication Date(Web):June 10, 2014
DOI:10.1021/jp503019f
Negatively charged Pressler-type heteropolytungstate K12.5Na1.5[NaP5W30O110] (P5W30) clusters and graphene oxide (GO) were constructed into polyoxotungstates/graphene (POTs/G) nanocomposite multilayer with protonated poly(ethylenimine) (PEI) via layer-by-layer self-assembly. The growth process of (PEI/P5W30–GO)n multilayer films was monitored by UV–visible spectroscopy and cyclic voltammetry. The atomic force microscopy images clearly showed the morphology of single-sheet GO in multilayer films. The UV-light irradiation of multilayers afforded reduced graphene oxide (RGO) in the multilayers. The changes in composition of C 1s in GO, W 4f in P5W30, and N 1s in PEI were detected by X-ray photoelectron spectroscopy. A possible photoreduction mechanism of GO was proposed. The electrochemical behavior of (PEI/P5W30–RGO)n multilayers modified on a glassy carbon electrode at room temperature and their electrocatalytic activity toward oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) were investigated. At a potential of −0.6 V, the multilayers clearly exhibited electrocatalytic activity for ORR via almost a four-electron reduction pathway to H2O. A remarkable electrocatalytic HER could be detected on the (PEI/P5W30–RGO)n multilayer, whereas the (PEI/P5W30–GO)n multilayer did not show any HER signal in the same potential range. This study investigated and extended the application of POTs/G nanocomposites to the electrocatalysis of ORR and HER.
Co-reporter:Si-Fu Tang, Xiao-Bo Pan, Xiao-Xia Lv, Shi-Hai Yan, Xian-Rui Xu, Liang-Jun Li and Xue-Bo Zhao
CrystEngComm 2013 vol. 15(Issue 10) pp:1860-1873
Publication Date(Web):20 Dec 2012
DOI:10.1039/C2CE26828K
Hydrothermal reactions of benzene-1,3,5-triyltris(methylene)triphosphonic acid (H6L1) or (2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene)triphosphonic acid (H6L2) with metal sulfates, 4,4′-bipyridyl (4,4′-bipy), 2,2′-bipyridyl (2,2′-bipy), 1,10-phenanthroline (1,10-phen) and 1,2-di(4-pyridyl)ethylene (dpe), afforded eight new transition metal trisphosphonates, namely, [Cu2(H3L1)2(H2O)2][H2dpe][H2O]4 (1), [Ni1.5(H3L2)(H2O)2][H2O] (2), [Ni(H4L2)(1,10-phen)(H2O)2] (3), [Ni(H4L2)(2,2′-bipy)(H2O)2] (4), [Cu(H4L2)(4,4′-bipy)] (5), [Cu(H4L2)(1,10-phen)][H2O] (6), [Cu(H4L2)(2,2′-bipy)(H2O)][H2O]0.13 (7), and [Mn1.5(H3L2)(H2O)2][H2O]1.1 (8). The single-crystal X-ray diffraction measurements indicate that compounds 2 and 8 are isostructural and feature 3D framework structures with (5,6,8)-net topology; 1, 5 and 6 exhibit 2D layered structures; whereas 3, 4 and 7 have 0D dimer structures. The trisphosphonate ligands (H6L1 and H6L2) in these eight compounds adopt either cis–cis–cis or cis–trans–trans conformation with or without the existence of an auxiliary N-containing ligand. The attachment of methyl groups to the benzene core can enhance the crystallinity and enrich the structure diversity. The introduction of 2,2′-bipy and 1,10-phen usually result in low dimensionality whereas 4,4′-bipy can extend the structure to a higher dimensionality. The activated sample of compound 5 has a permanent 1D nanoporous structure and shows high selective adsorption of CO2 over CH4.
Co-reporter:Xiaoxia Lv;Sifu Tang;Liangjun Li;Jinjun Cai;Chao Wang;Xianrui Xu
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 29) pp:5081-5085
Publication Date(Web):
DOI:10.1002/ejic.201300714
Abstract
Two isomorphic microporous metal–organic frameworks (MOFs), [Co2L(H2O)2]·4.5H2O (1) and [Ni2L(H2O)2]·3.5H2O (2), were synthesized by the reaction of an aminopolycarboxylate ligand (H4L) with Co and Ni hydroxides under hydrothermal conditions. The exquisite assembly of the carboxylate, imino groups, and metal ions resulted in a 1D special nanotube that could be used as a blueprint for the construction of MOFs. By joining the nanotubes with the V-shaped –CH2(C6H)(CH3)3CH2– spacer, a 3D framework with 1D triangular channels was formed. The two isostructural frameworks exhibited stability up to 350 °C. Gas sorption studies for N2, H2, CO2, and CH4 confirmed their permanent porosity.
Co-reporter:Liangjun Li;Sifu Tang;Xiaoxia Lv;Jinjun Cai;Chao Wang
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 36) pp:6111-6118
Publication Date(Web):
DOI:10.1002/ejic.201301010
Abstract
A series of three-dimensional rare-earth coordination polymers, [M2(bpdc)3(H2O)4] (M = Y [1], Sm [2], Eu [3], Gd [4], Tb [5], Dy [6], Er [7], and Yb [8]) were synthesized by solvothermal reactions of 2,2′-bipyridine-5,5′-dicarboxylate (bpdc) with corresponding metal salts. Single-crystal and powder X-ray diffraction analyses demonstrated that these coordination polymers are isostructural. The carboxyl groups of the bpdc ligand are coordinated to metal ions and the 2,2′-bipyridine moieties are left free due to the preferable affinity of rare-earth metals for oxygen-donor atoms. The adjacent eight-coordinate MO8 cores show dicapped trigonal prismatic environments; they are interconnected by carboxyl groups and are further bridged through the bipyridyl linkers to give quite dense three-dimensional networks. Photoluminescent studies at room temperature reveal intense red and green luminescent emissions for EuIII and TbIII analogues, respectively. Furthermore, it is noteworthy that bpdc shows an effective antenna effect in sensitizing emissions from EuIII and TbIII ions. Thermogravimetric analyses demonstrate that these coordination polymers exhibit exceptional thermal stability (decomposing at T > 580 °C under N2 for compound 1). Water-resistance measurements of these coordination polymers show excellent hydrothermal stability.
Co-reporter:Liangjun Li, Sifu Tang, Xiaoxia Lv, Min Jiang, Chao Wang and Xuebo Zhao
New Journal of Chemistry 2013 vol. 37(Issue 11) pp:3662-3670
Publication Date(Web):14 Aug 2013
DOI:10.1039/C3NJ00700F
A metal–organic framework NPC-5 was synthesized via reaction of a methyl-functionalized ligand 2,4,6-trimethyl benzene-1,3,5-triyl-isophthalate (TMBTI) with Co(NO3)2·6(H2O) under solvothermal conditions. The steric hindrance induced by the methyl groups on the central phenyl ring led to a non-planar configuration of the ligand and further resulted in a small cubicuboctahedron SBB sustained (3, 24)-connected rht network, which comprised three types of cages and exhibited high porosity. Experimental results showed that despite the use of different synthetic methods the same structure was obtained. Gas sorption study of this MOF revealed high CO2 and CH4 uptake capacities and relatively low adsorption enthalpies.
Co-reporter:Xianrui Xu, Xiaobo Pan, Sifu Tang, Xiaoxia Lv, Liangjun Li, Jincai Wu, Xuebo Zhao
Inorganic Chemistry Communications 2013 Volume 29() pp:89-93
Publication Date(Web):March 2013
DOI:10.1016/j.inoche.2012.12.029
Two sodium complexes, [(μ3-MDBP)Na2(THF)2]2[(μ3-OCH2CH2OCH3)Na]2 (1) and [(μ1-MDBP)Na(μ2-H2O)(THF)]2(THF)2 (2) have been synthesized and structurally characterized. Experimental results show that complex 1 initiates efficiently the ring opening polymerization of l-lactide in a controlled fashion, yielding polymers with narrow polydispersity indexes in a wide range of monomer-to-initiator ratios.Two new sodium complexes, [(μ3-MDBP)Na2(THF)2]2[(μ3-OCH2CH2OCH3)Na]2 (1) and [(μ1-MDBPH)Na(μ2-H2O)(THF)]2(THF)2 (2) were synthesized by reaction of sodium or sodium hydroxide with the bisphenol ligand of 6,6′-methylenebis(2,4-ditert-butylphenol) (MDBP-H2). And experimental results show that complex 1 is an excellent initiator for the ring-opening polymerization of l-lactide.Highlights► Two binuclear and hexanuclear sodium complexes of bisphenol have been synthesized. ▶ The catalytic activities of complex 1 for ROP of lactides have been investigated. ▶ The positive experimental results showed that complex 1 was an excellent catalyst.
Co-reporter:Jinjun Cai;Yanlong Xing;Menglong Yang
Adsorption 2013 Volume 19( Issue 5) pp:919-927
Publication Date(Web):2013 October
DOI:10.1007/s10450-013-9499-2
On the basis of impregnation method, several stationary phases were prepared using γ-Al2O3 with the solution of transition metal salts and the breakthrough curves of gas chromatograph for H2 isotopes were analyzed under the temperature of liquid nitrogen. The effects of carrier gas, flow rate and doping concentration on the separation performance for H2 and D2 were systematically investigated. The overall results showed that the surface areas and adsorptive capacities of modified γ-Al2O3 were slightly lower than unmodified one while the separation performance and symmetry of chromatographic peaks of the former were more excellent. In addition, the chromatographic peaks of ortho- and para-H2 were no longer separated and the retention time shortened to half on columns of modified γ-Al2O3. All the magnetic transition metal ions modified γ-Al2O3 did very well for the separation of H2/D2 under the conditions of neon as carrier gas with a flow rate of 60 mL/min and column lengths of 1.0 m and injection amounts of 0.1 mL. Especially, the MnCl2 modified γ-Al2O3 exhibited the best performance for separating H2/D2 with an optimum doping concentration of 20 wt%.
Co-reporter:Jinjun Cai, Yanlong Xing and Xuebo Zhao
RSC Advances 2012 vol. 2(Issue 23) pp:8579-8586
Publication Date(Web):13 Jun 2012
DOI:10.1039/C2RA01284G
Quantum effects on the molecular adsorption and migration in confined porous materials can not be ignored if the difference between the pore size and molecular hard core is no longer large compared to the de Broglie wavelength of gas molecules. Extensive studies of the quantum sieving have been focused on nanoporous materials due to their potential applications in separating hydrogen (H2) isotopes. This article reviews state-of-the-art research activities in the field of separation, discussing the feasibility of separating H2 isotopes by quantum sieving in nanoporous materials including zeolites, carbons and organic framework materials. The overall results indicate that an effective separation of H2 isotopes is possible via combining the equilibrium and kinetic selectivity of adsorption induced by a quantum sieving effect. A fundamental understanding of the factors that affect the quantum molecular sieving is discussed. We hope to outline a clear insight into the perspectives and challenges on this novel separation technique for H2 isotopes in the subsequent course of researches.
Co-reporter:Liangjun Li, Sifu Tang, Chao Wang, Xiaoxia Lv, Min Jiang, Huaizhi Wu and Xuebo Zhao
Chemical Communications 2014 - vol. 50(Issue 18) pp:NaN2307-2307
Publication Date(Web):2013/12/10
DOI:10.1039/C3CC48275H
A UiO type MOF with Lewis basic bipyridyl sites was synthesized and structurally characterized. After being activated by Soxhlet-extraction, this MOF exhibits high storage capacities for H2, CH4 and CO2, and shows unusual stepwise adsorption for liquid CO2 and solvents, indicating a sequential filling mechanism on different adsorption sites.
Co-reporter:Xiaoxia Lv, Liangjun Li, Sifu Tang, Chao Wang and Xuebo Zhao
Chemical Communications 2014 - vol. 50(Issue 52) pp:NaN6889-6889
Publication Date(Web):2014/04/02
DOI:10.1039/C4CC00334A
A metal–organic framework with chiral pores and decorated imidazole and methyl groups was constructed. Upon activation, this MOF undergoes a pore contraction and shows very high selectivity for CO2/N2 and CO2/CH4, indicating a synergistic effect of dynamic pores and functional groups.
Co-reporter:Si-Fu Tang, Jin-Jun Cai, Liang-Jun Li, Xiao-Xia Lv, Chao Wang and Xue-Bo Zhao
Dalton Transactions 2014 - vol. 43(Issue 16) pp:NaN5973-5973
Publication Date(Web):2013/11/28
DOI:10.1039/C3DT53167H
A 3D porous aluminum(III) trisphosphonate, constructed from 1D inorganic aluminum phosphate chains and tripodal organic linkers, contains large hexagonal channels (1.24 nm in diameter) and a highly accessible void (50.3%) which allow it to have a fast and relatively high uptake of H2, N2 and CO2.
Co-reporter:Min Jiang, Liangjun Li, Dandan Zhu, Hongyu Zhang and Xuebo Zhao
Journal of Materials Chemistry A 2014 - vol. 2(Issue 15) pp:NaN5329-5329
Publication Date(Web):2014/01/20
DOI:10.1039/C3TA15319C
A highly porous metal–organic framework (MOF) containing copper metal centres and nanocages was modified onto a glassy carbon electrode as a noble-metal-free electrocatalyst for oxygen reduction reaction. The nanocages in the metal–organic framework were fully activated by the solvent-exchange method. Although both the as-prepared MOF and activated MOF samples showed electrochemical activity of Cu2+/Cu+ redox pairs by cyclic voltammetric studies, only the activated MOF samples could catalyze an oxygen reduction reaction. In order to avoid detachment of the activated sample from the glassy carbon electrodes surface owing to a low-effective electron-transfer pathway during electrochemical scanning in aqueous solution, reduced graphene oxide (RGO) was immobilized onto a glassy carbon electrode surface as a binder and electron transfer mediator under MOF active layer. The MOF layer on RGO immobilized glassy carbon electrode can catalyze the oxygen reduction reaction through a 2–4 electrons reduction pathway. Furthermore, the occurrence potential of ORR versus Ag/AgCl by MOF catalyst shifted to the positive near 100 mV in comparison with other MOF catalysts.
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![[1,1':4',1''-Terphenyl]-3,3'',5,5''-tetracarboxylic acid, 2',3',5',6'-tetramethyl-](/data/chemimg/3714600/1119195-99-1_b.png)
