Shengjun Deng

Anchoring H3PW12O40 on 3-aminopropyltriethoxysilane modified graphene oxide: enhanced adsorption capacity and photocatalytic activity toward methyl orange

H3PW12O40 (PW12) was hybridized with 3-aminopropyltriethoxysilane modified graphene oxide (GO–NH2) sheets using a facile impregnation method, for the removal of organic pollutants in water. The obtained hybrid (PW12/GO–NH2) was characterized by elemental analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), transmission electron microscopy (TEM), and photo-electrochemical measurements. Its removal efficiency for organic pollutants was evaluated by the removal of methyl orange (MO). The results show that about 61.8% of MO is adsorbed onto the PW12/GO–NH2 hybrid upon 2 h of mixing, and after 2 h of irradiation under a high-pressure mercury lamp, MO is further decreased to 17.7%. The adsorption capacity of PW12/GO–NH2 hybrids is enhanced as compared with GO–NH2, probably due to enhanced electrostatic attraction and hydrogen-bonding interactions between the hybrid and MO. And the hybrid exhibits a better photocatalytic activity than the homogenous photocatalyst PW12 (1.36 times), which is probably attributed to the effective separation of photo-generated electron–hole pairs. Furthermore, the trapping experiment of active species during the photocatalytic degradation was carried out over PW12/GO–NH2, revealing that the oxidation of MO by O2˙− and ˙OH plays a major role in the photocatalytic degradation process.

A Novel 3D Coordination Polymer Bearing Rare NbO-x-d Subnets: Synthesis, Structure, and Properties

Employing the multicarboxylate and N-donor mixed ligands to react with Zn(NO3)2·6H2O affords a new 3D compound [Zn3(HBPTC)2(bmp)2(H2O)2]·2H2O (1) (H4BPTC = biphenyl-3,3′,4,4′-tetracarboxylic acid, bmp = 3,6-bis(imidazol-1-yl)pyridazine). Structural analyses show that compound 1 possesses a (4,4)-connected neutral framework bearing rare NbO-x-d subnets, and it represents the first replica of the theoretically predicted NbO-x-d/Im-3m→Imm2 topology net. Moreover, compound 1 can demonstrate the interesting reversible structural transformation property induced by water molecules. Additionally, thermal stability and luminescence properties of 1 were investigated.

A supramolecular organic framework with ant topology featuring interdigitation and interpenetration

H4BOPTC reacts with IMI to yield a supramolecular organic framework, formulated as [IMIH+]2√[H2BOPTC2 − ]√0.5H2O (1) (IMI = imidazole, H4BOPTC = benzophenone-3,3′,4,4′-tetracarboxylic acid). Single-crystal X-ray diffraction analysis reveals that 1 shows a novel architecture with two-level hierarchical entanglement. H2BOPTC2 − connects to IMIH+ through hydrogen bonds, providing 1D ribbon. The basic ribbons are entangled into a 3D net with ant topology. Then the ant nets further interpenetrate to give the final entangled framework. The thermal stability, optical band gap energy and photoluminescent property of 1 have also been investigated.

In situ Synthesis, Crystal Structure and Photoluminescence of a Novel Coordination Polymer with (4,6,6)-Connected sqc111 Topology

Employing the mixed ligands to react with Cd(NO3)2·4H2O afforded a new 3D coordination polymer [Cd3(BPTC)(bmp)2(ox)(H2O)4] (1) (H4BPTC = biphenyl-3,3′,4,4′-tetracarboxylic acid, bmp = 3,6-bis(imidazol-1-yl)pyridazine, H2ox = oxalic acid), in which ox2− was from the in situ oxidation of ethanol. Compound 1 bears a novel trinodal (4,6,6)-connected net structure, and it is the first replica of the theoretically predicted sqc111 topology net. Moreover, the thermal and photoluminescent properties for 1 were also investigated.

Two 3D Coordination Polymers with New Topology Based on Mixed Ligands: Synthesis, Structure, and Photoluminescence Properties

Employing tetracarboxylate and imidazole mixed ligands to react with different transition meat salts afford two new 3D coordination polymers, {[Zn2(BPTC)(BBI)2]·(H2O)3·DMSO}n (1) and {[Cd2(BPTC)(BBI)2]·H2O}n (2) (H4BPTC = biphenyl-3,3′,4,4′-tetracarboxylic acid, BBI = 1,1′-(1,4-butanediyl)bis(imidazole)). Both these two coordination polymers are 4-connected network topologies. Compound 1 features a unprecedented 3-nodal (4,4,4)-connected network topology with the point symbol {64·82}, and 2 displays a (4,4)-connected binodal network bearing new topology with the point symbol of {72·84}2{73·83}. Additionally, thermal stability and photoluminescence properties of 1 and 2 were investigated.

Time modulation of defects in UiO-66 and application in oxidative desulfurization

A defective porous metal–organic framework, UiO-66, prepared by simply tuning the synthesis time, shows excellent efficiency for oxidative desulfurization.

IMPROVEMENT OF PREFERENTIAL CO OXIDATION ACTIVITY OVER CUO/CO3O4-CEO2 CATALYSTS: EFFECT OF CO/CE RATIO

A series of Co3O4-CeO2 supports with different Co/Ce ratio have been synthesized by using polyethyleneglycol (PEG) as a surfactant. The catalytic performance tests indicated the activity of the catalysts is better than the corresponding support. In addition, CuO/(0.7)Co3O4-CeO2 displayed the best activity with 100% CO conversion and 93% O2 selectivity at 120 °C. Furthermore, the stability test of CuO/(0.7)Co3O4-CeO2 expressed the activity can be retained at 80% for 80h at 100 °C. Catalysts and supports were characterized by BET, XRD, TPR and TPD techniques. Discussion of the results showed that the strongest lattice distortion and the best reducibility of Co3O4-CeO2 supports were both negative factors for the catalytic activity. More precisely, an appropriate Co/Ce ratio can restrain the stronger interaction between cobalt oxide and ceria to promote the formation of reducible copper species.

An abnormal threefold interpenetrated diamond-like network formed by assembly of H2BOPTC2– with DABCOH22+: a new route for the construction of diamond-like SOFs

Solvothermal reaction of H4BOPTC and DABCO afforded a supramolecular organic framework (SOF), formulated as []·[H2BOPTC2–] (1) [1,4-diazabicyclo[2.2.2]octane (DABCO) and benzophenone-3,3′,4,4′-tetracarboxylic acid (H4BOPTC)]. The structure of 1 was characterised by elemental analysis, IR and single-crystal X-ray diffraction. It reveals that self-assembly of H2BOPTC2– forms (6.3) nets and the nets connect to linear spacer to give an abnormal threefold interpenetrated diamond-like framework, which demonstrates a new route and expands the selection of tectons for constructing diamond-like SOFs. The thermal stability and photoluminescent property of 1 have also been investigated. Self-assembly of H2BOPTC2– and linear spacer affords an abnormal threefold interpenetrated diamond-like network. This work reveals a new promising route and expands the selection of tectons for the construction of diamond-like supramolecular organic frameworks.

Supramolecular assembly of [H(4−n)BPTC]n− with pipzH22+: 1D negatively charged rectangular tubes and a 2D neutral fes 4·82 network

Controlling the ratio of biphenyl-3,3′,4,4′-tetracarboxylic acid to piperazine produces two interesting organic crystals, respectively, containing 1D negatively charged rectangular tubes and a 2D neutral fes 4·82 network, and the two crystals are both sufficiently robust to retain crystallinity after the water molecules have been completely removed.