Metal organic framework g-C 3 N 4 /MIL-53(Fe) heterojunctions with enhanced photocatalytic activity for Cr(VI) reduction under visible light

Nine new coordination polymers, namely, [Mn2(L)(H2O)4]·H2O (1), [Cd(L)0.5(H2O)] (2), [Zn5(L)2(μ3-O)2(H2O)4]·2H2O (3), [Zn4(L)2(μ3-O)2][Zn(H2O)5]·2H2O (4), [Zn2(L)(biim-4)0.5(H2O)3]·H2O (5), [Cd2(L)(bpy)(H2O)]·2H2O·0.5(CH3CH2OH) (6), [Cu2(H2L)2(bpy)2] (7), [Cu2(L)(bpy)(H2O)] (8), and [Cu2(L)(bpy)1.5(H2O)2.5] (9), where H4L = 1,2,3,4-benzenetetracarboxylic acid, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), and bpy = 4,4′-bipyridine, have been synthesized under hydrothermal conditions. Compound 1 displays a rare trinodal (3,4,7)-connected (42·6)(45·6)(47·68·86) topology. 2 possesses an α-Po net. 3 is a novel 3D framework based on pentanuclear ZnII clusters. By adjustment of the pH values of the reaction mixture of 3 with a Na2CO3 solution, a structurally different compound, 4, was obtained, which exhibits a 3D porous framework with the [Zn(H2O)6]2+ cations located in the channels. 5 is an unusual example of a trinodal (3,5)-connected network with a Schlafli symbol of (42·6)(62·8)(42·62·85·10), whereas 6, co...

Series of 2D and 3D Coordination Polymers Based on 1,2,3,4-Benzenetetracarboxylate and N-Donor Ligands: Synthesis, Topological Structures, and Photoluminescent Properties

A series of MIL-53(Fe)-graphene nanocomposite photocatalysts were synthesized by a facile one-pot solvothermal reaction. All materials have been thoroughly characterized by FT-IR, SEM, TEM, PXRD, UV–vis DRS and PL analysis. It was demonstrated that the introducing of graphene on the MIL-53(Fe) would minimize the recombination of photogenerated electron-hole pairs, thus, leading to the enhancement of photocatalytic activity. MIL-53(Fe)-graphene nanocomposite was an efficient catalyst towards the photocatalytic selectively oxidation of alcohols to the corresponding aldehydes or ketones under visible light and ambient conditions. High selectivity of the aldehydes or ketones (99%) were obtained. Meanwhile, the catalyst can be recycled at least four times without loss of catalytic efficiency. A possible photocatalytic reaction mechanism involving a direct photogenerated hole-oxidation process was also investigated in detail by the active species trapping experiments and the related electrochemical analysis.

MIL-53(Fe)-graphene nanocomposites: Efficient visible-light photocatalysts for the selective oxidation of alcohols

Bifunctional Bi12O17Cl2/MIL-100(Fe) composites toward photocatalytic Cr(VI) sequestration and activation of persulfate for bisphenol A degradation.

An InIII-based anionic framework (InIII-MOF) with 4-connected SrAl2 topology was constructed. The InIII-MOF with permanent porosity functions as a host for encapsulation of Ln3+ ions through ion-exchange processes. The photophysical properties of the as-prepared Ln3+@InIII-MOF were investigated and the results showed that the InIII-MOF could serve as an antenna to sensitize Ln3+ cations, especially suitable for Tb3+ and Eu3+ ions. The possible sensitization mechanism has been studied by surface photovoltage spectroscopy. Additionally, the InIII-MOF could also act as a host material when applied in the separation and purification of cationic dyes, which is highly based on the size and charge of organic dyes. Moreover, it can be used as a chromatographic column stationary phase to separate cationic dyes more efficiently and selectively. It is believed that the as-prepared InIII-MOF may have potential applications in optical materials and environmental fields.

http://or.nsfc.gov.cn/bitstream/00001903-5/216766/1/1000014382888.pdf

An InIII-based anionic metal–organic framework: sensitization of lanthanide (III) ions and selective absorption and separation of cationic dyes

Three novel NiII coordination polymers [Ni2(HCOO)4(H2O)4]n (1), [Na2Ni(btec)(H2O)8]n (2; H4btec = 1,2,4,5-benzenetetracarboxylic acid) and [{Ni(pdc)(H2O)2}·H2O]n (3; H2pdc = pyridine-2,5-dicarboxylic acid) have been hydrothermally synthesized and their structures determined by single-crystal X-ray diffraction. The formate groups in complex 1 bridge the NiII ions to form a infinite 3D structure. Complex 2 also possesses a infinite 3D structure and the coordination environment of the NiII ion is a perfect octahedron. Complex 3 is a 2D infinite coordination polymer. The surface photovoltage spectra of complexes 1–3 indicate that they all show three positive surface photovoltage (SPV) responses in the range of 300–800 nm and all show p-type semiconductor characteristics. Although the intensities of the SPV responses are obviously different, this can mainly be attributed to the difference of their structures. The field-induced surface photovoltage spectra (FISPS) of complexes 1–3 confirm their p-type semiconductor characteristics. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis, Structure and Surface Photovoltage of a Series of NiII Coordination Polymers

Crystal structure and surface photovoltage of a series of Ni(II) coordination supramolecular polymer

Synthesis, crystal structure and photoelectric property of Mn(II/IV) coordination complexes

Three MnII coordination supramolecular complexes [Mn(pdc)(H2O)]n1, {[Mn(pdc) (phen)(H2O)]·3H2O}n2, and {[Mn(cyan)2(H2O)4]·2HCl·2(Hcyan)} 3 (H2pdc = pyridine-2,3-dicarboxylic acid, Hcyan = cyanuric acid, phen = 1,10-phenanthroline) were hydrothermally synthesized and their structures determined by single-crystal X-ray diffraction. The pdc group in complex 1 bridges the MnII ions to form an infinite 3D structure. In complex 2, the MnII ion is bridged to a 1D infinite chain by pdc groups and the chain is further connected to a 2D structure by hydrogen bonds. The 3D structure of complex 3 is formed by hydrogen bonds and O···Cl weak interactions. Surface photovoltage spectroscopy (SPS) of complexes 1–3 indicate that they all possess positive SPV response in the range of 300–800 nm and show p-type semiconductor characteristic. The intensities of the SPV responses are obviously different, and this can mainly be attributed to the differences in their structures. Field-induced surface photovoltage spectroscopy (FISPS) of complexes 1–3 confirms their p-type semiconductor characteristic.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Crystal Structure and Surface Photovoltage Properties of MnII Coordination Supramolecules

Three cadmium(II) coordination polymers [Cd(NA)2(H2O)2]n (1), {[Cd(NA)(phen)(NO3)]·(H2O)1/2}n (2), {[Cd(NA)(CH3C6H4COO)(H2O)2]·(CH3C6H4COOH)}n (3) (HNA = nicotinic acid, phen = 1, 10-phenanthroline) have been synthesized by hydrothermal method. Their single-crystal structures were determined by X-ray diffractometry. The absorption, excitation and emission spectra were investigated and all the complexes emit strong fluorescence: λemmax = 544 nm (λex = 492 nm), 1; λemmax = 466 nm (λex = 393 nm), 2; λemmax = 430 nm (λex = 313 nm), 3. At room temperature in the solid state the fluorescence lifetimes of the complexes were investigated and the relationships between the spectra were discussed as well as the connections of luminescence and crystal structures.

Li-Ping Sun

Papers

Synthesis, Structure and Surface Photovoltage of a Series of NiII Coordination Polymers

Crystal structure and surface photovoltage of a series of Ni(II) coordination supramolecular polymer

Synthesis, crystal structure and photoelectric property of Mn(II/IV) coordination complexes

Crystal Structure and Surface Photovoltage Properties of MnII Coordination Supramolecules

Syntheses, Crystal Structures and Photophysical Properties of a Series of Cadmium(II) Coordination Polymers