Time filter

Source Type

Qi K.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Qi K.,Shenyang Normal University | Li D.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Fu J.,Peking University | And 5 more authors.
Journal of Physical Chemistry C | Year: 2014

Using ionic liquids as controlling agents is known to effectively affect the morphologies of TiO2 crystals. To obtain a profound understanding of this observation, density functional theory calculations with inclusion of Grimme treatment of the dispersion forces (DFT+D) have been performed to study a typical ionic liquid 1-ethyl-3-methylimidazolium bromide ([Emim]Br) adsorption on the low-index TiO2 facets, and the equilibrium crystal shape of TiO2 has been predicted using Wulff'S rule. [Emim]Br is found to adsorb most strongly on (110) for rutile and (100) for anatase. The gap of surface energy shows an obvious increase after [Emim]Br adsorption, especially, between (101) and (001) for anatase and also between (110) and (001) for rutile. This gap variation results in increasing the (100) facet exposure of anatase, and an increase in the length-to-diameter ratio of rutile nanocrystals, which is verified by our experiments. This study is meaningful to gain further understanding of how ionic liquids achieve shape-controlled nanocrystals synthesis by turning surface chemistry, which will push a valuable step toward the ultimate goal, controlling synthesis of inorganic nanomaterials. © 2014 American Chemical Society.

Zhou X.-Q.,Nankai University | Zhou X.-Q.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Zhou X.-Q.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Sun Q.,Nankai University | And 13 more authors.
Dalton Transactions | Year: 2015

Six novel copper(ii) complexes of [CuL1Cl]ClO4 (1), [CuL1(acac)]PF6 (2), [CuL2(R)Cl]2(PF6)2 (3), [CuL2(S)Cl]2(PF6)2 (4), [CuL2(R)(acac)]PF6 (5) and [CuL2(S)(acac)]PF6 (6), (L1 = 1-naphthyl-N,N-[bis(2-pyridyl)methyl]amine, L2 = R/S-1-naphthyl-N,N-[bis(2-pyridyl)methyl]ethanamine, acac = diacetone) were synthesized to serve as artificial nucleases. All complexes were structurally characterized using X-ray crystallography. The crystal structures showed the presence of distorted square-planar CuLCl (1, 3 and 4) and distorted tetragonal-pyramidal CuL(acac) (2, 5 and 6) geometry. The interaction of these complexes with calf thymus DNA (CT-DNA) was researched by means of several spectroscopy methods, which indicated that the complexes were bound to CT-DNA by an intercalation binding mode. DNA cleavage experiments revealed that the complexes exhibited remarkable DNA cleavage activities in the presence of H2O2, and single oxygen (1O2) or hydroxyl radicals may serve as the major cleavage active species. In particular, the in vitro cytotoxicity of the complexes on four human cancer cell lines (HeLa, MCF-7, Bel-7404 and HepG-2) demonstrated that the six compounds had broad-spectrum anti-cancer activity with low IC50 values. The stronger cytotoxicity and DNA cleavage activity of the chiral enantiomers compared with chiral analogues verified the influence of chirality on the antitumor activity of complexes. Meanwhile, the protein binding ability was revealed by quenching of tryptophan emission with the addition of complexes using BSA as a model protein. The results indicated that the quenching mechanism of BSA by the complexes was a static process. © The Royal Society of Chemistry 2015.

Zhao P.,Nankai University | Zhao P.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Han Y.,Tianjin Normal University | Dong X.,Nankai University | And 5 more authors.
ECS Journal of Solid State Science and Technology | Year: 2015

Nowadays, waste tires bring the world increasing environmental and economic issues. Although pyrolysis seems to be a feasible process, a proper application of generated residues needs to be solved urgently. In this work, activated carbons (ACs) derived from the industrial pyrolytic tire char were first evaluated as potential electrode materials for supercapacitor. The obtained ACs display good eletrochemical properties, with initial specific capacitance of about 200 F g-1 at 1 A g-1, long cycling life, low equivalent series resistance and relaxation time, which indicate the ACs are suitable for supercapacitor. © 2015 The Electrochemical Society.

Zhao P.,Nankai University | Zhao P.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Liu S.,Nankai University | Liu S.,Key Laboratory of Advanced Energy Materials Chemistry MOE | And 3 more authors.
ECS Electrochemistry Letters | Year: 2015

Nitrogen-doped hierarchical porous carbons were synthesized by direct pyrolysis of a double metal organic salt, the disodium zinc tetrahydrate of ethylenediamine tetraacetic acid (EDTA) at 600-700°C. The carbon obtained at 700°C has the highest surface area (2818 m2 g-1), pore volume (2.851 cm3 g-1), and abundant nitrogen-containing functional groups as well as oxygen function groups and exhibits high specific capacitance (∼258 F g-1 at 1 A g-1 in 6 mol L-1 KOH aqueous electrolyte), excellent rate capability, and long cycle life. © 2015 The Electrochemical Society.

Li J.-L.,Nankai University | Li J.-L.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Jiang L.,Nankai University | Jiang L.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | And 14 more authors.
New Journal of Chemistry | Year: 2015

Two new mononuclear complexes [CuL(η2-SO4)] (1) and [NiL(η-SO4)(H2O)2]·3(H2O)·CH3CH2OH (2), where L is bis(2-quinolinyl methyl) benzyl-amine, have been synthesized and characterized by X-ray crystallography, ESI-MS and elemental analysis techniques. Complex 1 possesses a distorted square pyramidal geometry while complex 2 possesses distorted octahedral geometry. Interestingly, 2 dissolves in DMF-H2O mixed solvent, while 1 shows good water solubility. Both electronic absorption and EB displacement assay show that these complexes could bind to CT-DNA through partial intercalation. Though the DNA-binding abilities of 1 and 2 are similar, their chemical nuclease activities exhibit a great difference. Under physiological conditions, 1 could effectively convert pBR322 plasmid DNA from Form I to Form II at about 50 μM without any external agent, which shows self-oxidation cleavage activity; however, 2 shows poor DNA cleavage activity at 75 μM even in the presence of H2O2. At the same time, 1 also displays about 11-fold potential than 2 against HeLa cells with IC50 values 6.89 μM (1) and 74.85 μM (2). The IC50 value of 1 is even lower than the widely used drug cisplatin. The redox activity of Cu(II) and Ni(II) may play a main role in the biological activity of the two complexes, but the exact mechanism is still unclear. In addition, interactions of complexes with BSA have also been explored by fluorescence and UV-visible spectroscopic methods. The results indicated that complexes could quench the intrinsic fluorescence of BSA in a static quenching process. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.

Discover hidden collaborations