Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable compos...Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable composite architectures. Herein, we demonstrate a metal–organic framework(MOF)-assisted strategy for the synthesis of a hierarchical hybrid nanostructure composed of Fe_2O_3 nanotubes assembled in Co_3O_4 host. Starting from MOF composite precursors(Fe-based MOF encapsulated in a Cobased host matrix), a complex structure of Co_3O_4 host and engulfed Fe_2O_3 nanotubes was prepared by a simple annealing treatment in air. By virtue of their structural and compositional features, these hierarchical composite particles reveal enhanced lithium storage properties when employed as anodes for lithium-ion batteries.展开更多
A magnetic metal organic framework（MMOF） was synthesized and used to separate Sr^2＋ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of st...A magnetic metal organic framework（MMOF） was synthesized and used to separate Sr^2＋ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr^2＋ in aqueous solution indicated that the adsorption of Sr^2＋ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr^2＋ conformed to the Freundlich isotherm model（R2 = 0.9919）. The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide （90）Sr.展开更多
Liquid phase catalytic hydroxylation of phenol by Fe-containing metal-organic framework, Fe-BTC (BTC = 1,3,5-benzenetricarboxylate) using 30% H2O2 as an oxidant and H2O as solvent showed good activity and stability un...Liquid phase catalytic hydroxylation of phenol by Fe-containing metal-organic framework, Fe-BTC (BTC = 1,3,5-benzenetricarboxylate) using 30% H2O2 as an oxidant and H2O as solvent showed good activity and stability under mild reaction conditions. Phenol reacts with hydrogen peroxide over Fe-BTC to produce two main products, viz., catechol and hydroquinone. The effect of temperature, time, substrate/hydrogen peroxide mole ratio and amount of catalyst on catalytic performance were studied. The catalyst could be reused four times without losing significant loss of catalytic performance. The crystallinity and structure of catalyst were unchanged during the catalysis reaction, as confirmed by comparison of XRD and SEM of the fresh and reused catalyst. A reaction mechanism is proposed based on the experimental results.展开更多
A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized un...A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized under solvothermal conditions,and structurally characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.It crystallizes in orthorhombic system,space group Pnma with a = 16.1102（9）,b = 33.5805（19）,c = 16.8593（10） ？,β = 97.344（11）°,V = 9120.7（9） ？-3,Z = 4,F（000） = 5184,the final R = 0.0530 and w R = 0.1306.In complex 1,the Tm（Ⅲ） ions adopt two types of coordination fashions.Complex 1 shows onedimensional（1-D） Tm-Zn heteronuclear zigzag chains,and these chains are further linked by H3 mimda ligands into Tm-Zn heteronuclear 2-D lattice-like arrays.The 2-D heteronuclear units were connected through [Zn6（mimda）6] rings to give rise to the Tm-Zn heteronuclear cages.Finally,H3 mimda ligands connected the cages into a 3-D heterometallic framework by the combination of [TmO7]n and Tm-Zn heteronuclear cages.In addition,the thermal stability and luminescent property have been investigated.展开更多
We investigated the adsorption performance of five Fe-based MOFs(Fe-BTC,MIL-100(Fe),MIL-101(Fe),MIL-53(Fe)and MIL-88 C(Fe))for removal of antimonite(Sb(Ⅲ))and antimonate(Sb(Ⅴ))from water.Among these MOFs,MIL-101(Fe)...We investigated the adsorption performance of five Fe-based MOFs(Fe-BTC,MIL-100(Fe),MIL-101(Fe),MIL-53(Fe)and MIL-88 C(Fe))for removal of antimonite(Sb(Ⅲ))and antimonate(Sb(Ⅴ))from water.Among these MOFs,MIL-101(Fe)exhibited the best adsorption capacities for both Sb(Ⅲ)and Sb(Ⅴ)(151.8 and 472.8 mg/g,respectively)which were higher than those of most adsorbents previously reported.The effect of steric hindrance was evident during Sb removal using the Fe-based MOFs,and the proper diameter of the smallest cage windows/channels should be considered an important parameter during the evaluation and selection of MOFs.Additionally,the adsorption capacities of MIL-101(Fe)for Sb(Ⅴ)decreased with increasing initial p H values(from 3.0 to 8.0),while the opposite trend was observed for Sb(Ⅲ).Chloride,nitrate and sulfate ions had a negligible influence on Sb(Ⅴ)adsorption,while NO3-and SO42-improved Sb(Ⅲ)adsorption.This result implies that inner sphere complexes might form during both Sb(Ⅲ)and Sb(Ⅴ)adsorption.展开更多
Developing non-precious metal catalyst with high activity, good stability and low cost for electrocatalytic oxygen reduction reaction（ORR） is critical for the wide application of energy conversion system. Here, we d...Developing non-precious metal catalyst with high activity, good stability and low cost for electrocatalytic oxygen reduction reaction（ORR） is critical for the wide application of energy conversion system. Here, we developed a cost–effective synthetic strategy via silica assistance to obtain a novel FeC/Fe–N–C（named as COPBP-PB-Fe-900-SiO） catalyst with effective active sites of Fe–Nand FeC from the rational design two-dimensional covalent organic polymer（COPBP-PB）. The nitrogen-rich COP effectively promotes the formation of active Fe–Nsites. Additionally, the silica not only can effectively suppress the formation of large Fe-based particles in the catalysts, but also increases the degree of carbonization of the catalyst.The as-prepared COPBP-PB-Fe-900-SiOcatalyst exhibits high electrocatalytic activity for ORR with a halfwave potential of 0.85 V vs. reversible hydrogen electrode（RHE）, showing comparable activity as compared with the commercial Pt/C catalysts in alkaline media. Moreover, this catalyst also shows a high stability with a nearly constant onset potential and half-wave potential after 10,000 cycles. The present work is highly meaningful for developing ORR electrocatalysts toward wide applications.展开更多
Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been design...Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.展开更多
文摘Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable composite architectures. Herein, we demonstrate a metal–organic framework(MOF)-assisted strategy for the synthesis of a hierarchical hybrid nanostructure composed of Fe_2O_3 nanotubes assembled in Co_3O_4 host. Starting from MOF composite precursors(Fe-based MOF encapsulated in a Cobased host matrix), a complex structure of Co_3O_4 host and engulfed Fe_2O_3 nanotubes was prepared by a simple annealing treatment in air. By virtue of their structural and compositional features, these hierarchical composite particles reveal enhanced lithium storage properties when employed as anodes for lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China[Grant No.20477058]by the Chinese Ministry of Science and Technology[Grant No.2014YF211000]
文摘A magnetic metal organic framework（MMOF） was synthesized and used to separate Sr^2＋ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr^2＋ in aqueous solution indicated that the adsorption of Sr^2＋ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr^2＋ conformed to the Freundlich isotherm model（R2 = 0.9919）. The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide （90）Sr.
文摘Liquid phase catalytic hydroxylation of phenol by Fe-containing metal-organic framework, Fe-BTC (BTC = 1,3,5-benzenetricarboxylate) using 30% H2O2 as an oxidant and H2O as solvent showed good activity and stability under mild reaction conditions. Phenol reacts with hydrogen peroxide over Fe-BTC to produce two main products, viz., catechol and hydroquinone. The effect of temperature, time, substrate/hydrogen peroxide mole ratio and amount of catalyst on catalytic performance were studied. The catalyst could be reused four times without losing significant loss of catalytic performance. The crystallinity and structure of catalyst were unchanged during the catalysis reaction, as confirmed by comparison of XRD and SEM of the fresh and reused catalyst. A reaction mechanism is proposed based on the experimental results.
基金Supported by the Foundation for Science&Technology Innovation Talents in Henan Province(Nos.14HASTIT014,and 16410010012)Natural Science Foundation of China(Nos.21671114)the Foundation of Education Committee of Henan province,China(No.14B150033)
文摘A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized under solvothermal conditions,and structurally characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.It crystallizes in orthorhombic system,space group Pnma with a = 16.1102（9）,b = 33.5805（19）,c = 16.8593（10） ？,β = 97.344（11）°,V = 9120.7（9） ？-3,Z = 4,F（000） = 5184,the final R = 0.0530 and w R = 0.1306.In complex 1,the Tm（Ⅲ） ions adopt two types of coordination fashions.Complex 1 shows onedimensional（1-D） Tm-Zn heteronuclear zigzag chains,and these chains are further linked by H3 mimda ligands into Tm-Zn heteronuclear 2-D lattice-like arrays.The 2-D heteronuclear units were connected through [Zn6（mimda）6] rings to give rise to the Tm-Zn heteronuclear cages.Finally,H3 mimda ligands connected the cages into a 3-D heterometallic framework by the combination of [TmO7]n and Tm-Zn heteronuclear cages.In addition,the thermal stability and luminescent property have been investigated.
基金supported by the National Natural Science Foundation of China (No. 41201302)the Natural Science Foundation of Shanghai (No. 17ZR1407000)the Fundamental Research Funds for the Central Universities (No. 222201514337)
文摘We investigated the adsorption performance of five Fe-based MOFs(Fe-BTC,MIL-100(Fe),MIL-101(Fe),MIL-53(Fe)and MIL-88 C(Fe))for removal of antimonite(Sb(Ⅲ))and antimonate(Sb(Ⅴ))from water.Among these MOFs,MIL-101(Fe)exhibited the best adsorption capacities for both Sb(Ⅲ)and Sb(Ⅴ)(151.8 and 472.8 mg/g,respectively)which were higher than those of most adsorbents previously reported.The effect of steric hindrance was evident during Sb removal using the Fe-based MOFs,and the proper diameter of the smallest cage windows/channels should be considered an important parameter during the evaluation and selection of MOFs.Additionally,the adsorption capacities of MIL-101(Fe)for Sb(Ⅴ)decreased with increasing initial p H values(from 3.0 to 8.0),while the opposite trend was observed for Sb(Ⅲ).Chloride,nitrate and sulfate ions had a negligible influence on Sb(Ⅴ)adsorption,while NO3-and SO42-improved Sb(Ⅲ)adsorption.This result implies that inner sphere complexes might form during both Sb(Ⅲ)and Sb(Ⅴ)adsorption.
基金supported by the National Key Research and Development Program of China(2017YFA0206500)NSF of China(51502012+8 种基金2167602021620102007)Beijing Natural Science Foundation(2162032)The Start-up fund for talent introduction of Beijing University of Chemical Technology(buctrc201420buctrc201714)Talent cultivation of State Key Laboratory of OrganicInorganic CompositesThe Fundamental Research Funds for the Central Universities(ZD1502)Distinguished scientist program at BUCT(buctylkxj02)the“111”project of China(B14004)
文摘Developing non-precious metal catalyst with high activity, good stability and low cost for electrocatalytic oxygen reduction reaction（ORR） is critical for the wide application of energy conversion system. Here, we developed a cost–effective synthetic strategy via silica assistance to obtain a novel FeC/Fe–N–C（named as COPBP-PB-Fe-900-SiO） catalyst with effective active sites of Fe–Nand FeC from the rational design two-dimensional covalent organic polymer（COPBP-PB）. The nitrogen-rich COP effectively promotes the formation of active Fe–Nsites. Additionally, the silica not only can effectively suppress the formation of large Fe-based particles in the catalysts, but also increases the degree of carbonization of the catalyst.The as-prepared COPBP-PB-Fe-900-SiOcatalyst exhibits high electrocatalytic activity for ORR with a halfwave potential of 0.85 V vs. reversible hydrogen electrode（RHE）, showing comparable activity as compared with the commercial Pt/C catalysts in alkaline media. Moreover, this catalyst also shows a high stability with a nearly constant onset potential and half-wave potential after 10,000 cycles. The present work is highly meaningful for developing ORR electrocatalysts toward wide applications.
基金supported by the National Natural Science Foundation of China(NSFC, No. 21771191)the Shandong Natural Science Fund (No. ZR2017QB012)+2 种基金the Applied Basic Research Projects of Qingdao (No.16-5-1-95-jch)the Fundamental Research Funds for the Central Universities (Nos.16CX05015A,18CX06003A, YCX2018071)the Foundation of State Key Laboratory of Structural Chemistry (No. 20160006)
文摘Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.
