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Sample records for cu zn complexes

  1. pyridine Zn(II) and Cu(II) Complexes

    African Journals Online (AJOL)

    NICO

    2014-09-03

    Sep 3, 2014 ... The kinetics, mechanism and polymer microstructure studies of ring-opening polymerization (ROP) of lactides (LA) by Zn(II) and Cu(II) ... transparency, ease of processing and ease of microbial decompo- sition or degradation.

  2. Hydrogen motion in the Cu-H complex in ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Boerrnert, Felix; Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden (Germany)

    2008-07-01

    The Cu-H complex in ZnO consists of Cu on Zn site and a hydrogen atom bound to a nearby O atom with the O-H bond oriented in the basal plane of the hexagonal lattice to the c axis. The motion of hydrogen in the Cu-H complex is studied by the stress-induced dichroism. Stress applied at room temperature along [10 anti 10] results in an alignment of the Cu-H bond. The reorientation process was found to be thermally activated with the activation energy of 0.52{+-}0.04 eV. The connection of the hydrogen movement in the Cu-H complex with the hydrogen diffusion in ZnO is discussed and consequences for the existence of interstitial hydrogen in ZnO at room temperature are presented.

  3. Chemical behavior of Cu, Zn, Cd, and Pb in a eutrophic reservoir: speciation and complexation capacity.

    Science.gov (United States)

    Tonietto, Alessandra Emanuele; Lombardi, Ana Teresa; Choueri, Rodrigo Brasil; Vieira, Armando Augusto Henriques

    2015-10-01

    This research aimed at evaluating cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) speciation in water samples as well as determining water quality parameters (alkalinity, chlorophyll a, chloride, conductivity, dissolved organic carbon, dissolved oxygen, inorganic carbon, nitrate, pH, total suspended solids, and water temperature) in a eutrophic reservoir. This was performed through calculation of free metal ions using the chemical equilibrium software MINEQL+ 4.61, determination of labile, dissolved, and total metal concentrations via differential pulse anodic stripping voltammetry, and determination of complexed metal by the difference between the total concentration of dissolved and labile metal. Additionally, ligand complexation capacities (CC), such as the strength of the association of metals-ligands (logK'ML) and ligand concentrations (C L) were calculated via Ruzic's linearization method. Water samples were taken in winter and summer, and the results showed that for total and dissolved metals, Zn > Cu > Pb > Cd concentration. In general, higher concentrations of Cu and Zn remained complexed with the dissolved fraction, while Pb was mostly complexed with particulate materials. Chemical equilibrium modeling (MINEQL+) showed that Zn(2+) and Cd(2+) dominated the labile species, while Cu and Pb were complexed with carbonates. Zinc was a unique metal for which a direct relation between dissolved species with labile and complexed forms was obtained. The CC for ligands indicated a higher C L for Cu, followed by Pb, Zn, and Cd in decreasing amounts. Nevertheless, the strength of the association of all metals and their respective ligands was similar. Factor analysis with principal component analysis as the extraction procedure confirmed seasonal effects on water quality parameters and metal speciation. Total, dissolved, and complexed Cu and total, dissolved, complexed, and labile Pb species were all higher in winter, whereas in summer, Zn was mostly present in the

  4. Synthesis, characterization and phosphotriesterase mimetic activity of some Zn(II) and Cu(II) complexes

    Indian Academy of Sciences (India)

    Mamata Singh; Ray J Butcher; Jerry P Jasinski; James A Golen; Govindasamy Mugesh

    2012-11-01

    We report here the synthesis and characterization of a few phenolate-based ligands bearing tertamino substituent and their Zn(II) and Cu(II) metal complexes. Three mono/binuclear Zn(II) and Cu(II) complexes [Zn(L1)(H2O)].CH3OH.H2O (1) (H2 L1 = 6,6′-(((2-dimethylamino)ethylazanediyl)bis(methylene))bis(2, 4-dimethylphenol), [Zn2(L2)2] (2) (H2L2 = 2,2′-(((2-dimethylamino)ethyl)azanediyl)bis(methylene)bis(4-methylphenol) and [Cu2(L3)2.CH2 Cl2] (3) (H2L3 = (6,6′-(((2-(diethylamino)ethyl)azanediyl)bis(methylene)) bis(methylene))bis(2,4-dimethylphenol) were synthesized by using three symmetrical tetradendate ligands containing N2O2 donor sites. These complexes are characterized by a variety of techniques including; elemental analysis, mass spectrometry, 1H, 13C NMR spectroscopic and single crystal X-ray analysis. The new complexes have been tested for the phosphotriesterase (PTE) activity with the help of 31P NMR spectroscopy. The 31P NMR studies show that mononuclear complex [Zn(L1)(H2O)].CH3OH.H2O (1) can hydrolyse the phosphotriester i.e., p-nitrophenyl diphenylphosphate (PNPDPP), more efficiently than the binuclear complexes [Zn2(L2)2] (2) and [Cu2(L3)2.CH2Cl2] (3). The mononuclear Zn(II) complex (1) having one coordinated water molecule exhibits significant PTE activity which may be due to the generation of a Zn(II)-bound hydroxide ion during the hydrolysis reactions in CHES buffer at pH 9.0.

  5. Heavy metal (Zn and Cu) complexation and molecular size distribution in wastewater treatment plant effluent.

    Science.gov (United States)

    Chaminda, G G T; Nakajima, F; Furumai, H

    2008-01-01

    The size distributions of zinc and copper species in the effluent of a wastewater treatment plant were determined by a combination of ultrafiltration and chelating disk cartridge fractionation. The results showed that 75-87% of total Zn and 84-86% of total Cu were strongly complexed or particle-bound in the final effluents. It was also found that the major part of Cu was bound to ligands in the < 500 Da fraction while the trend for Zn was not so clear and exhibited significant seasonal variability. Labile Cu and Zn were detected not only in the smallest fraction (< 500 Da) but also in the larger fractions. It meant that the labile species in the effluent were not equivalent to free metal ions. Conditional stability constants and ligand concentrations were also determined from the measured metal concentrations by square wave anodic stripping voltammetry. Existence of two types of ligand for each metal was inferred from the experimental data. Conditional stability constant obtained for the stronger type Ligand of Zn was higher than that of Cu, although the estimated Ligand concentrations were almost similar.

  6. Divacancy complexes induced by Cu diffusion in Zn-doped GaAs

    Science.gov (United States)

    Elsayed, M.; Krause-Rehberg, R.; Korff, B.; Ratschinski, I.; Leipner, H. S.

    2013-08-01

    Positron annihilation spectroscopy was applied to investigate the nature and thermal behavior of defects induced by Cu diffusion in Zn-doped p-type GaAs crystals. Cu atoms were intentionally introduced in the GaAs lattice through thermally activated diffusion from a thin Cu capping layer at 1100 °C under defined arsenic vapor pressure. During isochronal annealing of the obtained Cu-diffused GaAs in the temperature range of 450-850 K, vacancy clusters were found to form, grow and finally disappear. We found that annealing at 650 K triggers the formation of divacancies, whereas further increasing in the annealing temperature up to 750 K leads to the formation of divacancy-copper complexes. The observations suggest that the formation of these vacancy-like defects in GaAs is related to the out-diffusion of Cu. Two kinds of acceptors are detected with a concentration of about 1016 - 1017 cm-3, negative ions and arsenic vacancy copper complexes. Transmission electron microscopy showed the presence of voids and Cu precipitates which are not observed by positron measurements. The positron binding energy to shallow traps is estimated using the positron trapping model. Coincidence Doppler broadening spectroscopy showed the presence of Cu in the immediate vicinity of the detected vacancies. Theoretical calculations suggested that the detected defect is VGaVAs-2CuGa.

  7. Uniaxial stress study of the Cu-H complex in ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2006-10-15

    The influence of uniaxial stress on the vibrational mode of the Cu-H complex at 3192 cm{sup -1} in ZnO is studied. It is shown that the split patterns are consistent with the stretching mode of a bond-centered hydrogen located in the basal plane between substitutional Cu and O. Quantitative analysis of the stress effects reveals two low energy modes with frequencies of 25 and 49 cm{sup -1}. Upon substituting deuterium for hydrogen they shift to 22 and 36 cm{sup -1}, respectively. The origin of the low energy modes is discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Effect of ZnTe/ZnTe:Cu complex back-contact on device characteristics of CdTe solar cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    ZnTe/ZnTe:Cu complex layers deposited by vacuum co-evaporation have been in- troduced to CdS/CdTe solar cells. The C-V and I-V curves have been investigated and the effects of un-doped ZnTe layer thickness as well as annealing temperatures on I-V characteristics of CdTe solar cells have been studied. The results show that the “roll over” and “cross over” phenomena of dark and light I-V curves can be eliminated by use of ZnTe/ZnTe:Cu layer and the fill factor for a typical sample has increased to 73%, where there is no high resistance transparent layer. The reasons have been discussed combined with the energy band diagram of CdTe solar cells.

  9. Zn (II and Cu (II Halide Complexes of Poly(propylene amine Dendrimer Analysed by Infrared and Raman Spectroscopies

    Directory of Open Access Journals (Sweden)

    Ivo Grabchev

    2013-01-01

    Full Text Available Two nondestructive and complementary spectral methods as infrared and Raman spectroscopies have been used for characterizations of poly(propylene amine dendrimers comprising 1,8-naphthalimide units in the dendrimer periphery and their metal complexes with Cu2+ at Zn2+ ions.

  10. Cu(II AND Zn(II COMPLEX COMPOUNDS WITH BIGUANIDES AROMATIC DERIVATIVES. SYNTHESIS, CHARACTERIZATION, BIOLOGICAL ACTIVITY

    Directory of Open Access Journals (Sweden)

    Ticuţa Negreanu-Pîrjol

    2011-05-01

    Full Text Available In this paper we report the synthesis, physical-chemical characterization and antimicrobial activity of some new complex compounds of hetero-aromatic biguanides ligands, chlorhexidine base (CHX and chlorhexidine diacetate (CHXac2 with metallic ions Cu(II and Zn(II, in different molar ratio. The synthesized complexes were characterized by elemental chemical analysis and differential thermal analysis. The stereochemistry of the metallic ions was determined by infrared spectra, UV-Vis, EPR spectroscopy and magnetic susceptibility in the aim to establish the complexes structures. The biological activity of the new complex compounds was identified in solid technique by measuring minimum inhibition diameter of bacterial and fungal culture, against three standard pathogen strains, Escherichia coli ATCC 25922, Staphilococcus aureus ATCC 25923 and Candida albicans ATCC 10231. The results show an increased specific antimicrobial activity for the complexes chlorhexidine:Cu(II 1:1 and 1:2 compared with the one of the Zn(II complexes.

  11. On Cu diffusion in ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Herklotz, F.; Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden (Germany)

    2009-07-01

    Copper in ZnO is of special interest since recent theoretical and experimental studies found ferromagnetic behavior of ZnO:Cu at room temperature. In addition, Cu is a deep acceptor in ZnO and one of the causes of the green emission band. Experimental studies of Cu diffusion in bulk ZnO single crystals were carried out in the temperature range 1030 to 1180 C. Concentration profiles of substitutional Cu were determined via IR absorption at 5817 cm{sup -1}. Our findings reveal that the diffusion coefficient of Cu is 7.6 x 10{sup 7} exp(-4.56 eV/k{sub B}T) cm{sup 2}s{sup -1}. This is about a factor of 25 higher than reported in the earlier studies, which probed the total Cu concentration. The discrepancy is explained by the formation of Cu complexes, which occurs at high concentrations. Diffusion mechanisms are discussed.

  12. Electrochemical and theoretical complexation studies for Zn and Cu with individual polyphenols

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, I. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Salinas, I. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Santamaria, C. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Garcia-Mina, J.M. [INABONOS, Poligono Arazuri, 31160 Orcoyen, Navarra (Spain); Fernandez, J.M. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain)]. E-mail: jmfdez@unav.es

    2005-07-06

    Zn and Cu interactions with three selected flavonoids (catechin, quercetin and rutin) have been electrochemically monitored. It has been shown that catechin takes one atom of metal per molecule; quercetin takes two atoms, and rutin is able to take up to three atoms. Not all ligands bind metals equally strong, and weakly bonded metals can be distinguished. Zn shows a sluggish kinetics and, at the same time, the highest conditional formation constants. The method could be applied to a real sample. Theoretical models are proposed for the most favourable compounds.

  13. Characterization and performance of Cu/ZnO/Al2O3 catalysts prepared via decomposition of M(Cu,Zn)-ammonia complexes under sub-atmospheric pressure for methanol synthesis from H2 and CO2

    Institute of Scientific and Technical Information of China (English)

    Danjun Wang; Jun Zhao; Huanling Song; Lingjun Chou

    2011-01-01

    Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M(Cu,Zn)-ammonia complexes (DMAC) at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol (212 g/(Lcat·h); T =513 K,p =3 MPa,S V =12000 h-1).

  14. Pyrazole bridged dinuclear Cu(II) and Zn(II) complexes as phosphatase models: Synthesis and activity

    Science.gov (United States)

    Naik, Krishna; Nevrekar, Anupama; Kokare, Dhoolesh Gangaram; Kotian, Avinash; Kamat, Vinayak; Revankar, Vidyanand K.

    2016-12-01

    Present work describes synthesis of dibridged dinuclear [Cu2L2(μ2-NN pyr)(NO3)2(H2O)2] and [Zn2L(μ-OH)(μ-NNpyr)(H2O)2] complexes derived from a pyrazole based ligand bis(2-hydroxy-3-methoxybenzylidene)-1H-pyrazole-3,5-dicarbohydrazide. The ligand shows dimeric chelate behaviour towards copper against monomeric for zinc counterpart. Spectroscopic evidences affirm octahedral environment around the metal ions in solution state and non-electrolytic nature of the complexes. Both the complexes are active catalysts towards phosphomonoester hydrolysis with first order kcat values in the range of 2 × 10-3s-1. Zinc complex exhibited promising catalytic efficiency for the hydrolysis. The dinuclear complexes hydrolyse via Lewis acid activation, whereby the phosphate esters are preferentially bound in a bidentate bridging fashion and subsequent nucleophilic attack to release phosphate group.

  15. Unsaturated b-ketoesters and their Ni(II, Cu(II and Zn(II complexes

    Directory of Open Access Journals (Sweden)

    MUHAMMED BASHEER UMMATHUR

    2009-03-01

    Full Text Available A new series of b-ketoesters in which the keto group is attached to the olefinic linkage were synthesized by the reaction of methyl acetoacetate and aromatic aldehydes under specified conditions. The existence of these compounds predominantly in the intramolecularly hydrogen bonded enol form was well demonstrated from their IR, 1H-NMR and mass spectral data. Details on the formation of their [ML2] complexes with Ni(II, Cu(II and Zn(II and the nature of the bonding are discussed on the basis of analytical and spectral data.

  16. Antibacterial Activities of Newly Synthesized Azo Anils And its Oxalato-Bridged Binuclear {Cu(II and Zn(II} Complexes

    Directory of Open Access Journals (Sweden)

    M. Ameen

    2014-12-01

    Full Text Available Novel oxalato-bridged binuclear metal {Cu(II and Zn(II} complexes; [{(L1M(II}2OX] (L1= 2-({2-hydroxy-5-[(4-nitrophenyldiazenyl]benzylidene}aminobenzoic acid, OX = oxalate and [{(L2M(II}2OX], (L2 = 2-{[(2-hydroxyphenylimino]methyl}-4-[(4-nitrophenyldiazenyl] phenol, OX = oxalate were synthesized. Azo anils and corresponding Metal {Cu((II and Zn(II} complexes were characterised by Elemental Combustion System, Atomic Absorption Spectroscopy (AAS, Fourier Transform Infrared (FTIR spectroscopy, UV-Visible, Spectroscopy and 13C-1H-Nuclear Magnetic Resonance spectroscopy. Elemental Analyses, FTIR and UV-Vis were used for structural characterization of metal complexes and distorted octahedral geometry for M(II complexes came into being. The antibacterial activities of azo anils ligands, oxalate ion, CuCl2.2H2O, Zn(CH3COO2.2H2O and metal {Cu(II and Zn(II} complexes against gram-positive (Bacillis subtilis and gram-negative (Escherichia coli were evaluated. The antibacterial activities were performed to asses inhibition potential of ligand and their metal {Cu(II and Zn(II} complexes. The results revealed that antibacterial activities of azo anils become more pronounced when free ligands were coordinated to central metal atom.

  17. Preparation and Optoelectronic Characteristics of ZnO/CuO-Cu2O Complex Inverse Heterostructure with GaP Buffer for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Yi-Feng Lin

    2013-10-01

    Full Text Available This study reports the optoelectronic characteristics of ZnO/GaP buffer/CuO-Cu2O complex (COC inverse heterostructure for solar cell applications. The GaP and COC layers were used as buffer and absorber in the cell structure, respectively. An energy gap widening effect and CuO whiskers were observed as the copper (Cu layer was exerted under heat treatment for oxidation at 500 °C for 10 min, and arose from the center of the Cu2O rods. For preparation of the 30 nm-thick GaP buffer by sputtering from GaP target, as the nitrogen gas flow rate increased from 0 to 2 sccm, the transmittance edge of the spectra demonstrated a blueshift form 2.24 to 3.25 eV. Therefore, the layer can be either GaP, GaNP, or GaN by changing the flow rate of nitrogen gas.

  18. Antiviral Activity of Substituted Chalcones and their Respective Cu(ii, Ni(ii and Zn(ii Complexes

    Directory of Open Access Journals (Sweden)

    K. G. Mallikarjun

    2005-01-01

    Full Text Available Complexes of Cu(II, Ni(II and Zn(II with of 3-(phenyl-1-(2’-hydroxynaphthyl – 2 – propen – 1 – one (PHPO , 3 - (4-chlorophenyl - 1- (2’-hydroxynaphthyl–2–propen – 1 – one (CPHPO, 3 - (4 -methoxyphenyl -1-(2’-hydroxynapthyl-2-propen-1-one(MPHPO,3 - (3,4-dimethoxyphenyl –1-(2’-hydroxynaphthyl – 2 - propen– 1 – one (DMPHPO have been prepared and the purity of the samples were checked by elemental analysis. The ligands and their Cu(II, Ni(II and Zn(II complexes were tested on the infectivity of tobacco ring spot virus(TRSV using cowpea (Vigna Sinensis as a local lesions assay host. All the compounds were tested at different concentrations (250 ppm to 1500 ppmon the infectivity of the virus by applying them either with virus inoculum or 24 h before of after virus inoculation to the test plants. The compounds were found to have varied effects on virus infectivity depending on compounds concentration and method of application. The statistical significance of the data was determined by using analysis of variance.

  19. Synthesis, Characterization and Fluorescence Properties of Zn(II) and Cu(II) Complexes: DNA Binding Study of Zn(II) Complex.

    Science.gov (United States)

    Lavaee, Parirokh; Eshtiagh-Hosseini, Hossein; Housaindokht, Mohammad Reza; Mague, Joel T; Esmaeili, Abbas Ali; Abnous, Khalil

    2016-01-01

    Zinc(II) and copper(II) complexes containing Schiff base, 2- methoxy-6((E)-(phenylimino) methyl) phenol ligand (HL) were synthesized and characterized by elemental analysis, IR, NMR, and single crystal X-ray diffraction technique. The fluorescence properties and quantum yield of zinc complex were studied. Our data showed that Zn complex could bind to DNA grooves with Kb = 10(4) M(-1). Moreover, Zn complex could successfully be used in staining of DNA following agarose gel electrophoresis. MTT assay showed that Zn complex was not cytotoxic in MCF-7 cell line. Here, we introduce a newly synthesized fluorescence probe that can be used for single and double stranded DNA detection in both solution and agarose gels.

  20. Influence of Chemical Effect on the Kβ/Kα Intensity Ratios and Kβ Energy Shift of Co, Ni, Cu, and Zn Complexes

    Institute of Scientific and Technical Information of China (English)

    G. Apaydma, V. Ayhkg; Z. Biyiklioglu; E. Tirasoglu; H. Kantekin

    2008-01-01

    Chemical effects on the Kβ/Kα intensity ratios and ΔE energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a 241 Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed the effects of different ligands on the Kβ/Kα intensity ratios and ΔE energy differences for Co, Ni, Cu, and Zn complexes. We tried to investigate chemical effects on central atoms using the behaviors of different ligands in these complexes. The experimental values of Kβ/Kα were compared with the theoretical and other experimental values of pure Co, Ni, Cu, and Zn.

  1. Synthesis and characterization of new unsymmetrical 'side-off' tetra and hexa coordinate homobinuclear Cu(II) and heterobinuclear Cu(II)-Zn(II) complexes: Magnetic, electrochemical and kinetic studies

    Science.gov (United States)

    Shanmuga Bharathi, K.; Sreedaran, S.; Kalilur Rahiman, A.; Narayanan, V.

    A new class of phenol based unsymmetrical side-off tetra and hexa coordinate homobinuclear Cu(II) and heterobinuclear Cu(II)-Zn(II) complexes have been synthesized and characterized by elemental and spectral analysis. The electronic spectra of all the complexes show "Red shift" in LMCT band, for the ligand H2L2 compared to that of the ligand H2L1 due to the relatively higher electron donating nature of their substitutents. The homobinuclear Cu(II) complexes (1 and 2) illustrate an antiferromagnetic interaction (μeff: 1.58 and 1.60 BM) at 298 K with a broad EPR signal. Variable temperature magnetic moment study of the binuclear copper (II) complexes shows that the extent of antiferromagnetic coupling is greater in the case of H2L2 complexes than H2L1 complexes (-2 J values: 192 cm-1 and 184 cm-1 respectively). The heterobinuclear Cu(II)-Zn(II) complexes (3 and 4) have a magnetic moment value close to the spin only value with four hyperfine EPR signals. Electrochemical studies of the complexes reveal that all the binuclear complexes show two irreversible one-electron transfer reduction waves in the cathodic region. There is an "anodic shift" in the first reduction potential of the complexes, of the ligand H2L1 when compared to that of the ligand H2L2 due to the presence of relatively higher electron donating N-substituents in the later case than in the former case. The catecholase activity of the complexes reveals that the homobinuclear Cu(II) complexes show higher catalytic activity than the corresponding heterobinuclear Cu(II)-Zn(II) complexes. In the hydrolysis of 4-nitrophenylphosphate, the heterobinuclear Cu(II)-Zn(II) complexes show better catalytic activity than the corresponding homobinuclear Cu(II) complexes.

  2. Syntheses, crystal structures and DNA-binding studies of Cu(II) and Zn(II) complexes bearing asymmetrical aroylhydrazone ligand

    Science.gov (United States)

    Li, Yueqin; Yang, Zhiwei; Zhou, Minya; He, Jing; Wang, Xuehong; Wu, Yanlong; Wang, Zhuye

    2017-02-01

    Zn(II) and Cu(II) complexes with benzophenone benzoyl hydrazone (HBBH) and benzophenone salicylylhydrazone (HBSH) have been synthesized and characterized by different physico-chemical and spectroscopic techniques (UV-vis, IR and NMR). The molecular structures of these complexes [Zn(BBH)2, Cu(BBH)2 and Cu(BSH)2Cl2H2O] have also been determined by single X-ray diffraction technique. In Zn(BBH)2 and Cu(BBH)2 complexes, each ligand coordinates to metal through enol tautomeric form by azomethine-N and carbonylate-O resulting a 4-coordinate distorted tetrahedral geometry. While in Cu(BSH)2Cl2H2O, each ligand coordinates to metal through keto tautomeric form resulting distorted octahedral geometry in which two chlorine atoms occupy the axial positions. The DNA interaction propensity of the complexes with Herring sperm DNA, studied at physiological pH by spectrophotometric, spectrofluorometric, viscometric techniques and cyclic voltammetry, revealed intercalation as the possible binding mode. Fascinatingly, Cu(BSH)2Cl2H2O was found to exhibit greater binding strength than the others. A strong hyperchromism effect and a slight red shift were exhibited by all complexes. The intrinsic binding constants are of moderate values and are about 3.28 × 104 M-1, 4.73 × 104 M-1 and 5.80 × 104 M-1, respectively. Cyclic voltammetry studies of the complexes binding with DNA indicate quasireversible oxidation and reduction potentials. The results suggest that the binding affinity of complexes lies in the order Cu(BSH)2Cl2H2O > Cu(BBH)2 > Zn(BBH)2.

  3. On diffusion of Cu in ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Herklotz, F., E-mail: frank.herklotz@physik.tu-dresden.d [Institut fuer Angewandte Physik, Technische Universitaet Dresden, 01062 Dresden (Germany); Lavrov, E.V.; Weber, J. [Institut fuer Angewandte Physik, Technische Universitaet Dresden, 01062 Dresden (Germany)

    2009-12-15

    An experimental study of Cu diffusion in bulk ZnO single crystals in the temperature range 1012-1220 deg. C is presented. Concentration profiles of substitutional Cu were determined by IR absorption at 5817cm{sup -1}. Our findings reveal that Cu in ZnO diffuses faster than previously reported [G. Mueller, R. Helbig, J. Phys. Chem. Solids 32 (1971) 1971]. The discrepancy is tentatively explained by the formation of Cu complexes, which occurs at high Cu concentrations.

  4. Syntheses, structures and properties of Zn(II) and Cu(II) complexes based on N2-2-methylenepyridinyl 1,2,3-triazole ligand

    Science.gov (United States)

    Chen, Yunfeng; Wu, Jun; Ma, Shan; Zhou, Shilei; Meng, Xianggao; Jia, Lihui; Pan, Zhiquan

    2015-06-01

    Four new Zn(II) and Cu(II) coordinated polymers ([ZnL2N3]ClO4 (1), [Cu2L2(CH3CN)]Cl4 (2) [CuL](NO3)2 (3), [Cu(H2O)L](SO4) (4) L = 2-((4-phenyl-2H-1,2,3-triazol-2-yl)methyl) pyridine (ptmp)) have been reported. All the compounds have been characterized by IR spectrum, elemental analyses and X-ray crystallography diffraction. Single-crystal X-ray diffraction analyses show that one-dimensional polymers are formed in these four complexes. Chain-like structures are formed in complex 1, 2 and 3, which are connected by azide, chloride and nitrate anions, respectively. In complex 4, one-dimensional left-handed polymer is formed by a μ2-SO4 bridge. The fluorescent and electrochemical properties of these four complexes were investigated. It was found that these three Cu(II) complexes displayed a quenching of fluorescence, while Zn(II) complex exhibited a clear enhanced fluorescence.

  5. Chiral discrimination asserted by enantiomers of Ni (II), Cu (II) and Zn (II) Schiff base complexes in DNA binding, antioxidant and antibacterial activities.

    Science.gov (United States)

    Khan, Noor-ul Hasan; Pandya, Nirali; Prathap, K Jeya; Kureshy, Rukhsana Ilays; Abdi, Sayed Hasan Razi; Mishra, Sandhya; Bajaj, Hari Chandra

    2011-10-15

    Chiral Schiff base ligands (S)-H(2)L and (R)-H(2)L and their complexes (S-Ni-L, R-Ni-L, S-Cu-L, R-Cu-L, S-Zn-L and R-Zn-L) were synthesized, characterized and examined for their DNA binding, antioxidant and antibacterial activities. The complexes showed higher binding affinity to calf thymus DNA with binding constant ranging from 2.0×10(5) to 4.5×10(6) M(-1). All the complexes also exhibited remarkable superoxide (56-99%) and hydroxyl scavenging (45-89%) activities as well as antibacterial activities against gram (+) and gram (-) bacteria. However, none of the complexes showed antifungal activity. Conclusively, S enantiomers of the complexes were found to be relatively more efficient for DNA interaction, antioxidant and antibacterial activities than their R enantiomers. This study reveals the possible utilization of chiral Schiff base complexes for pharmaceutical applications.

  6. Synthesis, characterization, photoluminescence, and electrochemical studies of novel mononuclear Cu(II) and Zn(II) complexes with the 1-benzylimidazolium ligand

    Science.gov (United States)

    Bibi, Sherino; Mohammad, Sharifah; Manan, Ninie Suhana Abdul; Ahmad, Jimmy; Kamboh, Muhammad Afzal; Khor, Sook Mei; Yamin, Bohari M.; Abdul Halim, Siti Nadiah

    2017-08-01

    Two new mononuclear coordination complexes [Cu(bim)4Cl2]ṡ2H2O (1) and [Zn(bim)2Cl2] (2) containing the 1-benzylimidazole (bim) ligand were successfully synthesized. Both complexes were characterized by IR, UV-vis, and fluorescence spectroscopies, single crystal and powder X-ray diffraction measurements, and thermogravimetric analysis. Self-assembly during the recrystallization process resulted in the formation of octahedral and tetrahedral Cu(II) and Zn(II) complexes, respectively. The single crystals obtained are representative of the bulk material, as shown by the powder X-ray diffraction patterns. Cyclic voltammetry measurements showed that complex 1 undergoes a quasi-reversible redox reaction, while complex 2 undergoes reduction alone, and no oxidation peak was observed; this is due to the stability of the reduced form of complex 2.

  7. The Dispersion Characteristics of the Complex Permeability of NiZnCu Ferrite and its Composite Materials

    Directory of Open Access Journals (Sweden)

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The paper deals with the frequency dependence of complex permeability for the Ni0.27Zn0.63Cu0.1Fe2O4 sintered ferrite produced by conventional ceramic method and its composite materials made of this ferrite (in the form of powder and non-magnetic polymer matrix (polyvnyl chloride - PVC. The experimental and theoretical curves of the complex permeability were compared. The contribution of both domain wall motion and spin rotational mangetisation processes on th complex permeability in high-frequency region (up to 1 GHz is discussed. In the case of composite materials, the simple magnetic circuit approach is taken into account. In composites, the real part of the complex permeability in the frequency region above 100 MHz is larger than that of the prepared sintered ferrite. This is attibuted to the shift of the spin and domain wall resonance frequencies toward the higher frequency region by introducing demagnetising fields of magnetic particles in the composite.

  8. Difference of Electron Capture and Transfer Dissociation Mass Spectrometry on Ni2+-, Cu2+-, and Zn2+-Polyhistidine Complexes in the Absence of Remote Protons

    Science.gov (United States)

    Asakawa, Daiki; De Pauw, Edwin

    2016-07-01

    Electron capture dissociation (ECD) and electron transfer dissociation (ETD) in metal-peptide complexes are dependent on the metal cation in the complex. The divalent transition metals Ni2+, Cu2+, and Zn2+ were used as charge carriers to produce metal-polyhistidine complexes in the absence of remote protons, since these metal cations strongly bind to neutral histidine residues in peptides. In the case of the ECD and ETD of Cu2+-polyhistidine complexes, the metal cation in the complex was reduced and the recombination energy was redistributed throughout the peptide to lead a zwitterionic peptide form having a protonated histidine residue and a deprotonated amide nitrogen. The zwitterion then underwent peptide bond cleavage, producing a and b fragment ions. In contrast, ECD and ETD induced different fragmentation processes in Zn2+-polyhistidine complexes. Although the N-Cα bond in the Zn2+-polyhistidine complex was cleaved by ETD, ECD of Zn2+-polyhistidine induced peptide bond cleavage accompanied with hydrogen atom release. The different fragmentation modes by ECD and ETD originated from the different electronic states of the charge-reduced complexes resulting from these processes. The details of the fragmentation processes were investigated by density functional theory.

  9. Conductometric Studies of Thermodynamics of Complexation of Co2+, Ni2+, Cu2+, and Zn2+ Cations with Aza-18-crown-6 in Binary Acetonitrile-Methanol Mixtures

    Directory of Open Access Journals (Sweden)

    Mehdi Taghdiri

    2012-01-01

    Full Text Available The complexation reactions between aza-18-crown-6 (A18C6 and Co2+, Ni2+, Cu2+, and Zn2+ ions were studied conductometrically in different acetonitrile-methanol mixtures at various temperatures. The formation constants of the resulting 1 : 1 complexes were calculated from the computer fitting of the molar conductance-mole ratio data at different temperatures. Selectivity of A18C6 for Co2+, Ni2+, Cu2+, and Zn2+ cations is sensitive to the solvent composition. At 20°C and in acetonitrile solvent, the stability of the resulting complexes varied in the order but the order was reversed byadding 20% methanol. The enthalpy and entropy changes of the complexation reactions were evaluated from the temperature dependence of formation constants. It was found that the stability of the resulting complexes decreased with increasing methanol in the solvent mixture. The TΔS° versus ΔH° plot of thermodynamic data obtained shows a fairly good linear correlation indicating the existence of enthalpy-entropy compensation in the complexation reactions. In addition, binding energies of Ni2+, Cu2+, and Zn2+ complexes with A18C6 were calculated at B3LYP/6-31G level of theory.

  10. Synthesis, Optical and Thermal Properties of Cu ( Ⅰ)、 Zn (Ⅱ)Complexes of Schiff Base%Cu(Ⅱ)、Zn(Ⅱ)Schiff碱配合物的合成及其光热性质

    Institute of Scientific and Technical Information of China (English)

    贤景春; 窦甜甜; 王顺文

    2011-01-01

    用5-硝基水杨醛与色氨酸缩合制备了一种Schiff碱配体,将其与过渡金属Cu(Ⅱ)、Zn(Ⅱ)进行作用合成出两种新型的配合物.采用元素分析、差热-热重、IR、UV、摩尔电导率等对配体和配合物进行了表征,并测定了化合物的荧光性质和对超氧离子的催化歧化作用.%In this paper a new 5-nitro-salicylaldehyde-tryptophane Schiff base ligand and its complex containing Cu( Ⅱ ) ,Zn(Ⅱ ) were synthesized. The compositions and structures of the ligand and its complexes have been characterized by The elemental analyses, thermal analyses,IR spectra, UV spectra and molar conductivity. The fluorescence property and The Dismutation to O2- free radical has also been investigated.

  11. Complex permeability spectra of PbO and Ta2O5 added nanocrystalline MgCuZn ferrites

    Science.gov (United States)

    V, Seetha Rama Raju

    2015-05-01

    PbO and Ta2O5 added MgCuZn ferrites are prepared by the Microwave-Hydrothermal (M-H) processing. The nanocrystalline ferrites are sintered to a temperature of 900 °C/4 h. SEM pictures reveal that, the addition of PbO causes a small amount of grain growth, whereas the addition of Ta2O5 causes a fine-grained microstructure. The complex permeability spectra (μ*=μ‧-iμ″) of the prepared samples were measured in the frequency range from 1 MHz to 1.8 GHz, the μ* spectra are analyzed into two magnetization processes with focus on the particle size of ferrite samples. In addition to the spin rotation relaxation in 130-200 MHz, it is initially identified the contribution from reversible domain wall bowing rising at 6-40 MHz. The magnetic state of the ferrite is also influenced by the addition of PbO and Ta2O5. The spin rotation mechanism of the present ferrites is enhanced by the preparation of nanocrystalline samples.

  12. Surface characterization of ZnO/ZnMn{sub 2}O{sub 4} and Cu/Mn{sub 3}O{sub 4} powders obtained by thermal degradation of heterobimetallic complexes

    Energy Technology Data Exchange (ETDEWEB)

    Barrault, Joeel, E-mail: joel.barrault@univ-poitiers.fr [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France); Makhankova, Valeriya G., E-mail: leram@univ.kiev.ua [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Khavryuchenko, Oleksiy V.; Kokozay, Vladimir N. [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Ayrault, Philippe [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France)

    2012-03-15

    From the selective transformation of the heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes with 2,2 Prime -bipyridyl by thermal degradation at relatively low (350 Degree-Sign C) temperature, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Morphology of the powder surface was examined by scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX). Surface composition was determined by X-ray photoelectron spectroscopy (XPS). Specific surface of the powders by nitrogen adsorption was found to be 33{+-}0.2 and 9{+-}0.06 m{sup 2} g{sup -1} for Zn-Mn and Cu-Mn samples, respectively, which is comparable to those of commercial products. - Graphical abstract: From the selective transformation of heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Highlights: Black-Right-Pointing-Pointer Thermal degradation of heterometallic complexes results in fine disperse particles. Black-Right-Pointing-Pointer Core-shell Cu/Mn{sub 3}O{sub 4} particles are obtained. Black-Right-Pointing-Pointer ZnMn{sub 2}O{sub 4} spinel layer covers ZnO particles.

  13. Process of electroless plating Cu-Sn-Zn ternary alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  14. Syntheses and Crystal Structures of Two Novel 1-D Metal Complexes with Dicyanamide:[Zn(pheen)(dca)2]n and [Cu(quin)2(dca)2]n

    Institute of Scientific and Technical Information of China (English)

    吴阿清; 郑发鲲; 蔡丽珍; 郭国聪; 黄锦顺

    2004-01-01

    The two complexes [Zn(phen)(dca)2]n 1 (phen = 1,10-phenanthroline, dca = di-cyanamide) and [Cu(quin)2(dca)2]n 2 (quin = quinoline) were synthesized by self-assembly reactions of Zn(CH3COO)2·4H2O with Nadca and phen ligands, and CuCl2(2H2O with Nadca and quin ligands, respectively. Their crystal structures were determined by single-crystal X-ray diffraction analyses. Crystallographic data for complex 1: (C16H8N8Zn)n, Mr = 377.67, monoclinic, space group P21/c, a = 10.1322(5), b = 11.0218(6), c = 14.1351(6) (A), β = 101.077(2)°, V = 1549.1(1) (A)3, Z = 4 , Dc = 1.619 g/cm3, μ(MoKα) = 1.602 mm-1, F(000) = 760, R = 0.0698 and wR = 0.1558; and for complex 2: (C22H14N8Cu)n, Mr = 453.95, orthorhombic, space group Cmc21, a = 16.679(4), b = 9.153(2), c = 12.937(3) (A), V = 1975.0(7) (A)3, Z = 4, Dc = 1.527 g/cm3, μ(MoKα) = 1.134 mm-1, F(000) = 924, R = 0.0486 and wR = 0.0981. The structures of complexes 1 and 2 consist of infinite zigzag chains, and their metal atoms have slightly distorted square pyramidal coordination environments with two N atoms of phen or quin ligands and three nitrile N atoms of dca ligands. The secondary long Zn-N bonds and π-π stacking interactions make the chains into a three-dimensional network in complex 1.

  15. The synthesis of N-Zn, N-Cu complexes involving 2-amino pyridine and ethylenediamine ligands and application to the Henry reaction

    Indian Academy of Sciences (India)

    Luo Mei; Tang Hai Ming; Li Qian Rong; Sun Jie; Yang Shan Zhong; Li Xue Liang

    2009-07-01

    The synthesis and characterization of a series of N-Zn, N-Cu complexes with 2-amino pyridine and ethylenediamine ligands (1a-b and 2a-b) have been described. They were synthesized with a simple, one-pot method, and the crystal structures of 1a, 1b, 2a and 2b were determined by X-ray crystallography. The complexes were also characterized by NMR, IR, and elemental analysis. They were used as the catalysts in an application to the Henry reaction, and high yields were obtained under the optimum conditions.

  16. Theoretical studies on densities, stability and detonation properties of 2D polymeric complexes Cu(DAT)₂Cl₂ and its new analogues Zn(DAT)₂Cl₂.

    Science.gov (United States)

    Shu, Yuanjie; Li, Huarong; Gao, Shijie; Xiong, Ying

    2013-04-01

    A novel environmentally friendly octahedrally coordinated 2D polymeric complexes bis(1,5-diaminotetrazole) -dichlorozinc(II) (Zn(DAT)2Cl2) was first designed based on the the crystal data of bis(1,5-diaminotetrazole)- dichlorocopper(II) (Cu(DAT)2Cl2). Density functional theory (DFT) was used to predict the optimized geometries at TPSSTPSS/6-311G(d, p) level. Densities and detonation properties were evaluated using the electron cloud enclosed volume and VLW equation of state (VLW EOS), respectively. Calculation results show that the density of Zn(DAT)2Cl2 (2.117 g · cm(-1)) is a bit more than that of Cu(DAT)2Cl2 (2.106 g · cm(-1)). The calculated high positive heat of formation (HOF) predicts that the stabilities of the title compounds decrease in the order Zn(DAT)2Cl2 > Cu(DAT)2Cl2, which agrees with the result of bond dissociation energies (BDE). Even though they have the same molecule structures, their first scission steps are different. Furthermore, the title two compounds show good detonation velocities and pressures compared with that of bis-(5-nitro-2H-tetrazolato-N (2)) tetraamminecobalt(III) perchlorates (BNCP), and they are potential candidates for high-energy-density materials (HEDM).

  17. Biologically active new Fe(II, Co(II, Ni(II, Cu(II, Zn(II and Cd(II complexes of N-(2-thienylmethylenemethanamine

    Directory of Open Access Journals (Sweden)

    C. SPÎNU

    2008-04-01

    Full Text Available Iron(II, cobalt(II, nickel (II, copper (II, zinc(II and cadmium(II complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N-(2-thienylmethylenemethanamine (TNAM formed by the condensation of 2-thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand. Magnetic susceptibility data coupled with electronic, ESR and Mössbauer spectra suggest a distorted octahedral structure for the Fe(II, Co(II and Ni(II complexes, a square-planar geometry for the Cu(II compound and a tetrahedral geometry for the Zn(II and Cd(II complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II, Zn(II and Cd(II complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

  18. Cu(II), Zn(II) andMn(II) complexes of poly(methyl vinyl ether-alt-maleic anhydride). Synthesis, characterization and thermodynamic parameters

    Indian Academy of Sciences (India)

    Hidayet Mazi; Ali Gulpinar

    2014-01-01

    The complexes of poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) with Zn(II), Mn(II) and Cu(II) ions were synthesized from the reaction of the aqueous solution of copolymer and metal(II) chlorides at different temperatures ranging from 25° to 40°C. Elemental analysis of themetal-polymer complexes suggests that the metal to ligand ratio is 1:1. The formation constants of each complex were determined by the mol-ratio method. UV-Vis studies showed that the complex formation tendency increased in the following order: Zn(II) > Cu(II) > Mn(II). This order was confirmed by the Irving-William series and Pearson’s classification. The IR spectral data indicated the metal ions to be coordinated through the hydroxyl groups of the hydrolysed maleic anhydride. The intrinsic viscosity and thermal properties of the copolymer and metal-polymer complexes and their thermal stability are discussed.

  19. Synthesis and characterization of mono- and bimetallic complexes of Zn(II and Cu(II; new multifunctional unsymmetrical acyclic and macrocyclic phenol-based ligand

    Directory of Open Access Journals (Sweden)

    Hamid Golchoubian

    2013-10-01

    Full Text Available The dicompartmental macrocyclic ligand (L22- was prepared by [1:1] cyclic condensation of N,N′-dimethyacetate-N,N′-ethylene-di(5-methyl-3-formyl-2-hydroxybenzylamine with 1,3-diaminopropane. The ligand includes dissimilar N(amine2O2 and N(imine2O2 coordination sites sharing two phenolic oxygen atoms and containing two methyl acetate pedant arms on the amine nitrogen donor atoms. A series of mono- and bimetallic complexes were synthesized and characterized on the basis of elemental analysis, molar conductance measurement, IR and UV-Vis spectroscopy techniques. It was found that during the cyclization process the copper (II displaced from the N(amine2O2 to the N(imine2O2 coordination site and one of the methyl acetate pedant arms is dissociated. The heterodinuclear complex of [ZnL2Cu(-OAc]+ was prepared by a transmetallation reaction on the [ZnL2Zn(-OAc]+ by Cu(II. The characterization results showed that the two metal ions are bridged by two phenolic oxygen atoms and an acetate group, providing distorted five-coordination geometries for the both metal ions.

  20. Crystal Structures and Theoretical Calculation of Zn(Ⅱ) and Cu(Ⅱ) Supramolecular Complexes Based on Macrocyclic Triamine Ligand 1 ,4,7-Triazacyclodecane (tacd)

    Institute of Scientific and Technical Information of China (English)

    QUO,Hui; ZHU,Hai-Yan; HE,Xian-Ling; SU,Zhen-Ping; LI,Jun; ZHANG,Feng-Xing

    2007-01-01

    Two supramolecular complexes [Zn(tacd)2](C6H8O4)·6H2O (1) and [Cu(tacd)2]Cl2·4H2O (2) were synthesized and characterized by elemental analysis, IR spectra, TGA and single-crystal X-ray diffraction analysis. The crystal structure showed that the metal ions in complexes 1 and 2 had similar coordination circumstance. But for the complex 2, it formed a novel two-dimensional supramolecular network with 12-membered rings and four-membered rings via hydrogen bond interaction. The thermal gravimetric analyses indicated that the two complexes had similar steps of weight-loss. On the basis of experiment, the two complexes were calculated by DFT-B3LYP/6-31G(d) in Gaussian 03. The results of calculation are in good agreement with the experiment.

  1. Interplay of bifurcated hydrogen bonds in making of inclusion/pseudo-inclusion complexes of Ni(II), Cu(II) and Zn(II) of a salophen type ligand: Crystal structures and spectral aspects

    Science.gov (United States)

    Ambili, K. U.; Sithambaresan, M.; Kurup, M. R. Prathapachandra

    2017-04-01

    Three novel photoluminescent materials were synthesized by treating Ni(II), Cu(II) and Zn(II) acetate salts with a Schiff base prepared from 3-ethoxysalicylaldehyde and 2-aminobenzylamine. Among the prepared complexes, Ni(II) and Cu(II) complexes are inclusion compounds while Zn(II) complex is a pseudo-inclusion compound. They were characterized by elemental analysis, IR, UV-visible and EPR spectra. Single crystal XRD studies of these complexes suggest that Ni(II) and Cu(II) are in a distorted square planar environment while the spatial arrangement of donor atoms in Zn(II) complex is best described as distorted square based pyramid although significant distortion towards trigonal bipyramid is noticed. Stabilized crystal packing of the complexes is established via supramolecular interactions. The metal chelate rings as the π system for C-H···π interactions found in Cu(II) and Zn(II) complexes explicit the concept of metalloaromaticity. TG-DTG studies reveal that all the complexes are thermally stable. Both ligand and complexes exhibit intense photoluminescence in near UV region. However, Zn(II) complex giving an intense blue-green emission spectrum at maximum wavelength of 518 nm with shoulder peaks, could be used for optoelectronic applications.

  2. Synthesis, characterization, and antioxidant/cytotoxic activity of new chromone Schiff base nano-complexes of Zn(II), Cu(II), Ni(II) and Co(II)

    Science.gov (United States)

    Saif, M.; El-Shafiy, Hoda F.; Mashaly, Mahmoud M.; Eid, Mohamed F.; Nabeel, A. I.; Fouad, R.

    2016-08-01

    A chromone Schiff base complexes of Zn(II) (1), Cu(II) (2), Ni(II) (3) and Co(II) (4) were successfully prepared in nano domain with crystalline or amorphous structures. The spectroscopic data revealed that the Schiff base ligand behaves as a monoanionic tridentate ligand. The metal complexes exhibited octahedral geometry. Transmission electron microscope (TEM) analysis showed that Cu(II) complex have aggregated nanospheres morphology. The obtained nano-complexes were tested as antioxidant and antitumor agents. The H2L and its Cu(II) complex (2) were found to be more potent antioxidant (IC50(H2L) = 0.93 μM; IC50(Cu(II) complex) = 1.1 μM than standard ascorbic acid (IC50 = 2.1 μM) as evaluated by DPPH• method. The H2L and its complexes (1-4) were tested for their in vitro cytotoxicity against Ehrlich Ascites Carcinoma cell line (EAC). The Cu(II) nano-complex (2) effectively inhibited EAC growth with IC50 value of 47 μM in comparison with its parent compound and other prepared complexes. The high antioxidant activity and antitumor activity of Cu(II) nano-complex (2) were attributed to their chemical structure, Cu(II) reducing capacity, and nanosize property. The toxicity test on mice showed that Zn(II) (1) and Cu(II) (2) nano-complex have lower toxicity than the standard cis-platin.

  3. Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, and In Vitro Biological Activities

    OpenAIRE

    Jeslin Kanaga Inba, P.; B. Annaraj; Thalamuthu, S.; Neelakantan, M.A.

    2013-01-01

    A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2,2′-(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, ...

  4. Cytotoxicity of Cu(II) and Zn(II) 2,2'-bipyridyl complexes: dependence of IC50 on recovery time.

    Science.gov (United States)

    Shi, Yi; Toms, Bonnie B; Dixit, Namrata; Kumari, Niraj; Mishra, Lallan; Goodisman, Jerry; Dabrowiak, James C

    2010-08-16

    We measure the cytotoxicity of three metal complexes containing the 2,2'-bypyridine ligand, Cu(bpy)(NCS)(2), 1, [Cu(bpy)(2)(H(2)O)](PF(6))(2), 2, and Zn(bpy)(2)(NCS)(2), 3, toward neuroblastoma cells (SK-N-SH) and ovarian cancer cells (OVCAR-3) using two different cell assays. The cells were exposed to various concentrations of the compounds for 1 h and the percent inhibition of cell growth, I, measured for various times after exposure, i.e., as a function of the recovery time t. After developing the theory showing the relationship between I and t, the cytotoxicity data were analyzed to reveal that the two copper complexes, 1 and 2, cause the cells to divide at a slower rate than the controls during the recovery period, but the zinc complex, 3, had little or no effect on cell division during the recovery period. The usual metric for reporting cytotoxicity is IC(50), which is the concentration of agent required to inhibit cell growth to 50% of the control population. However, since IC(50) can depend on the recovery time, t, as is the case for 1 and 2, reporting IC(50) for a single recovery time can hide important information about the long-time effects of a cytotoxic agent on the health of the cell population. Mechanistic studies with the compounds revealed that the copper complexes, 1 and 2, cleave closed circular pBR322 DNA in the presence of ascorbate, while the zinc complex, 3, does not facilitate DNA cleavage under the same conditions. This difference in DNA cleavage activity may be related to the fact that Cu(II) is redox active and can readily change its oxidation state, while Zn(II) is redox inert and cannot participate in a redox cycle with ascorbate to break DNA.

  5. Isolation and spectroscopic characterization of Zn(II), Cu(II), and Pd(II) complexes of 1,3,4-thiadiazole-derived ligand

    Science.gov (United States)

    Karcz, Dariusz; Matwijczuk, Arkadiusz; Boroń, Bożena; Creaven, Bernadette; Fiedor, Leszek; Niewiadomy, Andrzej; Gagoś, Mariusz

    2017-01-01

    A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv-vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 to metal ions occurs most likely via one of the deprotonated hydroxyl groups of the resorcinyl moiety and one of the N atoms of the thiadiazole heterocycle.

  6. Structural, physicochemical characterization, theoretical studies of carboxamides and their Cu(II), Zn(II) complexes having antibacterial activities against E. coli

    Science.gov (United States)

    Aktan, Ebru; Gündüzalp, Ayla Balaban; Özmen, Ümmühan Özdemir

    2017-01-01

    The carboxamides; N,N‧-bis(thiophene-2-carboxamido)-1,3-diaminopropanol (L1) and N,N‧-bis(furan-2-carboxamido)-1,3-diaminopropanol (L2) were synthesized and characterized using 1H NMR, 13C NMR, LC-MS and FT-IR spectrum. The molecular geometries of these molecules were optimized by DFT/B3LYP method with 6-311G(d,p) basis set in Gaussian 09 software. The geometrical parameters, frontier molecular orbitals (FMOs) and molecular electrostatic potential (MEP) mapped surfaces were calculated by the same basis set. Dinuclear Cu(II) and Zn(II) complexes having general formula as [MLCl]2Cl2.nH2O (in which M = Cu(II),Zn(II); n = 0,2) were also synthesized and characterized using LC-MS and FT-IR spectrum, thermogravimetric analysis (TGA/DTA curves), magnetic moments and molar conductivities. Coordination was found to be through carbonyl oxygen and two chlorine atoms as bridging in distorted tetrahedral geometry. The optimized structures, geometrical parameters, frontier molecular orbitals (FMOs) and dipole moments of metal complexes were also obtained by DFT/B3LYP method with LanL2DZ basis set. Antibacterial activities of the compounds were screened against E. coli using microdilution method (MIC's in μg/mL). The activity results show that the corresponding compounds exhibit good to moderate antibacterial effects when compared with sulfamethoxazole and sulfisoxazole antibiotics as positive controls. Also, metal complexes have remarkable increase in their activities than parent ligands against E. coli which is mostly effected by [Cu(L2)Cl]2Cl2 complex as potential antibacterial agent.

  7. Synthesis and luminescent properties of novel Cu (II), Zn (II) polymeric complexes based on 1,10-phenanthroline and biphenyl groups

    Indian Academy of Sciences (India)

    Yan He; Chaofan Zhong; Yu Zhou; Hailiang Zhang

    2009-07-01

    A fully conjugated ligand 4,4'-bis(1,10-phenanthroline-[5,6-d]imidazole-2-yl)-biphenyl (BPIBP) based on 1,10-phenanthroline and biphenyl groups was firstly synthesized. The corresponding polymeric complexes, BPIBP (1) with Cu(II) (2) and Zn(II) (3), were synthesized and characterized by FT-IR, elemental Analysis, conductivity measurement. UV-Vis and fluorescence spectra at room temperature revealed that both the polymeric complexes 2 and 3 emit blue luminescence at 453 and 452 nm (em, max) in DMSO solution and blue/green luminescence at 527 and 536 nm (em, max) in solid state respectively, and the maximum wavelengths of the polymeric complexes 2 and 3 are red shifted, compared with the ligand 1. Thermal property measurements show that they have good thermal stability.

  8. Magnetic exchange in a low-dimensional complex oxide (Cu,Zn){sub 2}V{sub 2}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Kataev, V. E-mail: v.kataev@ifw-dresden.de; Pommer, J.; Choi, K.-Y.; Lemmens, P.; Ionescu, A.; Pashkevich, Yu.; Lamonova, K.; Moeller, A.; Freimuth, A.; Guentherodt, G

    2004-05-01

    Copper-divanadate Cu{sub 2-y}Zn{sub y}V{sub 2}O{sub 7} comprises trans-edge sharing chains of CuO{sub 5} polyhedra where Cu spins S=((1)/(2)) are antiferromagnetically coupled. Zn substitution for Cu induces a structural phase transition which affects strongly the magnetic properties. In particular, a substantial magnetic anisotropy found in one of the structural phases is strongly suppressed in the other one, owing to the changes of the local bonding geometry.

  9. Co(II), Ni(II), Cu(II) and Zn(II) complexes of a bipyridine bis-phenol conjugate: generation and properties of coordinated radical species.

    Science.gov (United States)

    Arora, Himanshu; Philouze, Christian; Jarjayes, Olivier; Thomas, Fabrice

    2010-11-14

    Four bis-phenolate complexes [Zn(II)L], [Ni(II)L], [Cu(II)L] and [Co(II)L] (where [H(2)L = 2,2'-[2,2']bipyridinyl-6-yl-bis-4,6-di-tert-butylphenol] have been synthesized. The copper(II) and nickel(II) complexes have been characterized by X-ray diffraction, showing a metal ion within a square planar geometry, slightly distorted towards tetrahedral. The cyclic voltametry (CV) curve of [Zn(II)L] consists of a single bi-electronic reversible wave at 0.06 V vs. Fc/Fc(+). The electrochemically generated dication is a diradical species [Zn(II)L˙˙](2+) that exhibits the typical phenoxyl π-π* band at 395 nm. It is EPR-silent due to magnetic interactions between the phenoxyl moieties. The CV curves of [Ni(II)L] and [Cu(II)L] exhibit two distinct ligand-centred one-electron oxidation waves. The first one is observed at E(1/2)(1) = 0.38 and 0.40 V for the nickel and copper complex, respectively, and corresponds to the formation of M(II)-coordinated phenoxyl radicals. Accordingly, [Ni(II)L˙](+) exhibits a strong absorption band at 960 nm and an (S = ½) EPR signal centred at g(iso) = 2.02. [Cu(II)L˙](+) is EPR-silent, in agreement with a magnetic coupling between the metal and the radical spin. In contrast with the other complexes, [Co(II)L] was found to react with dioxygen (mostly in the presence of pyridine), giving rise to a stable (S = ½) superoxo radical complex [Co(III)L(Py)(O(2)˙)]. One-electron oxidation of [Co(II)L] at -0.01 V affords a diamagnetic cobalt(III) complex [Co(III)L](+) that is inert towards O(2) binding, whereas two-electron oxidation leads to the paramagnetic phenoxyl radical species [Co(III)L˙](+) whose EPR spectrum features an (S = ½) signal at g(iso) = 2.00.

  10. Thiosemicarbazone Cu(II) and Zn(II) complexes as potential anticancer agents: syntheses, crystal structure, DNA cleavage, cytotoxicity and apoptosis induction activity.

    Science.gov (United States)

    Shao, Jia; Ma, Zhong-Ying; Li, Ang; Liu, Ya-Hong; Xie, Cheng-Zhi; Qiang, Zhao-Yan; Xu, Jing-Yuan

    2014-07-01

    Four novel thiosemicarbazone metal complexes, [Cu(Am4M)(OAc)]·H2O (1), [Zn(HAm4M)Cl2] (2), [Zn2(Am4M)2Br2] (3) and [Zn2(Am4M)2(OAc)2]·2MeOH (4) [HAm4M=(Z)-2-(amino(pyridin-2-yl)methylene)-N-methylhydrazinecarbothioamide], have been synthesized and characterized by X-ray crystallography, elemental analysis, ESI-MS and IR. X-ray analysis revealed that complexes 1 and 2 are mononuclear, which possess residual coordination sites for Cu(II) ion in 1 and good leaving groups (Cl(-)) for Zn(II) ion in 2. Both 3 and 4 displayed dinuclear units, in which the metal atoms are doubly bridged by S atoms of two Am4M(-) ligands in 3 and by two acetate ions in bi- and mono-dentate forms, respectively, in 4. Their antiproliferative activities on human epithelial cervical cancer cell line (HeLa), human liver hepatocellular carcinoma cell line (HepG-2) and human gastric cancer cell line (SGC-7901) were screened. Inspiringly, IC50 value (11.2±0.9 μM) of complex 1 against HepG-2 cells was nearly 0.5 fold of that against human hepatic cell lines LO2, showing a lower toxicity to human liver cells. Additionally, it displayed a stronger inhibition on the viability of HepG-2 cells than cisplatin (IC50=25±3.1 μM), suggesting complex 1 might be a potential high efficient antitumor agent. Furthermore, fluorescence microscopic observation and flow cytometric analysis revealed that complex 1 could significantly suppress HepG-2 cell viability and induce apoptosis. Several indexes, such as DNA cleavage, reactive oxygen species (ROS) generation, comet assay and cell cycle analysis indicated that the antitumor mechanism of complex 1 on HepG-2 cells might be via ROS-triggered apoptosis pathway. Copyright © 2014. Published by Elsevier Inc.

  11. Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole: synthesis, structures and their high catalytic activity for efficient cyclic carbonate synthesis.

    Science.gov (United States)

    Vignesh Babu, Heeralal; Muralidharan, Krishnamurthi

    2013-01-28

    The syntheses of Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole (DIP(2)pyr)H 1 and their catalytic activities in CO(2) fixation are reported. The structures of these complexes were characterized by IR, (1)H, (13)C NMR and single crystal X-ray diffraction techniques. The catalytic activities of these complexes for the cycloaddition of CO(2) to an epoxide under one atmosphere of pressure and mild temperature conditions to yield cyclic carbonate have been studied. Among the four complexes synthesized, the Zn(II) and Cu(II) complexes were found to be versatile whereas the Cu(II) complex was more selective in the conversion. They were highly effective for the conversion of monosubstituted terminal epoxides, disubstituted terminal and internal epoxides to their corresponding cyclic carbonates with good to high yields.

  12. Tetra- and hexadentate Schiff base ligands and their Ni(II), Cu(II) and Zn(II) complexes. Synthesis, spectral, magnetic and thermal studies.

    Science.gov (United States)

    Ismail, Tarek M A; Saleh, Akila A; El Ghamry, Mosad A

    2012-02-01

    Tetradentate N(2)O(2), N(4) Schiff bases, 1,2-bis(4-oxopent-2-ylideneamino) benzene (BOAB), 1-(4-oxopent-2-ylideneamino-2-[(2-hydroxyphenyl)ethylideneamino] benzene (OAHAB), 7,16-bis(4-chlorobenzylidene)-6,8,15,17-tetra-methyl-7,16-dihydro -5,9,14,18-tetraza-dibenzo[a,h] cyclo tetradecene (BCBDCT), 7,16-bis(2-hydroxy-benzylidene)-6,8,15,17-tetramethyl-7,16-dihydro-5,9,14,18-tetraza-dibenzo [a,h] cyclo tetradecene (BHBDCT) and hexadentate N(4)O(2) Schiff bases, 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(2-hydroxybenzylidene) pentane (BHAPHP), 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(4-chlorobenzylidene) pentane (BHAPCP) were prepared and characterized by elemental analysis, IR, UV-Vis, (1)H NMR and mass spectra. The solid complexes of the prepared Schiff base ligands with Ni(II), Cu(II) and Zn(II) ions were isolated and characterized by elemental and thermal analyses, IR, electronic and ESR spectra as well as conductance and magnetic susceptibility measurements. The results showed that most complexes have octahedral geometry but few can attain the tetrahedral arrangement. The TG analyses suggest high stability for most complexes followed by thermal decomposition in different steps. The kinetic and thermodynamic parameters for decomposition steps in Cu(II) complexes thermograms have been calculated.

  13. Cu2ZnSiS4

    Directory of Open Access Journals (Sweden)

    Kimberly A. Rosmus

    2011-04-01

    Full Text Available Single crystals of Cu2ZnSiS4, dicopper(I zinc silicon tetrasulfide, have been prepared via high-temperature solid-state synthesis. Cu2ZnSiS4 was found to have the wurtz-stannite structure type, like that of Li2CdGeS4, Li2CdSnS4, and Cu2CdSiS4. Each sulfur anion is tetrahedrally coordinated by two Cu cations, one Si cation, and one Zn cation, forming a three-dimensional honeycomb structure. When viewed along the c axis, the atoms are aligned in rows in which each cation alternates with the sulfur anions.

  14. Structural characterization of 1,8-naphthalimides and in vitro microbiological activity of their Cu(II) and Zn(II) complexes

    Science.gov (United States)

    Grabchev, Ivo; Yordanova, Stanislava; Bosch, Paula; Vasileva-Tonkova, Evgenia; Kukeva, Rositsa; Stoyanov, Stanimir; Stoyanova, Radostina

    2017-02-01

    Two new 1,8-naphthalimide derivatives (NI1 and NI2) have been synthesized and characterized. The photophysical properties of the new compounds have been investigated in organic solvents of different polarity. It has been shown that both compounds are solvent depended. Cu(II) and Zn(II) complexes of NI2 were obtained and characterized by IR-NMR, fluorescence and EPR spectroscopy. The influence of different metal cations on the fluorescence intensity has been investigated in acetonitrile solution. Antimicrobial composite PLA-metal complexes materials have been obtained for the first time. Microbiological activity of both metal complexes has been investigated in vitro against different Gram-positive and Gram-negative bacteria and two yeasts. The various antimicrobial activities and the minimum inhibitory concentrations (MICs) of both complexes have been determined. The microbiological activity of composite materials PLA-metal complexes in thin polymeric film has also been investigated. The results suggest that the new metal complexes could find application in designing new antimicrobial preparations to control the spread of infections.

  15. Supplementing Zn, Mn, and Cu from amino acid complexes and Co from cobalt glucoheptonate during the peripartal period benefits postpartal cow performance and blood neutrophil function.

    Science.gov (United States)

    Osorio, J S; Trevisi, E; Li, C; Drackley, J K; Socha, M T; Loor, J J

    2016-03-01

    The physiologic and metabolic stresses that dairy cows experience during the transition into early lactation can promote oxidative stress, inflammation, and immune dysfunction. Optimal supply of micronutrients such as trace minerals (e.g., Zn, Mn, Cu, and Co) via more bioavailable forms (e.g., AA complexes) might minimize these negative effects. Multiparous Holstein cows were enrolled at 60 d before dry-off (~110 d before calving) and remained on experiment until 30 d in milk (DIM). Cows were offered a common diet supplemented entirely with inorganic trace minerals (INO) from -110 to -30 d before calving. From -30 to calving cows received a common prepartal [1.5 Mcal/kg of dry matter (DM), 15% crude protein] diet, and from calving to 30 DIM a common postpartal (1.76 Mcal/kg of DM, 18% crude protein) diet. Both diets were partially supplemented with an INO mix of Zn, Mn, and Cu to supply 35, 45, and 6 mg/kg, respectively, of the total diet DM. Cows were assigned to treatments in a randomized complete block design to receive an oral bolus with a mix of INO (n=21) or organic AA complexes (AAC; n=16) of Zn, Mn, Cu, and Co to achieve supplemental levels of 75, 65, 11, and 1mg/kg, respectively, in the total diet DM. Inorganic trace minerals were provided in sulfate form and AAC were supplied via Availa Zn, Availa Mn, Availa Cu, and COPRO (Zinpro Corp., Eden Prairie, MN). Liver tissue was harvested on -30, -15, 10, and 30 d, and blood samples for biomarker analyses were obtained more frequently from -30 to 30 DIM. Short-term changes in blood ketones were measured via Precision Xtra (Abbott Diabetes Care, Alameda, CA) every other day from 1 to 15 d postpartum. Prepartal DM intake was lower in AAC cows. In contrast, a tendency for a diet by time (D × T) interaction resulted in greater postpartal DM intake of approximately 2 kg/d in cows fed AAC. Milk and milk protein yield had a D × T interaction because AAC cows produced approximately 3.3 kg/d more milk and 0.14 kg

  16. New macrocyclic schiff base complexes incorporating a homopiperazine unit: Synthesis of some Co(II), Ni(II),Cu(II) and Zn(II) complexes and crystal structure and theoretical studies

    Science.gov (United States)

    Keypour, Hassan; Rezaeivala, Majid; Ramezani-Aktij, Ameneh; Bayat, Mehdi; Dilek, Nefise; Ünver, Hüseyin

    2016-07-01

    A new macrocyclic Schiff base ligand, L, was synthesized by condensation reaction of 1,4-bis(2-formylphenyl)homopiperazine and 1,4-diaminobutane in acetonitrile. The Schiff base ligand was characterized by using elemental analyses, FT-IR, 1H, 13C NMR and mass spectroscopic techniques. The metal (II) complexes [ML], were synthesized from the reaction of MCl2.nH2O (M: Co, Ni, Cu and Zn) with Schiff base ligand, L and characterized by elemental analyses and FT-IR. X-ray crystal structure of [CoLCl]+ distorted square pyramidal geometry with an N4Cl core, arising from coordination by the four donor nitrogen atoms from the macrocyclic framework and one Cl atom. It crystallizes triclinic space group, P-1 with a = 7.1777(1) Å, b = 11.0357 (2) Å, c = 15.1520(2) Å, V = 1183.14(3), Z = 2, Dc = 1.556 g cm-3, μ (MoKα) = 0.156 mm-1. Also, the bonding situation between the [MCl]+ and Ligand (L) fragments in [MLCl]ClO4 (M = Co(II), Ni(II), Cu(II), Zn(II)) complexes were carried out by energy-decomposition analysis (EDA). The results showed that there is an increasing trend in the case of ΔEelstat of the complexes by changing the M from Co(II) to Zn(II).

  17. Interaction of Copper in CuZn-Superoxide Dismutase With Histidine

    Institute of Scientific and Technical Information of China (English)

    胡皆汉; 舒占永

    1994-01-01

    The interaction of CuZn-superoxide dismutase ( CuZn-SOD ) with the external histidine in aqueous solution has been studied in this work by ESR and NMR. It is found that the Cu(Ⅱ) of CuZn-SOD makes an exchanging interaction with the external substance in aqueous solution. Unlike in solid state, the Cu(Ⅱ) forms complex with external histidine, and keeps a motional equilibrium between the active centers and the complexes. Enzyme activity is also affected by this interaction. Some other amino acids are also discussed in this paper.

  18. [Investigation of spectroscopy of ZnCuInS/ZnSe/ZnS quantum dots].

    Science.gov (United States)

    Lin, Yi-Jun; Liu, Wen-Yan; Zhang, Yu; Bi, Ke; Zhang, Tie-Qiang; Feng, Yi; Wang, Yi-Ding

    2014-01-01

    ZnCuInS/ZnSe/ZnS quantum dots were non-toxic and heavy-metal free semiconductor nanocrystals. In the present paper, ZnCuInS/ZnSe/ZnS core/shell/shell quantum dots were prepared with the particle size of 3.3, 2.7 and 2.3 nm. The photoluminescence of ZnCuInS/ZnSe/ZnS quantum dots with different size were measured, and the wavelength of peak was blue-shifted with decreasing the diameter. The wavelength of absorption peaks and photoluminescence peaks were 510 nm, 611 nm (3.3 nm), 483 nm, 583 nm (2.7 nm) and 447 nm and 545 nm(2.3 nm). The obvious size-dependence of ZnCuInS/ZnSe/ZnS quantum dots was shown. The Stokes shifts of ZnCuInS/ZnSe/ZnS quantum dots were 398 meV (3.3 nm), 436 meV (2.7 nm) and 498 meV (2.3 nm). Such large Stokes shifts indicate that the emission should be ascribed to the defect-related recombination. The temperature-dependent photoluminescence of ZnCuInS/ZnSe/ZnS quantum dots with the particle size of 3.3 nm were measured. The wavelength of peaks was red-shifted with increasing temperature and the intensity of photoluminescence spectra was decreased with increasing temperature. Therefore, the emission was concluded to be the transition from the conduction band to defect state.

  19. Synthesis, characterization and biological activity of Cu(II), Ni(II) and Zn(II) complexes of biopolymeric Schiff bases of salicylaldehydes and chitosan.

    Science.gov (United States)

    de Araújo, Eliene Leandro; Barbosa, Hellen Franciane Gonçalves; Dockal, Edward Ralph; Cavalheiro, Éder Tadeu Gomes

    2017-02-01

    Schiff bases have been prepared from biopolymer chitosan and salicylaldehyde, 5-methoxysalicylaldehyde, and 5-nitrosalicylaldehyde. Ligands were synthesized in a 1:1.5mol ratio, and their Cu(II), Ni(II) and Zn(II) complexes in a 1:1mol ratio (ligand:metal). Ligands were characterized by (1)H NMR and FTIR, resulting in degrees of substitution from 43.7 to 78.7%. Complexes were characterized using FTIR, electronic spectra, XPRD. The compounds were confirmed by the presence of an imine bond stretching in the 1630-1640cm(-1) and νMetal-N and νMetal-O at Schiff base complexes presented lower thermal stability and crystallinity than the starting chitosan. Residues were the metallic oxides as confirmed by XPRD, whose amounts were used in the calculation of the percentage of complexed metal ions. Surface morphologies were analyzed with SEM-EDAX. Preliminary cytotoxicity tests were performed using MTT assay with HeLa cells. Despite the differences in solubility, the free bases presented relatively low toxicity.

  20. Phosphine-free synthesis of high quality ZnSe, ZnSe/ZnS, and Cu-, Mn-doped ZnSe nanocrystals.

    Science.gov (United States)

    Shen, Huaibin; Wang, Hongzhe; Li, Xiaomin; Niu, Jin Zhong; Wang, Hua; Chen, Xia; Li, Lin Song

    2009-12-21

    High quality zinc blende ZnSe and ZnSe/ZnS core/shell nanocrystals have been synthesized by two converse injection methods (i.e. zinc precursor injection or selenium precursor injection) when Se-ODE complex was chosen as the phosphine-free selenium precursor. Absorption spectroscopy, fluorescence spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize the as-synthesized ZnSe and ZnSe/ZnS nanocrystals. The quality of the as-prepared ZnSe nanocrystals reached the same high level compared with the method using phosphine selenium precursors since the quantum yields were between 40 and 60% and photoluminescence (PL) full width at half-maximum (FWHM) was well controlled between 14 and 17 nm. The parameter window for the growth of high quality ZnSe nanocrystals was found to be much broader and monodisperse ZnSe nanocrystals were synthesized successfully even when the reaction temperature was set as low as 240 degrees C. As cores, such zinc blende ZnSe nanocrystals were also used to synthesize ZnSe/ZnS core/shell nanocrystals with high fluorescence quantum yields of 70%. Cu(2+) or Mn(2+) doped ZnSe nanocrystals were also synthesized by simply modifying this phosphine-free method. The emission range has been extended to 500 and 600 nm with the use of Cu(2+) and Mn(2+) dopants compared with the emission coverage of ZnSe at around 400 nm. This is the first totally "green approach" (i.e. phosphine-free synthesis) for the synthesis of high quality ZnSe, ZnSe/ZnS, and Cu(2+) or Mn(2+) doped ZnSe nanocrystals.

  1. Immunometabolic Status during the Peripartum Period Is Enhanced with Supplemental Zn, Mn, and Cu from Amino Acid Complexes and Co from Co Glucoheptonate.

    Directory of Open Access Journals (Sweden)

    Fernanda Batistel

    Full Text Available The peripartum (or transition period is the most-critical phase in the productive life of lactating dairy cows and optimal supply of trace minerals through more bioavailable forms could minimize the negative effects associated with this phase. Twenty Holstein cows received a common prepartal diet and postpartal diet. Both diets were partially supplemented with an inorganic (INO mix of Zn, Mn, and Cu to supply 35, 45, and 6 ppm, respectively, of the diet dry matter (DM. Cows were assigned to treatments in a randomized completed block design, receiving an daily oral bolus with INO or organic trace minerals (AAC Zn, Mn, Cu, and Co to achieve 75, 65, 11, and 1 ppm supplemental, respectively, in the diet DM. Liver tissue and blood samples were collected throughout the experiment. The lower glutamic-oxaloacetic transaminase concentration after 15 days in milk in AAC cows indicate lower hepatic cell damage. The concentration of cholesterol and albumin increased, while IL-6 decreased over time in AAC cows compared with INO indicating a lower degree of inflammation and better liver function. Although the acute-phase protein ceruloplasmin tended to be lower in AAC cows and corresponded with the reduction in the inflammatory status, the tendency for greater serum amyloid A concentration in AAC indicated an inconsistent response on acute-phase proteins. Oxygen radical absorbance capacity increased over time in AAC cows. Furthermore, the concentrations of nitric oxide, nitrite, nitrate, and the ferric reducing ability of plasma decreased with AAC indicating a lower oxidative stress status. The expression of IL10 and ALB in liver tissue was greater overall in AAC cows reinforcing the anti-inflammatory response detected in plasma. The greater overall expression of PCK1 in AAC cows indicated a greater gluconeogenic capacity, and partly explained the greater milk production response over time. Overall, feeding organic trace minerals as complexed with amino acids

  2. Immunometabolic Status during the Peripartum Period Is Enhanced with Supplemental Zn, Mn, and Cu from Amino Acid Complexes and Co from Co Glucoheptonate

    Science.gov (United States)

    Batistel, Fernanda; Osorio, Johan S.; Ferrari, Annarita; Trevisi, Erminio; Socha, Michael T.; Loor, Juan J.

    2016-01-01

    The peripartum (or transition) period is the most-critical phase in the productive life of lactating dairy cows and optimal supply of trace minerals through more bioavailable forms could minimize the negative effects associated with this phase. Twenty Holstein cows received a common prepartal diet and postpartal diet. Both diets were partially supplemented with an inorganic (INO) mix of Zn, Mn, and Cu to supply 35, 45, and 6 ppm, respectively, of the diet dry matter (DM). Cows were assigned to treatments in a randomized completed block design, receiving an daily oral bolus with INO or organic trace minerals (AAC) Zn, Mn, Cu, and Co to achieve 75, 65, 11, and 1 ppm supplemental, respectively, in the diet DM. Liver tissue and blood samples were collected throughout the experiment. The lower glutamic-oxaloacetic transaminase concentration after 15 days in milk in AAC cows indicate lower hepatic cell damage. The concentration of cholesterol and albumin increased, while IL-6 decreased over time in AAC cows compared with INO indicating a lower degree of inflammation and better liver function. Although the acute-phase protein ceruloplasmin tended to be lower in AAC cows and corresponded with the reduction in the inflammatory status, the tendency for greater serum amyloid A concentration in AAC indicated an inconsistent response on acute-phase proteins. Oxygen radical absorbance capacity increased over time in AAC cows. Furthermore, the concentrations of nitric oxide, nitrite, nitrate, and the ferric reducing ability of plasma decreased with AAC indicating a lower oxidative stress status. The expression of IL10 and ALB in liver tissue was greater overall in AAC cows reinforcing the anti-inflammatory response detected in plasma. The greater overall expression of PCK1 in AAC cows indicated a greater gluconeogenic capacity, and partly explained the greater milk production response over time. Overall, feeding organic trace minerals as complexed with amino acids during the

  3. Spectroscopic, DNA binding ability, biological activity, DFT calculations and non linear optical properties (NLO) of novel Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes with ONS Schiff base

    Science.gov (United States)

    Abdel Aziz, Ayman A.; Elantabli, Fatma M.; Moustafa, H.; El-Medani, Samir M.

    2017-08-01

    The reaction of Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) with the synthesized N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol Schiff base ligand (H2L) at room temperature resulted in the formation of the five complexes; [Co(HL)2]H2O, 1; [M(HL)2] (M = Cu, Zn and Cd), (2-4) and [Hg(HL)Cl], 5. The ligand and its complexes were characterized based on elemental analyses, IR, 1H NMR, magnetic measurement, molar conductance, and thermal analysis. Coats and Redfern method was used to compute the kinetic and thermodynamic parameters. Antimicrobial activities of H2L and its complexes have been studied. The binding of Co(II), Cu(II) and Zn(II) complexes to calf thymus DNA (CT-DNA) has been investigated using UV-Vis and fluorescence absorption spectra. The results indicated that the ligand and its complexes may bind to DNA by intercalation modes, with a much higher binding affinity of the complexes than that of the ligand. The equilibrium geometries of the studied complexes are investigated theoretically at the B3LYP/LANL2DZ level of theory, and it was found that these geometries are non-linear. The calculated EHOMO and ELUMO energies of the studied complexes can be used to calculate the global properties. The calculated nonlinear optical parameters (NLO); first order hyperpolarizibility (β) of the studied complexes show promising optical properties.

  4. Synthesis, characterization and DNA binding/cleavage, protein binding and cytotoxicity studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of aminonaphthoquinone.

    Science.gov (United States)

    Kosiha, A; Parthiban, C; Elango, Kuppanagounder P

    2017-03-01

    The Co(II), Ni(II), Cu(II) and Zn(II) complexes of an aminonaphthoquinone ligand (L) have been prepared and characterized using analytical and spectral techniques. The structures of L and its Zn(II) complex are confirmed by single crystal X-ray diffraction study. The results indicate that Co(II), Ni(II) and Zn(II) complexes possess tetrahedral geometry while Cu(II) complex exhibits square planar structure. The interaction of L and its complexes with CT-DNA reveal that they could interact with CT-DNA through intercalation. The DNA cleavage studies of the L and its complexes indicate that the Cu(II) and Ni(II) complexes cleave the circular form of the DNA relatively to a greater extent than the other complexes. The results of the interaction of these compounds with bovine serum albumin (BSA) indicate that the complexes exhibit a strong binding to BSA over the L. The in vitro anticancer activities indicate that these compounds exhibit substantial activity against human breast (MCF7) and lung cancer (A549) cell lines. The characteristics of apoptosis in cell morphology have been observed using AO/EB and DAPI staining and the results suggest that an apoptotic mode of cell death with these compounds. The overall results and discussion indicate that coordination of metal ions with the ligand enhances the biological activity.

  5. Synthesis and characterization of Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate Schiff base derived from vanillin and DL-α-aminobutyric acid

    Science.gov (United States)

    Nair, M. Sivasankaran; Joseyphus, R. Selwin

    2008-09-01

    Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base derived from vanillin and DL-α-aminobutyric acid were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements, powder XRD and biological activity. The analytical data show the composition of the metal complex to be [ML(H 2O)], where L is the Schiff base ligand. The conductance data indicate that all the complexes are non-electrolytes. IR results demonstrate the tridentate binding of the Schiff base ligand involving azomethine nitrogen, phenolic oxygen and carboxylato oxygen atoms. The IR data also indicate the coordination of a water molecule with the metal ion in the complex. The electronic spectral measurements show that Co(II) and Ni(II) complexes have tetrahedral geometry, while Cu(II) complex has square planar geometry. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, whereas Ni(II) and Zn(II) complexes are crystalline in nature. Magnetic measurements show that Co(II), Ni(II) and Cu(II) complexes have paramagnetic behaviour. Antibacterial results indicated that the metal complexes are more active than the ligand.

  6. Synthesis, Characterization and Antitumor Activities of Co, Ni, Cu, Zn Complexes with 1,4,7,10- tetrakis (4- nitrobenzyl )- 1,4,7,10- tetraazacyclododecane Macrocyclic Ligand

    Institute of Scientific and Technical Information of China (English)

    孔德源; 谢雨礼; 谢毓元; 黄小荧

    2000-01-01

    New tetraazamacrocyclic ligand with 1, 4, 7, 10-tetrakis (4-nitrobenzyl) pendent groups (C36H40N8O8, Mr= 712.76) crystallized in the monoclinic system, P21/n space group with unit cell parameters: a=7. 834(2), b=22. 902(6), c =10. 147(3)A, β=106.53(2)°, V=1745(1)A3, Z=2, Dc=1. 356 g/cm3, λ(MoKa)=0. 71069 A ; μ=0. 92cm-1, F(000)=752, T=296K. The final R and Rw values are 0.065 and 0.066, respectively. The Cu( Ⅱ ), Ni( Ⅱ ), Co( Ⅱ ), Zn( Ⅱ ) complexes with this new ligand have been synthesized and characterized by elemental analyses, IR, UV, ESI-MS and molar conductance. The macrocyclic ligand molecular structure is centrosymmetrical. All complexes are in accordance with the general forN8O8). The central metal ions coordinate to four nitrogen atoms of azamacrocycle and two oxygen atoms of one nitrate ion. Preliminary pharmacological tests against P-388and A-549 tumor cell lines showed that all these complexes had considerable activities in vitro.

  7. Synthesis and Characterization of a New Bidentate Ligand 5-Substituted-(2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione and its Metal Complexes of Ag(I, Cu(II and Zn(II

    Directory of Open Access Journals (Sweden)

    Shabbir A. A. Kazi

    2011-01-01

    Full Text Available A new ligand (2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione (L and its Ag(I,Cu(II and Zn(II complexes were synthesized. The authenticity of the ligand and its transition metal complexes were established by elemental analyses, conductance and magnetic susceptibility measurements, as well as spectroscopic (IR, 1H NMR, electronic, mass and ESR and thermal studies. The IR spectral studies revealed the existence thiol-thione tautamerism in the ligand molecule. The magnetic and electronic spectral studies suggest an octahedral geometry for Cu(II and Zn(II complexes. The ligand acts as a bidentate coordinating through the N-3 nitrogen and the exocyclic sulfur atoms of oxadiazole rings. Antimicrobial screening of the ligand and its metal complexes were determined against the bacteria Escherichia coli and Salmonella paratyphiA.

  8. Spectroscopic, magnetic and thermal studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of 3-acetylcoumarin-isonicotinoylhydrazone and their antimicrobial and anti-tubercular activity evaluation

    Science.gov (United States)

    Hunoor, Rekha S.; Patil, Basavaraj R.; Badiger, Dayananda S.; Vadavi, Ramesh S.; Gudasi, Kalagouda B.; Chandrashekhar, V. M.; Muchchandi, I. S.

    2010-11-01

    Co(II), Ni(II), Cu(II) and Zn(II) complexes with a new heterocyclic Schiff base derived by the condensation of isonicotinoylhydrazide and 3-acetylcoumarin have been synthesized. 1H, 13C and 2D HETCOR NMR analyses confirm the formation of title compound and existence of the same in two isomeric forms. The metal complexes were characterized on the basis of various spectroscopic techniques like electronic, EPR, IR, 1H and 13C NMR studies, elemental analysis, magnetic properties and thermogravimetric analysis, and also by the aid of molar conductivity measurements. It is found that the Schiff base behaves as a monobasic tridentate ligand coordinating in the imidol form with 1:1 metal to ligand stoichiometry. Trigonal bipyramidal geometry has been assigned for Ni(II) and Cu(II) complexes, while tetrahedral for Co(II) and Zn(II) complexes. The compounds were subjected to antimicrobial and anti-tubercular activity screening using serial broth dilution method and Minimum Inhibitory Concentration (MIC) is determined. Zn(II) complex has shown significant antifungal activity with an MIC of 6.25 μg/mL while Cu(II) complex is noticeable for antibacterial activity at the same concentration. Anti-TB activity of the ligand has enhanced on complexation with Co(II) and Ni(II) ions.

  9. Synthesis, structural visualization, spectroscopic, and thermal studies of charge transfer Cu(II, Ni(II and Zn(II bromides-carbamide complexes at elevated temperature

    Directory of Open Access Journals (Sweden)

    Khlood Abou-Melha

    2015-09-01

    Full Text Available In the present study, the composition and structure of Cu(II, Ni(II and Zn(II compounds resulted from the chemical reactions of copper(II, nickel(II and zinc(II bromide salts with carbamide in aqueous media at 95 oC have been investigated, using IR, electron spin resonance ESR and x-ray powder diffraction spectroscopy as well as thermal analysis TG/DTG/DSC. The Cu2(OH3Br, [Ni2(NCO2(H2O2(Br2], and ZnCO3.xH2O compounds were achieved by a novel synthetic route through with a low cost precursor like carbamide. The infrared spectra of the results indicate absence of the individual bands of carbamide, but exhibited of the distinguished bands of hydroxyl, isocyanate, NCO, and ionic carbonate, CO32– for Cu(II, Ni(II and Zn(II compounds, respectively. Visualized investigations were performed to confirm crystal structure, validity and stability of the product compounds. A general reaction mechanisms describing the preparation of Cu(II, Ni(II, and Zn(II compounds were discussed.

  10. Soft X-ray Spectroscopy of a Complex Heterojunction in High-Efficiency Thin-Film Photovoltaics: Intermixing and Zn Speciation at the Zn(O,S)/Cu(In,Ga)Se 2 Interface

    Energy Technology Data Exchange (ETDEWEB)

    Mezher, Michelle; Garris, Rebekah; Mansfield, Lorelle M.; Blum, Monika; Hauschild, Dirk; Horsley, Kimberly; Duncan, Douglas A.; Yang, Wanli; Bär, Marcus; Weinhardt, Lothar; Ramanathan, Kannan; Heske, Clemens

    2016-11-11

    The chemical structure of the Zn(O,S)/Cu(In,Ga)Se2 interface in high-efficiency photovoltaic devices is investigated using X-ray photoelectron and Auger electron spectroscopy, as well as soft X-ray emission spectroscopy. We find that the Ga/(Ga+In) ratio at the absorber surface does not change with the formation of the Zn(O,S)/Cu(In,Ga)Se2 interface. Furthermore, we find evidence for Zn in multiple bonding environments, including ZnS, ZnO, Zn(OH)2, and ZnSe. We also observe dehydrogenation of the Zn(O,S) buffer layer after Ar+ ion treatment. Similar to high-efficiency CdS/Cu(In,Ga)Se2 devices, intermixing occurs at the interface, with diffusion of Se into the buffer, and the formation of S-In and/or S-Ga bonds at or close to the interface.

  11. Synthesis, characterization and biological activity of some new VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based NNO Schiff base derived from 2-aminothiazole

    Science.gov (United States)

    Kalanithi, M.; Kodimunthiri, D.; Rajarajan, M.; Tharmaraj, P.

    2011-11-01

    Coordination compounds of VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) with the Schiff base obtained through the condensation of 2-aminothiazole with 3-formyl chromone were synthesized. The compounds were characterized by 1H, 13C NMR, UV-Vis, IR, Mass, EPR, molar conductance and magnetic susceptibility measurements. The Cu(II) complex possesses tetrahedrally distorted square planar geometry whereas Co(II), Ni(II), and Zn(II) show distorted tetrahedral geometry. The VO(IV) complex shows square pyramidal geometry. The cyclic voltammogram of Cu (II) complex showed a well defined redox couple Cu(II)/Cu(I) with quasireversible nature. The antimicrobial activity against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger was screened and compared to the activity of the ligand. Emission spectrum was recorded for the ligand and the metal(II) complexes. The second harmonic generation (SHG) efficiency was measured and found to have one fourth of the activity of urea. The SEM image of the copper(II) complex implies that the size of the particles is 2 μm.

  12. Electron spin relaxation in pseudo-Jahn-Teller low-symmetry Cu(II) complexes in diaqua(L-aspartate)Zn(II).H(2)O crystals.

    Science.gov (United States)

    Hoffmann, S K; Hilczer, W; Goslar, J; Massa, M M; Calvo, R

    2001-11-01

    Low-temperature (4-55 K) pulsed EPR measurements were performed with the magnetic field directed along the z-axis of the g-factor of the low-symmetry octahedral complex [(63)Cu(L-aspartate)(2)(H2O)2] undergoing dynamic Jahn-Teller effect in diaqua(L-aspartate)Zn(II) hydrate single crystals. Spin-lattice relaxation time T(1) and phase memory time T(M) were determined by the electron spin echo (ESE) method. The relaxation rate 1/T(1) increases strongly over 5 decades in the temperature range 4-55 K. Various processes and mechanisms of T(1)-relaxation are discussed, and it is shown that the relaxation is governed mainly by Raman relaxation processes with the Debye temperature Theta(D)=204 K, with a detectable contribution from disorder in the doped Cu(2+) ions system below 12 K. An analytical approximation of the transport integral I(8) is given in temperature range T=0.025-10Theta(D) and applied for computer fitting procedures. Since the Jahn-Teller distorted configurations differ strongly in energy (delta(12)=240 cm(-1)), there is no influence of the classical vibronic dynamics mechanism on T(1). Dephasing of the ESE (phase relaxation) is governed by instantaneous diffusion and spectral diffusion below 20 K with resulting rigid lattice value 1/T(0)(M)=1.88 MHz. Above this temperature the relaxation rate 1/T(M) increases upon heating due to two mechanisms. The first is the phonon-controlled excitation to the first excited vibronic level of energy Delta=243 cm(-1), with subsequent tunneling to the neighbor potential well. This vibronic-type dynamics also produces a temperature-dependent broadening of lines in the ESEEM spectra. The second mechanism is produced by the spin-lattice relaxation. The increase in T(M) is described in terms of the spin packets forming inhomogeneously broadened EPR lines.

  13. Ni(II, Cu(II, AND Zn(II COMPLEXES DERIVED FROM A NEW SCHIFF BASE 2-((Z-(3-METHYLPYRIDIN-2- YLEIMINOMETHYLPHENOL AND SYNTHESIS OF NANO SIZED METAL OXIDE PARTICLES FROM THESE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Masoumeh Orojloo

    2015-11-01

    Full Text Available Synthesis, spectral identification, and magnetic properties of three complexes of Ni(II, Cu(II, and Zn(II are described. All three compounds have the general formula [M(L2(H2O2], where L = deprotonated phenol in the Schiff base 2-((z-(3-methylpyridin-2-yleiminomethylphenol. The three complexes were synthesized in a one-step synthesis and characterized by elemental analysis, Fourier transform infrared spectroscopy, electronic spectra, X-ray diffraction (XRD, and room temperature magnetic moments. The Cu(II and Ni(II complexes exhibited room temperature magnetic moments of 1.85 B.M. per copper atom and 2.96 B.M. per nickel atom. The X-band electron spin resonance spectra of a Cu(II sample in dimethylformamide frozen at 77 K (liquid nitrogen temperature showed a typical ΔMS = ± 1 transition. The complexes ([M(L2(H2O2] were investigated by the cyclic voltammetry technique, which provided information regarding the electrochemical mechanism of redox behavior of the compounds. Thermal decomposition of the complexes at 750 ºC resulted in the formation of metal oxide nanoparticles. XRD analyses indicated that the nanoparticles had a high degree of crystallinity. The average sizes of the nanoparticles were found to be approximately 54.3, 30.1, and 44.4 nm for NiO, CuO, and ZnO, respectively.

  14. Micellar effect on metal-ligand complexes of Co(II, Ni(II, Cu(II and Zn(II with citric acid

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    Nageswara Rao Gollapalli

    2009-12-01

    Full Text Available Chemical speciation of citric acid complexes of Co(II, Ni(II, Cu(II and Zn(II was investigated pH-metrically in 0.0-2.5% anionic, cationic and neutral micellar media. The primary alkalimetric data were pruned with SCPHD program. The existence of different binary species was established from modeling studies using the computer program MINIQUAD75. Alkalimetric titrations were carried out in different relative concentrations (M:L:X = 1:2:5, 1:3:5, 1:5:3 of metal (M to citric acid. The selection of best chemical models was based on statistical parameters and residual analysis. The species detected were MLH, ML2, ML2H and ML2H2. The trend in variation of stability constants with change in mole fraction of the medium is explained on the basis of electrostatic and non-electrostatic forces. Distributions of the species with pH at different compositions of micellar media are also presented.

  15. Schiff base ligand derived from (±trans-1,2-cyclohexanediamine and its Cu(II, Co(II, Zn(II and Mn(II complexes: Synthesis, characterization, styrene oxidation and hydrolysis study of the imine bond in Cu(II Schiff base complex

    Directory of Open Access Journals (Sweden)

    Sarkheil Marzieh

    2016-01-01

    Full Text Available A Schiff base ligand (H2L derived from 2´-hydroxypropiophenone and (±trans-1,2-cyclohexanediamine was synthesized. The reactions of MCl2.xH2O (M =Cu(II, Co(II, Zn(II and Mn(IIwith the di-Schiff base ligand (H2L were studied. This ligand when stirred with 1 equivalent of CuCl2.2H2O in the solution of ethanol and chloroform undergoes partial hydrolysis of the imino bond and the resultant tridentate ligand (HL′immediately forms complex[CuL´Cl]∙3/2CHCl3(1with N2O coordination sphere. Under the same condition, the reaction of H2L with MCl2.xH2O (M = Co(II (3, Zn(II (4 and Mn(II (5 gave complexes[ML]•1/2CHCl3∙3/2H2O (3-5with N2O2 coordination sphere and no hydrolytic cleavage was occurred. Also, the reaction of H2L with CuCl2.2H2O in THF gave the complex CuL (2with N2O2 coordination sphere. The ligand and complexes were characterized by FTIR, UV-Vis, 1H NMRand elemental analysis. The homogeneous catalytic activity of the complexes1, 3 and 5wasevaluated for the oxidation of styrene using tert-butyl hydroperoxide (TBHP as oxidant. Finally, the copper(II complex(1encapsulated in the nanopores of zeolite-Y by flexible ligand method (CuL´-Yand its encapsulation was ensured by different studies. The catalytic performance of heterogeneous catalyst in the styrene oxidation with TBHP was investigated. The catalytic tests showed that the homogenous and heterogeneous catalysts were active in the oxidation of styrene.

  16. Determination of Formation Constants of Co2+,Ni2+,Cu2+and Zn2+ Complexes with Humic and Fulvic Acids by Potentionmetric Titration Method

    Institute of Scientific and Technical Information of China (English)

    DUJIN-ZHOU; LUCHANG-QING; 等

    1994-01-01

    The formation constants of Co2+,Ni2+,Cu2+ and Zn2+ complexes with humic acid(HA) and fulvic acid(FA) in red soil wrer determined by the potentiometric titration method.The constants as a function of composition of the complexation solutions were obtained by two graphical approaches respetively,The formation constants decreased with increasing concentration of metal in the solution,The results provide unambiguous evidence for the heterogeneity of the function groups of humic substances,the formation constants of FA were much smaller than those of HA,and the formation constants of Cu2+ were much greater than those of Co2+ ,Ni2+ and Zn2+,The potentiometric titration methon for determining formation constants are also discussed in the article.

  17. Synthesis, characterization and thermogravimetric analysis of Co(II, Ni(II, Cu(II and Zn(II complexes supported by ONNO tetradentate Schiff base ligand derived from hydrazino benzoxazine

    Directory of Open Access Journals (Sweden)

    N. Kavitha

    2017-01-01

    Full Text Available A new series of Co(II, Ni(II, Cu(II and Zn(II metal complexes of a novel ligand 3-(2-(1-(2,4-DihydroxyPhenylethylidenehydrazinyl-2H-benzo[b][1,4]oxazin-2-one, (DPE-HBO were prepared and characterized. Microwave synthesis of the ligand was also carried out which gave a high increase in its yield within very short time. 3D molecular modeling structure of the ligand is obtained by using ArgusLab software. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analysis, thermal, infrared, electronic spectra, magnetic moments and conductivity measurements. ESR spectrum of Cu(II complex is studied. All the complexes show subnormal magnetic moments. ONNO donor atoms participate in coordination with Cu(II and Zn(II complexes exhibiting octahedral geometry. Co(II and Ni(II complexes behave differently with ONNO donor atoms showing two types of geometries i.e., octahedral and square planar within the same complex.

  18. Electrodeposition and properties of Zn, Cu, and Cu{sub 1−x} Zn{sub x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Özdemir, Rasim [Kilis Vocational High School, Kilis 7 Aralık University, 79000 Kilis (Turkey); Karahan, İsmail Hakkı, E-mail: ihkarahan@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Technology, Mustafa Kemal University, 31040 Hatay (Turkey)

    2014-11-01

    Highlights: • Cu, Zn and Cu–Zn deposits successfully deposited from the non-cyanide sulphate electrolyte. • The effect of alloying element was investigated on the electrical resistivity and the structure of Cu–Zn alloy. • The average crystallite size of the samples varied from 66 to 161 nm and decreased when the Zn and Cu combined in Cu–Zn. • Microstrain has been decreased with increasing crystallite size. • Electrical resistivity of alloy was obtained between the Zn and Cu films. - Abstract: The electrodeposition of Cu, Zn and Cu–Zn deposits from the non-cyanide Zn sulphate and Cu sulphate reduced by citrate at constant stirring speed has been investigated. The composition of the Cu–Zn bath was shown to influence the morphology, electrical resistivity, phase composition, and Cu and Zn content of the Cu–Zn deposits. Their structural and electrical properties have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDAX), cyclic voltammeter (CV) and current–voltage measurements against the temperature for electrical resistivity, respectively. XRD shows that Cu–Zn samples are polycrystalline phase. Resistivity results show that the copper film exhibits bigger residual resistivity than both the zinc and the Cu–Zn alloy. Theoretical calculations of the XRD peaks demonstrate that the average crystallite size of the Cu–Zn alloy decreased and microstrain increased when the Cu alloyed with zinc.

  19. Interfacial Reactions in the Ni/Sn- xZn/Cu Sandwich Couples

    Science.gov (United States)

    Yen, Yee-Wen; Lin, Chung-Yung; Lai, Mei-Ting; Chen, Wan-Ching

    2016-01-01

    The interfacial reactions in Ni/Sn- xZn/Cu sandwich couples which were reflowed at 270°C for 1 h and then aged at 160°C for 1-1000 h were investigated. When the 1000- μm-thick Sn-Zn alloy reacted with Ni and Cu in this couple, the results indicated that the (Ni, Cu)3Sn4, (Ni, Cu)5Zn21, and Ni5Zn21 phases were formed at Sn-1Zn/Ni, Sn-5Zn/Ni, and Sn-9Zn/Ni interfaces for 1 h reflowing, respectively. After 1000 h aging, each intermetallic compound (IMC) was converted to (Cu, Ni, Zn)6Sn5, (Ni, Cu, Sn)5Zn21/Ni5Zn21, and Ni5Zn21 (two layers) phases in the related couples. On the Cu side, the Cu6Sn5 phase in the Sn-1Zn/Cu interface and the Cu5Zn8 phase in the Sn-5Zn/Cu and Sn-9Zn/Cu interfaces were observed when the couple was reflowed at 270°C for 1 h. After 100 h aging, the (Cu, Ni, Zn)6Sn5, Cu5Zn8/(Cu, Zn)6Sn5, and Cu5Zn8 phases were formed at the Sn-1Zn/Cu, Sn-5Zn/Cu and Sn-9Zn/Cu interfaces. When the Sn-Zn alloy thickness was decreased to 500 μm, the (Cu, Ni, Zn)6Sn5 phase at the Sn-1Zn/Ni interface and the (Ni, Cu, Sn)5Zn21 phase at the Sn-5Zn/Ni and Sn-9Zn/Ni interfaces were observed after 1 h reflowing. When the couple was aged at 160°C for 1000 h, each IMC was converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Ni, Sn)Zn/Ni5Zn21 phases at the Sn-1Zn/Ni and Sn-(5, 9)Zn/Ni interfaces. (Cu, Ni, Zn)6Sn5 and Cu5Zn8 were, respectively, formed at the Sn-1Zn/Cu and Sn-(5, 9)Zn/Cu interfaces for 1 h reflowing. After 100 h aging, the IMCs were converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Zn)6Sn5 phases. This current study reveals that the IMC formation in Ni/(Sn- xZn)/Cu sandwich couples are very sensitive to the Zn concentration and thickness in Sn- xZn alloys.

  20. Periodic trends within a series of five-coordinate thiolate-ligated [MII(SMe2N4(tren))]+ (M = Mn, Fe, Co, Ni, Cu, Zn) complexes, including a rare example of a stable CuII-thiolate.

    Science.gov (United States)

    Brines, Lisa M; Shearer, Jason; Fender, Jessica K; Schweitzer, Dirk; Shoner, Steven C; Barnhart, David; Kaminsky, Werner; Lovell, Scott; Kovacs, Julie A

    2007-10-29

    A series of five-coordinate thiolate-ligated complexes [M(II)(tren)N4S(Me2)]+ (M = Mn, Fe, Co, Ni, Cu, Zn; tren = tris(2-aminoethyl)amine) are reported, and their structural, electronic, and magnetic properties are compared. Isolation of dimeric [Ni(II)(SN4(tren)-RS(dang))]2 ("dang"= dangling, uncoordinated thiolate supported by H bonds), using the less bulky [(tren)N4S](1-) ligand, pointed to the need for gem-dimethyls adjacent to the sulfur to sterically prevent dimerization. All of the gem-dimethyl derivatized complexes are monomeric and, with the exception of [Ni(II)(S(Me2)N4(tren)]+, are isostructural and adopt a tetragonally distorted trigonal bipyramidal geometry favored by ligand constraints. The nickel complex uniquely adopts an approximately ideal square pyramidal geometry and resembles the active site of Ni-superoxide dismutase (Ni-SOD). Even in coordinating solvents such as MeCN, only five-coordinate structures are observed. The MII-S thiolate bonds systematically decrease in length across the series (Mn-S > Fe-S > Co-S > Ni-S approximately Cu-S tren)]+, represents a rare example of a stable CuII-thiolate, and models the perturbed "green" copper site of nitrite reductase. In contrast to the intensely colored, low-spin Fe(III)-thiolates, the M(II)-thiolates described herein are colorless to moderately colored and high-spin (in cases where more than one spin-state is possible), reflecting the poorer energy match between the metal d- and sulfur orbitals upon reduction of the metal ion. As the d-orbitals drop in energy proceeding across the across the series M(2+) (M= Mn, Fe, Co, Ni, Cu), the sulfur-to-metal charge-transfer transition moves into the visible region, and the redox potentials cathodically shift. The reduced M(+1) oxidation state is only accessible with copper, and the more oxidized M(+4) oxidation state is only accessible for manganese.

  1. Metal-ion directed synthesis of N2O2 type chelate complexes of Ni(II), Cu(II) and Zn(II): spectral, thermal and single crystal studies.

    Science.gov (United States)

    Yadav, Seema; Ahmad, Musheer; Siddiqi, K S

    2012-12-01

    A set of Ni(II), Cu(II) and Zn(II) complexes of Schiff base have been synthesized by one pot condensation reaction of 2-hydroxy-4-methoxybenzophenone with 1,3-diaminopropane in 1:2:1 molar ratio. They have been characterized by elemental analysis, conductance measurement, thermal analysis (TGA/DTA), FT-IR, (1)H-NMR, EPR spectra, ESI-MS and electronic spectral studies. In order to establish the geometry, a single crystal X-ray structure for [Ni(L)] complex was determined. It crystallizes in monoclinic system having unit cell parameters a=14.015(5)Å, b=13.391(5)Å, c=14.931(5)Å and α=90.000(5)(o), β=112.237(5)(o), γ=90.000(5)(o) with P 2(1)/c space group. No π-π stacking interaction was obtained in molecular packing diagram. A square-planar geometry has been confirmed for Ni(II) complex. Furthermore, on the basis of elemental analysis, IR, UV-visible and EPR data a square-planar geometry for Cu(II) and a distorted octahedral geometry for the Zn(II) complex has been established. In case of Zn(II) complex NO(3)(-) group was found to be coordinated in monodentate fashion. The low molar conductivity values of the complexes measured in chloroform and DMSO suggest their non-ionic nature.

  2. Ferromagnetism in CuO-ZnO multilayers

    Science.gov (United States)

    Chandran, Sudakar; Kirby, B. J.; Padmanabhan, K.; Lawes, G.; Naik, R.; Kumar, Sanjiv; Naik, V. M.

    2008-03-01

    The magnetic properties of CuO-ZnO heterostructures are examined to elucidate the origin of the ferromagnetic signature in Cu doped ZnO. The CuO and ZnO layer thickness varied from 15 nm to 350 nm, and we observed no significant diffusion of either Cu^2+ in the ZnO layers or of Zn^2+ in the CuO layers using Rutherford backscattering spectrometry. Bulk magnetization measurements established that the multilayers exhibit a ferromagnetic moment at room temperature, with a saturation magnetization (˜2-5 emu/cc of CuO) that depends on the CuO size, but not the CuO-ZnO interfacial area. Polarized neutron reflection studies suggest that the ferromagnetism arises from the CuO layers, and not from the interdiffusion of CuO and ZnO. These results indicate that the ferromagnetism in these multicomponent structures arises from the uncompensated surface spins of CuO nanoparticles in the layer rather than from regions of interdiffusing ZnO and CuO.

  3. Synthesis, Spectral Characterization, Molecular Modeling, and Antimicrobial Studies of Cu(II, Ni(II, Co(II, Mn(II, and Zn(II Complexes of ONO Schiff Base

    Directory of Open Access Journals (Sweden)

    Padmaja Mendu

    2012-01-01

    Full Text Available A series of Cu(II, Ni(II, Co(II, Mn(II, and Zn(II complexes have been synthesized from the schiff base ligand L. The schiff base ligand [(4-oxo-4H-chromen-3-yl methylene] benzohydrazide (L has been synthesized by the reaction between chromone-3-carbaldehyde and benzoyl hydrazine. The nature of bonding and geometry of the transition metal complexes as well as schiff base ligand L have been deduced from elemental analysis, FT-IR, UV-Vis, 1HNMR, ESR spectral studies, mass, thermal (TGA and DTA analysis, magnetic susceptibility, and molar conductance measurements. Cu(II, Ni(II, Co(II, and Mn(II metal ions are forming 1:2 (M:L complexes, Zn(II is forming 1:1 (M:L complex. Based on elemental, conductance and spectral studies, six-coordinated geometry was assigned for Cu(II, Ni(II, Co(II, Mn(II, and Zn(II complexes. The complexes are 1:2 electrolytes in DMSO except zinc complex, which is neutral in DMSO. The ligand L acts as tridentate and coordinates through nitrogen atom of azomethine group, oxygen atom of keto group of γ-pyrone ring and oxygen atom of hydrazoic group of benzoyl hydrazine. The 3D molecular modeling and energies of all the compounds are furnished. The biological activity of the ligand and its complexes have been studied on the four bacteria E. coli, Edwardella, Pseudomonas, and B. subtilis and two fungi pencillium and tricoderma by well disc and fusion method and found that the metal chelates are more active than the free schiff base ligand.

  4. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

    Directory of Open Access Journals (Sweden)

    Nahid Nishat

    2016-09-01

    Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

  5. Synthesis and spectral studies of Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes of a new macroacyclic ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide

    Directory of Open Access Journals (Sweden)

    KALAGOUDA B. GUDASI

    2006-05-01

    Full Text Available A new macroacyclic amide ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide (BPD, formed by the condensation of 2,6-pyridinedicarbonyldichloride with 2-aminobenzothiazole, and its Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes were synthesized. Their structures were elucidated on the basis of elemental analyses, conductance measurements, magnetic moments, spectral (IR, NMR, UV-Visible, EPR and FAB and thermal studies. The complexes exhibit an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be 1:1 electrolytes. The pentadentate behavior of the ligand was proposed on the basis of spectral studies. The X-band EPR spectra of the Cu(II and Mn(II complexes in the polycrystalline state at room (300 K and liquid nitrogen temperature (77 K were recorded and their salient features are reported.

  6. ZnO/Cu2S/ZnO Multilayer Films: Structure Optimization and Its Detail Data for Applications on Photoelectric and Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Zhenxing Wang

    2017-01-01

    Full Text Available Monolayer Cu2S and ZnO, and three kinds of complex films, Cu2S/ZnO, ZnO/Cu2S, and ZnO/Cu2S/ZnO, were deposited on glass substrates by means of radio frequency (RF magnetron sputtering device. The impact of the thickness of ZnO and Cu2S on the whole transmittance, conductivity, and photocatalysis was investigated. The optical and electrical properties of the multilayer were studied by optical spectrometry and four point probes. Numerical simulation of the optical transmittance of the multilayer films has been carried out in order to guide the experimental work. The comprehensive performances of the multilayers as transparent conductive coatings were compared using the figure of merit. Compared with monolithic Cu2S and ZnO films, both the optical transmission property and photocatalytic performance of complex films such as Cu2S/ZnO and ZnO/Cu2S/ZnO change significantly.

  7. Synthesis, spectral characterization and biological evaluation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with thiosemicarbazone ending by pyrazole and pyridyl rings

    Science.gov (United States)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2014-08-01

    Here we present the synthesis of the new Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with chelating ligand (Z)-(2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene) hydrazinyl)(pyridin-2-ylamino)methanethiol. All the complexes were characterized by elemental analysis, IR, 1H NMR, UV-vis, magnetic susceptibility measurements and EPR spectral studies. IR spectra of complexes showed that the ligand behaves as NN neutral bidentate, NSN mononegative tridentate and NSNN mononegative tetradentate. The electronic spectra and the magnetic measurements suggested the octahedral geometry for all complexes as well as the EPR confirmed the tetragonal distorted octahedral for Cu(II) complex. Cd(II) complex showed the highest inhibitory antioxidant activity either using ABTS method. The SOD-like activity exhibited those Cd(II) and Zn(II) complexes have strong antioxidative properties. We tested the synthesized compounds for antitumor activity and showed that the ability to kill liver (HePG2) and breast (MCF-7) cancer cells definitely.

  8. Effect of Cu content and temperature on the properties of Cu2ZnSnSe4 solar cells

    Science.gov (United States)

    Sahayaraj, Sylvester; Brammertz, Guy; Buffière, Marie; Meuris, Marc; Vleugels, Jef; Poortmans, Jef

    2016-09-01

    The complexity involved in obtaining pure Kesterite Cu2ZnSnSe4 (CZTSe) thin film primarily arises due to its narrow region of stability, leading to the presence of unavoidable binary selenides of the constituent metals. This study offers an insight on the formation of Cu selenides when the amount of Cu is varied in the precursor from Cu poor to Cu rich. The amount of Cu selenides was found to decrease when the composition of CZTSe absorber approached Cu rich conditions but functional devices were not obtained. Detailed characterizations also showed that the Cu and Sn binary phases were present at the backside interface of CZTSe solar cells. However with an increase in the selenization temperature it was found that the amount of Cu selenides and other secondary phases could be drastically minimized or even eliminated leading to high efficiency devices.

  9. Effect of Cu content and temperature on the properties of Cu2ZnSnSe4 solar cells

    Directory of Open Access Journals (Sweden)

    Sahayaraj Sylvester

    2016-01-01

    Full Text Available The complexity involved in obtaining pure Kesterite Cu2ZnSnSe4 (CZTSe thin film primarily arises due to its narrow region of stability, leading to the presence of unavoidable binary selenides of the constituent metals. This study offers an insight on the formation of Cu selenides when the amount of Cu is varied in the precursor from Cu poor to Cu rich. The amount of Cu selenides was found to decrease when the composition of CZTSe absorber approached Cu rich conditions but functional devices were not obtained. Detailed characterizations also showed that the Cu and Sn binary phases were present at the backside interface of CZTSe solar cells. However with an increase in the selenization temperature it was found that the amount of Cu selenides and other secondary phases could be drastically minimized or even eliminated leading to high efficiency devices.

  10. Synthesis, characterisation and electrochemical behaviour of Cu(II), Co(II), Ni(II) and Zn(II) complexes derived from acetylacetone and p-anisidine and their antimicrobial activity

    Indian Academy of Sciences (India)

    N Raman; V Muthuraj; S Ravichandran; A Kulandaisamy

    2003-06-01

    Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesised using the Schiff base formed by the condensation of acetylacetone and p-anisidine. Microanalysis, molar conductance, magnetic susceptibility, IR, UV-Vis, 1H NMR, CV and EPR studies have been carried out to determine the structure of the complexes. From the data, it is found that all the complexes possess square-planar geometry. The EPR spectrum of the copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. All the title complexes were screened for antimicrobial activity by the well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values were calculated at 37°C for a period of 24 h. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand.

  11. Synthesis, spectroscopic, antimicrobial and DNA cleavage studies of new Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes with naphthofuran-2-carbohydrazide Schiff base

    Science.gov (United States)

    Halli, Madappa B.; Sumathi, R. B.

    2012-08-01

    A series of Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes have been synthesized with newly synthesized Schiff base derived from naphthofuran-2-carbohydrazide and cinnamaldehyde. The elemental analyses of the complexes are confined to the stoichiometry of the type MLCl2 [M = Co(II) and Cu(II)], ML2Cl2 [M = Ni(II), Cd(II), Zn(II) and Hg(II)] respectively, where L is Schiff base ligand. Structures have been proposed from elemental analyses, IR, electronic, mass, 1H NMR, ESR spectral data, magnetic, and thermal studies. The measured low molar conductance values in DMF indicate that the complexes are non-electrolytes. Spectroscopic studies suggest coordination occurs through azomethine nitrogen and carbonyl oxygen of the ligand with the metal ions. The Schiff base and its complexes have been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Salmonella typhi) and antifungal (Aspergillus niger, Aspergillus flavus, Cladosporium and Candida albicans) activities by minimum inhibitory concentration (MIC) method. The DNA cleavage studies by agarose gel electrophoresis method was studied for all the complexes.

  12. Cu-ZnO-C nanoreactors studied by in situ synchrotron SAXS spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Ching-I; Kang, Hsu-Ya [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wang, H. Paul, E-mail: wanghp@mail.ncku.edu.tw [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Lin, Wei-Keng [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Jeng, U-Ser; Su, Chiu-Hun [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

    2011-04-15

    Research highlights: {yields} Cu-ZnO-C nanoreactors formed by carbonization of Cu{sup 2+}- and Zn{sup 2+}-starch complexes. {yields} A threshold temperature for growth of coreshell nanoparticles at 433 K observed by in situ SAXS. {yields} Cu-ZnO-C nanoreactors are very effective in catalytic partial oxidation of methanol. - Abstract: By small angle X-ray scattering (SAXS) spectroscopy, changes of electronic density of selected element can be determined. A size growth of Cu-ZnO nanoparticles encapsulated in the carbon shell during temperature-programmed carbonization of Cu{sup 2+}- and Zn{sup 2+}-starch (Cu-to-Zn ratio = 1) at 343-523 K was observed by in situ SAXS. The Cu-ZnO-C behaves like a nanoreactor for catalytic partial oxidation of methanol (POM) to yield H{sub 2}-rich product gas. It seems that the enhanced POM may be associated with the high collision frequency of methanol, oxygen (as O atoms) and copper catalytic species in the confined nanoreactor.

  13. Effect of temperature on mechanical alloying of Cu-Zn and Cu-Cr system

    Institute of Scientific and Technical Information of China (English)

    ZUO Ke-sheng; XI Sheng-qi; ZHOU Jin-gen

    2009-01-01

    Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature, -10, -20 and -30 ℃, respectively. Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry(XRD), X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM). The results show that lowering temperature can delay mechanical alloying(MA) process of Cu-Zn system with negative mixing enthalpy, and promote MA process of Cu-Cr system with positive mixing enthalpy. As for Cu-Cr and Cu-Zn powders milled at -10 ℃, lamellar structures are firstly formed, while fewer lamellar particles can be found when the powder is milled at -20 ℃. When the alloyed powder is annealed at 1 000 ℃, Cu(Cr) solid solution is decomposed and Cr precipitates from Cu matrix, whereas Cu(Zn) solid solution keeps stable.

  14. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) Schiff base complexes derived from o-phenylenediamine and acetoacetanilide

    Indian Academy of Sciences (India)

    N Raman; Y Pitchaikani Raja; A Kulandaisamy

    2001-06-01

    Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) have been synthesised using a Schiff base formed by the condensation of -phenylenediamine with acetoacetanilide in alcohol medium. All the complexes were characterised on the basis of their microanalytical data, molar conductance, magnetic susceptibility, IR, UV-Vis 1H NMR and ESR spectra. IR and UV-Vis spectral data suggest that all the complexes are square-planar except the Mn(II) and VO(II) chelates, which are of octahedral and square pyramidal geometry respectively. The monomeric and neutral nature of the complexes was confirmed by their magnetic susceptibility data and low conductance values. The ESR spectra of copper and vanadyl complexes in DMSO solution at 300 K and 77 K were recorded and their salient features are reported.

  15. Tuning of properties of sprayed CuZnS films

    Science.gov (United States)

    Sreejith, M. S.; Deepu, D. R.; Kartha, C. Sudha; Vijayakumar, K. P.

    2014-04-01

    CuZnS is an alloy having mixed structure of CuxS and ZnS. Here we studied the structural, optical, compositional and electrical properties of CuZnS films prepared using chemical spray pyrolysis (CSP). Just by varying ratio of Cu to Zn was observed that material can be changed from P type to N type and electrical conductivity can be increased by 4 orders. Increase in concentration of Cu leads to decrease bandgap to 1.8 eV from 3.4 eV. CuZnS films having high concentration of copper can be used as good absorber and weakly doped films as buffer / window layers in solar cells.

  16. Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

    Science.gov (United States)

    Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

    2013-02-01

    New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

  17. Synthesis and properties of ZnO-HMD@ZnO-Fe/Cu core-shell as advanced material for hydrogen storage.

    Science.gov (United States)

    Bouazizi, N; Boudharaa, T; Bargougui, R; Vieillard, J; Ammar, S; Le Derf, F; Azzouz, A

    2017-04-01

    In this paper, a new synthetic strategy towards functionalized ZnO-HMD@ZnO-Fe/Cu core-shell using sol-gel process modified by chemical grafting of hexamethylenediamine (HMD) on the core and in-situ dispersion of Cu(0)/Fe(0) as metallic nanoparticles (M-NPs) on the shell. The as-prepared core-shell materials were fully characterized by transmission electron microscopy, X-ray powder diffractometry, diffuse reflectance and FT-IR spectrophotometery, photoluminescence, and complexes impedance spectroscopy measurements. The XRD patterns agreed with that of the ZnO typical wurtzite structure, indicating good crystallinity of ZnO-HMD@ZnO-Fe/Cu, with the presence of Fe(0) and Cu(0) phases. Hexamethylenediamine grafting and M-NPs insertion were highly activated and enhanced the core and shell interface by the physiochemical interaction. After functionalization, luminescence intensities and electrical properties of both core and core-shell nanoparticles are improved, indicating the effects of the surface groups on the charge transfer of ZnO-HMD@ZnO-Fe/Cu. The hydrogen capacity retention was depended strongly on the composition and structure of the obtained core-shell. Iron/Copper-loaded ZnO-HMD@ZnO materials exhibited the highest capacity for hydrogen storage. The excellent stability and performance of the ZnO-HMD@ZnO-Fe/Cu core-shell make it an efficient candidate for hydrogen storage.

  18. Cr(III,Mn(II,Fe(III,Co(II,Ni(II,Cu(II and Zn(II Complexes with Diisobutyldithiocarbamato Ligand

    Directory of Open Access Journals (Sweden)

    Mohammad Tarique

    2011-01-01

    Full Text Available The synthesis of sulphur and nitrogen containing dithiocarbamato ligand derived from diisobutylamine as well as its coordination compounds with 3d series transition metals is presented. These synthesized compounds were characterized on the basis of elemental analysis, conductometric measurements and IR spectral studies. The analytical data showed the stoichiometry 1:2 and 1:3 for the compounds of the types ML2 {M=Mn(II, Co(II, Ni(II, Cu(II and Zn(II} and M'L3{M'=Cr(III and Fe(III} respectively. The conductometric measurements proved the non-electrolytic behaviour of all the compounds. The bidentate nature of dithiocarbamato moiety was confirmed on the basis of IR spectral data.

  19. SERS and DFT investigation of 1-(2-pyridylazo)-2-naphthol and its metal complexes with Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II)

    Science.gov (United States)

    Szabó, László; Herman, Krisztian; Mircescu, Nicoleta E.; Fălămaş, Alexandra; Leopold, Loredana F.; Leopold, Nicolae; Buzumurgă, Claudia; Chiş, Vasile

    The development of surface-enhanced Raman scattering (SERS) as a prospective analytical methodology for detection of metal ions was shown in recent years by several studies on metal complexes. In this work, 1-(2-pyridylazo)-2-naphthol (PAN) and its Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II) complexes were studied by FTIR, FT-Raman and surface enhanced Raman spectroscopies. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculations were performed using the hybrid B3LYP exchange-correlation functional for the PAN molecule and its bidentate complexes. The calculated MEP distributions indicated the atoms with highest electronegativity, the adsorption to the silver surface occurring through these atoms. Based on experimental and theoretical data we were able to identify unique and representative features, useful for the identification of each PAN-metal complex.

  20. Room temperature ferromagnetism in Cu-doped ZnO synthesized from CuO and ZnO nanoparticles

    Science.gov (United States)

    Owens, Frank J.

    2009-11-01

    AC susceptibility and ferromagnetic resonance (FMR) measurements indicate that ZnO doped with Cu by a simple sintering process starting from nanoparticles of ZnO and CuO is ferromagnetic above room temperature. FMR measurements above room temperature indicate the ordering temperature to be above 520 K. The observation supports the recent theoretical calculations of Huang et al. which predict ferromagnetism in copper-doped ZnO.

  1. Effect of dietary Zn on high Cu intake in sheep

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P.J.

    1976-01-01

    The objective was to determine whether high dietary levels of Zn will ameliorate or prevent chronic Cu toxicity in lambs fed a high Cu containing finishing diet. Four-month-old crossbred lambs were individually fed a pelleted diet of 35% cottonseed hulls, 5% alfalfa, 1.6% urea, 57.4% corn meal, vitamins A and D and minerals. The ration supplements and number of head per treatment were: group 1, none (4); group 2, 45 ppm Cu (5);group 3, 45 ppm Cu plus 250 ppm Zn (5), group 4, 45 ppm Cu plus 500 ppm Zn. The Cu and Zn supplements were CuSO/sub 4/ and ZnO. Plasma aspartate transaminase (AspT) activity, measured biweekly, was first elevated after 41 days feeding. Thereafter, in group 2, one lamb died and the AspT levels of the others gradually increased to a point where death from chronic Cu toxicity seemed imminent; the lambs in all groups were then slaughtered after 91 days feeding. Mean plasma AspT (SF units/ml) and liver Cu and Zn (..mu..g/g DM) at slaughter were, respectively: group 1, 65, 232 and 118; group 2, 308, 1074 and 135; group 3, 130, 705 and 139; group 4, 194, 1145 and 179. Neither Zn level reduced (P > .05) liver Cu; both reduced (P < .05) AspT activity late in the study, but not to control levels (P < .05). Thus, chronic Cu toxicity may be delayed, but not prevented, by high Zn levels.

  2. SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON Co (II, Ni (II, Cu (II AND Zn (II COMPLEXES OF N, O, DONAR HETEROCYCLIC SCHIFF BASES Synthese, Charakterisierung und antimikrobiellen STUDIES ON Co (II, Ni (II, Cu (II und Zn (II-Komplexe von N, O, DONAR HETEROCYCLISCHE SCHIFF BASES

    Directory of Open Access Journals (Sweden)

    R.Shakru, N.J.P.Subhashini, Acharyanagarjuna,Shivaraj

    2011-08-01

    Full Text Available The Schiff base ligands L1 4-allyl-2-{[(5'-methyl-3'-isoxazolylimino]methyl}phenol [AMIIMP] and L2 N-[5'-methyl-3'-isoxazolyl]-[(EPyridine]methylidine]amine[MIPMA] have been synthesized by the condensation of 4-allyl 2- hydroxyl 1-benzaldehyde and Pyridine 3- carboxaldehyde with 3- amino 5-methy isoxazole. The metal chelates of L1 and L2 with Cobalt (II, Nickel (II, Copper (II and Zn (II metal ions have been synthesised and characterized on the basis of elemental analysis, IR, 1H- NMR, Mass, Electronic spectra and magnetic moment studies. From these studies it is found that ligands act as bivalent chelating agents coordinating through oxygen and nitrogen donor atoms in the case of AMIIMP, and pyridine nitrogen and imino nitrogen donar atoms of in the case of MIPMA. The chelates of Co (II, Ni (II and Zn (II appear to be octahedral geometry and Cu (II appears to be tetragonal geometry. Antimicrobial activity of the ligands and their metal complexes against bacteria (Bacillus, Pseudomonas and fungus (R. Solani, A. Niger has been carried out. It is found that the metal complexes have higher activities than those of free ligands.

  3. Spectroscopic and thermal degradation behavior of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes with thiopental sodium anesthesia drug

    Science.gov (United States)

    Refat, Moamen S.

    2013-04-01

    A new series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized with thiopental sodium anesthesia drug. The elemental analyses of the complexes are confined to stoichiometry of the formulas [M(TPL)3]ṡnH2O (M = Cr(III) or Fe(III); n = 6 or 5), [M(TPL)2(H2O)2]ṡnH2O (M = Mn(II), Co(II) or Ni(II); n = 0 or 4), and [M(TPL)2] (M = Cu(II) or Zn(II); n = 2 or 0) respectively, where TPL is thiopental chelating agent. Structures have been discussed and suggested upon elemental analyses, infrared, Raman, electronic, electron spin resonance, 1H NMR spectral data and magnetic studies. The X-ray powder diffraction (XRD) was performed of metal complexes. The XRD patterns indicate crystalline nature for the complexes. The measured low molar conductance values in dimethylsulfoxide indicate that the complexes are non-electrolyte nature. Spectroscopic discussion refer that coordination take place through three types: Cdbnd N (pyrimidine moiety) nitrogen and C2sbnd S (2-thiolate group) for Cr(III), Mn(II) and Fe(III), C6dbnd O (amido group) oxygen and C2sbnd S (2-thiolate group) for Co(II) and Ni(II), and Cu(II) and Zn(II) ions coordinated via Cdbnd N (pyrimidine moiety) nitrogen, C2dbnd S (2-thiolate group) and C6dbnd O (amido group) oxygen, respectively. The thermal behavior (TG/DTG/DTA) of the complexes was studied and kinetic parameters were determined by Horowitz-Metzger and Coats-Redfern methods. The thiopental and its complexes have been screened for their antimicrobial (G+ and G-) bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa) and fungi (Aspergillus flavus and Candida albicans) activities by minimum inhibitory concentration (MIC) method.

  4. Cu,Zn-superoxide dismutase without Zn is folded but catalytically inactive.

    Science.gov (United States)

    Nedd, Sean; Redler, Rachel L; Proctor, Elizabeth A; Dokholyan, Nikolay V; Alexandrova, Anastassia N

    2014-12-12

    Amyotrophic lateral sclerosis has been linked to the gain of aberrant function of superoxide dismutase, Cu,Zn-SOD1 upon protein misfolding. The mechanism of SOD1 misfolding is thought to involve mutations leading to the loss of Zn, followed by protein unfolding and aggregation. We show that the removal of Zn from SOD1 may not lead to an immediate unfolding but immediately deactivates the enzyme through a combination of subtle structural and electronic effects. Using quantum mechanics/discrete molecular dynamics, we showed that both Zn-less wild-type (WT)-SOD1 and its D124N mutant that does not bind Zn have at least metastable folded states. In those states, the reduction potential of Cu increases, leading to the presence of detectable amounts of Cu(I) instead of Cu(II) in the active site, as confirmed experimentally. The Cu(I) protein cannot participate in the catalytic Cu(I)-Cu(II) cycle. However, even without the full reduction to Cu(I), the Cu site in the Zn-less variants of SOD1 is shown to be catalytically incompetent: unable to bind superoxide in a way comparable to the WT-SOD1. The changes are more radical and different in the D124N Zn-less mutant than in the Zn-less WT-SOD1, suggesting D124N being perhaps not the most adequate model for Zn-less SOD1. Overall, Zn in SOD1 appears to be influencing the Cu site directly by adjusting its reduction potential and geometry. Thus, the role of Zn in SOD1 is not just structural, as was previously thought; it is a vital part of the catalytic machinery.

  5. Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine

    Science.gov (United States)

    Mohamed, Gehad G.; El-Gamel, Nadia E. A.

    2004-11-01

    The ternary piroxicam (Pir; 4-hydroxy-2-methyl- N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA cheletes were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

  6. Synthesis, characterization, thermal study and biological evaluation of Cu(II), Co(II), Ni(II) and Zn(II) complexes of Schiff base ligand containing thiazole moiety

    Science.gov (United States)

    Nagesh, G. Y.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

    2015-01-01

    The novel Schiff base ligand 2-(4-(dimethylamino)benzylidene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 4-dimethylaminobenzaldehyde and its newly synthesized Cu(II), Co(II), Ni(II) and Zn(II) complexes have been characterized by microanalysis, magnetic susceptibility, molar conductance, thermal analysis, FT-IR, 1H NMR, ESI mass, UV-Visible, ESR spectroscopy and powder X-ray diffraction data. The newly synthesized ligand behaves as a bidentate ON donor. The IR results confirmed the bidentate binding of the ligand involving oxygen atom of amide carbonyl and azomethine nitrogen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. In order to evaluate the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties of all the compounds against Artemia salina. Furthermore, the antioxidant activity of the ligand (L) and its metal complexes were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH), the ligand exhibited potent in vitro - antioxidant activity than its metal complexes.

  7. Characterization of ZnO/Cu/ZnO multilayers structure for solar cell devices

    Science.gov (United States)

    Rasheed, Hiba S.; Hassan, Z.; Ahmed, Naser M.; Sabah, Fayroz A.; Azzez, Shrook A.; Al-Hazim, Nabeel Z.

    2016-07-01

    A series of ZnO/Cu/ZnO multilayer films has been fabricated from zinc and copper metallic targets by simultaneous RF and DC magnetron sputtering. The influences of the ZnO and Cu layer thicknesses, and Ar flow rate on the optical, electrical and structural properties of the films were investigated. The optical and electrical properties of the multilayers were studied by optical spectrometry and four point probe measurements, respectively. The thickness of the ZnO layers were varied between 20 and 60 nm and the Cu layers were between 5 and 15 nm, the optimum thin film structures were deposited under 12 sccm Ar flow rate. Low sheet resistance and high transmittance were obtained when the film was prepared using thickness of ZnO (60 nm)/Cu (15 nm)/ZnO (60 nm).

  8. Novel copper(II)-dien-imidazole/imidazolate-bridged copper(II) complexes. Crystal structure of [Cu(dien)(Him)](ClO4)2 and of [(dien)Cu(mu-im)Cu(dien)](ClO4)3, a homobinuclear model for the copper(II) site of the CuZn-superoxide dismutase.

    Science.gov (United States)

    Patel, R N; Singh, Nripendra; Shukla, K K; Chauhan, U K

    2005-01-01

    The imidazolate-bridged binuclear copper(II)-copper(II) complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) and related mononuclear complexes [Cu(dien)(H(2)O)](ClO(4))(2), [Cu(dien)(Him)](ClO(4))(2) were synthesized with diethylenetriamine (dien) as capping ligand. The crystal structure of mononuclear [Cu(dien)(Him)](ClO(4))(2) and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) have been determined by single crystal X-ray diffraction methods. The mononuclear complex [Cu(dien)(Him)](ClO(4))(2) crystallizes in the orthorhombic, Pca2(1) with a = 9.3420(9) A, b = 12.3750(9) A, c = 14.0830(9) A, beta = 90.000(7)(o) and Z = 4 and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) crystallizes in the monoclinic space group P2(1)/a, with a = 15.017(7) A, b = 11.938(6) A, c = 15.386(6) A, beta = 110.30(4)(o) and Z = 4. The molecular structures show that copper(II) ions in an asymmetrically elongated octahedral coordination (type 4 + 1 + 1) and in binuclear complex Cu(1) atom has a asymmetrically elongated octahedral coordination (type type 4 + 1 + 1) and Cu(2) atom exhibits a square base pyramidal coordination (type 4 + 1). The bridging ligand (imidazolate ion, im) lies nearly on a straight line between two Cu(2+), which are separated by 5.812 A, slightly shorter than the value in copper-copper superoxide dismutase (Cu(2)-Cu(2)SOD). Magnetic measurements and electron spin resonance (ESR) spectroscopy of the binuclear complex have shown an antiferromagnetic exchange interaction. From pH-dependent cyclic voltametry (CV) and electronic spectroscopic studies the complex has been found to be stable over a wide pH range (7.75-12.50).

  9. Aqueous synthesis of internally doped Cu:ZnSe/ZnS core-shell nanocrystals with good stability.

    Science.gov (United States)

    Xu, Shuhong; Wang, Chunlei; Wang, Zhuyuan; Zhang, Haisheng; Yang, Jing; Xu, Qinying; Shao, Haibao; Li, Rongqing; Lei, Wei; Cui, Yiping

    2011-07-08

    To prepare biologically available Zn-based NCs in aqueous solution, we herein reported the synthesis of aqueous Cu:ZnSe/ZnS NCs with internally doped aqueous Cu:ZnSe NCs as the core template. Due to the dual protection of Cu impurities by the ZnSe core and ZnS shells, the as-prepared Cu:ZnSe/ZnS NCs show excellent stability in the open air, which overcomes the intrinsic instability of traditional aqueous Cu:ZnSe NCs. The as-prepared Cu:ZnSe/ZnS NCs possess extremely good stability, good biocompatibility and lower cytotoxicity, and thus can be used as a promising candidate for fluorescent NC-based biological applications.

  10. Synthesis and characterization of VO(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based azo-linked Schiff base ligand

    Science.gov (United States)

    Anitha, C.; Sheela, C. D.; Tharmaraj, P.; Johnson Raja, S.

    2012-12-01

    Azo-Schiff-base complexes of VO(II), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized and characterized by elemental analysis, IR, UV-Vis, 1H NMR, mass spectra, molar conductance, magnetic susceptibility measurement, electron spin resonance (EPR), CV, fluorescence, NLO and SEM. The conductance data indicate the nonelectrolytic nature of the complexes, except VO(II) complex which is electrolytic in nature. On the basis of electronic spectra and magnetic susceptibility octahedral geometry has been proposed for the complexes. The EPR spectra of copper and oxovanadium complexes in DMSO at 300 and 77 K were recorded and its salient features are reported. The redox behavior of the copper(II) complex was studied using cyclic voltammetry. The in vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella enterica typhi, Bacillus subtilis and Candida strains was studied and compared with that of free ligand by well-diffusion technique. The azo Schiff base exhibited fluorescence properties originating from intraligand (π-π∗) transitions and metal-mediated enhancement is observed on complexation and so the synthesized complexes can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. On the basis of the optimized structures, the second-order nonlinear optical properties (NLO) are calculated by using second-harmonic generation (SHG) and also the surface morphology of the complexes was studied by SEM.

  11. Analysis of CdS/CdTe devices incorporating a ZnTe:Cu/Ti Contact

    Energy Technology Data Exchange (ETDEWEB)

    Gessert, T.A. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States)]. E-mail: tim_gessert@nrel.gov; Asher, S. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States); Johnston, S. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States); Young, M. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States); Dippo, P. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States); Corwine, C. [National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401 (United States)

    2007-05-31

    High-performance CdS/CdTe photovoltaic devices can be produced using a ZnTe:Cu/Ti back contact deposited onto the CdTe layer. We observe that prolonged exposure of the ZnTe:Cu and Ti sputtering targets to an oxygen-containing plasma significantly reduces device open-circuit voltage and fill factor. High-resolution compositional analysis of these devices reveals that Cu concentration in the CdTe and CdS layers is lower for devices with poor performance. Capacitance-voltage analysis and related numerical simulations indicate that the net acceptor concentration in the CdTe is also lower for devices with poor performance. Photoluminescence analyses of the junction region reveal that the intensity of a luminescent peak associated with a defect complex involving interstitial Cu (Cu{sub i}) and oxygen on Te (O{sub Te}) is reduced in devices with poor performance. Combined with thermodynamic considerations, these results suggest that oxygen incorporation into the ZnTe:Cu sputtering target reduces the ability of sputtered ZnTe:Cu film to diffuse Cu into the CdTe.

  12. Accumulation of Cu and Zn in discarded antifouling paint particles by the marine gastropod, Littorina littorea

    Science.gov (United States)

    Gammon, Melanie; Turner, Andrew; Brown, Murray T.

    2009-10-01

    The short-term (5 day) accumulation of Cu and Zn in different tissues of the marine gastropod, Littorina littorea, has been studied in the presence of ˜10 mg l -1 of antifouling paint particles and pre- or simultaneously contaminated algal food ( Ulva lactuca). Accumulation of Cu was observed in the head-foot, digestive gland-gonad complex and gills to extents dependent on how and when food was contaminated and administered. However, retention of Zn was only observed in the gills and only when L. littorea and U. lactuca were simultaneously exposed to paint particles. Relative to the alga, faecal material was highly enriched in Zn, suggesting that the animal is able to rapidly eliminate this metal, most likely through the formation and egestion of insoluble phosphate granules. Thus, L. littorea is a useful biomonitor of marine contamination by antifouling applications in respect of Cu but not Zn.

  13. Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

    Directory of Open Access Journals (Sweden)

    M. Padma Latha

    2007-04-01

    Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

  14. FT-IR, micro-Raman and UV-vis spectroscopic and quantum chemical investigations of free 2,2'-dithiodipyridine and its metal (Co, Cu and Zn) halide complexes.

    Science.gov (United States)

    Gökce, Halil; Bahçeli, Semiha

    2013-10-01

    In this study the elemental analysis results, molecular geometries, vibrational and electronic absorption spectra of free 2,2'-dithiodipyridine(C10H8N2S2), (or DTDP) (with synonym, 2,2'-dipyridyl disulfide) and M(C10H8N2S2)Cl2 (M=Co, Cu and Zn) complexes have been reported. Vibrational wavenumbers of free DTDP and its metal halide complexes have been calculated by using DFT/B3LYP calculation method with 6-31++G(d,p) and Lanl2DZ basis sets, respectively, in the ground state, for the first time. The calculated fundamental vibrational frequencies are in a good agreement with experimental data. The HOMO, LUMO and MEP analyses of all compounds are performed by DFT method.

  15. A novel pyrazole biscoumarin based chemosensors for the selective detection of Cu(2+) and Zn(2+) ions.

    Science.gov (United States)

    Kandasamy, Karthikeyan; Ganesabaskaran, Sivaprasad; Pachamuthu, Muthusamy Poomalai; Ramanathan, Anand

    2015-09-05

    A novel chemosensor based on pyrazole biscoumarin molecule "4-hydroxy-3-((4-hydroxy-2-oxo-2H-chromen-3-yl)(1,3-diphenyl-1H-pyrazol-4-yl)methyl)-2H-chromen-2-one" (PBC) was synthesized by a simple method. The chemosensing properties of PBC towards transition metal ions like Cu(2+) and Zn(2+) by naked eye, UV-Visible and fluorescence spectroscopic methods were described. The PBC solution with Cu(2+) and Zn(2+) ion showed brown and blue colour respectively. The UV-Visible spectra of PBC with Cu(2+) and Zn(2+) ions exposed their corresponding absorption maxima. Further, the Job's plot method confirmed the 1:1 and 2:1 stoichiometry of the complex formation between the PBC with Cu(2+) and Zn(2+) ions respectively. The fluorescence enhancement of PBC on binding with Cu(2+) and Zn(2+) is due to the inhibition of photo induced electron transfer mechanism.

  16. A novel pyrazole biscoumarin based chemosensors for the selective detection of Cu2+ and Zn2+ ions

    Science.gov (United States)

    Kandasamy, Karthikeyan; Ganesabaskaran, Sivaprasad; Pachamuthu, Muthusamy Poomalai; Ramanathan, Anand

    2015-09-01

    A novel chemosensor based on pyrazole biscoumarin molecule "4-hydroxy-3-((4-hydroxy-2-oxo-2H-chromen-3-yl)(1,3-diphenyl-1H-pyrazol-4-yl)methyl)-2H-chromen-2-one" (PBC) was synthesized by a simple method. The chemosensing properties of PBC towards transition metal ions like Cu2+ and Zn2+ by naked eye, UV-Visible and fluorescence spectroscopic methods were described. The PBC solution with Cu2+ and Zn2+ ion showed brown and blue colour respectively. The UV-Visible spectra of PBC with Cu2+ and Zn2+ ions exposed their corresponding absorption maxima. Further, the Job's plot method confirmed the 1:1 and 2:1 stoichiometry of the complex formation between the PBC with Cu2+ and Zn2+ ions respectively. The fluorescence enhancement of PBC on binding with Cu2+ and Zn2+ is due to the inhibition of photo induced electron transfer mechanism.

  17. Electrodeposition of Zn and Cu–Zn alloy from ZnO/CuO precursors in deep eutectic solvent

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueliang [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zou, Xingli, E-mail: xinglizou@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Xionggang, E-mail: luxg@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Changyuan; Cheng, Hongwei; Xu, Qian [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zhou, Zhongfu [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Institute of Mathematics and Physics, Aberystwyth University, Aberystwyth SY23 3BZ (United Kingdom)

    2016-11-01

    Graphical abstract: Micro/nanostructured Zn and Cu–Zn alloy films have been electrodeposited directly from ZnO/CuO precursors in ChCl/urea-based DES, the typical nucleation-growth mechanism and the micro/nanostructures-formation process are determined. Display Omitted - Highlights: • Micro/nanostructured Zn films have been electrodeposited directly from ZnO precursor in deep eutectic solvent (DES). • The morphology of the Zn electrodeposits depends on the cathodic potential and temperature. • The electrodeposited Zn films exhibit homogeneous morphologies with controllable particle sizes and improved corrosion resistance. • Cu–Zn alloy films have also been electrodeposited directly from their metal oxides precursors in DES. - Abstract: The electrodeposition of Zn and Cu–Zn alloy has been investigated in choline chloride (ChCl)/urea (1:2 molar ratio) based deep eutectic solvent (DES). Cyclic voltammetry study demonstrates that the reduction of Zn(II) to Zn is a diffusion-controlled quasi-reversible, one-step, two electrons transfer process. Chronoamperometric investigation indicates that the electrodeposition of Zn on a Cu electrode typically involves three-dimensional instantaneous nucleation with diffusion-controlled growth process. Micro/nanostructured Zn films can be obtained by controlling the electrodeposition potential and temperature. The electrodeposited Zn crystals preferentially orient parallel to the (101) plane. The Zn films electrodeposited under more positive potentials and low temperatures exhibit improved corrosion resistance in 3 wt% NaCl solution. In addition, Cu–Zn alloy films have also been electrodeposited directly from CuO–ZnO precursors in ChCl/urea-based DES. The XRD analysis indicates that the phase composition of the electrodeposited Cu–Zn alloy depends on the electrodeposition potential.

  18. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid

    Science.gov (United States)

    Faheim, Abeer A.; Abdou, Safaa N.; Abd El-Wahab, Zeinab H.

    2013-03-01

    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H2L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, 1H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H2L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  19. Mono and binuclear Ag(I), Cu(II), Zn(II) and Hg(II) complexes of a new azo-azomethine as ligand: synthesis, potentiometric, spectral and thermal studies.

    Science.gov (United States)

    Ahmed, Ibrahim S; Moustafa, Moustafa M; Abd El Aziz, Mohamed M

    2011-05-01

    New azo-azomethine dyes were prepared by reaction of p-aminobenzoic acid, o-anisidine, o-nitroaniline, and p-bromoaniline with salicylaldehyde respectively to form azo compounds and then condensation by urea to form 4-(R-arylazo 2-salicylaldene)-urea azo-azomethine derivatives (I(a-d)). The complexes of these ligands with Ag(I), Cu(II), Zn(II) and Hg(II) metal ions were prepared. The structure of the free ligands and their complexes were characterized by using elemental analysis (C, H, N), (1)H NMR, IR and UV-Vis-spectra. The proton dissociation constants of the ligands and the stability constant of their complexes have been determined potentiometrically in 40% (v/v) alcohol-water medium as well as the stoichiometry of complexes were determined conductometrically. The data reveal that the stoichiometries for all complexes were prepared in molar ratios (1:1) and (1:2) (M:L). The electrolytic and nonelectrolytic natures of the complexes were assigned based on molar conductance measurements. The thermogravimetric (TG), and differential thermal analyses (DTA) were studied in nitrogen atmosphere with heating rate 10°C/min. The kinetic and thermodynamic parameters for thermal decomposition of complexes have been calculated by graphical method using Coats-Redfern (CR) method.

  20. Ternary complexes metal [Co(II), Ni(II), Cu(II) and Zn(II)]--ortho-iodohippurate (I-hip)--acyclovir. X-ray characterization of isostructural [(Co, Ni or Zn)(I-hip)(2)(ACV)(H(2)O)(3)] with stacking as a recognition factor.

    Science.gov (United States)

    Barceló-Oliver, M; Terrón, A; García-Raso, A; Fiol, J J; Molins, E; Miravitlles, C

    2004-11-01

    Four ternary metal--ortho-iodohippurate (I-hip)--acyclovir (ACV) complexes, [M(I-hip)(2)(ACV)(H(2)O)(3)] where M is Co(II) (1), Ni(II) (2), Cu (3) and Zn(II) have been obtained by reaction between the corresponding binary complexes M(II)(I-hip)(2)xnH(2)O and ACV. Three ternary complexes (M=Co, Ni and Zn) and the corresponding Zn(II)--ortho-iodohippurate binary derivative have been structurally characterized by X-ray diffraction: The studies show these three ternary complexes are isostructural and present, in solid state, an interesting stacking between the nucleobase and the aryl ring of the hippurate moiety, which probably promotes the formation of ternary complexes. Moreover, the two different ligands interact between them by means of ancillary hydrogen bonds with water molecules coordinated to the metal ion. It must be mentioned that these two recognition factors, hydrogen bonds plus stacking, could explain the reason for the isostructurality of these ternary derivatives with so different three metal ions, with diverses trends in coordination numbers and geometries. In solid state, there are two enantiomeric molecules that are related by an inversion center as the crystal-building unit (as a translational motif) for the ternary complexes.

  1. Cu-Zn disorder in Cu2ZnGeSe4: A complementary neutron diffraction and Raman spectroscopy study

    Science.gov (United States)

    Gurieva, G.; Többens, D. M.; Valakh, M. Ya.; Schorr, S.

    2016-12-01

    The crystal structure of the quaternary compound semiconductor Cu2ZnGeSe4 (CZGSe) was investigated by the complementary use of neutron diffraction, and Raman spectroscopy. The powder sample, which resulting from wavelength dispersive X-ray spectroscopy (WDX) turned out to be single phase Cu-rich CZGSe, was synthesized by solid state reaction of the pure elements in an evacuated silica tube at 700 °C. Raman spectroscopy confirmed the homogeneity and phase purity of the sample, in addition, the kesterite type structure was suggested. Rietveld analysis of the neutron diffraction data confirmed that the compound crystallizes in the tetragonal kesterite type structure. The refined site occupancy factors were used to determine the average neutron scattering lengths of the cation sites, giving insights into cation distribution and finally point defect types. Thus it has been shown, that additional to the CuZn-ZnCu anti-site defects in the lattice planes at z=¼ and ¾ (Cu-Zn disorder) also the off-stoichiometry type related point defects like Cui and CuZn occur in Cu-rich CZGSe.

  2. Fatigue crack behavior on a Cu-Zn-Al SMA

    OpenAIRE

    V. Di Cocco; Iacoviello, F.; Natali, S.; V. Volpe

    2014-01-01

    In recent years, mechanical property of many SMA has improved in order to introduce these alloys in specific field of industry. Main examples of these alloys are the NiTi, Cu-Zn-Al and Cu-Al-Ni which are used in many fields of engineering such as aerospace or mechanical systems. Cu-Zn-Al alloys are characterized by good shape memory properties due to a bcc disordered structure stable at high temperature called β-phase, which is able to change by means of a reversible transition to...

  3. In vitro DNA binding, pBR322 plasmid cleavage and molecular modeling study of chiral benzothiazole Schiff-base-valine Cu(II) and Zn(II) complexes to evaluate their enantiomeric biological disposition for molecular target DNA.

    Science.gov (United States)

    Alizadeh, Rahman; Afzal, Mohd; Arjmand, Farukh

    2014-10-15

    Bicyclic heterocyclic compounds viz. benzothiazoles are key components of deoxyribonucleic acid (DNA) molecules and participate directly in the encoding of genetic information. Benzothiazoles, therefore, represent a potent and selective class of antitumor compounds. The design and synthesis of chiral antitumor chemotherapeutic agents of Cu(II) and Zn(II), L- and -D benzothiazole Schiff base-valine complexes 1a &b and 2a &b, respectively were carried out and thoroughly characterized by spectroscopic and analytical techniques. Interaction of 1a and b and 2a and b with CT DNA by employing UV-vis, florescence, circular dichroic methods and cleavage studies of 1a with pBR322 plasmid, molecular docking were done in order to demonstrate their enantiomeric disposition toward the molecular drug target DNA. Interestingly, these studies unambiguously demonstrated the greater potency of L-enantiomer in comparison to D-enantiomer.

  4. In vitro DNA binding, pBR322 plasmid cleavage and molecular modeling study of chiral benzothiazole Schiff-base-valine Cu(II) and Zn(II) complexes to evaluate their enantiomeric biological disposition for molecular target DNA

    Science.gov (United States)

    Alizadeh, Rahman; Afzal, Mohd; Arjmand, Farukh

    2014-10-01

    Bicyclic heterocyclic compounds viz. benzothiazoles are key components of deoxyribonucleic acid (DNA) molecules and participate directly in the encoding of genetic information. Benzothiazoles, therefore, represent a potent and selective class of antitumor compounds. The design and synthesis of chiral antitumor chemotherapeutic agents of Cu(II) and Zn(II), L- and -D benzothiazole Schiff base-valine complexes 1a &b and 2a &b, respectively were carried out and thoroughly characterized by spectroscopic and analytical techniques. Interaction of 1a and b and 2a and b with CT DNA by employing UV-vis, florescence, circular dichroic methods and cleavage studies of 1a with pBR322 plasmid, molecular docking were done in order to demonstrate their enantiomeric disposition toward the molecular drug target DNA. Interestingly, these studies unambiguously demonstrated the greater potency of L-enantiomer in comparison to D-enantiomer.

  5. Spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV/VIS), thermogravimetric and antimicrobial studies of Ca(II), Mn(II), Cu(II), Zn(II) and Cd(II) complexes of ferulic acid

    Science.gov (United States)

    Kalinowska, M.; Piekut, J.; Bruss, A.; Follet, C.; Sienkiewicz-Gromiuk, J.; Świsłocka, R.; Rzączyńska, Z.; Lewandowski, W.

    2014-03-01

    The molecular structure of Mn(II), Cu(II), Zn(II), Cd(II) and Ca(II) ferulates (4-hydroxy-3-methoxycinnamates) was studied. The selected metal ferulates were synthesized. Their composition was established by means of elementary and thermogravimetric analysis. The following spectroscopic methods were used: infrared (FT-IR), Raman (FT-Raman), nuclear magnetic resonance (13C, 1H NMR) and ultraviolet-visible (UV/VIS). On the basis of obtained results the electronic charge distribution in studied metal complexes in comparison with ferulic acid molecule was discussed. The microbiological study of ferulic acid and ferulates toward Escherichia coli, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus and Proteus vulgaris was done.

  6. Adsorption Behavior for CO on Modified MCM-41 with Zn and CuCl

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Zn-Cu(Ⅰ)/HMCM-41 catalysts were successfully prepared in laboratory scale by solid-state ion exchange with CuCl salt, together with introduction of Zn to improve the dispersion degree of the active component Cu(Ⅰ) on the surface. With increase of the amounts of Zn and CuCl from 0% to 9.0% and 25.0% respectively, CO adsorption the amounts of increased from 10.6 μmol/g to 183.0 μmol/g correspondingly. The in situ FT-IR spectra for CO adsorption demonstrated that there existed two dynamic equilibriums between surface carbonyl complexes: Cu(CO)3+ Cu(CO)2++ CO and Cu(CO)2+ Cu(CO)+ + CO. The equilibriums can be shifted reversibly by changing the temperature and pressure. Due to the modified MCM-41 mesoporous materials possess both of the acidic and metallic carbonyl centers, this kind of material can be developed into mesoporous bifunctional catalysts for carbonylation reactions, in which larger molecules are involved.

  7. Thermal formation of atomic vacancies in {gamma} Cu-Zn

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, Carlos [Instituto de Fisica de Materiales Tandil, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, B7000GHG Tandil (Argentina); Romero, Ricardo [Instituto de Fisica de Materiales Tandil, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, B7000GHG Tandil (Argentina); Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Pinto 399, B7000GHG Tandil (Argentina); Somoza, Alberto [Instituto de Fisica de Materiales Tandil, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, B7000GHG Tandil (Argentina) and Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Pinto 399, B7000GHG Tandil (Argentina)]. E-mail: asomoza@exa.unicen.edu.ar

    2006-02-15

    g positron annihilation lifetime spectroscopy, the temperature dependence of the formation of thermal vacancies in the {gamma} phase of the Cu-Zn alloy was studied. Thermal equilibrium measurements were made in situ between 135K and about 950K. The experimental data were interpreted in terms of the well-established positron two-state trapping model. From the evolution of the lifetime parameters between {approx}400K and {approx}800K, an Arrhenius plot for trapping rate, directly linked to the vacancy concentration, exhibits the usual linear behavior. As a result, a value for the vacancy formation enthalpy for the complex cubic structure studied was estimated at H{sub v}{sup f}=0.46+/-0.03eV.

  8. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II, Cu(II, Ni(II, and Zn(II Complexes with Amino Acid-Derived Compounds

    Directory of Open Access Journals (Sweden)

    Zahid H. Chohan

    2006-01-01

    Full Text Available A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II, copper(II, nickel(II, and zinc(II metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L1–(L5 were derived by condensation of β-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc via the azomethine-N and deprotonated-O of the respective amino acid. The stoichiometric reaction between the metal(II ion and synthesized ligands in molar ratio of M: L (1: 1 resulted in the formation of the metal complexes of type [M(L(H2O4]Cl (where M = Co(II, Cu(II, and Zn(II and of M: L (1: 2 of type [M(L2(H2O2] (where M = Co(II, Cu(II, Ni(II, and Zn(II. The magnetic moment data suggested for the complexes to have an octahedral geometry around the central metal atom. The electronic spectral data also supported the same octahedral geometry of the complexes. Elemental analyses and NMR spectral data of the ligands and their metal(II complexes agree with their proposed structures. The synthesized ligands, along with their metal(II complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa, and Salmonella typhi and two Gram-positive (Bacillus subtilis and Staphylococcus aureus bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glaberata. The results of these studies show the metal(II complexes to be more antibacterial/antifungal against one or more species as compared to the uncomplexed ligands. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Five compounds, (3, (7, (10, (11, and (22, displayed potent cytotoxic

  9. Speciation of Cu and Zn during composting of pig manure amended with rock phosphate.

    Science.gov (United States)

    Lu, Duian; Wang, Lixia; Yan, Baixing; Ou, Yang; Guan, Jiunian; Bian, Yu; Zhang, Yubin

    2014-08-01

    Pig manure usually contains a large amount of metals, especially Cu and Zn, which may limit its land application. Rock phosphate has been shown to be effective for immobilizing toxic metals in toxic metals contaminated soils. The aim of this study work was to investigate the effect of rock phosphate on the speciation of Cu and Zn during co-composting of pig manure with rice straw. The results showed that composting process and rock phosphate addition significantly affected the changes of metal species. During co-composting, the exchangeable and reducible fractions of Cu were transformed to organic and residue fractions, thus the bioavailable Cu fractions were decreased. The rock phosphate addition enhanced the metal transformation depending on the level of rock phosphate amendment. Zinc was found in the exchangeable and reducible fractions in the compost. The bioavailable Zn fraction changed a little during the composting process. The composting process converted the exchangeable Zn fraction into reducible fraction. Addition of an appropriate amount (5.0%) of rock phosphate could advance the conversion. Rock phosphate could reduce metal availability through adsorption and complexation of the metal ions on inorganic components. The increase in pH and organic matter degradation could be responsible for the reduction in exchangeable and bioavailable Cu fractions and exchangeable Zn fraction in rock phosphate amended compost.

  10. Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: antimicrobial evaluation and anticancer studies.

    Science.gov (United States)

    Dhahagani, K; Mathan Kumar, S; Chakkaravarthi, G; Anitha, K; Rajesh, J; Ramu, A; Rajagopal, G

    2014-01-03

    Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by (1)H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M=Cu(II), Co(II)), Zn(II), or VO(IV); MPMP=2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X=Cl, (L1H), X=Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

  11. Copper doping of ZnO crystals by transmutation of {sup 64}Zn to {sup 65}Cu: An electron paramagnetic resonance and gamma spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Recker, M. C.; McClory, J. W., E-mail: John.McClory@afit.edu; Holston, M. S.; Golden, E. M.; Giles, N. C. [Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio 45433 (United States); Halliburton, L. E. [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States)

    2014-06-28

    Transmutation of {sup 64}Zn to {sup 65}Cu has been observed in a ZnO crystal irradiated with neutrons. The crystal was characterized with electron paramagnetic resonance (EPR) before and after the irradiation and with gamma spectroscopy after the irradiation. Major features in the gamma spectrum of the neutron-irradiated crystal included the primary 1115.5 keV gamma ray from the {sup 65}Zn decay and the positron annihilation peak at 511 keV. Their presence confirmed the successful transmutation of {sup 64}Zn nuclei to {sup 65}Cu. Additional direct evidence for transmutation was obtained from the EPR of Cu{sup 2+} ions (where {sup 63}Cu and {sup 65}Cu hyperfine lines are easily resolved). A spectrum from isolated Cu{sup 2+} (3d{sup 9}) ions acquired after the neutron irradiation showed only hyperfine lines from {sup 65}Cu nuclei. The absence of {sup 63}Cu lines in this Cu{sup 2+} spectrum left no doubt that the observed {sup 65}Cu signals were due to transmuted {sup 65}Cu nuclei created as a result of the neutron irradiation. Small concentrations of copper, in the form of Cu{sup +}-H complexes, were inadvertently present in our as-grown ZnO crystal. These Cu{sup +}-H complexes are not affected by the neutron irradiation, but they dissociate when a crystal is heated to 900 °C. This behavior allowed EPR to distinguish between the copper initially in the crystal and the copper subsequently produced by the neutron irradiation. In addition to transmutation, a second major effect of the neutron irradiation was the formation of zinc and oxygen vacancies by displacement. These vacancies were observed with EPR.

  12. Research Update: Stable single-phase Zn-rich Cu2ZnSnSe4 through In doping

    Science.gov (United States)

    Hartnauer, Stefan; Körbel, Sabine; Marques, Miguel A. L.; Botti, Silvana; Pistor, Paul; Scheer, Roland

    2016-07-01

    Alloying in the system Cu2ZnSnSe4-CuInSe2-ZnSe (CZTISe) is investigated experimentally and theoretically. The goal is to distinguish single-phase and multi-phase regions within the Cu2ZnSnSe4-2CuInSe2-4ZnSe pseudo-ternary phase diagram. CZTISe thin films are prepared by co-evaporation of the chemical elements and are investigated in real-time during growth using in situ angle dispersive X-ray diffraction. The focus is mainly on thin films along the Cu2ZnSnSe4-2CuInSe2 isopleth with small ZnSe addition as well as on films along the Cu2ZnSnSe4-4ZnSe isopleth with small CuInSe2 addition. For both cases, ab initio calculations with density-functional theory are performed to estimate the stability of the alloy with respect to the formation of secondary phases. Both in experiment and calculation, we find a surprisingly large single-phase region in the Cu2ZnSnSe4 corner of the pseudo-ternary phase diagram slightly off the Cu2ZnSnSe4-4ZnSe isopleth. This may help avoiding secondary phase formation under Zn-rich conditions and open up new possibilities for the application of CZTISe thin films in solar cells.

  13. Corrosion resistance of benzotriazole passivated Cu-Zn-Al shape memory alloy in artificial Ringer's solution

    Institute of Scientific and Technical Information of China (English)

    LIANG Chenghao; CHEN Bangyi; CHEN Wan; WANG Hua

    2005-01-01

    The corrosion resistance of the Cu-Zn-Al shape memory alloy passivated by benzotriazole was investigated by salt spraying test and electrochemical methods in artificial Ringer's solution. The results showed that after benzotriazole passivation, the corrosion resistance of the Cu-Zn-Al shape memory alloy was improved evidently. The anodic polarization current density of the passivated alloy decreased, the mass loss reduced, the anodic passivation accelerated, the anodic active dissolution was inhibited effectively, and the surface tarnishing was restrained. Infrared reflection spectrum test showed that Cu(Ⅰ)-benzoaiazole or Cu(Ⅱ)-benzotriazole complex layer was formed on the surface of the Cu-Zn-Al shape memory alloy after passivation. This layer appeared plane, well adhesion, and presented homogeneous golden metallic luster. The corrosion resistance of the Cu-Zn-Al shape memory alloy passivated by benzotriazole is improved for the formation of an electrochemical stable baffle layer on passivated surface. This layer separates the metal substrate from the outside corrosion medium effectively and retards the corrosion process of dezincification.

  14. Synthesis and photodynamic activity of unsymmetrical A3B tetraarylporphyrins functionalized with l-glutamate and their Zn(II) and Cu(II) metal complex derivatives.

    Science.gov (United States)

    Arredondo-Espinoza, Eder U; López-Cortina, Susana T; Ramírez-Cabrera, Mónica A; Balderas-Rentería, Isaías

    2016-08-01

    Four novel unsymmetrical A3B porphyrins 1, 2, 3 and 4 were synthesized following Lindsey procedure. Porphyrins 3 and 4 include one and three l-glutamate groups, respectively, and all porphyrins were metallated with Zn(II) (1a-4a) or Cu(II) (1b-4b). Porphyrins and metalloporphyrins presented values of singlet oxygen quantum yields (ΦD) ranging from 0.21 to 0.67. The tetraaryl derivatives in this study showed phototoxicity in SiHa cells with IC50 values ranging from IC50 value. Comparing the phototoxic activity between all porphyrins, functionalization of porphyrins with glutamate increased 100 times phototoxic activity (1 (IC50 4.81±0.34μM) vs. 3 (IC50 0.04±0.02μM) and 2 (IC50 5.19±0.42μM) vs. 4 (IC50 0.05±0.01μM)). This increased activity could be attributed to reduced hydrophobicity and increased ΦΔ, given by functionalization with l-glutamate. Metalloporphyrins 3a (IC50 0.04±0.01μM) and 4a (IC50<0.01μM) presented the best values ​​of phototoxic activity. Therefore, functionalization and zinc metalation increased the phototoxic activity. SiHa cells treated with porphyrins 3, 4, 3a and 4a at a final concentration of 10μM, showed increased activity of caspase-3 enzyme compared to the negative control; indicating the induction of apoptosis. Differential gene expression pattern in SiHa cells was determined; treatments with metalloporphyrins 4a and 4b were performed, respectively, comparing the expression with untreated control. Treatments in both cases showed similar gene expression pattern in upregulated genes, since they share about 25 biological pathways and a large number of genes. According to the new photophysical properties related to the structural improvement and phototoxic activity, these molecules may have the potential application as photosensitizers in the photodynamic therapy.

  15. Exploring the activated state of Cu/ZnO-Zn, a model catalyst for methanol synthesis

    NARCIS (Netherlands)

    Batyrev, E.D.; Shiju, N.R.; Rothenberg, G.

    2012-01-01

    The interaction of Cu clusters with ZnO(0001)-Zn terminated crystal faces is studied after reduction at high temperatures by a combination of scanning tunneling microscopy, scanning tunneling spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy. We find that tiny

  16. Colloidal synthesis of Cu-ZnO and Cu@CuNi-ZnO hybrid nanocrystals with controlled morphologies and multifunctional properties.

    Science.gov (United States)

    Zeng, Deqian; Gong, Pingyun; Chen, Yuanzhi; Zhang, Qinfu; Xie, Qingshui; Peng, Dong-Liang

    2016-06-02

    Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications. The utilization of low-cost non-noble metals to construct novel metal-semiconductor hybrid nanocrystals is important and meaningful for their large-scale applications. In this study, a facile solution approach is developed for the synthesis of Cu-ZnO hybrid nanocrystals with well-controlled morphologies, including nanomultipods, core-shell nanoparticles, nanopyramids and core-shell nanowires. In the synthetic strategy, Cu nanocrystals formed in situ serve as seeds for the heterogeneous nucleation and growth of ZnO, and it eventually forms various Cu-ZnO hetero-nanostructures under different reaction conditions. These hybrid nanocrystals possess well-defined and stable heterostructure junctions. The ultraviolet-visible-near infrared spectra reveal morphology-dependent surface plasmon resonance absorption of Cu and the band gap absorption of ZnO. Furthermore, we construct a novel Cu@CuNi-ZnO ternary hetero-nanostructure by incorporating the magnetic metal Ni into the pre-synthesized colloidal Cu nanocrystals. Such hybrid nanocrystals possess a magnetic Cu-Ni intermediate layer between the ZnO shell and the Cu core, and exhibit ferromagnetic/superparamagnetic properties which expand their functionalities. Finally, enhanced photocatalytic activities are observed in the as-prepared non-noble metal-ZnO hybrid nanocrystals. This study not only provides an economical way to prepare high-quality morphology-controlled Cu-ZnO hybrid nanocrystals for potential applications in the fields of photocatalysis and photovoltaic devices, but also opens up new opportunities in designing ternary non-noble metal-semiconductor hybrid nanocrystals with multifunctionalities.

  17. Punicalagin Green Functionalized Cu/Cu2O/ZnO/CuO Nanocomposite for Potential Electrochemical Transducer and Catalyst

    Science.gov (United States)

    Fuku, X.; Kaviyarasu, K.; Matinise, N.; Maaza, M.

    2016-09-01

    A novel ternary Punica granatum L-Cu/Cu2O/CuO/ZnO nanocomposite was successfully synthesised via green route. In this work, we demonstrate that the green synthesis of metal oxides is more viable and facile compare to other methods, i.e., physical and chemical routes while presenting a potential electrode for energy applications. The prepared nanocomposite was characterised by both microscopic and spectroscopic techniques. High-resolution scanning electron microscopy (HRSEM) and X-ray diffraction (XRD) techniques revealed different transitional phases with an average nanocrystallite size of 29-20 mm. It was observed that the nanocomposites changed from amorphous-slightly crystalline Cu/Cu2O to polycrystalline Cu/Cu2O/CuO/ZnO at different calcination temperatures (room temperature-RT- 600 °C). The Cu/Cu2O/ZnO/CuO metal oxides proved to be highly crystalline and showed irregularly distributed particles with different sizes. Meanwhile, Fourier transform infrared (FTIR) spectroscopy confirmed the purity while together with ultraviolet-visible (UV-Vis) spectroscopy proved the proposed mechanism of the synthesised nanocomposite. UV-Vis showed improved catalytic activity of the prepared metal oxides, evident by narrow band gap energy. The redox and electrochemical properties of the prepared nanocomposite were achieved by cyclic voltammetry (CV), electrochemical impedance (EIS) and galvanostatic charge-discharge (GCD). The maximum specific capacitance ( C s) was calculated to be 241 F g-1 at 50 mV s-1 for Cu/Cu2O/CuO/ZnO nanoplatelets structured electrode. Moreover, all the CuO nanostructures reveal better power performance, excellent rate as well as long term cycling stability. Such a study will encourages a new design for a wide spectrum of materials for smart electronic device applications.

  18. Synthesis, spectroscopic, molecular structure, antioxidant, antimicrobial and antitumor behavior of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of O2N type tridentate chromone-2-carboxaldehyde Schiff's base ligand

    Science.gov (United States)

    Ammar, Reda A.; Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Al-Bedair, Lamia A.

    2017-08-01

    Tridentate Schiff's base (HL) ligand was synthesized via condensation of salicylaldehyde and 3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR), magnetic moment, EPR, and thermal measurements. The IR spectra showed that HL was coordinated to the metal ions in tridentate manner with O2N donor sites of the azomethine N, deprotonated phenolic-OH and carbonyl-O. The activation of thermodynamic parameters are calculated using Coast-Redfern and Horowitz-Metzger (HM). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations, UV-Vis and magnetic moment measurements, ESR and ligand field parameters. Antioxidant activities have also been performed for all the compounds. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all inspected compounds were evaluated towards human liver Carcinoma (HepG2) cell line.

  19. Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD.

    Science.gov (United States)

    Bóka, Beáta; Myari, Alexandra; Sóvágó, Imre; Hadjiliadis, Nick

    2004-01-01

    Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD were studied by potentiometric and spectroscopic (UV-Vis, CD and EPR) techniques. The results reveal that both ligands have effective metal binding sites, but the tripeptide is a much stronger complexing agent than the tetrapeptide. The formation of a macrochelate via the coordination of the imidazolyl residues is suggested in the copper(II)-Ac-HisValHis-NH2 system in the acidic pH range, while a 4N complex predominates at physiological pH. The interaction of Ac-HisValHis-NH2 with zinc(II) results in the formation of a precipitate indicating polynuclear complex formation. Both copper(II)-Ac-HisValHis-NH2 and copper(II)-HisValHis systems exhibit catalytic activity toward the dismutation of superoxide anion at physiological pH, but the saturated coordination sphere of the metal ions in both systems results in low reactivity as compared to the native enzyme.

  20. Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate ONO donor Schiff base ligand: Synthesis, characterization, thermal, non-isothermal kinetics and DFT calculations

    Science.gov (United States)

    Kusmariya, Brajendra S.; Mishra, A. P.

    2017-02-01

    We report here four mononuclear Co(II), Ni(II), Cu(II) and Zn(II) coordination compounds of general formula [M(L)2] {L = dcp; M = CoII, CuII & ZnII} and [M(L)(H2O)]·H2O {L = dcp; M = NiII} derived from tridentate 2,4-dichloro-6-{[(3-chloro-2-hydroxy-5-nitrophenyl)imino]methyl}phenol (dcp) ligand. These compounds were synthesized and characterized by elemental analysis, FT-IR, uv-vis, 1H NMR, molar conductance, magnetic moment, thermal, PXRD and SEM-EDX. The Powder X-ray Diffraction patterns and SEM analyses showed the crystalline nature of synthesized compounds. The peak broadening was explained in terms of crystallite size and the lattice strain using Scherrer and Williamson-Hall method. Thermogravimetric analysis was performed to determine the thermal stability of synthesized compounds under nitrogen atmosphere up to 820 K at 10 Kmin-1 heating rate. The kinetic and thermodynamic parameters of thermal decomposition were calculated using Coats-Redfern (C-R), Piloyan-Novikova (P-N) and Horowitz-Metzger (H-M) methods assuming first order degradation. The calculated optical band gap values of complexes were found to be in semiconducting range. To support the experimental findings, and derive some fruitful information viz. frequency calculations, HOMO-LUMO, energy gap (ΔE), molecular electrostatic potential (MEP), spin density, absorption spectra etc.; theoretical calculations by means of DFT and TD-DFT at B3LYP level were incorporated.

  1. Influence of Zn content and annealing process on electrical property of CuZn alloy

    Institute of Scientific and Technical Information of China (English)

    罗丰华; 尹志民; 汪明朴; 左铁镛

    2001-01-01

    The relationship among annealing temperature, microstructure and electrical resistivity of Cu-(8%~13%)Zn (mole fraction) alloys was studied. The results show that the relationship between the electrical resistivity of cold deformation CuZn alloy and annealing temperature is related to the recovery and recrystallization of the processes. The increments of electrical resistivity due to strain are restored mainly on the process of recovery and recrystallization. The room temperature resistivity of soft state alloys is linear to the Zn contents. The extended application of Matthissen rule on high concentration solid solution was discussed.

  2. Influence of terminal acryloyl arms on the coordination chemistry of a ditopic pyrimidine-hydrazone ligand: comparison of Pb(II), Zn(II), Cu(II), and Ag(I) complexes.

    Science.gov (United States)

    Hutchinson, Daniel J; Hanton, Lyall R; Moratti, Stephen C

    2013-03-01

    A new ditopic pyrimidine-hydrazone ligand, 6-hydroxymethylacryloyl-2-pyridinecarboxaldehyde, 2,2'-[2,2'-(2-methyl-4,6-pyrimidinediyl)bis(1-methylhydrazone)] (L2), was synthesized with terminal acryloyl functional groups to allow incorporation into copolymer gel actuators. NMR spectroscopy was used to show that L2 adopted a horseshoe shape with transoid-transoid pym-hyz-py linkages. Metal complexation studies were performed with L2 and salts of Pb(II), Zn(II), Cu(II), and Ag(I) ions in CH3CN in a variety of metal to ligand ratios. Reacting L2 with an excess amount of any of the metal ions resulted in linear complexes where the pym-hyz-py linkages were rotated to a cisoid-cisoid conformation. NMR spectroscopy showed that the acryloyl arms of L2 did not interact with the bound metal ions in solution. Seven of the linear complexes (1-7) were crystallized and analyzed by X-ray diffraction. Most of these complexes (4-7) also showed no coordination between the acryloyl arms and the metal ions; however, complexes 1-3 showed some interactions. Both of the acryloyl arms were coordinated to Pb(II) ions in [Pb2L2(SO3CF3)4] (1), one through the carbonyl oxygen donor and the other through the alkoxy oxygen donor. One of the acryloyl arms of [Cu2L2(CH3CN)3](SO3CF3)4 (2) was coordinated to one of the Cu(II) ions through the carbonyl oxygen donor. There appeared to be a weak association between the alkoxy donors of the acryloyl arms and the Pb(II) ions of [Pb2L2(ClO4)4]·CH3CN (3). Reaction of excess AgSO3CF3 with L2 was repeated in CD3NO2, resulting in crystals of {[Ag7(L2)2(SO3CF3)6(H2O)2] SO3CF3}∞ (8), the polymeric structure of which resulted from coordination between the carbonyl donors of the acryloyl arms and the Ag(I) ions. In all cases the coordination and steric effects of the acryloyl arms did not inhibit isomerization of the pym-hyz bonds of L2 or the core shape of the linear complexes.

  3. Synthesis, spectroscopic and DNA binding ability of Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

    Science.gov (United States)

    Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed

    2017-06-01

    A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L)2]·l2H2O, [Ni(L)Cl·(H2O)2].5H2O, [Cu(L)Cl] and [Zn(L)(CH3COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, (1)H &(13)C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (Kb). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Synthesis and Characterization of (E)-Cinnamoylferrocene Dithioylcarbohydrazones and Their Cu( Ⅱ ) and Zn( Ⅱ )Complexes%(反)-肉桂酰基二茂铁缩二硫代碳酰腙及其Cu(Ⅱ)、Zn(Ⅱ)配合物的合成与表征

    Institute of Scientific and Technical Information of China (English)

    刘永红; 刘晓岚; 杨声; 马永祥

    2001-01-01

    合成了两种未见文献报道的Schiff碱HCFM[(反)-肉桂酰基二茂铁-(S)-甲基二硫代碳酰腙]及HCFB[(反)-肉桂酰基二茂铁-(S)-苄基二硫代碳酰腙]及其铜(Ⅱ)、锌(Ⅱ)的六个配合物Cu(CFM)2@H2O、Cu(CFM)OAc@H20、Cu(CFB)2@H20、zn(CFM)2@2H20、Zn(CFM)0Ac@H20、Zn(CFB)2,考察了它们的物理性质,并利用元素分析、IR、1H NMR谱及摩尔电导表征了它们的组成、可能结构及配位过程.实验结果表明:这两种Schiff碱都是反式双齿配体,烯硫醇化失去质子后以负硫离子与过度金属离子形成共价键,氮原子与中心金属离子形成配位键.

  5. The properties of CdTe solar cells with ZnTe/ZnTe: Cu buffer layers

    Institute of Scientific and Technical Information of China (English)

    Song Huijin; Zheng Jiagui; Feng Lianghuan; Yan Qiang; Lei Zhi; Wu Lili; Zhang Jingquan; Li Wei; Li Bing

    2008-01-01

    CdS/CdTe solar cells with ZnTe/ZnTe:Cu buffer layers were fabricated and studied. The energy band structure of it was analyzed. The C-V, I-V characteristics and the spectral response show that the ZnTe/ZnTe:Cu buffer layers improve the back contact characteristic properties, the diode characteristics of the forward junction and the short-wave spectral response of the CdTe solar cells. The ZnTe/ZnTe:Cu buffer layers affect the solar cell conversion efficiency and its fill factor.

  6. Medical applications of Cu, Zn, and S isotope effects.

    Science.gov (United States)

    Albarede, Francis; Télouk, Philippe; Balter, Vincent; Bondanese, Victor P; Albalat, Emmanuelle; Oger, Philippe; Bonaventura, Paola; Miossec, Pierre; Fujii, Toshiyuki

    2016-10-01

    This review examines recent applications of stable copper, zinc and sulfur isotopes to medical cases and notably cancer. The distribution of the natural stable isotopes of a particular element among coexisting molecular species varies as a function of the bond strength, the ionic charge, and the coordination, and it also changes with kinetics. Ab initio calculations show that compounds in which a metal binds to oxygen- (sulfate, phosphate, lactate) and nitrogen-bearing moieties (histidine) favor heavy isotopes, whereas bonds with sulfur (cysteine, methionine) favor light isotopes. Oxidized cations (e.g., Cu(ii)) and low coordination numbers are expected to favor heavy isotopes relative to their reduced counterparts (Cu(i)) and high coordination numbers. Here we discuss the first observations of Cu, Zn, and S isotopic variations, three elements closely related along multiple biological pathways, with emphasis on serum samples of healthy volunteers and of cancer patients. It was found that heavy isotopes of Zn and to an even greater extent Cu are enriched in erythrocytes relative to serum, while the difference is small for sulfur. Isotopic variations related to age and sex are relatively small. The (65)Cu/(63)Cu ratio in the serum of patients with colon, breast, and liver cancer is conspicuously low relative to healthy subjects. The characteristic time over which Cu isotopes may change with disease progression (a few weeks) is consistent with both the turnover time of the element and albumin half-life. A parallel effect on sulfur isotopes is detected in a few un-medicated patients. Copper in liver tumor tissue is isotopically heavy. In contrast, Zn in breast cancer tumors is isotopically lighter than in healthy breast tissue. (66)Zn/(64)Zn is very similar in the serum of cancer patients and in controls. Possible reasons for Cu isotope variations may be related to the cytosolic storage of Cu lactate (Warburg effect), release of intracellular copper from cysteine

  7. Phase transformation of Al-Zn (Cu) alloys and the phase diagram of Al-Zn-Cu system%Al-Zn(Cu)合金的相变和Al-Zn-Cu系相图

    Institute of Scientific and Technical Information of China (English)

    郝士明; 李洪晓; 陈辉

    2005-01-01

    The room temperature phase diagram of Al-Zn-Cu system is the important basis for judging the phase constituents of the materials at the usage condition. New results about the room temperature phase diagram of the low copper side in the Al-Zn-Cu systems have been shown in this study. Miscibility gap of fcc phase in the Al-Zn-Cu system has also been studied by experimental diffusion-couple method and thermodynamic calculation. Properties of this miscibility gap have been known. It is practically significant for the study on the aging behavior and for the control of the microstructure and properties of the Al alloys with Zn and Cu element.

  8. Conduction behavior conversion for Cu-doped ZnS/n-type Si devices with different Cu contents

    Science.gov (United States)

    Ni, Wei-Shih; Lin, Yow-Jon

    2015-06-01

    Currents through Cu-doped ZnS (ZnCuS)/n-type Si structures were studied. The electrical conduction investigations suggest that the carrier transport behavior is governed by the Poole-Frenkel emission for ZnCuS/n-type Si devices having the low Cu concentration. However, the carrier transport behavior is governed by the thermionic emission for ZnCuS/n-type Si devices having the high Cu concentration. The photoluminescence result revealed that sulfur vacancy ( V S) is the origin of conduction behavior conversion. It is shown that the increased Cu concentration leads to the reduced formation probability of V S. The dependence of V S on the film composition was identified for providing a guide to control the current transport behavior of ZnCuS/n-type Si devices.

  9. Spectroscopic studies on photoelectron transfer from 2-(furan-2-yl)-1-phenyl-1H-phenanthro[9,10-d]imidazole to ZnO, Cu-doped ZnO and Ag-doped ZnO.

    Science.gov (United States)

    Thanikachalam, V; Arunpandiyan, A; Jayabharathi, J; Karunakaran, C; Ramanathan, P

    2014-09-01

    The 2-(furan-2-yl)-1-phenyl-1H-phenanthro[9,10-d]imidazole [FPI] has been designed and synthesized as fluorescent sensor for nanoparticulate ZnO. The present work investigates the photoelectron transfer (PET) from FPI to ZnO, Cu-doped ZnO and Ag- doped ZnO nanoparticles using electronic and life time spectral measurements. Broad absorption along with red shift indicates the formation of charge-transfer complex [FPI-Nanoparticles]. The photophysical studies indicate lowering of HOMO and LUMO energy levels of FPI on adsorption on ZnO due to FPI- ZnO interaction. The obtained binding constant implies that the binding of FPI with nanoparticles was influenced by the surface modification of ZnO nanoparticles with Cu and Ag.

  10. Uptake and accumulation of potentially toxic metals (Zn, Cu and Pb) in soils and plants of Durgapur industrial belt.

    Science.gov (United States)

    Kisku, Ganesh Chandra; Pandey, Poonam; Negi, Mahendra Pratap Singh; Misra, Virendra

    2011-11-01

    Uptake and accumulation of metals in crops may cause possible health risks through food chain. A field survey was conducted to investigate the accumulation of potentially toxic metals contamination in soil and plants irrigated with complexed industrial effluents. Concentration of Zn, Cu and Pb was 205-255,101-130,118-177 microg g(-1) in rhizosphere soils and 116-223, 57-102 and 63-95 microg g(-1) d. wt. in root and 95-186, 44-75 and 27-58 microg g(-1) d. wt. in shoot, respectively. The trend in Cu and Pb was in the order: soil > root > shoot > seed while in Zn it was soil > root > seed > shoot. Roots accumulated a larger fraction of soil Cu (70%) > Zn (67%) > Pb (54%). Bioaccumulation coefficient of soil to root ranged from 51-98 for Zn, 54-85 for Cu and 43-63 for Pb.Analysis of variance showed marginal change in bioaccumulation coefficient, noticed between plants (p > 0.05) while it varied significantly (p shoot > seed/fruit) while decreased between metals from Zn to Pb (Zn > Cu > Pb). Out of the three, two Cu and Pb accumulated to phyotoxic levels while Zn was within threshold limit of phytotoxicity.

  11. Electrodeposited Cu2ZnSnS4 thin films

    CSIR Research Space (South Africa)

    Valdes, M

    2014-05-01

    Full Text Available Electrochimica Acta Vol. 128, pp 393-399 Electrodeposited Cu2ZnSnS4thin films M. Valdesa, M. Modibedib, M. Matheb, T. Hilliec,d, M. Vazqueza,∗ aDivisión Electroquimica y Corrosión, INTEMA, UNMdP-CONICET, J. B. Justo 4302 B7608FDQ Mar del Plata, Argentina...

  12. Tuning the emission of aqueous Cu:ZnSe quantum dots to yellow light window.

    Science.gov (United States)

    Wang, Chunlei; Hu, Zhiyang; Xu, Shuhong; Wang, Yanbin; Zhao, Zengxia; Wang, Zhuyuan; Cui, Yiping

    2015-07-31

    Synthesis of internally doped Cu:ZnSe QDs in an aqueous solution still suffers from narrow tunable emissions from the blue to green light window. In this work, we extended the emission window of aqueous Cu:ZnSe QDs to the yellow light window. Our results show that high solution pH, multiple injections of Zn precursors, and nucleation doping strategy are three key factors for preparing yellow emitted Cu:ZnSe QDs. All these factors can depress the reactivity of CuSe nuclei and Zn monomers, promoting ZnSe growth outside CuSe nuclei rather than form ZnSe nuclei separately. With increased ZnSe QD size, the conduction band and nearby trap state energy levels shift to higher energy sites, causing Cu:ZnSe QDs to have a much longer emission.

  13. Cloning of a putative extracellular Cu/Zn superoxide dismutase and functional differences of superoxide dismutases in invasive and indigenous whiteflies.

    Science.gov (United States)

    Gao, Xian-Long; Li, Jun-Min; Xu, Hong-Xing; Yan, Gen-Hong; Jiu, Min; Liu, Shu-Sheng; Wang, Xiao-Wei

    2015-02-01

    Superoxide dismutases (SODs) are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase (ecCuZnSOD) complementary DNA was cloned and characterized from the whitefly, Bemisia tabaci. Quantitative polymerase chain reaction analysis showed that the expression level of BtecCuZnSOD was more than 10-fold higher in the invasive Middle East Asia Minor 1 (MEAM1) than in the native Asia II 3 species of the B. tabaci species complex. After exposure to low temperature (4 °C), the expression of Bt-ecCuZnSOD gene was significantly up-regulated in MEAM1 but not in Asia II 3. Furthermore, the expression level of B. tabaci intracellular CuZnSOD (Bt-icCuZnSOD), Bt-ecCuZnSOD and mitochondrial MnSOD (Bt-mMnSOD) was compared after transferring MEAM1 and Asia II 3 whiteflies from favorable (cotton) to unfavorable host plants (tobacco). On cotton, both CuZnSOD genes were expressed at a higher level in MEAM1 compared with Asia II 3. Interestingly, after transferring onto tobacco, the expression of Bt-ecCuZnSOD was significantly induced in Asia II 3 but not in MEAM1. On the other hand, while Bt-mMnSOD was expressed equally in both species on cotton, Bt-mMnSOD messenger RNA was up-regulated in MEAM1 on tobacco. Consistently, enzymatic activity assays of CuZnSOD and MnSOD demonstrated that CuZnSOD might play an important protective role against oxidative stress in Asia II 3, whereas MnSOD activation was critical for MEAM1 whiteflies during host adaptation. Taken together, our results suggest that the successful invasion of MEAM1 is correlated with its constitutive high activity of CuZnSOD and inducible expression of MnSOD under stress conditions.

  14. Organic/inorganic nanocomposites of ZnO/CuO/chitosan with improved properties

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xingfa, E-mail: xingfamazju@aliyun.com [School of Environmental and Material Engineering, Center of Advanced Functional Materials, Yantai University, Yantai, 264005 (China); State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, 310027 (China); Zhang, Bo; Cong, Qin; He, Xiaochun; Gao, Mingjun [School of Environmental and Material Engineering, Center of Advanced Functional Materials, Yantai University, Yantai, 264005 (China); Li, Guang [National Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027 (China)

    2016-08-01

    To extend the visible light response of ZnO, ZnO/CuO heterostructured nanocomposite was synthesized by a hydrothermal approach. At the same time, chitosan (Ch) is considered as a very promising natural polymer. It holds not only abundant resource and low cost, but also has excellent adsorption properties to a broad range of organic pollutants and some heavy metal ions. To improve the adsorption properties of ZnO/CuO nanocomposite, ZnO/CuO/chitosan organic-inorganic composites were prepared with precipitation method. The as-prepared nanocomposites were characterized by TEM (Transmission electron microscopy), SAED pattern (Selected Area Electron Diffraction), SEM (scanning electron microscopy), UV–Vis (Ultraviolet–visible spectroscopy), PL (Photoluminescence), XRD (X-ray diffraction), TGA (Thermo Gravimetric Analyzer), Fourier transform infrared spectroscopy spectra (FTIR) et al. To examine the surface and interface properties of nanocomposites, chemical prototype sensor arrays were constructed based on ZnO, ZnO/CuO, ZnO/Cu{sub 2}O, ZnO/CuO/chitosan, ZnO/Cu{sub 2}O/chitosan nanocomposites and QCM (quartz crystal microbalance) arrays devices. The adsorption response behaviors of the sensor arrays to some typical volatile compounds were examined under similar conditions. The results indicated that with comparison to ZnO nanostructure, the ZnO/CuO nanocomposite exhibited enhanced adsorption properties to some typical volatile compounds greatly, and the adsorption properties of ZnO/CuO/chitosan are much better than that of ZnO/CuO nanocomposite. The adsorption of ZnO/CuO system is super to that of ZnO/Cu{sub 2}O. Therefore, ZnO/CuO/chitosan nanocomposite not only showed broadening visible light response, but also possessed of excellent adsorption properties, and has good potential applications in photocatalysts, chemical sensors, biosensors, self-cleaning coating fields et al. - Highlights: • ZnO/CuO nanocomposites exhibited good response in near whole visible

  15. CuZn Alloy- Based Electrocatalyst for CO2 Reduction

    KAUST Repository

    Alazmi, Amira

    2014-06-01

    ABSTRACT CuZn Alloy- Based Electrocatalyst for CO2 Reduction Amira Alazmi Carbon dioxide (CO2) is one of the major greenhouse gases and its emission is a significant threat to global economy and sustainability. Efficient CO2 conversion leads to utilization of CO2 as a carbon feedstock, but activating the most stable carbon-based molecule, CO2, is a challenging task. Electrochemical conversion of CO2 is considered to be the beneficial approach to generate carbon-containing fuels directly from CO2, especially when the electronic energy is derived from renewable energies, such as solar, wind, geo-thermal and tidal. To achieve this goal, the development of an efficient electrocatalyst for CO2 reduction is essential. In this thesis, studies on CuZn alloys with heat treatments at different temperatures have been evaluated as electrocatalysts for CO2 reduction. It was found that the catalytic activity of these electrodes was strongly dependent on the thermal oxidation temperature before their use for electrochemical measurements. The polycrystalline CuZn electrode without thermal treatment shows the Faradaic efficiency for CO formation of only 30% at applied potential ~−1.0 V vs. RHE with current density of ~−2.55 mA cm−2. In contrast, the reduction of oxide-based CuZn alloy electrode exhibits 65% Faradaic efficiency for CO at lower applied potential about −1.0 V vs. RHE with current density of −2.55 mA cm−2. Furthermore, stable activity was achieved over several hours of the reduction reaction at the modified electrodes. Based on electrokinetic studies, this improvement could be attributed to further stabilization of the CO2•− on the oxide-based Cu-Zn alloy surface.

  16. Aging behavior and fatigue crack propagation of high Zn-containing Al-Zn-Mg-Cu alloys with zinc variation

    National Research Council Canada - National Science Library

    Kai Wen Yunqiang Fan Guojun Wang Longbing Jin Xiwu Li Zhihui Li Yongan Zhang Baiqing Xiong

    2017-01-01

    In the present work, the influence of two-step aging treatments on hardness, electrical conductivity and mechanical properties of two high Zn-containing Al-Zn-Mg-Cu alloys with zinc content variation...

  17. Effect of Heat Treatment on the Microstructure and Corrosion Resistance of Cu-Zn Alloy

    Institute of Scientific and Technical Information of China (English)

    Xu Tao; Zhang Hailong; Xiao Nianxin; Zhao Xiangling

    2007-01-01

    The microstructure of Cu-Zn alloy with different heat treatment conditions in 3.5% NaCl + NH3 solution were observed, and the average corrosion rates and electrochemical data of Cu-Zn alloy were measured, as well as the effect of heat treatment on microstructure and corrosion resistance of Cu-Zn alloy was analyzed. The results show that the microstructure of Cu-Zn alloy has been changed due to the heat treatment. As a results, the better corrosion resistance can be obtained for the Cu-Zn alloy quenched from 900℃ for 0.5h followed by tempered at 100℃ for 2h.

  18. Colloidal synthesis of Cu-ZnO and Cu@CuNi-ZnO hybrid nanocrystals with controlled morphologies and multifunctional properties

    Science.gov (United States)

    Zeng, Deqian; Gong, Pingyun; Chen, Yuanzhi; Zhang, Qinfu; Xie, Qingshui; Peng, Dong-Liang

    2016-06-01

    Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications. The utilization of low-cost non-noble metals to construct novel metal-semiconductor hybrid nanocrystals is important and meaningful for their large-scale applications. In this study, a facile solution approach is developed for the synthesis of Cu-ZnO hybrid nanocrystals with well-controlled morphologies, including nanomultipods, core-shell nanoparticles, nanopyramids and core-shell nanowires. In the synthetic strategy, Cu nanocrystals formed in situ serve as seeds for the heterogeneous nucleation and growth of ZnO, and it eventually forms various Cu-ZnO hetero-nanostructures under different reaction conditions. These hybrid nanocrystals possess well-defined and stable heterostructure junctions. The ultraviolet-visible-near infrared spectra reveal morphology-dependent surface plasmon resonance absorption of Cu and the band gap absorption of ZnO. Furthermore, we construct a novel Cu@CuNi-ZnO ternary hetero-nanostructure by incorporating the magnetic metal Ni into the pre-synthesized colloidal Cu nanocrystals. Such hybrid nanocrystals possess a magnetic Cu-Ni intermediate layer between the ZnO shell and the Cu core, and exhibit ferromagnetic/superparamagnetic properties which expand their functionalities. Finally, enhanced photocatalytic activities are observed in the as-prepared non-noble metal-ZnO hybrid nanocrystals. This study not only provides an economical way to prepare high-quality morphology-controlled Cu-ZnO hybrid nanocrystals for potential applications in the fields of photocatalysis and photovoltaic devices, but also opens up new opportunities in designing ternary non-noble metal-semiconductor hybrid nanocrystals with multifunctionalities.Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications

  19. Classification of lattice defects in the kesterite Cu2ZnSnS4 and Cu2ZnSnSe4 earth-abundant solar cell absorbers.

    Science.gov (United States)

    Chen, Shiyou; Walsh, Aron; Gong, Xin-Gao; Wei, Su-Huai

    2013-03-20

    The kesterite-structured semiconductors Cu2ZnSnS4 and Cu2ZnSnSe4 are drawing considerable attention recently as the active layers in earth-abundant low-cost thin-film solar cells. The additional number of elements in these quaternary compounds, relative to binary and ternary semiconductors, results in increased flexibility in the material properties. Conversely, a large variety of intrinsic lattice defects can also be formed, which have important influence on their optical and electrical properties, and hence their photovoltaic performance. Experimental identification of these defects is currently limited due to poor sample quality. Here recent theoretical research on defect formation and ionization in kesterite materials is reviewed based on new systematic calculations, and compared with the better studied chalcopyrite materials CuGaSe2 and CuInSe2 . Four features are revealed and highlighted: (i) the strong phase-competition between the kesterites and the coexisting secondary compounds; (ii) the intrinsic p-type conductivity determined by the high population of acceptor CuZn antisites and Cu vacancies, and their dependence on the Cu/(Zn+Sn) and Zn/Sn ratio; (iii) the role of charge-compensated defect clusters such as [2CuZn +SnZn ], [VCu +ZnCu ] and [ZnSn +2ZnCu ] and their contribution to non-stoichiometry; (iv) the electron-trapping effect of the abundant [2CuZn +SnZn ] clusters, especially in Cu2ZnSnS4. The calculated properties explain the experimental observation that Cu poor and Zn rich conditions (Cu/(Zn+Sn) ≈ 0.8 and Zn/Sn ≈ 1.2) result in the highest solar cell efficiency, as well as suggesting an efficiency limitation in Cu2ZnSn(S,Se)4 cells when the S composition is high. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Molecular characterization and oxidative stress response of an intracellular Cu/Zn superoxide dismutase (CuZnSOD) of the whitefly, Bemisia tabaci.

    Science.gov (United States)

    Li, Jun-Min; Su, Yun-Lin; Gao, Xian-Long; He, Jiao; Liu, Shu-Sheng; Wang, Xiao-Wei

    2011-07-01

    Superoxide dismutases (SODs) are important for the survival of insects under environmental and biological stresses; however, little attention has been devoted to the functional characterization of SODs in whitefly. In this study, an intracellular copper/zinc superoxide dismutase of whitefly (Bemisia tabaci) (Bt-CuZnSOD) was cloned. Sequence analysis indicated that the full length cDNA of Bt-CuZnSOD is of 907 bp with a 471 bp open reading frame encoding 157 amino acids. The deduced amino acid sequence shares common consensus patterns with the CuZnSODs of various vertebrate and invertebrate animals. Phylogenetic analysis revealed that Bt-CuZnSOD is grouped together with intracellular CuZnSODs. Bt-CuZnSOD was then over-expressed in E. coli and purified using GST purification system. The enzymatic activity of purified Bt-CuZnSOD was assayed under various temperatures. When whiteflies were exposed to low (4°C) and high (40°C) temperatures, the in vivo activity of Bt-CuZnSOD was significantly increased. Furthermore, we measured the activities of several antioxidant enzymes, including SOD, catalase and peroxidase, in the whitefly after transferring the whitefly from cotton to tobacco (an unfavorable host plant). We found that the activity of SOD increased rapidly on tobacco plant. Taken together, these results suggest that the Bt-CuZnSOD plays a major role in protecting the whitefly against various stress conditions.

  1. New influence factor inducing difficulty in selective flotation separation of Cu-Zn mixed sulfide minerals

    Science.gov (United States)

    Deng, Jiu-shuai; Mao, Ying-bo; Wen, Shu-ming; Liu, Jian; Xian, Yong-jun; Feng, Qi-cheng

    2015-02-01

    Selective flotation separation of Cu-Zn mixed sulfides has been proven to be difficult. Thus far, researchers have found no satisfactory way to separate Cu-Zn mixed sulfides by selective flotation, mainly because of the complex surface and interface interaction mechanisms in the flotation solution. Undesired activation occurs between copper ions and the sphalerite surfaces. In addition to recycled water and mineral dissolution, ancient fluids in the minerals are observed to be a new source of metal ions. In this study, significant amounts of ancient fluids were found to exist in Cu-Zn sulfide and gangue minerals, mostly as gas-liquid fluid inclusions. The concentration of copper ions released from the ancient fluids reached 1.02 × 10-6 mol/L, whereas, in the cases of sphalerite and quartz, this concentration was 0.62 × 10-6 mol/L and 0.44 × 10-6 mol/L, respectively. As a result, the ancient fluid is a significant source of copper ions compared to mineral dissolution under the same experimental conditions, which promotes the unwanted activation of sphalerite. Therefore, the ancient fluid is considered to be a new factor that affects the selective flotation separation of Cu-Zn mixed sulfide ores.

  2. Interfacial Phenomena in Al/Al, Al/Cu, and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions

    Science.gov (United States)

    Pstruś, Janusz; Gancarz, Tomasz

    2014-05-01

    The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)EUT, (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.

  3. Dynamic Behavior of CuZn Nanoparticles under Oxidizing and Reducing Conditions

    DEFF Research Database (Denmark)

    Holse, Christian; Elkjær, Christian Fink; Nierhoff, Anders Ulrik Fregerslev;

    2015-01-01

    The oxidation and reduction of CuZn nanoparticles was studied using X-ray photoelectron spectroscopy (XPS) and in situ transmission electron microscopy (TEM). CuZn nanoparticles with a narrow size distribution were produced with a gas-aggregation cluster source in conjunction with mass......-filtration. A direct comparison between the spatially averaged XPS information and the local TEM observations was thus made possible. Upon oxidation in O2, the as-deposited metal clusters transform into a polycrystalline cluster consisting of separate CuO and ZnO nanocrystals. Specifically, the CuO is observed...... to segregate to the cluster surface and partially cover the ZnO nanocrystals. Upon subsequent reduction in H2 the CuO converts into metallic Cu with ZnO nanocrystal covering their surface. In addition, a small amount of metallic Zn is detected suggesting that ZnO is reduced. It is likely that Zn species can...

  4. Electron paramagnetic resonance in Cu-doped ZnO

    Science.gov (United States)

    Buchheit, R.; Acosta-Humánez, F.; Almanza, O.

    2016-04-01

    In this work, ZnO and Cu-doped ZnO nanoparticles (Zn1-xCuxO, x = 3%), with a calcination temperature of 500∘C were synthesized using the sol-gel method. The particles were analyzed using atomic absorption spectroscopy (AAS), X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) at X-band, measurement in a temperature range from 90 K to room temperature. AAS confirmed a good correspondence between the experimental doping concentration and the theoretical value. XRD reveals the presence of ZnO phase in hexagonal wurtzite structure and a nanoparticle size for the samples synthesized. EPR spectroscopy shows the presence of point defects in both samples with g-values of g = 1.959 for shallow donors and g = 2.004 for ionized vacancies. It is important when these materials are required have been used as catalysts, as suggested that it is not necessary prepare them at higher temperature. A simulation of the Cu EPR signal using an anisotropic spin Hamiltonian was performed and showed good coincidence with the experimental spectra. It was shown that Cu2+ ions enter interstitial octahedral sites of orthorhombic symmetry in the wurtzite crystal structure. Temperature dependence of the EPR linewidth and signal intensity shows a paramagnetic behavior of the sample in the measurement range. A Néel temperature TN = 78 ± 19 K was determined.

  5. Biodegradable coordination polymer: Polycondensation of glutaraldehyde and starch in complex formation with transition metals Mn(II, Co(II, Ni(II, Cu(II and Zn(II

    Directory of Open Access Journals (Sweden)

    Nahid Nishat

    2016-11-01

    Full Text Available Starch a biopolymer, possesses many unique characteristics features accompanied with some shortcoming simultaneously. Some synthetic compounds are of great help to these demerits of starch and so by an addition of all these alternatively may acquire the tailor made features of starch-based compounds. By combining the individual advantages of starch and some other compounds and elements, starch-based biodegradable polymers were prepared for potential applications in biomedical and environmental fields. In this research, the structural analysis and characterization studies of starch glutaraldehyde polycondensed polymer were undertaken, and then the formation of polymer metal complexes with transition metal in coordinated form are carried out. FT-IR spectroscopy and 1H NMR and 13C NMR spectroscopy were used to analyze the functionality of the synthesized compound. CHN of the synthesized compound was supported by FT-IR and NMR which again proved helpful for structural analysis. Electronic spectroscopy confirmed the geometry of the synthesized compounds. Thermal studies were carried out by thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. Besides this the biodegradable studies were carried out by ASTM standards of biodegradable materials by CO2 evolution in respirometric titration method. All the polymers showed good thermal strength and reduced biodegradation on attachment of transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II.

  6. Synthesis, spectral studies, thermal behavior, and antibacterial activity of Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

    Institute of Scientific and Technical Information of China (English)

    Mohammad Azarkish; Tahereh Sedaghat

    2012-01-01

    Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-1,3-diphenylpropen- 1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry.The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.

  7. Synthesis of highly non-stoichiometric Cu2ZnSnS4 nanoparticles with tunable bandgaps

    Science.gov (United States)

    Hamanaka, Yasushi; Oyaizu, Wataru; Kawase, Masanari; Kuzuya, Toshihiro

    2017-01-01

    Non-stoichiometric Cu2ZnSnS4 nanoparticles with average diameters of 4-15 nm and quasi-polyhedral shape were successfully synthesized by a colloidal method. We found that a non-stoichiometric composition of Zn to Cu in Cu2ZnSnS4 nanoparticles yielded a correlation where Zn content increased with a decrease in Cu content, suggesting formation of lattice defects relating to Cu and Zn, such as a Cu vacancy (VCu), antisite with Zn replacing Cu (ZnCu), and/or defect cluster of VCu and ZnCu. The bandgap energy of Cu2ZnSnS4 nanoparticles systematically varies between 1.56 and 1.83 eV depending on the composition ratios of Cu and Zn, resulting in a wider bandgap for Cu-deficient Cu2ZnSnS4 nanoparticles. These characteristics can be ascribed to the modification in electronic band structures due to formation of VCu and ZnCu on the analogy of ternary copper chalcogenide, chalcopyrite CuInSe2, in which the top of the valence band shifts downward with decreasing Cu contents, because much like the structure of CuInSe2, the top of the valence band is composed of a Cu 3 d orbital in Cu2ZnSnS4.

  8. Fatigue crack behavior on a Cu-Zn-Al SMA

    Directory of Open Access Journals (Sweden)

    V. Di Cocco

    2014-10-01

    Full Text Available In recent years, mechanical property of many SMA has improved in order to introduce these alloys in specific field of industry. Main examples of these alloys are the NiTi, Cu-Zn-Al and Cu-Al-Ni which are used in many fields of engineering such as aerospace or mechanical systems. Cu-Zn-Al alloys are characterized by good shape memory properties due to a bcc disordered structure stable at high temperature called β-phase, which is able to change by means of a reversible transition to a B2 structure after appropriate cooling, and reversible transition from B2 secondary to DO3 order, under other types of cooling. In β-Cu-Zn-Al shape memory alloys, the martensitic transformation is not in equilibrium at room temperature. It is therefore often necessary to obtain the martensitic structure, using a thermal treatment at high temperature followed by quenching. The martensitic phases can be either thermally-induced spontaneous transformation, or stressinduced, or cooling, or stressing the β- phase. Direct quenching from high temperatures to the martensite phase is the most effective because of the non-diffusive character of the transformation. The martensite inherits the atomic order from the β-phase. Precipitation of many kinds of intermetallic phases is the main problem of treatment on cu-based shape memory alloy. For instance, a precipitation of α-phase occurs in many low aluminum copper based SMA alloy and presence of α-phase implies a strong degradation of shape recovery. However, Cu-Zn-Al SMA alloys characterized by aluminum contents less than 5% cover a good cold machining and cost is lower than traditional NiTi SMA alloys. In order to improve the SMA performance, it is always necessary to identify the microstructural changing in mechanical and thermal conditions, using X-Ray analyses. In this work a Cu-Zn-Al SMA alloy obtained in laboratory has been microstructurally and metallographically characterized by means of X-Ray diffraction and Light

  9. Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

    Science.gov (United States)

    Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan

    2013-01-01

    A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

  10. First-principles study of defect formation in the photovoltaic semiconductors Cu2GeS3 and Cu2ZnGeS4 for comparison with Cu2SnS3, Cu2ZnSnS4, and CuInSe2

    Science.gov (United States)

    Nishihara, Hironori; Maeda, Tsuyoshi; Shigemi, Akio; Wada, Takahiro

    2017-04-01

    The formation energies of neutral Cu, Ge, and S vacancies in monoclinic Cu2GeS3 and those of neutral Cu, Zn, Ge, and S vacancies in kesterite-type Cu2ZnGeS4 were evaluated by first-principles pseudopotential calculations using plane-wave basis functions. The calculations were performed at typical points in a schematic ternary phase diagram of a Cu-Ge-S system for Cu2GeS3 and in Cu-(Zn1/2Ge1/2)-S and Cu29S16-ZnS-GeS2 pseudoternary phase diagrams for Cu2ZnGeS4. The results have been compared with those for Cu2SnS3, Cu2ZnSnS4, and CuInSe2 calculated with the same version of the CASTEP program code. The results indicate that Cu vacancies are easily formed in Cu2GeS3 and Cu2ZnGeS4 under the Cu-poor condition as in the cases of Cu2SnS3, Cu2ZnSnS4, and CuInSe2, suggesting that Cu2GeS3 and Cu2ZnGeS4 are also preferable p-type absorber materials for thin-film solar cells. Desirable preparation conditions of these thin films for photovoltaic application are discussed using the calculated formation energies of antisite defects.

  11. Corrosion Resistance of Zn and Cu Coated Steel Pipes as a Substitute for Cu Pipe in an Air Conditioner System

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Gyeong; Park, Chan Jin; Hong, Sung Kil [Chonnam National University, Gwangju (Korea, Republic of)

    2009-02-15

    We investigated the corrosion resistance of Zn and Cu coated steel pipes as a substitute for Cu pipe in an air-conditioner system. In addition, the galvanic corrosion tendency between two dissimilar metal parts was studied. The corrosion resistance of the Cu electroplated steel was similar to that of Cu, while the corrosion rate of the Zn electro-galvanized and the galvalume (Zn-55 % Al) coated steels was much higher and not suitable for Cu substitute in artificial sea water and acidic rain environments. Furthermore, the galvanic difference between Cu electroplated steel and Cu was so small that the Cu coated steel pipe can be used as a substitute for Cu pipe in an air-conditioner system.

  12. The Brittleness Of Zn-Cu-Ti Sheet Alloys

    Directory of Open Access Journals (Sweden)

    Boczkal G.

    2015-09-01

    Full Text Available At temperatures below 5°C, the ductility of ZnCuTi alloy sheets is observed to suffer a drastic drop in direction transverse to the rolling direction. Studies have shown that the critical temperature at which this phenomenon occurs is strongly dependent on the alloy structure and parameters of the sheet metal production process. Quite important is also the role of micro-inhomogeneity arising in the chemical composition of the alloy matrix, directly related with the structure of intermetallic precipitates containing Cu and Ti.

  13. Fractionation of Cu and Zn isotopes during adsorption onto amorphous Fe(III) oxyhydroxide: Experimental mixing of acid rock drainage and ambient river water

    Science.gov (United States)

    Balistrieri, Laurie S.; Borrok, David M.; Wanty, Richard B.; Ridley, W. Ian

    2008-01-01

    Fractionation of Cu and Zn isotopes during adsorption onto amorphous ferric oxyhydroxide is examined in experimental mixtures of metal-rich acid rock drainage and relatively pure river water and during batch adsorption experiments using synthetic ferrihydrite. A diverse set of Cu- and Zn-bearing solutions was examined, including natural waters, complex synthetic acid rock drainage, and simple NaNO3 electrolyte. Metal adsorption data are combined with isotopic measurements of dissolved Cu (65Cu/63Cu) and Zn (66Zn/64Zn) in each of the experiments. Fractionation of Cu and Zn isotopes occurs during adsorption of the metal onto amorphous ferric oxyhydroxide. The adsorption data are modeled successfully using the diffuse double layer model in PHREEQC. The isotopic data are best described by a closed system, equilibrium exchange model. The fractionation factors (αsoln-solid) are 0.99927 ± 0.00008 for Cu and 0.99948 ± 0.00004 for Zn or, alternately, the separation factors (Δsoln-solid) are -0.73 ± 0.08‰ for Cu and -0.52 ± 0.04‰ for Zn. These factors indicate that the heavier isotope preferentially adsorbs onto the oxyhydroxide surface, which is consistent with shorter metal-oxygen bonds and lower coordination number for the metal at the surface relative to the aqueous ion. Fractionation of Cu isotopes also is greater than that for Zn isotopes. Limited isotopic data for adsorption of Cu, Fe(II), and Zn onto amorphous ferric oxyhydroxide suggest that isotopic fractionation is related to the intrinsic equilibrium constants that define aqueous metal interactions with oxyhydroxide surface sites. Greater isotopic fractionation occurs with stronger metal binding by the oxyhydroxide with Cu > Zn > Fe(II).

  14. Fractionation of Cu and Zn isotopes during adsorption onto amorphous Fe(III) oxyhydroxide: Experimental mixing of acid rock drainage and ambient river water

    Science.gov (United States)

    Balistrieri, L.S.; Borrok, D.M.; Wanty, R.B.; Ridley, W.I.

    2008-01-01

    Fractionation of Cu and Zn isotopes during adsorption onto amorphous ferric oxyhydroxide is examined in experimental mixtures of metal-rich acid rock drainage and relatively pure river water and during batch adsorption experiments using synthetic ferrihydrite. A diverse set of Cu- and Zn-bearing solutions was examined, including natural waters, complex synthetic acid rock drainage, and simple NaNO3 electrolyte. Metal adsorption data are combined with isotopic measurements of dissolved Cu (65Cu/63Cu) and Zn (66Zn/64Zn) in each of the experiments. Fractionation of Cu and Zn isotopes occurs during adsorption of the metal onto amorphous ferric oxyhydroxide. The adsorption data are modeled successfully using the diffuse double layer model in PHREEQC. The isotopic data are best described by a closed system, equilibrium exchange model. The fractionation factors (??soln-solid) are 0.99927 ?? 0.00008 for Cu and 0.99948 ?? 0.00004 for Zn or, alternately, the separation factors (??soln-solid) are -0.73 ?? 0.08??? for Cu and -0.52 ?? 0.04??? for Zn. These factors indicate that the heavier isotope preferentially adsorbs onto the oxyhydroxide surface, which is consistent with shorter metal-oxygen bonds and lower coordination number for the metal at the surface relative to the aqueous ion. Fractionation of Cu isotopes also is greater than that for Zn isotopes. Limited isotopic data for adsorption of Cu, Fe(II), and Zn onto amorphous ferric oxyhydroxide suggest that isotopic fractionation is related to the intrinsic equilibrium constants that define aqueous metal interactions with oxyhydroxide surface sites. Greater isotopic fractionation occurs with stronger metal binding by the oxyhydroxide with Cu > Zn > Fe(II).

  15. 水杨醛类Schiff碱的Cu(Ⅱ),Zn(Ⅱ)配合物的微波合成%The microwave synthesis in liquid state of salicyladehyde Schiff base and metal complexes

    Institute of Scientific and Technical Information of China (English)

    彭丽莉; 叶婧聪

    2004-01-01

    在微波辐射条件下研究了水杨醛缩邻苯二胺和乙二胺席夫碱及其与过渡金属 [Cu(Ⅱ)、Zn(Ⅱ)]配合物的液相合成反应,并对微波辐射条件下的液相配位反应条件进行了探索.

  16. Effect of Cu/(Zn+Sn) ratio on the properties of co-evaporated Cu{sub 2}ZnSnSe{sub 4} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Suresh Babu, G.; Kishore Kumar, Y.B.; Uday Bhaskar, P.; Raja Vanjari, Sundara [Sri Venkateswara University, Solar Energy Laboratory, Department of Physics, S.V.U. Campus, Tirupati 517 502 (India)

    2010-02-15

    The effect of Cu/(Zn+Sn) ratio on the properties of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin films is investigated. CZTSe thin films with Cu/(Zn+Sn) ratio in the range 0.85-1.15 are deposited using 4-source co-evaporation technique onto glass substrates held at a substrate temperature T{sub s}=623 K and post-deposition annealed at T{sub pa}=723 K for 1 h in the selenium atmosphere. Powder X-ray diffraction (XRD) patterns reveal that CZTSe films deposited with Cu/(Zn+Sn) ratio in the range 0.90-1.10 are single phase and polycrystalline. CZTSe films, deposited with Cu/(Zn+Sn) ratio of 0.85 contain ZnSe as secondary phase and films with ratio of 1.15 contain Cu{sub 2-X}Se as the secondary phase. The films are found to exhibit kesterite structure. Band gap of the films is found to increase with decrease in Cu/(Zn+Sn) ratio. Electrical resistivity of the films is found to lie in the range 0.02-23-{omega}-cm depending on Cu/(Zn+Sn) ratio. (author)

  17. Synthesis of CuS/ZnO Nanocomposite and Its Visible-Light Photocatalytic Activity

    OpenAIRE

    Lianping Zhu; Min Zheng; Juan Lu; Mengfei Xu; Hyo Jin Seo

    2014-01-01

    The CuS/ZnO nanocomposite was successfully synthesized by a simple mechanical method, without adding any surfactants. TEM images showed that CuS existed in the nanocomposite and the size of CuS/ZnO nanocomposite particle was around 35 nm. CuS worked as an electron absorber in the nanocomposite, which was beneficial for the improvement of photocatalysis of ZnO. It was also proved by the experiments performed under the visible light irradiation that CuS could help ZnO degrade methylene blue (MB...

  18. Tolerance of spermatogonia to oxidative stress is due to high levels of Zn and Cu/Zn superoxide dismutase.

    Directory of Open Access Journals (Sweden)

    Fritzie T Celino

    Full Text Available BACKGROUND: Spermatogonia are highly tolerant to reactive oxygen species (ROS attack while advanced-stage germ cells such as spermatozoa are much more susceptible, but the precise reason for this variation in ROS tolerance remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the Japanese eel testicular culture system that enables a complete spermatogenesis in vitro, we report that advanced-stage germ cells undergo intense apoptosis and exhibit strong signal for 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage marker, upon exposure to hypoxanthine-generated ROS while spermatogonia remain unaltered. Activity assay of antioxidant enzyme, superoxide dismutase (SOD and Western blot analysis using an anti-Copper/Zinc (Cu/Zn SOD antibody showed a high SOD activity and Cu/Zn SOD protein concentration during early spermatogenesis. Immunohistochemistry showed a strong expression for Cu/Zn SOD in spermatogonia but weak expression in advanced-stage germ cells. Zn deficiency reduced activity of the recombinant eel Cu/Zn SOD protein. Cu/Zn SOD siRNA decreased Cu/Zn SOD expression in spermatogonia and led to increased oxidative damage. CONCLUSIONS/SIGNIFICANCE: These data indicate that the presence of high levels of Cu/Zn SOD and Zn render spermatogonia resistant to ROS, and consequently protected from oxidative stress. These findings provide the biochemical basis for the high tolerance of spermatogonia to oxidative stress.

  19. Phenoxide bridged tetranuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes: Electrochemical, magnetic and antimicrobial studies

    Science.gov (United States)

    Kamath, Anupama; Kulkarni, Naveen V.; Netalkar, Priya P.; Revankar, Vidyanand K.

    2011-09-01

    Phenoxide bridged later first row transition metal(II) complexes have been prepared by the interaction of later 3d transition metal(II) chlorides with tetranucleating compartmental Schiff base ligand system derived from 2,6-diformyl-4-methylphenol, p-phenylenediamine and 2-hydrazinobenzothiazole. Ligand and complexes were characterized by analytical, spectral (IR, UV-visible, ESR, FAB-mass and fluorescence), magnetic and thermal studies. All complexes are found to have octahedral geometry. The mutual influence of metal centres in terms of cooperative effect on the electronic, magnetic, electrochemical and structural properties was investigated. The Schiff base and its complexes have been screened for their antibacterial (against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa) and antifungal activities (against Aspergillus niger, and Candida albicans).

  20. Production of hydrogen from methanol over Cu/ZnO and Cu/ZnO/Al2O3 catalysts prepared by homogeneous precipitation : Steam reforming and oxidative steam reforming

    OpenAIRE

    2006-01-01

    Two series of Cu/ZnO and Cu/ZnO/Al2O3 catalysts with varying Cu/Zn ratio have been prepared by the homogeneous precipitation (hp) method using urea hydrolysis. Steam reforming and oxidative steam reforming of methanol were performed using the hp-Cu/Zn-based catalysts for catalytic production of hydrogen. The hp-Cu/ZnO/Al2O3 catalyst showed a higher activity than the hp-Cu/ZnO catalysts. In both cases, the catalytic activity was well correlated with the surface area of Cu metal, and the maximu...

  1. [Bioconcentration and translocation of Cu and Zn by Brassica sinensis L. planted in high Cu and Zn contaminated pig manure-applied soils].

    Science.gov (United States)

    Zhang, Yan; Cui, Xiao-yong; Luo, Wei; Shi, Peng; Lü, Yong-long

    2011-05-01

    In recent years, Cu and Zn have been widely used in pig fodders in large-scale animal feeding, causing Cu and Zn contamination in soils and effecting plants in land application of pig manure. It is of great concern to the world that pig manure is used in the dose greater than the organic fertilizer criterion. It is very important to clarify bioconcentration and translocation of Cu and Zn in vegetables in order to assess human health risk of these heavy metals accumulated in soil and to safely produce vegetables. Bioconcentration and translocation of Cu and Zn by Brassica sinensis L. planted in pig manure-applied soils were studied using pot experiments. Pig manure with great concentrations of Cu and Zn (Cu = 1114.7 mg x kg(-1), Zn = 1496.8 mg x kg(-1)) were applied to soils at six rates, i.e., 0, 25, 50, 100, 200 and 500 t x hm(-2). The results indicate that the concentration of Zn was greater than that of Cu in both aboveground and underground parts of B. sinensis. Both Cu and Zn concentrations in the underground part were greater than those in upper-ground for every treatment. There were significant differences for both Cu and Zn concentrations in shoots between CK and the treatment with application rate above 50 t x hm(-2). Bioconcentration factor of Cu in B. sinensis increased with pig manure application rate from 0.11 to 0.17, while that of Zn decreased from 0.47 to 0.11. The proportion of Cu and Zn transported from roots to shoots decreased 25% and 38% with the increase of pig manure application, respectively. It indicates that pig manure application can reduce bioconcentration of Zn in B. sinensis, and build up Cu accumulation which leads to human health risk. The ratio of Zn:Cu in every part of B. sinensis decreased with manure application rate increment. This result prompted that uptake and translocation capacity discrepancy of Cu and Zn decreased with manure application rate increment in B. sinensis.

  2. In Vitro Antibacterial Studies of Ciprofloxacin-imines and Their Complexes with Cu(II),Ni(II),Co(II), and Zn(II)

    OpenAIRE

    Imran, Muhammad; IQBAL, Javed; Iqbal, Shahid; IJAZ, Nazia

    2007-01-01

    Some new transition metal complexes of ciprofloxacin-imines derived from ciprofloxacin and p-substituted anilines were synthesized and characterized on the basis of physical properties, conductance measurements, elemental analysis, UV/Vis., infrared and nuclear magnetic resonance spectroscopy. These ligands as well as their metal complexes were also evaluated for their antibacterial activity against several bacterial strains, such as Staphylococcus aureus, Bacillus subtilus, Salmonella typhae...

  3. Electronic structure and optical properties of Cu-doping and Zn vacancy impurities in ZnTe.

    Science.gov (United States)

    Li, Qing-Fang; Hu, Ge; She, Qing; Yao, Jing; Feng, Wen-Jiang

    2013-09-01

    The geometric structures of perfect ZnTe, that with Zn vacancy (Zn0.875Te), and Cu-doped ZnTe (Zn0.875Cu0.125Te) were optimized using the pseudopotential plane wave (PP-PW) method based on the density functional theory (DFT) within generalized gradient approximation (GGA). The cohesive energy, band structure, density of states, and Mulliken populations were calculated and discussed in detail. On the other hand, an accurate calculation of linear optical functions (the dielectric function, refraction index, reflectivity, conductivity function, and energy-loss spectrum) was performed. The results demonstrated that compared to the perfect ZnTe, the lattice parameters of Zn0.875Te and Zn0.875Cu0.125Te were changed and the cell volumes decreased to some extent due to the vacancy and introduction of impurity. A vacancy acceptor level and an acceptor impurity level were produced in Zn0.875Te and Zn0.875Cu0.125Te, respectively. By comparison, Cu doping in the ZnTe system is relatively stable while the monovacancy system is not.

  4. Metallothionein Zn(2+)- and Cu(2+)-clusters from first-principles calculations

    DEFF Research Database (Denmark)

    Greisen, Per Junior; Jespersen, Jakob Berg; Kepp, Kasper Planeta

    2012-01-01

    Detailed electronic structures of Zn(ii) and Cu(ii) clusters from metallothioneins (MT) have been obtained using density functional theory (DFT), in order to investigate how oxidative stress-caused Cu(ii) intermediates affect Zn-binding to MT and cooperatively lead to Cu(i)MT. The inferred accura...

  5. ZnO/Cu(InGa)Se.sub.2 solar cells prepared by vapor phase Zn doping

    Science.gov (United States)

    Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

    2007-02-20

    A process for making a thin film ZnO/Cu(InGa)Se.sub.2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se.sub.2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se.sub.2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se.sub.2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se.sub.2.

  6. Cu and Zn Speciation in an Acid Soil Amended with Alkaline Biosolids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fractionation of metals in a granite-derived acid sandy loam soil amended with alkaline-stabilised sewage sludge biosolids was conducted in order to assess metal bioavailability and environmental mobility. Soil solution was extracted by a centrifugation and filtration technique. Metal speciation in the soil solution was determined by a cation exchange resin method. Acetic acid and EDTA extracting solutions were used for extraction of metals in soil solid surfaces. Metal distribution in different fractions of soil solid phase was determined using a three-step sequential extraction scheme. The results show that the metals in the soil solution existed in different fractions with variable lability and metals in the soil solid phase were also present in various chemical forms with potentially different bioavailability and environmental mobility. Alkalinestabilised biosolids could elevate solubility of Cu and proportion of Cu in organically complexed fractions both in soil liquid and solid phases, and may therefore increase Cu mobility. In contrast, the biosolids lowered the concentrations of water-soluble Zn (labile fraction) and exchangeable Zn and may hence decrease bioavailability and mobility of Zn. However, Fe and Mn oxides bound and organic matter bound fractions are likely to be Zn pools in the sludge-amended soil. These consequences possibly result from the liming effect and metal speciation of the sludge product and the difference in the chemistry between the metals in soil.

  7. Solution Studies on Co(II, Ni(II, Cu(II, and Zn(II Complexes of Hexamethylenetetramine in Aqueous and Non-Aqueous Solvents

    Directory of Open Access Journals (Sweden)

    Awawou G. Paboudam

    2014-01-01

    Full Text Available Potentiometric studies in aqueous medium and spectrophotometric study in non-aqueous medium were used to understand the behavior of hexamethylenetetramine (HMTA complexes. The protometric studies of HMTA enabled us to confirm that only one basic site of this ligand is protonated in acidic medium and this ligand is decomposed in acidic medium. In aqueous medium, only hexa-aqua complexes in which HMTA is present in the second coordination sphere forming H-bonds with hydrogen atoms of coordinated and uncoordinated water molecules are obtained. In non-aqueous solvents, HMTA coordinates to metal ions displaying diversity in the structures of the resulting complexes in which HMTA can either be monodentate, bridged bidentate, tridentate, or tetradentate.

  8. StudyonTwo-stagesPressureLeachingofZn,CuandFeFromCu-Pb-ZnComplexPolymetallicOre%从铜铅锌复杂多金属精矿中两段加压浸出锌铜铁试验研究

    Institute of Scientific and Technical Information of China (English)

    刘述平; 李博; 王昌良; 唐湘平

    2013-01-01

    T he experimental sample is a Cu-Pb-Zn complex polymetallic ore .Leaching of Zn ,Cu and Fe from the ore by a two-stages pressure leaching process was researched .Using the solution in which H2 SO4 initial concentration is 105 g/L ,Fe concentration is 15 g/L ,Zn concentration is 55 g/L as leaching agent ,the first-stage leaching was conducted under the conditions of leching temperature of 120 ℃ ,leaching time of 2 h ,the ratio between liquid and solid of 4 mL/g ,total pressure of 1 .9 MPa , stirring speed of 600 r/min ,additive usage of 0 .3% ,the leaching rate of Zn was about 72% ,while Cu wasn’t leached ,the removal rate of Fe was 95% .The second-stage leaching of the first-stage leaching residue was conducted under the conditions of H2SO4 initial concentration of 140 g/L ,the ratio between liquid and solid of 4 mL/g ,total pressure of 1 .9 MPa ,stirring speed of 600 r/min ,leaching temperature of 160 ℃ ,leaching time of 3 h ,additive usage of 0 .3% ,leaching rate of Zn ,Cu and Fe were 85 .91% ,77 .76% and 58 .84% ,respectively .The second-stage leaching solution was used to prepare the leaching agent for the first-stage leaching .The first-stage leaching solution with lower concentation of H2 SO4 and Fe is easy to be purified in subsequent ,the purified solution meets with the requirement of zinc electrodepositing .%针对某地铜铅锌复杂多金属精矿,研究了采用两段加压浸出法浸出锌、铜、铁。试验结果表明:以H2 SO4初始质量浓度105 g/L、Fe质量浓度约15 g/L、Zn质量浓度约55 g/L的溶液为浸出剂,在温度120℃、浸出时间2 h、液固体积质量比4 mL/g、总压力1.9 M Pa、搅拌转速600 r/min、添加剂加入量为矿石质量的0.3%条件下进行一次浸出,锌浸出率为72%左右,铜基本不被浸出,溶液中铁去除率为95%;对一次浸出渣,在硫酸初始质量浓度140 g/L、液固体积质量比4 mL/g、总压力1.9 M Pa、搅拌转速600 r/min、温度160

  9. Zinc and copper behaviour at the soil-river interface: New insights by Zn and Cu isotopes in the organic-rich Rio Negro basin

    Science.gov (United States)

    Guinoiseau, Damien; Gélabert, Alexandre; Allard, Thierry; Louvat, Pascale; Moreira-Turcq, Patricia; Benedetti, Marc F.

    2017-09-01

    The complex behaviour of Zn and Cu at the soil-river interface was investigated in soil and riverine water samples from the Rio Negro basin, a secondary tributary of the Rio Amazonas, using their stable isotope compositions. This acidic and organic river drains two types of intensely weathered terrains: podzols in its upstream part, and lateritic soils downstream. Bulk soil particles, suspended particulate matter (SPM) as well as colloidal fractions were sampled across the whole basin during low and high water stages. In the basin, Zn and Cu are mostly exported from lateritic soils and transported by organic colloids where significant losses are observed in the downstream part of the river. The use of δ66Zn and δ65Cu measurements reveals distinct stories for these two metals in suspended sediments and colloids. In the colloids, the constant δ66Zncoll across the basin is induced by the same weak association mode between Zn and organic ligands, regardless of the origin of the water. By contrast, in SPM, the speciation of Zn and thus δ66ZnSPM differ according to the type of drained soils. Zn is associated with organic complexes in particles exported with water draining podzol whereas Zn2+ is incorporated in the structure of the remaining kaolinite clays in lateritic output. The stronger reactivity of Cu than Zn with organic ligands induces its complete complexation. Copper is controlled by refractory particulate organic matter (POM) and by reactive colloidal organic matter; the latter being enriched in 65Cu due to stronger binding interactions than in POM. While the Cu content remains constant in the upstream part of the Rio Negro, downstream, the decrease of SPM and colloidal Cu fluxes is associated with a constant δ65CuSPM and with an increase of δ65Cucoll at the Rio Negro outlet. Geochemical mass balance modelling, based on SPM, Cu and Zn fluxes in SPM and their associated isotopic signatures, confirms distinct host phases for Zn and Cu, and identifies the

  10. Thermal Decomposition Studies of Layered Metal Hydroxynitrates (Metal: Cu, Zn, Cu/Co, and Zn/Co

    Directory of Open Access Journals (Sweden)

    Thimmasandra Narayan Ramesh

    2015-01-01

    Full Text Available Layered metal hydroxynitrates and mixed metal hydroxynitrates (copper/cobalt hydroxynitrates and zinc/cobalt hydroxynitrates at different mole ratios were synthesized by hydrolysis of urea and metal nitrates at 140°C. Layered metal hydroxyl nitrates derive their structure from brucite mineral and generally crystallize in hexagonal and monoclinic phases. Isothermal decomposition studies of Cu2(OH3(NO3, Co2(OH3(NO3, Cu1.5Co0.5(OH3(NO3, Cu1.34Co0.66(OH3(NO3, Zn5(OH8(NO32(H2O2, Zn3.75Co1.25(OH8(NO32(H2O2, and Zn3.35Co1.65(OH8(NO32(H2O2 samples were carried out at different intervals of temperature and the structural transformations during the process were monitored using powder X-ray diffractograms. Biphasic mixture of metal hydroxynitrate/metal oxide is observed in case of cobalt/zinc based layered hydroxynitrates, while copper hydroxynitrate or copper/cobalt metal hydroxynitrate decomposes in a single step. The decomposition temperatures of layered metal hydroxynitrates and mixed layered metal hydroxides depend on the method of preparation, their composition and the nature of metal ion, and their coordination.

  11. Atmospheric corrosion of Cu, Zn, and Cu-Zn alloys protected by self-assembled monolayers of alkanethiols

    Science.gov (United States)

    Hosseinpour, Saman; Forslund, Mattias; Johnson, C. Magnus; Pan, Jinshan; Leygraf, Christofer

    2016-06-01

    In this article results from earlier studies have been compiled in order to compare the protection efficiency of self-assembled monolayers (SAM) of alkanethiols for copper, zinc, and copper-zinc alloys exposed to accelerated indoor atmospheric corrosion conditions. The results are based on a combination of surface spectroscopy and microscopy techniques. The protection efficiency of investigated SAMs increases with chain length which is attributed to transport hindrance of the corrosion stimulators in the atmospheric environment, water, oxygen and formic acid, towards the copper surface. The transport hindrance is selective and results in different corrosion products on bare and on protected copper. Initially the molecular structure of SAMs on copper is well ordered, but the ordering is reduced with exposure time. Octadecanethiol (ODT), the longest alkanethiol investigated, protects copper significantly better than zinc, which may be attributed to the higher bond strength of Cu-S than of Zn-S. Despite these differences, the corrosion protection efficiency of ODT for the single phase Cu20Zn brass alloy is equally efficient as for copper, but significantly less for the heterogeneous double phase Cu40Zn brass alloy.

  12. Water-gas shift reaction on CuO-ZnO catalysts: I. Structure and catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Kalchev, M.G.; Andreev, A.A. [Institute of Catalysis, Sofia (Bulgaria); Zotov, N.S. [Institute of Applied Mineralogy, Sofia (Bulgaria)

    1995-11-01

    The physicochemical properties of CuO-ZnO samples with different CuO contents were investgated by a complex of physical methods: DSC, XPS, EPR, TPR, and XRD. The samples containing {approximately}25 wt % CuO exhibited a maximum catalytic activity in the water-gas shift reaction. The catalytic activity was attributed to copper ions aggregated on the highly dispersed and defective CuO surface and to an anion-modified ZnO surface. Aggregates of copper ions, formed on metal species and probably modified with hydroxyl and carbonate groups, were shown to play a decisive role in the catalytic activity of the samples containing more than 15 wt % CuO.

  13. Cu,Zn SOD in Shandong families with amyotrophic lateral sclerosis

    Institute of Scientific and Technical Information of China (English)

    GU Hong-yan; ZHANG Feng-zhen; JIANG Han-Ming; SUN Ling-Yun; ZAI Jing; ZHANG Yuan-ying

    2004-01-01

    Objective: To understand the relationship between Cu,Zn SOD and amyotrophic lateral sclerosis. Methods: The patients were clinically examined and classified according to the E1 Escorial Criteria, then we obtained blood samples from the patients for Cu,Zn SOD analysis and SOD assay. Amino acid analysis of Cu,Zn SOD were fully automated in instruments called amino acid analyzers. SOD assay was determined by cytochrome c method Results: Amino acid analysis of Cu,Zn SOD from patients with familial ALS was normal. The activity of Cu,Zn SOD was normal both in familial and sporadic form of ALS compared with normal person. Conclusion: Amyotrophic lateral sclerosis is not related to Cu,Zn SOD.

  14. Tensile behavior of Sn-0.7Cu with Zn addition at various deformation temperatures

    Institute of Scientific and Technical Information of China (English)

    Zhongbing LUO; Jie ZHAO; Junshan ZHANG; Lai WANG

    2011-01-01

    The tensile behavior of Sn-0.7Cu and Sn-0.7Cu-lZn was compared at various deformation temperatures. Refined microstructure and γ-CuZn particles were discovered with Zn addition. The strengths of Zn-containing solder were higher than that of Sn-0.7Cu at room and subzero temperatures. With the elevation of deformation temperature, they both decreased and they were nearly the same at 80 ℃. The works of fracture exhibited the similar evolution law. For Sn-0.7Cu solder, the elongation after fracture was smaller and the reduction of area was bigger than those of Sn-0.7Cu-1Zn. This shows that Zn addition improved the deformation stability, which is attributed to the modification of the microstructure. Dimples in fracture surface became smaller and shallower with the decreasing temperature. Ductile fracture was discovered in all the samples.

  15. Research of Interaction Between Zn Based Solders and Cu, Al Substrates

    Directory of Open Access Journals (Sweden)

    Prach Michal

    2014-06-01

    Full Text Available The paper deals with the study of interaction between Cu, Al substrates (purity 5N and ZnAl4, ZnAg6Al6 zinc solders for higher application temperatures. Soldering was performed with power ultrasound in the air without flux application at temperature 420 °C. Acting time of ultrasonic vibration was 3 s and ultrasound frequency was 40 kHz. Soldered joints were assessed by optical light microscopy and EDX microanalysis. Intermetallic layers (IM CuZn4 and Cu5Zn8 were formed at the Cu/ZnAl4 boundary. The βZn-αAl mechanical mixture was formed at the Al/ZnAl4 boundary. AgZn3 and Cu5Zn8 IM layers were formed at the Cu/ZnAg6Al6 boundary, and mechanical mixture of βZn-αAl and AgZn3 intermetallic mixture were formed at the boundary Al/ZnAg6Al6.

  16. Metathesis synthesis and characterization of complex metal fluoride, KMF3 (M = Mg, Zn, Mn, Ni, Cu and Co) using mechanochemical activation

    Indian Academy of Sciences (India)

    V Manivannan; P Parhi; Jonathan W Kramer

    2008-12-01

    Metathesis synthesis of complex metal fluorides using mechanochemical activation has been reported. The high lattice energy of the byproduct KCl helps the reaction towards product formation in under 20 min. The proposed process, in contrast to the available methods of synthesis, is very rapid, economical and results in products with controlled morphology. The structural, optical and chemical properties of synthesized powders are determined by powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, magnetization measurements and diffused reflectance spectra in the UV–VIS range.

  17. Concentrative phenomenon of relative content ratios of Cu, Pb and Zn in soils

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is discovered that there is the concentrative phenomenon of relative content ratios of Cu, Pb and Zn in soil by studying their parageneous association in soil, meterites and rocks with the relative content ratios. This not only is helpful to understand the trends of Cu, Cd and Zn enriched and dispersed in the evolution course of earth matter, but also provide evidence for geochemical self-organization that there may be in the process of Cu, Pb and Zn translation and distribution.

  18. Detection of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases in co-evaporated Cu2ZnSnSe4 thin-films

    Science.gov (United States)

    Schwarz, Torsten; Marques, Miguel A. L.; Botti, Silvana; Mousel, Marina; Redinger, Alex; Siebentritt, Susanne; Cojocaru-Mirédin, Oana; Raabe, Dierk; Choi, Pyuck-Pa

    2015-10-01

    Cu2ZnSnSe4 thin-films for photovoltaic applications are investigated using combined atom probe tomography and ab initio density functional theory. The atom probe studies reveal nano-sized grains of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 composition, which cannot be assigned to any known phase reported in the literature. Both phases are considered to be metastable, as density functional theory calculations yield positive energy differences with respect to the decomposition into Cu2ZnSnSe4 and ZnSe. Among the conceivable crystal structures for both phases, a distorted zinc-blende structure shows the lowest energy, which is a few tens of meV below the energy of a wurtzite structure. A band gap of 1.1 eV is calculated for both the Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases. Possible effects of these phases on solar cell performance are discussed.

  19. Enhanced wetting of Cu on ZnO by migration of subsurface oxygen vacancies

    DEFF Research Database (Denmark)

    Beinik, Igor; Helström, Matti; Jensen, Thomas Nørregaard;

    2015-01-01

    is of utmost importance. The Cu/ZnO system is among the most investigated of such systems in model studies, but the presence of subsurface ZnO defects and their important role for adhesion on ZnO have been unappreciated so far. Here we reveal that the surface-directed migration of subsurface defects affects...... the Cu adhesion on polar ZnO(0001) in the technologically interesting temperature range up to 550 K. This leads to enhanced adhesion and ultimately complete wetting of ZnO(0001) by a Cu overlayer. On the basis of our experimental and computational results we demonstrate a mechanism which implies...

  20. Low temperature sintering of MgCuZn ferrite and its electrical and magnetic properties

    Indian Academy of Sciences (India)

    S R Murthy

    2001-08-01

    The low temperature sintering of MgCuZn ferrite was investigated using the usual ceramic method. The effect of Cu substitution on the properties of MgZn ferrites was also investigated and it was found that the densification of MgCuZn ferrite is dependent upon Cu concentration. The sintered ferrite with a density of 4.93 g/cm3 and electrical resistivity > 1011-cm was obtained for the ferrite with 12 mol% Cu at relatively low sintering temperature (910°C). The magnetic properties of the ferrites also improved by the Cu substitution. The chip inductors made of the ferrite fired at 910 C with 12 mol% Cu exhibited higher d.c. resistance. From these studies it is concluded that the good quality chip inductor can be obtained using the MgCuZn ferrites.

  1. CuO and ZnO nanoparticles: phytotoxicity, metal speciation, and induction of oxidative stress in sand-grown wheat

    Energy Technology Data Exchange (ETDEWEB)

    Dimkpa, Christian O., E-mail: cdimkpa@usu.edu [Utah State University, Department of Biological Engineering (United States); McLean, Joan E. [Utah State University, Utah Water Research Laboratory (United States); Latta, Drew E. [Argonne National Laboratory, Biosciences Division (United States); Manangon, Eliana [University of Utah, Department of Geology and Geophysics (United States); Britt, David W. [Utah State University, Department of Biological Engineering (United States); Johnson, William P. [University of Utah, Department of Geology and Geophysics (United States); Boyanov, Maxim I. [Argonne National Laboratory, Biosciences Division (United States); Anderson, Anne J. [Utah State University, Department of Biological Engineering (United States)

    2012-09-15

    Metal oxide nanoparticles (NPs) are reported to impact plant growth in hydroponic systems. This study describes the impact of commercial CuO (<50 nm) and ZnO (<100 nm) NPs on wheat (Triticum aestivum) grown in a solid matrix, sand. The NPs contained both metallic and non-metallic impurities to different extents. Dynamic light scattering and atomic force microscopy (AFM) assessments confirmed aggregation of the NPs to submicron sizes. AFM showed transformation of ZnO NPs from initial rhomboid shapes in water to elongated rods in the aqueous phase of the sand matrix. Solubilization of metals occurred in the sand at similar rates from CuO or ZnO NPs as their bulk equivalents. Amendment of the sand with 500 mg Cu and Zn/kg sand from the NPs significantly (p = 0.05) reduced root growth, but only CuO NPs impaired shoot growth; growth reductions were less with the bulk amendments. Dissolved Cu from CuO NPs contributed to their phytotoxicity but Zn release did not account for the changes in plant growth. Bioaccumulation of Cu, mainly as CuO and Cu(I)-sulfur complexes, and Zn as Zn-phosphate was detected in the shoots of NP-challenged plants. Total Cu and Zn levels in shoot were similar whether NP or bulk materials were used. Oxidative stress in the NP-treated plants was evidenced by increased lipid peroxidation and oxidized glutathione in roots and decreased chlorophyll content in shoots; higher peroxidase and catalase activities were present in roots. These findings correlate with the NPs causing increased production of reactive oxygen species. The accumulation of Cu and Zn from NPs into edible plants has relevance to the food chain.

  2. The effect of Cu/Zn molar ratio on CO2 hydrogenation over Cu/ZnO/ZrO2/Al2O3 catalyst

    Science.gov (United States)

    Shaharun, Salina; Shaharun, Maizatul S.; Mohamad, Dasmawati; Taha, Mohd F.

    2014-10-01

    Catalytic hydrogenation of carbon dioxide (CO2) to methanol is an attractive way to recycle and utilize CO2. A series of Cu / ZnO / Al2O3/ZrO2 catalysts (CZAZ) containing different molar ratios of Cu/Zn were prepared by the co-precipitation method and investigated in a stirred slurry autoclave system. The catalysts were characterized by temperature-programmed reduction (TPR), field emission scanning electron microscopy-energy dispersive analysis (FESEM-EDX), X-ray diffraction (XRD) and N2 adsorption-desorption. Higher surface area, SABET values (42.6-59.9 m2/g) are recorded at low (1) and high (5) Cu/Zn ratios with the minimum value of 35.71 m2/g found for a Cu/Zn of 3. The reducibility of the metal oxides formed after calcination of catalyst samples was also affected due to change in metal-support interaction. At a low reaction temperature of 443 K, total gas pressure of 3.0 MPa and 0.1 g/mL of the CZAZ catalyst, the selectivity to methanol decreased as the Cu/Zn molar ratio increased, and the maximum selectivity of 67.73 was achieved at Cu/Zn molar ratio of 1. With a reaction time of 3h, the best performing catalyst was CZAZ75 with Cu/Zn molar ratio of 5 giving methanol yield of 79.30%.

  3. Elastocaloric effect in CuAlZn and CuAlMn shape memory alloys under compression.

    Science.gov (United States)

    Qian, Suxin; Geng, Yunlong; Wang, Yi; Pillsbury, Thomas E; Hada, Yoshiharu; Yamaguchi, Yuki; Fujimoto, Kenjiro; Hwang, Yunho; Radermacher, Reinhard; Cui, Jun; Yuki, Yoji; Toyotake, Koutaro; Takeuchi, Ichiro

    2016-08-13

    This paper reports the elastocaloric effect of two Cu-based shape memory alloys: Cu68Al16Zn16 (CuAlZn) and Cu73Al15Mn12 (CuAlMn), under compression at ambient temperature. The compression tests were conducted at two different rates to approach isothermal and adiabatic conditions. Upon unloading at a strain rate of 0.1 s(-1) (adiabatic condition) from 4% strain, the highest adiabatic temperature changes (ΔTad) of 4.0 K for CuAlZn and 3.9 K for CuAlMn were obtained. The maximum stress and hysteresis at each strain were compared. The stress at the maximum recoverable strain of 4.0% for CuAlMn was 120 MPa, which is 70% smaller than that of CuAlZn. A smaller hysteresis for the CuAlMn alloy was also obtained, about 70% less compared with the CuAlZn alloy. The latent heat, determined by differential scanning calorimetry, was 4.3 J g(-1) for the CuAlZn alloy and 5.0 J g(-1) for the CuAlMn alloy. Potential coefficients of performance (COPmat) for these two alloys were calculated based on their physical properties of measured latent heat and hysteresis, and a COPmat of approximately 13.3 for CuAlMn was obtained.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'.

  4. Effect of Cu doping on the properties of ZnTe:Cu thin films and CdS/CdTe/ZnTe solar cells

    Science.gov (United States)

    Tang, J.; Mao, D.; Trefny, J. U.

    1997-02-01

    The effects of Cu doping concentration and post-deposition annealing treatment on the properties of ZnTe thin films were investigated in an effort to decrease the Cu doping concentration and improve the long-term stability of CdS/CdTe/ZnTe solar cells. The structural, compositional, and electrical properties were studied systematically using x-ray diffraction (XRD), electron microprobe, Hall effect and conductivity measurements. XRD measurements indicated that the crystalline phase of as-deposited and low-temperature annealed ZnTe films is dependent on Cu doping concentration. Low-Cu-doped films exhibited zincblende phase, whereas high-Cu-doped films showed wurtzite phase. After annealing at high temperature (⩾350 °C), all films exhibited zincblende structure. Electron probe microanalysis revealed a deficiency of cations in low-Cu-doped films and an excess of cations in high-Cu-doped films. Hall effect measurements revealed a dependence of hole mobility on Cu doping concentration with the highest mobility (20 cm2/Vṡs) obtained at a low Cu concentration. Carrier concentrations higher than mid-1016cm-3 were obtained at a Cu concentration of 2 at. % and relatively low annealing temperatures. Studies of the activation energy of dark conductivity suggested that intrinsic defects (e.g., Zn vacancies) are the dominant acceptors for Cu concentrations lower than 4.5 at. %. Finally, ZnTe films with Cu concentrations as low as 1 at. % were used successfully as a back contact layer in CdTe based solar cells. Fill factors over 0.70 were obtained using ZnTe films of low Cu concentrations.

  5. Efficient Thermolysis Route to Monodisperse Cu2ZnSnS4 Nanocrystals with Controlled Shape and Structure

    Science.gov (United States)

    Zhang, Xiaoyan; Guo, Guobiao; Ji, Cheng; Huang, Kai; Zha, Chenyang; Wang, Yifeng; Shen, Liming; Gupta, Arunava; Bao, Ningzhong

    2014-05-01

    Monodisperse Cu2ZnSnS4 (CZTS) nanocrystals with tunable shape, crystalline phase, and composition are synthesized by efficient thermolysis of a single source precursor of mixed metal-oleate complexes in hot organic solvents with dissolved sulfur sources. Suitable tuning of the synthetic conditions and the Cu/(Zn + Sn) ratio of the precursor has enabled precise control of the crystalline phase in the form of kesterite, or a newly observed wurtzite structure. Nanocrystals with morphology in the form of spherical, rice-like, or rod-like shapes are obtained over a wide range of compositions (0.5 <= Cu/(Zn + Sn) <= 1.2). Both the final products and intermediates for each shape exhibit consistent composition and structure, indicating homogenous nucleation and growth of single-phase nanocrystals. Thin films prepared from colloidal nanocrystal suspensions display interesting shape-dependent photoresponse behavior under white light illumination from a solar simulator.

  6. Quantifying point defects in Cu2ZnSn(S,Se)4 thin films using resonant x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Kevin H. [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA; Christensen, Steven T. [National Renewable Energy Laboratory, Golden, Colorado 80401, USA; Harvey, Steven P. [National Renewable Energy Laboratory, Golden, Colorado 80401, USA; Teeter, Glenn [National Renewable Energy Laboratory, Golden, Colorado 80401, USA; Repins, Ingrid L. [National Renewable Energy Laboratory, Golden, Colorado 80401, USA; Toney, Michael F. [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA

    2016-10-17

    Cu 2ZnSn(S,Se)4 is an interesting, earth abundant photovoltaic material, but has suffered from low open circuit voltage. To better understand the film structure, we have measured resonant x-ray diffraction across the Cu and Zn K-edges for the device quality thin films of Cu 2ZnSnS4 (8.6% efficiency) and Cu 2ZnSn(S,Se)4 (3.5% efficiency). This approach allows for the confirmation of the underlying kesterite structure and quantification of the concentration of point defects and vacancies on the Cu, Zn, and Sn sublattices. Rietveld refinement of powder diffraction data collected at multiple energies is used to determine that there exists a high level of Cu Zn and Zn Cu defects on the 2c and 2d Wyckoff positions. We observe a significantly lower concentration of Zn Sn defects and Cu or Zn vacancies.

  7. Quantifying point defects in Cu2ZnSn(S,Se)4 thin films using resonant x-ray diffraction

    Science.gov (United States)

    Stone, Kevin H.; Christensen, Steven T.; Harvey, Steven P.; Teeter, Glenn; Repins, Ingrid L.; Toney, Michael F.

    2016-10-01

    Cu2ZnSn(S,Se)4 is an interesting, earth abundant photovoltaic material, but has suffered from low open circuit voltage. To better understand the film structure, we have measured resonant x-ray diffraction across the Cu and Zn K-edges for the device quality thin films of Cu2ZnSnS4 (8.6% efficiency) and Cu2ZnSn(S,Se)4 (3.5% efficiency). This approach allows for the confirmation of the underlying kesterite structure and quantification of the concentration of point defects and vacancies on the Cu, Zn, and Sn sublattices. Rietveld refinement of powder diffraction data collected at multiple energies is used to determine that there exists a high level of CuZn and ZnCu defects on the 2c and 2d Wyckoff positions. We observe a significantly lower concentration of ZnSn defects and Cu or Zn vacancies.

  8. Preparation of Cu2ZnSnS4 thin films by hybrid sputtering

    Science.gov (United States)

    Tanaka, Tooru; Nagatomo, Takeshi; Kawasaki, Daisuke; Nishio, Mitsuhiro; Guo, Qixin; Wakahara, Akihiro; Yoshida, Akira; Ogawa, Hiroshi

    2005-11-01

    In order to fabricate Cu2ZnSnS4 thin films, hybrid sputtering system with two sputter sources and two effusion cells is used. The Cu2ZnSnS4 films are fabricated by the sequential deposition of metal elements and annealing in S flux, varying the substrate temperature. The Cu2ZnSnS4 films with stoichiometric composition are obtained at the substrate temperature up to 400 °C, whereas the film composition becomes quite Zn-pool at the substrate temperature above 450 °C. The Cu2ZnSnS4 film shows p-type conductivity, and the optical absorption coefficient and the band gap of the Cu2ZnSnS4 film prepared in this experiment are suitable for fabricating a thin film solar cell.

  9. X-ray excited ZnS:Cu,Co afterglow nanoparticles for photodynamic activation

    Science.gov (United States)

    Ma, Lun; Zou, Xiaoju; Bui, Brian; Chen, Wei; Song, Kwang Hyun; Solberg, Timothy

    2014-07-01

    Copper and cobalt co-doped ZnS (ZnS:Cu,Co) afterglow nanoparticles were conjugated to photosensitizer tetrabromorhodamine-123 (TBrRh123) and efficient energy transfer from the nanoparticles to TBrRh123 was observed. In addition to their X-ray excited luminescence, the ZnS:Cu,Co nanoparticles also show long lasting afterglow, which continuously serve as a light source for photodynamic therapy (PDT) activation. Compared to TBrRh123 or ZnS:Cu,Co alone, the ZnS:Cu,Co-TBrRh123 conjugates show low dark toxicity but high X-ray induced toxicity to human prostate cancer cells. The results indicate that the ZnS:Cu,Co afterglow nanoparticles have a good potential for PDT activation.

  10. ZnCuInS/ZnSe/ZnS Quantum Dot-Based Downconversion Light-Emitting Diodes and Their Thermal Effect

    Directory of Open Access Journals (Sweden)

    Wenyan Liu

    2015-01-01

    Full Text Available The quantum dot-based light-emitting diodes (QD-LEDs were fabricated using blue GaN chips and red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. The power efficiencies were measured as 14.0 lm/W for red, 47.1 lm/W for yellow, and 62.4 lm/W for green LEDs at 2.6 V. The temperature effect of ZnCuInS/ZnSe/ZnS QDs on these LEDs was investigated using CIE chromaticity coordinates, spectral wavelength, full width at half maximum (FWHM, and power efficiency (PE. The thermal quenching induced by the increased surface temperature of the device was confirmed to be one of the important factors to decrease power efficiencies while the CIE chromaticity coordinates changed little due to the low emission temperature coefficients of 0.022, 0.050, and 0.068 nm/°C for red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. These indicate that ZnCuInS/ZnSe/ZnS QDs are more suitable for downconversion LEDs compared to CdSe QDs.

  11. Dielectric behaviour of Zn substituted Cu nano-ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Parashar, Jyoti, E-mail: phyjyoti.2@gmail.com [Department of Physics, University of Rajasthan, Jaipur 302055 (India); Saxena, V.K.; Jyoti; Bhatnagar, Deepak [Department of Physics, University of Rajasthan, Jaipur 302055 (India); Sharma, K.B. [Department of Physics, S.S. Jain Subodh P.G. College, Jaipur 302004 (India)

    2015-11-15

    Herein, the dielectric properties such as permittivity (real part ε′ and imaginary part ε′′) and dielectric loss tangent (tan δ) are reported for Zn substituted Cu ferrites (Cu{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4}; 0≤x≤1) composite using the sol–gel auto-combustion method. The variations of real and imaginary part of dielectric constant, tan δ and AC conductivity (σ{sub ac}) are studied at room temperature in the frequency range of 100 Hz–120 MHz. The real part of dielectric constant decrease with increasing frequency and the imaginary part (ε′′) varies with frequency showing the characteristic peak for each sample. The relation of tan δ with frequency shows relaxation spectra. Further, the σ{sub ac} tended to increase with increase in frequency. The variation in dielectric constant may be explained on the basis of space charge polarization, according to Maxwell and Wagner two-layer model. The dielectric constant and tan δ as a function of temperature are also studied with different temperatures ranging from 323 K to 583 K. - Highlights: • Zn substituted Cu nano-ferrite samples bearing formula Cu{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4}(0≤x≤1) are synthesized by the sol–gel auto combustion method. • The variation of real and imaginary parts of dielectric constant, dielectric loss tangent (tan δ) and AC conductivity with frequency are reported in the frequency range from 100 Hz to 120 MHz at room temperature. • The real part of dielectric constant (ε′) decreases with increasing frequency where as the AC conductivity (σ{sub ac}) increases with increase in frequency. The relation of tan δ with frequency shows relaxation spectra. • The variation in dielectric constant may be explained on the basis of space charge polarization, according to Maxwell and Wagner two-layer model. • Dielectric constant as a function of temperature is studied at different temperatures ranging from 323 K to 583 K.

  12. The Effects of Sputtering Target Preparation and Deposition Temperature on ZnTe:Cu Film Properties

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, Brooke R.; Ohno, T. R.; Burst, James M.; Duenow, Joel N.; Perkins, Craig L.; To, Bobby; Gessert, Timothy A.

    2015-06-14

    A back contact containing a sputtered ZnTe:Cu interface layer can produce high-performing thin-film CdS/CdTe photovoltaic devices. We have found that varying the ZnTe:Cu sputtering target fabrication processes and deposition temperature can affect material properties of the ZnTe:Cu films and the resulting device performance. Two different target 'recipes' with various copper contents were used to study changes in the compositional, structural, optical, and electrical properties of ZnTe:Cu films. Substrate temperature during deposition was also varied to investigate the temperature dependence of the films. It was found that the target recipe, Cu concentration in the target, and deposition temperature affect the composition of the ZnTe:Cu films, which impacts their structural, optical, and electrical properties.

  13. Facile synthesis and photocatalytic activity of bi-phase dispersible Cu-ZnO hybrid nanoparticles.

    Science.gov (United States)

    Liu, Xiao; Liu, HongLing; Zhang, WenXing; Li, XueMei; Fang, Ning; Wang, XianHong; Wu, JunHua

    2015-01-01

    Bi-phase dispersible Cu-ZnO hybrid nanoparticles were synthesized by one-pot non-aqueous nanoemulsion with the use of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) show high crystallinity of the Cu-ZnO hybrid nanoparticles and an average particle size of ~19.4 nm. The ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL) demonstrate well dispersibility and excellent optical performance of Cu-ZnO hybrid nanoparticles both in organic and aqueous solvent. The X-ray photoelectron spectroscopy (XPS) confirms Cu(1+) and Cu(2+) in ZnO. The observation using Sudan red (III) as probe molecule reveals that the Cu-ZnO hybrid nanoparticles possess enhanced photocatalytic activity and stability which are promising for potential applications in photocatalysis.

  14. Stability of Hume-Rothery phases in Cu Zn alloys at pressures up to 50 GPa

    Science.gov (United States)

    Degtyareva, V. F.; Degtyareva, O.; Sakharov, M. K.; Novokhatskaya, N. I.; Dera, P.; Mao, H. K.; Hemley, R. J.

    2005-12-01

    The crystal structure of the γ-brass phase Cu5Zn8 is confirmed with single-crystal x-ray diffraction and CCD detector to be cubic with 52 atoms in the unit cell, space group I\\bar {4}3m , and the refined atomic positions are in good agreement with previously reported data. The structural behaviour of α-(fcc), β-(bcc), and γ-brass (cI52) phases of the Cu-Zn alloy system has been studied under pressure using diamond anvil cells and powder x-ray diffraction with synchrotron radiation. The appearance of additional peaks in the diffraction patterns of α- and β-phases indicates the beginning of transitions to new phases at 17 and 37 GPa, respectively. The complex cubic γ-brass phase is observed to be stable up to at least 50 GPa. The bulk modulus K0 was determined as 140(4) GPa for α-, 139(5) GPa for β-, and 121(2) GPa for γ-phase assuming K0' = 4. The structural stability of brass phases of the Cu-Zn system under pressure is discussed in terms of a Hume-Rothery mechanism.

  15. Zn—Cu Interaction Affecting Zn Adsorption and Plant Availability in a Metal—Contaminated Soil

    Institute of Scientific and Technical Information of China (English)

    D.L.Rimmer; LuoYongming

    1996-01-01

    In a previous greenhouse experiment,we showed that there was an interaction between cu and Zn,which affected growth and metal uptake by young barley plants grown on soil to which Cd,Cu,Pb,and Zn had been added.We suggested that the underlying mechanism was the control of the amount of plant-available Zn by competitive adsorption between Cu and Zn,In order to test this hypothesis,the adsorption of Zn alone,and in the presence of added Cd,Cu and Pb,has been measured using the same soil.Following adsorption,the extractability of the Zn in CaCl2 solution was measured .The adsorption isotherms showed that of the added metals only Cu had a large effect on Zn adsorption.The effect of Cu was to reduce Zn adsoption and to increase the amount of CaCl2-extractable(i.e.plant-available) Zn,in agreement with the conclusions from the greenhouse experiment.The magnitude of the effect of Cu on plant-avalilable Zn was similar in both experiments.

  16. Mixed ligand complexes of Cu(II)/Zn(II) ions containing (m-)/(p-) carboxylato phenyl azo pentane 2,4-dione and 2,2‧-bipyridine/1,10 phenanthroline: Synthesis, characterization, DNA binding, nuclease and topoisomerase I inhibitory activity

    Science.gov (United States)

    Hasan, Md. Amin; Kumari, Niraj; Singh, Kanhaiya; Singh, Kiran; Mishra, Lallan

    2016-01-01

    Metal complexes of type [Cu(L1H)2(bpy)] (1), [Zn(L1H)2(bpy)] (2), [Cu(L2H)2(bpy)] (3) and [Cu(L2H)2(Phen)] (4) (L1H2 = 3-[N‧-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, L2H2 = 4-[N‧-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, bpy = 2,2‧-bipyridine, Phen = 1,10 phenanthroline) are synthesized and characterized using spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, electronic absorption and emission) and elemental analysis data. The assembly of the complexes involving intramolecular H-bonding is displayed using corresponding crystal structure. Binding of the complexes separately with Calf Thymus DNA is monitored using UV-vis spectral titrations. The displacement of ethidium bromide (EB) bound to DNA by the complexes, in phosphate buffer solution (pH ∼ 7.2) is monitored using fluorescence spectral titrations. Nuclease activity of the complexes follow the order 4 > 3 > 1 > 2. The gel electrophoretic mobility assay measurement in presence of minor groove binder 4‧,6-diamidino-2-phenylindole (DAPI), suggests that complexes preferably bind with the minor groove of DNA. Topoisomerase I inhibitory activity of the complexes 3 and 4 inhibit topoisomerase I activity with IC50 values of 112 and 87 μM respectively.

  17. Mixed ligand complexes of Cu(II)/Zn(II) ions containing (m-)/(p-) carboxylato phenyl azo pentane 2,4-dione and 2,2'-bipyridine/1,10 phenanthroline: Synthesis, characterization, DNA binding, nuclease and topoisomerase I inhibitory activity.

    Science.gov (United States)

    Hasan, Md Amin; Kumari, Niraj; Singh, Kanhaiya; Singh, Kiran; Mishra, Lallan

    2016-01-05

    Metal complexes of type [Cu(L1H)2(bpy)] (1), [Zn(L1H)2(bpy)] (2), [Cu(L2H)2(bpy)] (3) and [Cu(L2H)2(Phen)] (4) (L1H2=3-[N'-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, L2H2=4-[N'-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, bpy=2,2'-bipyridine, Phen=1,10 phenanthroline) are synthesized and characterized using spectroscopic techniques (FT-IR, (1)H NMR, (13)C NMR, electronic absorption and emission) and elemental analysis data. The assembly of the complexes involving intramolecular H-bonding is displayed using corresponding crystal structure. Binding of the complexes separately with Calf Thymus DNA is monitored using UV-vis spectral titrations. The displacement of ethidium bromide (EB) bound to DNA by the complexes, in phosphate buffer solution (pH∼7.2) is monitored using fluorescence spectral titrations. Nuclease activity of the complexes follow the order 4>3>1>2. The gel electrophoretic mobility assay measurement in presence of minor groove binder 4',6-diamidino-2-phenylindole (DAPI), suggests that complexes preferably bind with the minor groove of DNA. Topoisomerase I inhibitory activity of the complexes 3 and 4 inhibit topoisomerase I activity with IC50 values of 112 and 87μM respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Microstructure Properties of Rapidly Solidified Al-Zn-Mg-Cu Alloys

    Directory of Open Access Journals (Sweden)

    Emad M. Ahmed

    2014-01-01

    Full Text Available The Rietveld X-ray diffraction analysis was applied to analyze the weight fraction of precipitation phases and microstructure characterizations of rapidly solidified Al-8Zn-4Mg-xCu, x = 1, 4, 8, and 10 alloys (in wt.%, prepared by melt spun technique. A good agreement between observed and calculated diffraction pattern was obtained and the conventional Rietveld factors (Rp, Rwp, and GOF converged to satisfactory values. Solid solubilities of Zn, Mg, and Cu in α-Al were extended to high values. Besides, metastable Al0.71Zn0.29, intermetallic Al2CuMg, Al2Cu, and CuMgZn phases have been observed for x = 4, 8, and 10 Cu alloys. The crystal structure and microstructure characterizations exhibit strong Cu content dependence.

  19. Relationship between BMD and Zn, Cu, Ca Levels in the Hair and Meal in Elderly People

    Institute of Scientific and Technical Information of China (English)

    LI Wanli; TIAN Yuhui; SONG Xiaofei; ZHANG Min; SHEN Guanxin

    2005-01-01

    The relationship between bone mineral density (BMD) and Zn, Cu, Ca levels in the meal and hair of urban and rural elderly people were studied. 470 subjects above 60 years old (urban 205 and rural 265), 178 males with an average age of 65.70±3.48 and 292 females with an average age of 65.90±4.02, were inquired. The BMD and Zn, Cu, Ca levels in the meal and hair were measured. The detected BMD in urban and rural female old people was significantly lower than that of the males; The contents of Ca and Zn in the meal of the urban females were significantly lower than those of the urban males; The Ca, Zn in the meal and Zn in the hair of the rural females were significantly lower than those of rural males (P< 0.05 or 0.01). The BMD, Ca intakes, Ca and Zn in the hair of the rural old people were significantly lower than those of the urban old people (P<0.05 or 0.01). There was a correlation between BMD with the Ca, Zn of the hair and dietary Ca,Zn, Cu or between dietary Zn with Ca, Zn in the hair and Ca, Cu intakes. The Zn, Cu and Ca levels in the meal nutrients were correlated with BMD to some degrees. Lack of Ca and Zn in the meal can cause the reduction of BMD.

  20. Cu isotope variability in Bavariás largest Cu-Zn deposit in Kupferberg (NE Bavaria, Germany)

    Science.gov (United States)

    Höhn, Stefan; Frimmel, Hartwig E.; Debaille, Vinciane; Debouge, Wendy

    2016-04-01

    Kupferberg, a small town c. 15 km northeast of Kulmbach, owns its existence to Bavaria's largest Cu-Zn deposit, which was mined intermittently from the 13th to the 19th century. The deposit is located in the Saxothuringian Zone of the Variscan basement in northeastern Bavaria. It is positioned between the allochthonous Münchberg metamorphic complex in the east and a major northwest-southeast tending regional fault zone, the "Franconian Lineament", in the west. The deposit is hosted by an Early Palaeozoic volcano-sedimentary succession of the Randschiefer Formation (RF) and consists of a northwest-southeast directed string of several stratiform, sulfide-rich ore lenses. These lenses show a remarkably simple mineralogy dominated by quartz, carbonate, pyrite and chalcopyrite with minor amounts of sphalerite and chlorite. The genesis of the Cu-Zn mineralization has remained speculative. A purely syngenetic model, supported by the generally laminated appearance of the ore, has to be questioned because of the ore lenses occurring in different tectonic units. Urban & Vaché (1972) proposed supergene enrichment between the Cretaceous and the Tertiary as most critical. To test such a supergene versus hypogene Cu-mineralization, we investigated the Cu isotopic composition of primary and secondary Cu phases as well as the trace element distribution in three pyrite generations. The pyrite generation that is coeval with the principal Cu-mineralization in the form of chalcopyrite has Co/Ni ratios (on average 35) typical of hydrothermal, possibly metamorphic, formation. Chalcopyrite, present at highly variable modal proportions, yielded a narrow range in δ65Cu from -0.26 to 0.36 ‰Ḃoth the absolute values and the narrow range are similar to the δ65Cu range known for hydrothermal chalcopyrite in crustal rocks (Markl et al. 2006). Metamorphism has been shown to further restrict the range in δ65Cu (Ikehata et al. 2011) - an effect that might be applicable to Kupferberg. In

  1. Thermal behavior of MOCVD-grown Cu-clusters on ZnO(1010).

    Science.gov (United States)

    Kroll, Martin; Löber, Thomas; Schott, Vadim; Wöll, Christof; Köhler, Ulrich

    2012-02-01

    Scanning tunnelling microscopy (STM) and X-ray photoelectron spectroscopy (XPS, AES) were used to study MOCVD of Cu-clusters on the mixed terminated ZnO(1010) surface in comparison to MBE Cu-deposition. Both deposition methods result in the same Cu cluster morphology. After annealing to 670 K the amount of Cu visible above the oxide surface is found to decrease substantially, indicating a substantial diffusion of Cu atoms inside the ZnO-bulk. The spectroscopic data do not show any evidence for changes in the Cu oxidation state during thermal treatment up to 770 K.

  2. Cu2+ in layered compounds: origin of the compressed geometry in the model system K2ZnF4:Cu2+.

    Science.gov (United States)

    Aramburu, J A; García-Lastra, J M; García-Fernández, P; Barriuso, M T; Moreno, M

    2013-06-17

    Many relevant properties (including superconductivity and colossal magnetoresistance) of layered materials containing Cu(2+), Ag(2+), or Mn(3+) ions are commonly related to the Jahn-Teller instability. Along this line, the properties of the CuF6(4-) complex in the K2ZnF4 layered perovskite have recently been analyzed using a parametrized Jahn-Teller model with an imposed strain [Reinen, D. Inorg. Chem.2012, 51, 4458]. Here, we present results of ab initio periodic supercell and cluster calculations on K2ZnF4:Cu(2+), showing unequivocally that the actual origin of the unusual compressed geometry of the CuF6(4-) complex along the crystal c axis in that tetragonal lattice is due to the presence of an electric field due to the crystal surrounding the impurity. Our calculations closely reproduce the experimental optical spectrum. The calculated values of the equilibrium equatorial and axial Cu(2+)-F(-) distances are, respectively, R(ax) = 193 pm and R(eq) = 204 pm, and so the calculated distortion R(ax) - R(eq) = 11 pm is three times smaller than the estimated through the parametrized Jahn-Teller model. As a salient feature, we find that if the CuF6(4-) complex would assume a perfect octahedral geometry (R(ax) = R(eq) = 203 pm) the antibonding a(1g)*(∼3z(2) - r(2)) orbital is placed above b(1g)*(∼x(2) - y(2)) with a transition energy E((2)A(1g) → (2)B(1g)) = 0.34 eV. This surprising fact stresses that about half the experimental value E((2)A(1g) → (2)B(1g)) = 0.70 eV is not due to the small shortening of the axial Cu(2+)-F(-) distance, but it comes from the electric field, E(R)(r), created by the rest of the lattice ions on the CuF6(4-) complex. This internal field, displaying tetragonal symmetry, is thus responsible for the compressed geometry in K2ZnF4:Cu(2+) and the lack of symmetry breaking behind the ligand relaxation. Moreover, we show that the electronic energy gain in this process comes from bonding orbitals and not from antibonding ones. The present

  3. Radiative recombination in Cu2ZnSnSe4 thin films with Cu deficiency and Zn excess

    Science.gov (United States)

    Yakushev, M. V.; Márquez-Prieto, J.; Forbes, I.; Edwards, P. R.; Zhivulko, V. D.; Mudryi, A. V.; Krustok, J.; Martin, R. W.

    2015-12-01

    Thin films of Cu2ZnSnSe4 (CZTSe) with copper deficiency and zinc excess were fabricated at Northumbria University by the selenisation of metallic precursors deposited on Mo/glass and bare glass substrates. Absorption and photoluminescence (PL) measurements were used to examine the film on glass whereas films on Mo/glass were used to produce a solar cell with efficiency of 8.1%. Detailed temperature and excitation intensity analysis of PL spectra allows identification of the main recombination mechanisms as band-to-tail and band-to-band transitions. The latter transition was observed in the spectra from 6 to 300 K.

  4. Structural, chemical and optical evaluation of Cu-doped ZnO nanoparticles synthesized by an aqueous solution method

    Energy Technology Data Exchange (ETDEWEB)

    Iribarren, A., E-mail: augusto@imre.oc.uh.cu [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Hernández-Rodríguez, E. [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Maqueira, L. [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Facultad de Química, Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba)

    2014-12-15

    Highlights: • Cu-doped ZnO nanoparticles obtained by chemical synthesis. • Substitutional or interstitial Cu into ZnO lead specific structural, chemical, and optical changes. • Incorporation efficiency of Cu atoms in ZnO as a function of the Cu concentration in the precursor dissolution. - Abstract: In this work a study of ZnO and Cu-doped ZnO nanoparticles obtained by chemical synthesis in aqueous media was carried out. Structural analysis gave the dominant presence of wurtzite ZnO phase forming a solid solution Zn{sub 1−x}Cu{sub x}O. For high Cu doping CuO phase is also present. For low Cu concentration the lattice shrinks due to Cu atoms substitute Zn atoms. For high Cu concentration the lattice enlarges due to predominance of interstitial Cu. From elemental analysis we determined and analyzed the incorporation efficiency of Cu atoms in Zn{sub 1−x}Cu{sub x}O as a function of the Cu concentration in the precursor dissolution. Combining structural and chemical results we described the Cu/Zn precursor concentrations r{sub w} in which the solid solution of Cu in ZnO is predominant. In the region located at r{sub w} ≈ 0.2–0.3 it is no longer valid. For Cu/Zn precursor concentration r{sub w} > 0.3 interstitial Cu dominates, and some amount of copper oxide appears. As the Cu concentration increases, the effective size of nanoparticles decreases. Photoluminescence (PL) measurements of the Cu-doped ZnO nanoparticles were carried out and analyzed.

  5. Polarized Raman spectroscopy of Cu-poor and Zn-rich single-crystal Cu2ZnSnSe4

    Science.gov (United States)

    Nam, Dahyun; Kim, Jungcheol; Lee, Jae-Ung; Nagaoka, Akira; Yoshino, Kenji; Cha, Wonsuk; Kim, Hyunjung; Hwang, In Chul; Yoon, Kyung Byung; Cheong, Hyeonsik

    2014-10-01

    Cu2ZnSnSe4 (CZTSe) is a p-type semiconductor which has been developed as an absorber layer of polycrystalline thin film solar cells. Generally, Cu-poor and Zn-rich compositions tend to give the highest solar conversion efficiencies. Raman spectroscopy has been used to detect secondary phases such as ZnSe and Cu2SnSe3 in CZTSe thin films. However, the fundamental phonon modes in single-crystal CZTSe with a composition matching that of high-efficiency thin film solar cells have not yet been fully understood. We performed polarized Raman measurements on Cu-poor and Zn-rich single-crystal CZTSe and identified 12 peaks, including two low-frequency peaks. By comparing the polarization dependence of the Raman peaks with a group theoretical analysis, we concluded that the crystal structure of CZTSe single-crystal is kesterite and made appropriate peak assignments.

  6. Absolute densities of Cu, Zn, Sn, and S atoms in magnetron sputtering plasmas employing a Cu2ZnSnS4 target

    Science.gov (United States)

    Nafarizal, Nayan; Sasaki, Koichi

    2016-07-01

    Absolute densities of Cu, Zn, Sn, and S atoms in magnetron sputtering plasmas were measured by ultraviolet absorption spectroscopy and vacuum ultraviolet absorption spectroscopy. A stoichiometric Cu2ZnSnS4 (CZTS) target was used in this work. It was found that, at various Ar pressures, the S density ranged between (2-8) × 1010 cm-3, the Cu and Sn densities ranged between (0.6-3) × 1010 cm-3, and the Zn density ranged between (2-3) × 109 cm-3. The effective depositing flux, which was evaluated from the absolute densities and the sticking probabilities, was comparable with that evaluated from the deposition rate of the CZTS film. However, the composition ratio of Cu, Zn, Sn, and S in the gas phase deviated from the ideal stoichiometry of CZTS. We discussed the possible mechanisms for the difference among the element compositions of the target, the deposited film, and the gas-phase densities.

  7. Cu and Zn adsorption to a heterogeneous natural sediment: Influence of leached cations and natural organic matter.

    Science.gov (United States)

    Fisher-Power, Leanne M; Cheng, Tao; Rastghalam, Zahra Sadat

    2016-02-01

    Adsorption of heavy metals by natural sediments has important implications to the fate and transport of contaminants in subsurface environments. Although the importance of major multivalent cations and dissolved organic matter (DOM) in heavy metal adsorption had been previously demonstrated, the leaching of major cations and DOM from sediments and its influence on heavy metal adsorption have not been fully examined. In this study, the concentrations of Ca, Mg, Al, Fe, and natural organic matter that leached from a natural sediment in Cu and Zn adsorption experiments were measured and used in surface complexation models to elucidate their effects on Cu and Zn adsorption. Experimental results showed that the leaching of cations and DOM was substantial and pH-dependent. The leached concentrations of Ca and Mg were reasonably simulated based on BaCl2 extractable Ca and Mg at pH MINTEQ simulations showed that the leached cations markedly decreased Cu adsorption at pH 6 due to formation of Cu-DOM aqueous complexes, but increase Zn adsorption at pH 4-7 due to formation of aqueous complexes between DOM and major cations, which reduced competition from these cations against Zn for binding sites on the sediment.

  8. Investigations on Cu2+-substituted Ni-Zn ferrite nanoparticles

    Science.gov (United States)

    Amarjeet; Kumar, Vinod

    2016-11-01

    CuxNi(1-x)/2Zn(1-x)/2Fe2O4 (x = 0.1, 0.3 and 0.5) nanoparticles were prepared by chemical co-precipitation method. The developed nanoparticles were characterized for structural properties by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Peak position in the X-ray diffraction pattern confirmed the single spinel phase of the developed particles. Infrared (IR) spectroscopy in mid-IR range showed the presence of characteristic absorption bands corresponding to octahedral and tetrahedral bonds in the spinel structure of prepared samples. Thermo-gravimetric analysis (TGA) measurements showed a considerable weight loss in the developed samples above 700∘C. Frequency dependence of the electrical properties of the developed material pellets was studied in the frequency range of 1 kHz-5 MHz. Temperature dependence of the dielectric constant of Cu0.1Ni0.45Zn0.45Fe2O4 was studied at different temperatures, i.e. at 425, 450 and 475 K, in the frequency range of 1 kHz-5 MHz. It was found that the electrical conductivity decreases with increasing Cu2+ ion content while it increases with the increase in temperature.

  9. Oxidación de Fenol con Catalizadores de CuO/Al2O3, CuO/ZnAl2O4 y CuO-ZnO-AlxOy Oxidation of Phenol with CuO/Al2O3, CuO/ZnAl2O4 and CuO-ZnO-AlxOy Catalysts

    Directory of Open Access Journals (Sweden)

    Isaías Hernández

    2006-01-01

    Full Text Available Fenol en agua residual industrial fue oxidado catalíticamente con O2 en un reactor por lotes. Para este fin, se evaluaron tres series de catalizadores preparados por impregnación de Cu(NO2 en Al2O3 y en ZnAl2O4 y por precipitación de nitratos de Cu, Zn y Al. Se caracterizaron por difracción de rayos-X, absorción atómica, microscopia electrónica, adsorción de N2 y termorreducción programada. Se observó CuO sobre las superficies de todos los catalizadores. Se encontró una fase amorfa solo en los catalizadores soportados en Al2O3 con alta área y en los demás fue cristalina con bajas áreas. La mayor velocidad de reacción fue obtenida por el catalizador másico de 22% de Cu. La velocidad de reacción máxima para todos los catalizadores fue cercana a una concentración de 20% de Cu. Durante la reacción se produjeron compuestos orgánicos oxigenados que aumentaron la acidez del agua residual, la cual atacó la superficie de los catalizadores disolviendo una parte pequeña de Cu, Zn y Al.Fenol in industrial residual water was oxidized catalytically with O2 in a batch reactor. For this purpose, three series of catalysts were evaluated which were prepared by impregnation of Cu(NO2 on Al2O3, on ZnAl2O4 and by precipitation of nitrates of Cu, Zn and Al. They were characterized by x-ray diffraction, atomic absorption, electronic microscopy, adsorption of N2 and temperature programmed reduction. CuO very dispersed was observed on the surface of all the catalysts. It was found an amorphous phase in the Al2O3 supported catalysts with high surface area and in the other ones it was crystalline with low areas. The highest reaction rate was obtained for the massive catalyst with 22% of Cu. The maximum of reaction rate for all the catalysts was near to 20% of Cu. During the reaction it was produced oxygenated organic compounds which increased the acidity of the residual water, which attacked the surface of the catalysts dissolving a small amount of

  10. Pine bark as bio-adsorbent for Cd, Cu, Ni, Pb and Zn

    DEFF Research Database (Denmark)

    Cutillas-Barreiro, L.; Ansias-Manso, L.; Fernandez Calviño, David;

    2014-01-01

    % for Pb2+, 83-84% for Cu2+, 78-84% for Cd2+, 77-83% for Zn2+, and 70-75% for Ni2+, and it was faster for low concentrations, with Pb suffering the highest retention, followed by Cu, Cd, Ni and Zn. The fitting to the Freundlich and Langmuir models was satisfactory. Desorption increased in parallel...

  11. Formation of ferric flocks for the removal of Zn and Cu from dockyard wastewater

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Arevalo, Edurado; Stichnothe, Heinz

    2006-01-01

    Wastewater from wash down of boat hulls contains typically Cu, Zn and organometallic biocides, e.g. tributyltin (TBT). In some cases this wastewater is led directly into the marine system. In the present paper a cheap flocculation method (iron flocculants) for removal of Cu and Zn from...

  12. Activation of a Cu/ZnO catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Andreasen, Jens Wenzel; Rasmussen, F.B.; Helveg, S.;

    2006-01-01

    The structural changes during activation by temperature-programmed reduction of a Cu/ZnO catalyst for methanol synthesis have been studied by several in situ techniques. The catalyst is prepared by coprecipitation and contains 4.76 wt% Cu, which forms a substitutional solid solution with Zn...

  13. Selective recovery of Cu, Zn, and Ni from acid mine drainage.

    Science.gov (United States)

    Park, Sang-Min; Yoo, Jong-Chan; Ji, Sang-Woo; Yang, Jung-Seok; Baek, Kitae

    2013-12-01

    In Korea, the heavy metal pollution from about 1,000 abandoned mines has been a serious environmental issue. Especially, the surface waters, groundwaters, and soils around mines have been contaminated by heavy metals originating from acid mine drainage (AMD) and mine tailings. So far, AMD was considered as a waste stream to be treated to prevent environmental pollutions; however, the stream contains mainly Fe and Al and valuable metals such as Ni, Zn, and Cu. In this study, Visual MINTEQ simulation was carried out to investigate the speciation of heavy metals as functions of pH and neutralizing agents. Based on the simulation, selective pH values were determined to form hydroxide or carbonate precipitates of Cu, Zn, and Ni. Experiments based on the simulation results show that the recovery yield of Zn and Cu were 91 and 94 %, respectively, in a binary mixture of Cu and Zn, while 95 % of Cu and 94 % of Ni were recovered in a binary mixture of Cu and Ni. However, the recovery yield and purity of Zn and Ni were very low because of similar characteristics of Zn and Ni. Therefore, the mixture of Cu and Zn or Cu and Ni could be recovered by selective precipitation via pH adjustment; however, it is impossible to recover selectively Zn and Ni in the mixture of them.

  14. Synthesis CuO-ZnO nanocomposite and its application as an antibacterial agent

    Science.gov (United States)

    Widiarti, N.; Sae, J. K.; Wahyuni, S.

    2017-02-01

    The synthesis of CuO-ZnO composites and their application as anti-bacterial have been conducted. Nanocomposite CuO-ZnO was synthesized using sol-gel method. The nanocomposite products were characterized by XRD, DR-UV, SAA, FTIR, SEM-EDX. The results of the XRD analysis showed that the CuO-ZnO composite has a nanometer size with the average of 15.99 nanometer. The DR-UV analysis showed that the CuO-ZnO composite has a band-gap of 2.28 eV in the average. The analysis of SAA showed that the CuO-ZnO has a surface area of 23.20 m2/g in average. FTIR investigation revealed that the vibration of ZnO was observed at 432.05 cm-1 whereas CuO at 524.64 cm-1 and 594, 06 cm-1. The SEM-EDX analysis showed that the ZnO has a hexagonal structure whereas the CuO has a monoclinic structure. The CuO-ZnO nanocomposite has the ability as an antibacterial against S. aureus as gram-positive and E. coli as Gram-negative bacteria.

  15. Formation of ferric flocks for the removal of Zn and Cu from dockyard wastewater

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Arevalo, Edurado; Stichnothe, Heinz

    2006-01-01

    Wastewater from wash down of boat hulls contains typically Cu, Zn and organometallic biocides, e.g. tributyltin (TBT). In some cases this wastewater is led directly into the marine system. In the present paper a cheap flocculation method (iron flocculants) for removal of Cu and Zn from the wastew...

  16. First-principles investigation of Cu-doped ZnS with enhanced photocatalytic hydrogen production activity

    Science.gov (United States)

    Dong, Ming; Zhou, Peng; Jiang, Chuanjia; Cheng, Bei; Yu, Jiaguo

    2017-01-01

    The band structure and electronic properties of Cu-doped wurtzite ZnS were investigated by density functional theory calculations. According to the formation energies, the substitutional Cu and S vacancy defects are stable among the examined doping species. Particularly, the hybridization of substitutional Cu 3d and S 3p orbitals narrows the band gap of substitutional Cu-doped ZnS (CuZn-ZnS), while the high effective mass ratio of photogenerated holes and electrons (mh∗/me∗) in the CuZn-ZnS is beneficial for the separation and migration of the photogenerated charge carriers. Lab-synthesized CuZn-ZnS sample exhibited enhanced visible-light absorption and photocatalytic hydrogen production activity compared to pure ZnS.

  17. On the concentration and separation of the trace-elements fe, cu, zn, mn, pb, mo and co : Paper chromatography

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    Paper chromatographic separations are described by which the minor constituents of biological ashes are separated either into: (Pb) - Mn - Co - (Pb) - Cu - Fe, Mo, Zn; or into: Cu, Mn, Co - Pb - Fe - Mo - Zn.

  18. Reversible switching of ferromagnetism in ZnCuO nanorods by electric field

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Changwei, E-mail: Changweizou@hotmail.com; Wang, Hongjun; Liang, Feng; Shao, Lexi [Department of Physics and Development Center for New Materials Engineering and Technology in Universities of Guangdong, Lingnan Normal University, Zhanjiang 524048 (China)

    2015-04-06

    The reproducible switching of ferromagnetism in ZnCuO nanorods by applying a reversible electric field has been realized. High-resolution transmission electron microscopy images showed a hexagonal wurtzite structure with no detectable trace of secondary phase or precipitation of Cu impurity in the ZnCuO nanorods. The Cu concentrations in the ZnCuO nanorods were tested by energy dispersive spectroscopy and x-ray photoelectron spectroscopy and found to be about 2.7 at. %. The switching mechanism is confirmed in terms of the formation and rupture of conductive filaments, with oxygen vacancies (V{sub O}) localized mainly on surface of the ZnCuO nanorods. Subsequently, the variation of V{sub O} concentration during the resistive switching process modulates the ferromagnetism of the ZnCuO nanorods. The saturation magnetization at low resistance state is apparently 6.4 times larger than that at high resistance state for an Au/ZnCuO/ITO structure. An indirect double-exchange model has been used to explain the ferromagnetism in ZnCuO nanorods.

  19. Continuous determination of Cu, Al, Zn in Ag- Cu- Al- Zn quarternary alloy by titration%滴定法连续测定银铜铝锌四元合金中Cu,Al,Zn

    Institute of Scientific and Technical Information of China (English)

    麦丽碧

    2004-01-01

    采用连续滴定的方法同时测定Cu,Al,Zn.加入一定量的EDTA标准溶液,使Cu2+,Al3+,Zn2+全部与EDTA络合,用Zn2+盐滴定过量EDTA,然后加氟盐置换出EDTA-Al中的EDTA,用硫脲抗坏血酸和邻菲啰啉置换出EDTA-Cu中的EDTA,并分别用Zn2+盐滴定,从总量中减去Al量和Cu量即得Zn量.滴定Cu,Al,Zn回收率均在98%以上,本法分析快速准确.

  20. Quantifying the promotion of Cu catalysts by ZnO for methanol synthesis

    DEFF Research Database (Denmark)

    Kuld, Sebastian; Thorhauge, Max; Falsig, Hanne

    2016-01-01

    Promoter elements enhance the activity and selectivity of heterogeneous catalysts. Here, we show how methanol synthesis from synthesis gas over copper (Cu) nanoparticles is boosted by zinc oxide (ZnO) nanoparticles. By combining surface area titration, electron microscopy, activity measurement......, density functional theory calculations, and modeling, we show that the promotion is related to Zn atoms migrating in the Cu surface. The Zn coverage is quantitatively described as a function of the methanol synthesis conditions and of the size-dependent thermodynamic activities of the Cu and Zn...

  1. Molecular distortion and charge transfer effects in ZnPc/Cu(111)

    KAUST Repository

    Amin, B.

    2013-04-23

    The adsorption geometry and electronic properties of a zinc-phthalocyanine molecule on a Cu(111) substrate are studied by density functional theory. In agreement with experiment, we find remarkable distortions of the molecule, mainly as the central Zn atom tends towards the substrate to minimize the Zn-Cu distance. As a consequence, the Zn-N chemical bonding and energy levels of the molecule are significantly modified. However, charge transfer induces metallic states on the molecule and therefore is more important for the ZnPc/Cu(111) system than the structural distortions.

  2. Cooperative cytotoxic activity of Zn and Cu in bovine serum albumin-conjugated ZnS/CuS nano-composites in PC12 cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hua-Jie, E-mail: wanghuajie972001@163.com; Yu, Xue-Hong; Wang, Cai-Feng; Cao, Ying, E-mail: caoying1130@sina.com [Henan Normal University, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, College of Chemistry and Chemical Engineering (China)

    2013-11-15

    Series of self-assembled and mono-dispersed bovine serum albumin (BSA)-conjugated ZnS/CuS nano-composites with different Zn/Cu ratios had been successfully synthesized by a combination method of the biomimetic synthesis and ion-exchange strategy under the gentle conditions. High-resolution transmission electron microscopy observation, Fourier transform infrared spectra and zeta potential analysis demonstrated that BSA-conjugated ZnS/CuS nano-composites with well dispersity had the hierarchical structure and BSA was a key factor to control the morphology and surface electro-negativity of final products. The real-time monitoring by atomic absorption spectroscopy and powder X-ray diffraction revealed that the Zn/Cu ratio of nano-composites could be controlled by adjusting the ion-exchange time. In addition, the metabolic and morphological assays indicated that the metabolic proliferation and spread of rat pheochromocytoma (PC12) cells could be inhibited by nano-composites, with the high anti-cancer activity at a low concentration (4 ppm). What were more important, Zn and Cu in nano-composites exhibited a positive cooperativity at inhibiting cancer cell functions. The microscope observation and biochemical marker analysis clearly revealed that the nano-composites-included lipid peroxidation and disintegration of membrane led to the death of PC12 cells. Summarily, the present study substantiated the potential of BSA-conjugated ZnS/CuS nano-composites as anti-cancer drug.

  3. A second copper zinc superoxide dismutase (CuZnSOD) in the blue crab Callinectes sapidus: cloning and up-regulated expression in the hemocytes after immune challenge.

    Science.gov (United States)

    Sook Chung, J; Bachvaroff, T R; Trant, J; Place, A

    2012-01-01

    The full-length cDNA (1362 nucleotides, GenBank JF736621) encoding an extracellular copper zinc superoxide dismutase initially isolated from an EST library of the blue crab Callinectes sapidus was characterized using 3' RACE and named Cas-ecCuZnSOD-2. The open reading frame of Cas-ecCuZnSOD-2 contains 203 deduced amino acids with the conserved active catalytic center for copper and zinc binding and the post-translational modification at two putative N-glycosylation and nine phosphorylation sites. Overall, the deduced amino acids of Cas-ecCuZnSOD-2 shared only 35% sequence identity with that of Cas-ecCuZnSOD (GenBank AF264031) which was previously found in C. sapidus, while it showed ∼75% sequence identity to Scylla paramamosain ecCuZnSOD (GenBank FJ774661). The expression profile of Cas-ecCuZnSOD-2 and the other three C. sapidus SODs: ecCuZn, cytMn- and mitMn SODs was largely ubiquitous among the tested tissues obtained from a juvenile female at intermolt: brain, eyestalk ganglia, pericardial organs, and thoracic ganglia complex (nervous system); hepatopancreas (digestive system); heart, artery and hemocytes (circulatory system); gill and antennal gland (excretory system), hypodermis, and Y-organ (endocrine organ). Our study reports, for the first time in the crustaceans, expression analyses for all four Cas-SODs in hemocytes after immune challenges. Crabs challenged with lipopolysaccharides (LPS) injection had a remarkable induction of Cas-ecCuZnSOD-2 expression along with three other SODs in hemocytes, suggesting that Cas-SODs including Cas-ecCuZnSOD-2 are involved in the defense system, possibly innate immunity and immunocompetency of C. sapidus. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Photocatalytic Characterization of Fe- and Cu-Doped ZnO Nanorods Synthesized by Cohydrolysis

    Directory of Open Access Journals (Sweden)

    Young Rang Uhm

    2013-01-01

    Full Text Available Fe- and Cu-doped ZnO nanorods have been synthesized by a novel process employing a hydrolysis of metal powders. Zn, Fe, and Cu nanopowders were used as starting materials and incorporated into distilled water. The solution was refluxed at 60°C for 24 h to obtain the precipitates from the hydrolysis of Zn and dopants (Cu and Fe. The TEM results for ZnO with and without metal doping showed that the produced powders had a rod-like shape. The rod shape was attributable to the zinc oxide from the hydrolysis of Zn. With an increasing doping content, the UV-vis spectra were shifted to a long wavelength and this result indicates that the band gap was changed by the metal doping. The values of phenol degrading Fe- and Cu-doped ZnO by a solar simulator were measured to be 60 and 75%, respectively.

  5. Cu2ZnSnSe4 thin-film solar cells fabricated using Cu2SnSe3 and ZnSe bilayers

    Science.gov (United States)

    Kim, Kang Min; Liao, Kuang Hsiang; Tampo, Hitoshi; Shibata, Hajime; Niki, Shigeru

    2015-04-01

    Evaporated Cu2SnSe3 (CTSe) and ZnSe bilayers are used as precursors for the fabrication of Cu2ZnSnSe4 (CZTSe) thin films. Large grains (i.e., >1 µm) in CZTSe were obtained at a relatively low annealing temperature of 500 °C. The stacking order of precursors strongly affected the chemical composition of CZTSe thin films even under identical growth conditions. Zn loss in CTSe/ZnSe/Mo precursors occurred during CTSe deposition, whereas ZnSe/CTSe/Mo precursors showed improved stability in composition. The CZTSe solar cells fabricated using ZnSe/CTSe bilayer precursors with annealing showed a conversion efficiency of over 7%.

  6. As-cast microstructure of Al-Zn-Mg and Al-Zn-Mg-Cu alloys added erbium

    Institute of Scientific and Technical Information of China (English)

    MAO Jian-wei; JIN Tou-nan; XU Guo-fu; NIE Zuo-ren

    2005-01-01

    The effects of different contents of rare earth element, and erbium, on the as-cast microstructures of Al-6Zn-2Mg and Al-6Zn-2Mg-1.8Cu alloys were studied by optical microscopy, scanning electron microscopy, X-ray diffractometry, transmission electron microscopy and EDS analysis. The results show that the netlike structure of as-cast alloys can be remarkably refined, and the distance of dendritic structure decreases, with Er addition. However, the improvement results on Al-Zn-Mg-Cu are not better than that of Al-Zn-Mg. Er and Al can interact to form Al3Er phase, which is coherent with α(Al) matrix, with trace Er addition to the Al-Zn-Mg alloy. The refinement effect of Al-Zn-Mg alloys is familiar with the formation and precipitation of coherent Al3Er phases. The ternary compound AlCuEr, similar with AlCuSc phase, will form when Er is added to Al-Zn-Mg-Cu alloy, which suppresses the formation of Al3Er phase and doesn't solve in the following heat treatment.

  7. Cation/Anion Substitution in Cu2ZnSnS4 for Improved Photovoltaic Performance

    OpenAIRE

    Balakrishna Ananthoju; Jeotikanta Mohapatra; Jangid, Manoj K.; Bahadur, D.; Medhekar, N. V.; ASLAM, M.

    2016-01-01

    Cations and anions are replaced with Fe, Mn, and Se in CZTS in order to control the formations of the secondary phase, the band gap, and the micro structure of Cu2ZnSnS4. We demonstrate a simplified synthesis strategy for a range of quaternary chalcogenide nanoparticles such as Cu2ZnSnS4 (CZTS), Cu2FeSnS4 (CFTS), Cu2MnSnS4 (CMTS), Cu2ZnSnSe4 (CZTSe), and Cu2ZnSn(S0.5Se0.5)4 (CZTSSe) by thermolysis of metal chloride precursors using long chain amine molecules. It is observed that the crystal s...

  8. Research on Cu2ZnSnTe4 crystals and heterojunctions based on such crystals

    Directory of Open Access Journals (Sweden)

    Kovaliuk T. T.

    2015-12-01

    Full Text Available The paper reports on the results of the studies of magnetic, kinetic and optical properties of Cu2ZnSnTe4 crystals. The Cu2ZnSnTe4 crystals showed diamagnetic properties (the magnetic susceptibility almost independent of the magnetic field and temperature. The Cu2ZnSnTe4 crystals possessed p-type of conductivity and the Hall coefficient was independent on temperature. The temperature dependence of the electrical conductivity of the Cu2ZnSnTe4 crystal shows metallic character, i. e. decreases with the increase of temperature, that is caused by the lower charge carrier mobility at higher temperature. Thermoelectric power of the samples ispositive that also indicates on the prevalence of p-type conductivity. Heterojunctions n-TiN/p-Cu2ZnSnTe4, n-TiO2/p-Cu2ZnSnTe4 and n-MoO/p-Cu2ZnSnTe4 were fabricated by the reactive magnetron sputtering of TiN, TiO2 and MoOx thin films, respectively, onto the substrates made of the Cu2ZnSnTe4 crystals. The dominating current transport mechanisms in the n-TiN/p-Cu2ZnSnTe4 and n-TiO2/p-Cu2ZnSnTe4 heterojunctions were established to be the tunnel-recombination mechanism at forward bias and tunneling at reverse bias.

  9. Sputtered Ni-Zn under bump metallurgy (UBM) for Sn-Ag-Cu solders

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Jin; Kim, Young Min [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Ho, E-mail: kimyh@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Ni-Zn UBM can effectively suppress the growth of IMCs and the consumption of UBM. Black-Right-Pointing-Pointer The growth of (Ni, Cu){sub 3}Sn{sub 4} was retarded at the SAC305/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Only a single (Cu, Ni){sub 6}Sn{sub 5} formed at the SAC107/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Segregated Zn atoms on IMC layers retarded the interdiffusion of Cu, Ni, and Sn. Black-Right-Pointing-Pointer Sputtered Ni-Zn UBM is promising for Pb-free solder flip chip applications. - Abstract: We developed a new sputtered under bump metallurgy (UBM) based on Ni-20wt% Zn thin films for Pb-free solders. This study focuses on the interfacial reactions between two Pb-free solders (Sn3.0Ag0.5Cu and Sn1.0Ag0.7Cu) and a Ni-Zn alloy UBM. By adding Zn to Ni UBM, Zn is incorporated into intermetallic compounds (IMCs) to form a quaternary Cu-Ni-Zn-Sn phase at the solder/Ni-Zn interface after reflow and subsequent isothermal aging. The Ni-Zn UBM sufficiently reduces the interfacial reaction and IMCs formation rates as well as UBM consumption rates compared to a Ni UBM. In particular, the formation of (Ni, Cu){sub 3}Sn{sub 4} IMC was significantly retarded by adding Zn into UBM.

  10. Evolution of intermetallic phases of Al-Zn-Mg-Cu alloy during heat treatment

    Institute of Scientific and Technical Information of China (English)

    FAN Xi-gang; JIANG Da-ming; MENG Qing-chang; LI Nian-kui; SUN Zhao-xia

    2006-01-01

    Al-Zn-Mg-Cu alloy is a favorable choice for aerospace applications requiring good combination of strength and toughness,which is greatly influenced by the coarse intermetallic particles. The evolution of intermetallic particles in an Al-Zn-Mg-Cu alloy during heat treatment was studied by field emission gun scanning electron microscopy (FEG-SEM) and X-ray diffractometry(XRD).The results show that there are lamellar eutectic structure (α(Al)+Mg(Zn,Al,Cu)2) and Al7Cu2Fe particles in the solidified structure.The Al7Cu2Fe particles are embedded in the eutectic structure. The content of eutectic structure decreases with the increase of holding time and disappears after 24 h. The size and morphology of Al7Cu2Fe particles exhibit no change during the heat treatment. It is found that the Al2CuMg phase is formed during the treatment at 460 ℃. A transformation process from the primary eutectic phase Mg(Zn,Al,Cu)2 to Al2CuMg is observed, and the transformation mechanism and kinetics are analyzed. The Al2CuMg constituents form in the primary Mg(Zn,Al,Cu)2 phase, and grow along the eutectic microstructure.

  11. Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles

    Indian Academy of Sciences (India)

    MAGDALENA BARWIOLEK; ROBERT SZCZĘSNY; EDWARD SZŁYK

    2016-07-01

    Cu(II) complexes with Schiff bases derived from ethylenediamine (en) and 2-pyridinecarboxaldehyde (pyca), 2,5-dimethoxybenzaldehyde (dmbaH) or 4-imidazolecarboxaldehyde (4Him) were obtained and studied by elemental analysis, UV-VIS and IR spectra. Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers of the studied Cu(II) complexes were deposited on Si(111) or ZnO/Si(111) substrates by a spin coating method and characterized with a scanningelectron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. For Cu(II) layers the most intensive fluorescence bands due to intra-ligand transitions were observed between 462 and 503 nm. The fluorescence intensity of thin layers was corelated to the rotation speed. In the case of the [Cu(II)(en(4Him)₂)Cl₂](2a)/ZnO/Si and [Cu(en(dmbaH)₂)Cl₂](3a)/ZnO/Si layers the quenching of the emission band from ZnO at 440 nm (λex = 330 nm) associated with various intrinsic or extrinsic lattice defects was noted.

  12. Highly efficient photocatalytic degradation of organic dyes by Cu doped ZnO nanostructures.

    Science.gov (United States)

    Kuriakose, Sini; Satpati, Biswarup; Mohapatra, Satyabrata

    2015-10-14

    Copper doped ZnO nanostructures have been synthesized by a facile wet chemical method. Structural properties of as-synthesized nanomaterials have been studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy, while UV-visible absorption spectroscopy and Raman spectroscopy have been used to study their optical properties. Sunlight driven photocatalytic degradation of methylene blue (MB) and methyl orange (MO) dyes in water was used to evaluate the photocatalytic activities of Cu doped ZnO nanostructures using UV-visible absorption spectroscopy. The results showed that there is an optimum Cu doping level which leads to the highly enhanced photocatalytic activity of Cu doped ZnO nanostructures, as compared to pure ZnO nanostructures. A mechanism for the enhanced photocatalytic activity of Cu-ZnO nanostructures is tentatively proposed. The enhanced photocatalytic activity of Cu-ZnO nanostructures is attributed to the combined effects of improved separation of photogenerated charge carriers due to optimal Cu doping in ZnO nanostructures and the formation of ZnO-CuO nanoheterojunctions.

  13. Crevice Corrosion of the Shape Memory Alloy Cu-Zn-Al%Cu-Zn-Al形状记忆合金的缝隙腐蚀

    Institute of Scientific and Technical Information of China (English)

    郭海霞; 梁成浩

    2001-01-01

    The crevice corrosion of the benzotriazole(BTA) passive specimensof the shape memory alloy Cu-Zn-Al in Hank's artificial body fluid has been studied using electrochemical tests. The results show that the shape memory alloy Cu-Zn-Al exhibits better property than the annealed alloy Cu-Zn-Al. T he reason is that the martensite single phase in the alloy Cu-Zn-Al improves electrochemical property and inhibits active solution. The occurring of crevice corrosion is attributed to the metal ions concentration cell. BTA passivation improves the crevice corrosion resistance of the alloy.%采用电化学方法研究了Cu-Zn-Al形状记忆合金及其BTA钝化处理试样在Hank's人工体液中的缝隙腐蚀行为。结果表明:在人工体液中,Cu-Zn-Al形状记忆合金的耐缝隙腐蚀性能优于未进行热处理的Cu-Zn-Al合金,其作用机理是单相马氏体组织改善了合金的电化学行为,抑制了活性溶解。缝隙腐蚀的发生是由于形成了金属离子浓差电池。经BTA钝化后,Cu-Zn-Al形状记忆合金的耐缝隙腐蚀性能得到改善。

  14. First-principle Calculations of Mechanical Properties of Al2Cu, Al2CuMg and MgZn2 Intermetallics in High Strength Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    LIAO Fei

    2016-12-01

    Full Text Available Structural stabilities, mechanical properties and electronic structures of Al2Cu, Al2CuMg and MgZn2 intermetallics in Al-Zn-Mg-Cu aluminum alloys were determined from the first-principle calculations by VASP based on the density functional theory. The results show that the cohesive energy (Ecoh decreases in the order MgZn2 > Al2CuMg > Al2Cu, whereas the formation enthalpy (ΔH decreases in the order MgZn2 > Al2Cu > Al2CuMg. Al2Cu can act as a strengthening phase for its ductile and high Young's modulus. The Al2CuMg phase exhibits elastic anisotropy and may act as a crack initiation point. MgZn2 has good plasticity and low melting point, which is the main strengthening phase in the Al-Zn-Mg-Cu aluminum alloys. Metallic bonding mode coexists with a fractional ionic interaction in Al2Cu, Al2CuMg and MgZn2, and that improves the structural stability. In order to improve the alloys' performance further, the generation of MgZn2 phase should be promoted by increasing Zn content while Mg and Cu contents are decreased properly.

  15. Highly efficient visible light photocatalysis of novel CuS/ZnO heterostructure nanowire arrays

    Science.gov (United States)

    Lee, Mikyung; Yong, Kijung

    2012-05-01

    Here, a facile approach for the fabrication of CuS nanoparticle (NP)/ZnO nanowire (NW) heterostructures on a mesh substrate through a simple two-step solution method is demonstrated. Successive ionic layer adsorption and reaction (SILAR) was employed to uniformly deposit CuS NPs on the hydrothermally grown ZnO NW array. The synthesized CuS/ZnO heterostructure NWs exhibited superior photocatalytic activity under visible light compared to bare ZnO NWs. This strong photocatalytic activity under visible light is due to the interfacial charge transfer (IFCT) from the valence band of the ZnO NW to the CuS NP, which reduces CuS to Cu2S. After repeated cycles of photodecolorization of Acid Orange 7 (AO7), the photocatalytic behavior of CuS/ZnO heterostructure NWs exhibited no significant loss of activity. Furthermore, our CuS/ZnO NWs/mesh photocatalyst floats in solution via partial superhydrophobic modification of the NWs.

  16. The stabilization of martensite in Cu-Zn-Al-Ti-B shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R.; Stipcich, M. [Univ. Nacional del Centro de la Provincia de Buenos Aires, Tandil (AR). Inst. de Fisica de Materiales Tandil (IFIMAT); Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (Argentina)

    2001-11-01

    Recent studies on aging effects in the martensite phase have shown that the addition of Ti-B to Cu-Zn-Al shape memory alloy has a notable influence on stabilization characteristics of this alloy. The overall process is delayed and the stabilization magnitude is significantly diminished. In an attempt to understand this effect the experimental results are analyzed within a cluster rearrangement model. The characteristic energy values are determined and compared with those obtained in single crystal experiments. The obtained results suggest the formation of vacancy-Ti complexes that increase the average vacancy migration energy for about 25%. (orig.)

  17. Cu-doped ZnO nanoparticles: Synthesis, structural and electrical properties

    Science.gov (United States)

    Singhal, Sonal; Kaur, Japinder; Namgyal, Tsering; Sharma, Rimi

    2012-04-01

    Pure and Cu doped ZnO nanopowders (5, 10, 15, 20, 25 and 30 at% Cu) have been synthesized using co-precipitation method. Transmission Electron Microscopic analysis has shown the morphology of ZnO nanopowders to be quasi-spherical. Powder X-ray Diffraction studies have revealed the systematic doping of Cu into the ZnO lattice up to 10% Cu, though the peaks corresponding to CuO in 10% Cu are negligibly very small. Beyond this level, there was segregation of a secondary phase corresponding to the formation of CuO. Fourier Transform Infrared spectra have shown a broad absorption band at ∼490 cm-1 for all the samples, which corresponds to the stretching vibration of Zn-O bond. DC electrical resistivity has been found to decrease with increasing Cu content. The activation energy has also been observed to decrease with copper doping i.e. from ∼0.67 eV for pure ZnO to ∼0.41 eV for 30 at% Cu doped ZnO.

  18. Cu-doped ZnO nanoparticles: Synthesis, structural and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, Sonal, E-mail: sonal1174@gmail.com [Department of Chemistry, Panjab University, Chandigarh 160014 (India); Kaur, Japinder; Namgyal, Tsering; Sharma, Rimi [Department of Chemistry, Panjab University, Chandigarh 160014 (India)

    2012-04-15

    Pure and Cu doped ZnO nanopowders (5, 10, 15, 20, 25 and 30 at% Cu) have been synthesized using co-precipitation method. Transmission Electron Microscopic analysis has shown the morphology of ZnO nanopowders to be quasi-spherical. Powder X-ray Diffraction studies have revealed the systematic doping of Cu into the ZnO lattice up to 10% Cu, though the peaks corresponding to CuO in 10% Cu are negligibly very small. Beyond this level, there was segregation of a secondary phase corresponding to the formation of CuO. Fourier Transform Infrared spectra have shown a broad absorption band at {approx}490 cm{sup -1} for all the samples, which corresponds to the stretching vibration of Zn-O bond. DC electrical resistivity has been found to decrease with increasing Cu content. The activation energy has also been observed to decrease with copper doping i.e. from {approx}0.67 eV for pure ZnO to {approx}0.41 eV for 30 at% Cu doped ZnO.

  19. Calculation and measurement of helium generation and solid transmutations in Cu-Zn-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, L.R.; Oliver, B.M.; Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States); Muroga, T. [National Inst. of Fusion Science, Nagoya (Japan)

    1998-03-01

    A method was recently proposed by Garner and Greenwood that would allow the separation of the effects of solid and gaseous transmutation for Cu-Zn-Ni alloys. Pure copper produces zinc and nickel during neutron irradiation. {sup 63}Cu transmutes to {sup 64}Ni and {sup 64}Zn, in about a 2-to-1 ratio, and {sup 65}Cu transmutes to {sup 66}Zn. The {sup 64}Zn further transmutes to {sup 65}Zn which has been shown to have a high thermal neutron (n,{alpha}) cross-section. Since a three-step reaction sequence is required for natural copper, the amount of helium produced is much smaller than would be produced for the two-step, well-known {sup 58}Ni (n,{gamma}) {sup 59}Ni (n,{alpha}) reaction sequence. The addition of natural Zn and Ni to copper leads to greatly increased helium production in neutron spectra with a significant thermal component. Using a suitable Cu-Zn-Ni alloy matrix and comparative irradiation of thermal neutron-shielded and unshielded specimens, it should be possible to distinguish the separate influences of the solid and gaseous transmutants. Whereas helium generation rates have been previously measured for natural nickel and copper, they have not been measured for natural Zn or Cu-Ni-Zn alloys. The (N,{alpha}) cross section for {sup 65}Zn was inferred from helium measurements made with natural copper. By comparing helium production in Cu and Cu-Zn alloys, this cross section can be determined more accurately. In the current study, both the solid and helium transmutants were measured for Cu, Cu-5Ni, Cu-3.5Zn and Cu-5Ni-2Zn, irradiated in each of two positions in the HFIR JP-23 test. Highly accurate helium measurements were performed on these materials by isotope dilution mass spectrometry using a facility that was recently moved from Rockwell International to PNNL. It is shown that both the helium and solid transmutants for Cu-zn-Ni alloys can be calculated with reasonable certainty, allowing the development of a transmutation experiment as proposed by

  20. Synthesis and characterization of (Cd,Zn)S buffer layer for Cu2ZnSnSe4 solar cells

    Science.gov (United States)

    Ben Messaoud, Khaled; Buffière, Marie; Brammertz, Guy; Lenaers, Nick; Boyen, Hans-Gerd; Sahayaraj, Sylvester; Meuris, Marc; Amlouk, Mosbah; Poortmans, Jef

    2017-07-01

    In order to improve the electrical performances of Cu2ZnSnSe4 (CZTSe) based solar cells, the standard CdS buffer layer was replaced by (Cd,Zn)S processed by chemical bath deposition. The morphology and composition of the (Cd,Zn)S thin films were studied as a function of [Zn]/([Zn]  +  [Cd]) ratio in the chemical bath (80, 85 and 90%). The CZTSe/(Cd,Zn)S solar cells with and without Cd partial electrolyte (Cd PE) treatment were compared to CZTSe/CdS reference devices using current-voltage and external quantum efficiency measurements. The (Cd,Zn)S thin films show a non-homogeneity of Zn distribution and phase formation, with a shift from Zn(O,OH) x to ZnS phase when increasing the deposition time and a decrease of the layers thicknesses when increasing the Zn concentration in chemical bath. A model for the growth of (Cd,Zn)S thin films is proposed. The resulting CZTSe/(Cd,Zn)S devices show an important reduction of the barrier at the hetero-interface, which is attributed to the lower density of O contamination in (Cd,Zn)S compared to CdS, inducing a lower density of deep p-type recombination centers. Despite the reduced compensation of the buffer layer, CZTSe/(Cd,Zn)S devices show a deterioration of the open circuit voltage and the fill factor with the increase of Zn content in (Cd,Zn)S. These electrical losses were avoided by Cd PE treatment prior to the deposition of (Cd,Zn)S.

  1. Enhanced bake-hardening response of an Al–Mg–Si–Cu alloy with Zn addition

    Energy Technology Data Exchange (ETDEWEB)

    Guo, M.X., E-mail: mingxingguo@skl.ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Sha, G., E-mail: gang.sha@njust.edu.cn [School of Materials Science and Engineering, Nanjing University of Science and Technology, Jiangsu 210094 (China); Cao, L.Y. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Liu, W.Q. [Key Laboratory for Microstructures, Shanghai University, Shanghai 200444 (China); Zhang, J.S.; Zhuang, L.Z. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-07-15

    This study reports that Zn addition greatly enhances the bake-hardening response of an Al–Mg–Si–Cu alloy. The pre-aged alloy exhibits a high strength increment of 135 MPa after paint baking. Differential scanning calorimetry, atom probe tomography and high-resolution transmission electron microscopy reveal that Zn addition and pre-aging have significant effects on the solute nanostructure formation. Zn atoms partition into solute clusters/GP zones, and reduce the activation energy of β” precipitation in the alloy. - Highlights: • Zn addition can improve the bake-hardening response of an Al–Mg–Si–Cu alloy. • Zn addition can stabilize the solute clusters/GP zones from dissolution. • Zn addition can reduce the size of clusters formed in the pre-aging treatment. • Zn partitioned into solute clusters/GP zones and β” in the Zn-containing Al alloy.

  2. Non-isothermal precipitation behaviors of Al-Mg-Si-Cu alloys with different Zn contents

    Energy Technology Data Exchange (ETDEWEB)

    Guo, M.X., E-mail: mingxingguo@skl.ustb.edu.cn; Zhang, Y.; Zhang, X.K.; Zhang, J.S.; Zhuang, L.Z.

    2016-07-04

    The non-isothermal precipitation behaviors of Al–Mg–Si–Cu alloys with different Zn contents were investigated by differential scanning calorimetry (DSC) analysis, hardness measurement and high resolution transmission electron microscope characterization. The results show that Zn addition has a significant effect on the GP zone dissolution and precipitation of Al-Mg-Si-Cu alloys. And their activation energies change with the changes of Zn content and aging conditions. Precipitation kinetics can be improved by adding 0.5 wt% or 3.0 wt%Zn, while be suppressed after adding 1.5 wt%Zn. The Mg-Si precipitates (GP zones and β″) are still the main precipitates in the Al-Mg-Si-Cu alloys after heated up to 250 °C, and no Mg-Zn precipitates are observed in the Zn-added alloy due to the occurrence of Mg-Zn precipitates reversion. The measured age-hardening responses of the alloys are corresponding to the predicted results by the established precipitation kinetic equations. Additionally, a double-hump phenomenon of hardness appears in the artificial aging of pre-aged alloy with 3.0 wt% Zn addition, which resulted from the formation of pre-β″ and β″ precipitates. Finally, the precipitation mechanism of Al-Mg-Si-Cu alloys with different Zn contents was proposed based on the microstructure evolution and interaction forces between Mg, Si and Zn atoms.

  3. Effect of Ag on Sn–Cu and Sn–Zn lead free solders

    Directory of Open Access Journals (Sweden)

    Alam S.N.

    2015-06-01

    Full Text Available Lead and lead-containing compounds are considered as toxic substances due to their detrimental effect on the environment. Sn-based soldering systems, like Sn-Cu and Sn-Zn are considered as the most promising candidates to replace the eutectic Sn-Pb solder compared to other solders because of their low melting temperature and favorable properties. Eutectic Sn-0.7 wt.% Cu and near eutectic composition Sn-8 wt.% Zn solders have been considered here for study. For the Sn-Cu system, besides the eutectic Sn-0.7 wt.% Cu composition, Sn-1Cu and Sn-2Cu were studied. Three compositions containing Ag: Sn-2Ag-0.7Cu, Sn-2.5Ag-0.7Cu and Sn-4.5Ag-0.7Cu were also developed. Ag was added to the eutectic Sn-0.7 wt.% Cu composition in order to reduce the melting temperature of the eutectic alloy and to enhance the mechanical properties. For the Sn-Zn system, besides the Sn-8 wt.% Zn near eutectic composition, Sn-8Zn-0.05Ag, Sn-8Zn-0.1Ag and Sn-8Zn-0.2Ag solder alloys were developed. The structure and morphology of the solder alloys were analyzed using a scanning electron microscope (SEM, filed emission scanning electron microscope (FESEM, electron diffraction X-ray spectroscopy (EDX and X-ray diffraction (XRD. Thermal analysis of the alloys was also done using a differential scanning calorimeter (DSC. Trace additions of Ag have been found to significantly reduce the melting temperature of the Sn-0.7 wt.% Cu and Sn-8 wt.% Zn alloys.

  4. Effects of annealing on the ferromagnetism and photoluminescence of Cu-doped ZnO nanowires

    Science.gov (United States)

    Xu, H. J.; Zhu, H. C.; Shan, X. D.; Liu, Y. X.; Gao, J. Y.; Zhang, X. Z.; Zhang, J. M.; Wang, P. W.; Hou, Y. M.; Yu, D. P.

    2010-01-01

    Room temperature ferromagnetic Cu-doped ZnO nanowires have been synthesized using the chemical vapor deposition method. By combining structural characterizations and comparative annealing experiments, it has been found that both extrinsic (CuO nanoparticles) and intrinsic (Zn1-xCuxO nanowires) sources are responsible for the observed ferromagnetic ordering of the as-grown samples. As regards the former, annealing in Zn vapor led to a dramatic decrease of the ferromagnetism. For the latter, a reversible switching of the ferromagnetism was observed with sequential annealings in Zn vapor and oxygen ambience respectively, which agreed well with previous reports for Cu-doped ZnO films. In addition, we have for the first time observed low temperature photoluminescence changed with magnetic properties upon annealing in different conditions, which revealed the crucial role played by interstitial zinc in directly mediating high Tc ferromagnetism and indirectly modulating the Cu-related structured green emission via different charge transfer transitions.

  5. Relationship between color and composition of Cu-Mn-Zn alloys

    Institute of Scientific and Technical Information of China (English)

    张玉平; 张津徐; 吴建生

    2002-01-01

    The color of Cu-Mn-Zn alloys is quantitatively researched using the CIE L*a*b* color system. The color parameters such as L*, a* and b* are employed to describe the color and are measured by a spectrophotometer. Based on the color data of 46 experimental alloys, a series of formulae are established to correlate color parameters changed with the alloy composition. Therefore, the color of the ternary Cu-Mn-Zn alloys can be calculated and forecast easily. The results show that Mn plays a more important role in the color of Cu-Mn-Zn alloys than Zn does. In particular, the chroma values of ternary Cu-Mn-Zn alloys mainly depend on the Mn content.

  6. Improved photocatalytic activity of nanocrystalline ZnO by coupling with CuO

    Science.gov (United States)

    Xu, Linhua; Zhou, Yang; Wu, Zijun; Zheng, Gaige; He, Jiaojiao; Zhou, Yanjing

    2017-07-01

    Although ZnO as a photocatalyst has attracted wide attention in the word in recent years, it is still a big challenge to develop low-cost, visible-light responsive ZnO based photocatalysts which can be used on a large scale. In this work, the CuO/ZnO nanocomposites have been synthesized by a facile one-step hydrothermal method and the influence of CuO contents on the photocatalytic properties of the nanocomposites has been investigated. The crystalline phase of the CuO/ZnO nanocomposites is determined by X-ray diffraction (XRD); the morphology and microstructures of the samples are analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic performance of the samples is tested using methylene blue (MB)dyes as the simulated pollutant under irradiation of a Xe lamp. Compared with pure ZnO, the photocatalytic activity of the CuO/ZnO nanocomposites is largely improved, especially for the sample prepared by the precursor solution with the molar ratio of Zn2+: Cu2+=2:1. The improvement of the photocatalytic activity is attributed to two main factors: (1) the band coupling improves the separation efficiency of photogenerated electrons and holes; (2) the utilization efficiency for solar energy is enhanced in the CuO/ZnO coupling system.

  7. Lattice sites of implanted Cu and Ag in ZnO

    CERN Document Server

    Wahl, Ulrich; Correia, J G; Agne, Thomas; Alves, E; Carvalho-Soares, João

    2006-01-01

    The group $\\textrm{I}$b impurities Cu and Ag on substitutional Zn sites are among possible candidates for p-type doping of ZnO. In order to explore possible lattice sites of Cu and Ag in ZnO the radioactive impurities $^{67}\\!$Cu and $^{111}\\!$Ag were implanted at doses of $4\\!\\times\\!10^{12}$cm$^{-2}\\to1\\!\\times\\!10^{14}$cm$^{-2}$ at 60 keV into ZnO single crystals. The emission channeling effects of $\\beta\\!^{-}$ -particles from the decay were studied by means of position-sensitive electron detectors, giving direct evidence that in the as-implanted state large fractions of Cu and Ag atoms (60--70% for Cu and 30% for Ag) occupy almost ideal substitutional Zn sites with root mean square (rms) displacements of 0.014--0.017 nm. However, following vacuum annealing at 600 °C and above both Cu and Ag were found to be located increasingly on sites that are characterized by large rms displacements (0.03--0.05 nm) from Zn sites. We conclude that in high-temperature treated ZnO Cu and Ag are most likely not simply re...

  8. Molecular Cloning and Expression Analysis of Cu/Zn SOD Gene from Gynura bicolor DC.

    Directory of Open Access Journals (Sweden)

    Xin Xu

    2017-01-01

    Full Text Available Superoxide dismutase is an important antioxidant enzyme extensively existing in eukaryote, which scavenges reactive oxygen species (ROS and plays an essential role in stress tolerance of higher plants. A full-length cDNA encoding Cu/Zn SOD was cloned from leaves of Gynura bicolor DC. by rapid amplification of cDNA ends (RACE. The full-length cDNA of Cu/Zn SOD is 924 bp and has a 681 bp open reading frame encoding 227 amino acids. Bioinformatics analysis revealed that belonged to the plant SOD super family. Cu/Zn SODs of the Helianthus annuus, Mikania micrantha, and Solidago canadensis var. scabra all have 86% similarity to the G. bicolor Cu/Zn SOD. Analysis of the expression of Cu/Zn SOD under different treatments revealed that Cu/Zn SOD was a stress-responsive gene, especially to 1-MCP. It indicates that the Cu/Zn SOD gene would be an important gene in the resistance to stresses and will be helpful in providing evidence for future research on underlying molecular mechanism and choosing proper postharvest treatments for G. bicolor.

  9. 1,3,5,7-Tetrakis(tetrazol-5-yl)-adamantane: the smallest tetrahedral tetrazole-functionalized ligand and its complexes formed by reaction with anhydrous M(II)Cl2 (M = Mn, Cu, Zn, Cd).

    Science.gov (United States)

    Boldog, Ishtvan; Domasevitch, Konstantin V; Sanchiz, Joaquín; Mayer, Peter; Janiak, Christoph

    2014-09-07

    1,3,5,7-Tetrakis(tetrazol-5-yl)-adamantane (H4L) was probed as a building block for the synthesis of tetrazolato/halido coordination polymers with open-network structures. MCl2 (M = Cu, Cd, Zn, Mn) was reacted with H4L in DMF at 70 °C to yield [Cu4Cl4L(DMF)5]·DMF, ; [Cd4Cl4L(DMF)7]·DMF, ; [Zn3Cl2L(DMF)4]·2DMF, and [Mn2L(DMF)2(MeOH)4]·DMF·2MeOH·2H2O, . and (Fddd) are nearly isostructural and have zeolitic structures with a {4(3)·6(2)·8}, gis or gismondine underlying net, where the role of the tetrahedral nodes is served by the coordination bonded clusters and the adamantane moiety. (P21/n) has a porous structure composed of coordination bonded layers with a (4·8(2)) fes topology joined via trans-{Zn(tetrazolate)2(DMF)4} pillars with an overall topology of {4·6(2)}{4·6(6)·8(3)}, fsc-3,5-Cmce-2. (Pca21) is composed of stacked {Mn2L} hexagonal networks. In and the ligand fulfills a symmetric role of a tetrahedral building block, while in and it fulfills rather a role of an effective trigonal unit. Methanol-exchanged and activated displayed an unusual type IV isotherm with H2 type hysteresis for N2 sorption with an expected uptake at high P/P0, but with a smaller SBET = 505.5 m(2) g(-1) compared to the calculated 1789 m(2) g(-1), which is a possible result of the framework's flexibility. For H2 sorption 0.79 wt% (1 bar, 77 K) and 0.06 wt% (1 bar, RT) uptake and Qst = -7.2 kJ mol(-1) heat of adsorption (77 K) were recorded. Weak antiferromagnetic interactions were found in and with J1 = -9.60(1), J2 = -17.2(2), J3 = -2.28(10) cm(-1) and J = -0.76 cm(-1) respectively. The formation of zeolitic structures in and , the concept of structural 'imprinting' of rigid building blocks, and design opportunities suggested as a potential hexafunctionalized biadamantane building block.

  10. P-Cu2O/n-ZnO nanowires on ITO glass for solar cells.

    Science.gov (United States)

    Zhang, Jin; Que, Wenxiu; Zhong, Peng; Zhu, Gangqiang

    2010-11-01

    In this paper, the fabrication and characterization of a heterojunction solar cell based on p-Cu2O/n-ZnO nanowires on ITO glass are presented. ZnO aligned nanocrystal seed layer is firstly prepared by RF magnetron sputtering technique, and then vertical ZnO nanowire arrays with an acicular crystal structure are obtained by using a chemical bath deposition processing. The results indicate that the ZnO nanowires with a diameter of about 50 nm and 500 nm in length can be easily obtained. The absorption and transmittance of the ZnO nanowires are studied. It is also noted that the Cu2O can fill well into the space between ZnO nanowires by an electrodeposition process. Furthermore, the effect of the Cu2O orientation on the cell performance is also presented.

  11. Ecotoxicity of nanoparticles of CuO and ZnO in natural water

    Energy Technology Data Exchange (ETDEWEB)

    Blinova, I., E-mail: irina.blinova@kbfi.e [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Ivask, A. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Heinlaan, M. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014 (Estonia); Mortimer, M. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618 (Estonia); Kahru, A. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia)

    2010-01-15

    The acute toxicity of CuO and ZnO nanoparticles in artificial freshwater (AFW) and in natural waters to crustaceans Daphnia magna and Thamnocephalus platyurus and protozoan Tetrahymena thermophila was compared. The L(E)C{sub 50} values of nanoCuO for both crustaceans in natural water ranged from 90 to 224 mg Cu/l and were about 10-fold lower than L(E)C{sub 50} values of bulk CuO. In all test media, the L(E)C{sub 50} values for both bulk and nanoZnO (1.1-16 mg Zn/l) were considerably lower than those of nanoCuO. The natural waters remarkably (up to 140-fold) decreased the toxicity of nanoCuO (but not that of nanoZnO) to crustaceans depending mainly on the concentration of dissolved organic carbon (DOC). The toxicity of both nanoCuO and nanoZnO was mostly due to the solubilised ions as determined by specific metal-sensing bacteria. - Natural waters remarkably reduced the toxicity of nanoCuO but not nanoZnO.

  12. Tracing contamination sources in soils with Cu and Zn isotopic ratios.

    Science.gov (United States)

    Fekiacova, Z; Cornu, S; Pichat, S

    2015-06-01

    Copper (Cu) and zinc (Zn) are naturally present and ubiquitous in soils and are important micronutrients. Human activities contribute to the input of these metals to soils in different chemical forms, which can sometimes reach a toxic level for soil organisms and plants. Isotopic signatures could be used to trace sources of anthropogenic Cu and Zn pollution. The aim of this paper is to determine whether it is possible to identify (i) Cu and Zn contamination in soils and their sources, on the basis of their isotopic signatures, and (ii) situations that are a priori favorable or not for tracing Cu and Zn pollution using the isotopic approach. Therefore, we compiled data from the literature on Cu and Zn isotopes in soils, rocks and pollutants and added to this database the results of our own research. As only a few studies have dealt with agricultural contamination, we also studied a soil toposequence from Brittany, France, that experienced spreading of pig slurry for tens of years. In the surface horizons of the natural soils, the δ(65)Cu values vary from -0.15 to 0.44‰ and the δ(66)Zn from -0.03 to 0.43‰. Furthermore, vertical variations along soil profiles range from -0.95 to 0.44‰ for δ(65)Cu and from -0.53 to 0.64‰ for δ(66)Zn values. We concluded that pedogenetic processes can produce isotopic fractionation, yet, it is not always discernible and can be overprinted by an exogenous isotopic signature. Furthermore, some contaminants are enriched in heavy Cu or in light Zn compared to the rock or soil, but no generalization can be made. The anthropogenic inputs can be identified based on stable Cu and Zn isotope ratios if the isotope ratios of the sources are different from those of the soil, which needs to be tested for each individual case.

  13. Stabilization of As, Cr, Cu, Pb and Zn in soil using amendments--a review.

    Science.gov (United States)

    Kumpiene, Jurate; Lagerkvist, Anders; Maurice, Christian

    2008-01-01

    The spread of contaminants in soil can be hindered by the soil stabilization technique. Contaminant immobilizing amendments decrease trace element leaching and their bioavailability by inducing various sorption processes: adsorption to mineral surfaces, formation of stable complexes with organic ligands, surface precipitation and ion exchange. Precipitation as salts and co-precipitation can also contribute to reducing contaminant mobility. The technique can be used in in situ and ex situ applications to reclaim and re-vegetate industrially devastated areas and mine-spoils, improve soil quality and reduce contaminant mobility by stabilizing agents and a beneficial use of industrial by-products. This study is an overview of data published during the last five years on the immobilization of one metalloid, As, and four heavy metals, Cr, Cu, Pb and Zn, in soils. The most extensively studied amendments for As immobilization are Fe containing materials. The immobilization of As occurs through adsorption on Fe oxides by replacing the surface hydroxyl groups with the As ions, as well as by the formation of amorphous Fe(III) arsenates and/or insoluble secondary oxidation minerals. Cr stabilization mainly deals with Cr reduction from its toxic and mobile hexavalent form Cr(VI) to stable in natural environments Cr(III). The reduction is accelerated in soil by the presence of organic matter and divalent iron. Clays, carbonates, phosphates and Fe oxides were the common amendments tested for Cu immobilization. The suggested mechanisms of Cu retention were precipitation of Cu carbonates and oxy-hydroxides, ion exchange and formation of ternary cation-anion complexes on the surface of Fe and Al oxy-hydroxides. Most of the studies on Pb stabilization were performed using various phosphorus-containing amendments, which reduce the Pb mobility by ionic exchange and precipitation of pyromorphite-type minerals. Zn can be successfully immobilized in soil by phosphorus amendments and clays.

  14. ZnSe etching of Zn-rich Cu2ZnSnSe4: an oxidation route for improved solar-cell efficiency.

    Science.gov (United States)

    López-Marino, Simón; Sánchez, Yudania; Placidi, Marcel; Fairbrother, Andrew; Espindola-Rodríguez, Moisés; Fontané, Xavier; Izquierdo-Roca, Víctor; López-García, Juan; Calvo-Barrio, Lorenzo; Pérez-Rodríguez, Alejandro; Saucedo, Edgardo

    2013-10-25

    Cu2ZnSnSe4 kesterite compounds are some of the most promising materials for low-cost thin-film photovoltaics. However, the synthesis of absorbers for high-performing devices is still a complex issue. So far, the best devices rely on absorbers grown in a Zn-rich and Cu-poor environment. These off-stoichiometric conditions favor the presence of a ZnSe secondary phase, which has been proved to be highly detrimental for device performance. Therefore, an effective method for the selective removal of this phase is important. Previous attempts to remove this phase by using acidic etching or highly toxic organic compounds have been reported but so far with moderate impact on device performance. Herein, a new oxidizing route to ensure efficient removal of ZnSe is presented based on treatment with a mixture of an oxidizing agent and a mineral acid followed by treatment in an aqueous Na2S solution. Three different oxidizing agents were tested: H2O2, KMnO4, and K2Cr2O7, combined with different concentrations of H2SO4. With all of these agents Se(2-) from the ZnSe surface phase is selectively oxidized to Se(0), forming an elemental Se phase, which is removed with the subsequent etching in Na2S. Using KMnO4 in a H2SO4-based medium, a large improvement on the conversion efficiency of the devices is observed, related to an improvement of all the optoelectronic parameters of the cells. Improvement of short-circuit current density (J(sc)) and series resistance is directly related to the selective etching of the ZnSe surface phase, which has a demonstrated current-blocking effect. In addition, a significant improvement of open-circuit voltage (V(oc)), shunt resistance (R(sh)), and fill factor (FF) are attributed to a passivation effect of the kesterite absorber surface resulting from the chemical processes, an effect that likely leads to a reduction of nonradiative-recombination states density and a subsequent improvement of the p-n junction. Copyright © 2013 WILEY-VCH Verlag Gmb

  15. Cu2ZnSnS4 absorption layers with controlled phase purity

    OpenAIRE

    Chia-Ying Su; Chiu -Yen Chiu; Jyh-Ming Ting

    2015-01-01

    We report the synthesis and characterization of Cu2ZnSnS4 (CZTS) with controlled phase purity. The precursor was first prepared using sequential electrodeposition of Cu, Zn, and Sn in different orders. The Cu/(Sn+Zn) ratio in each stacking order was also varied. The precursor was subjected to annealing at 200°C and sulfurization at 500°C in a 5%-H2S/Ar atmosphere for the formation of CZTS. The phase evolutions during the electrodeposition and annealing stages, and the final phase formation at...

  16. Improved photocatalytic activity of ZnO coupled CuO nanocomposites synthesized by reflux condensation method

    Energy Technology Data Exchange (ETDEWEB)

    Mageshwari, K. [Department of Electronic Engineering, Hanyang University, Seoul (Korea, Republic of); PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore 641 029, Tamil Nadu (India); Nataraj, D. [Department of Physics, Bharathiar University, Coimbatore 641 046 (India); Pal, Tarasankar [Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302 (India); Sathyamoorthy, R., E-mail: rsathya59@gmail.com [PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore 641 029, Tamil Nadu (India); Park, Jinsub, E-mail: jinsubpark@hanyang.ac.kr [Department of Electronic Engineering, Hanyang University, Seoul (Korea, Republic of)

    2015-03-15

    Highlights: • CuO–ZnO nanocomposites were synthesized by reflux condensation method. • Photodegradation of methyl orange and methylene blue dyes was investigated. • Morphological studies show 3D flower-like CuO microspheres adorned with ZnO nanorods. • Optical analysis showed characteristic absorption bands of CuO and ZnO. • CuO–ZnO nanocomposites exhibited superior photocatalytic activity than CuO. - Abstract: Nanostructured CuO–ZnO nanocomposites were successfully synthesized for different Zn{sup 2+} concentrations by reflux condensation method without using any surfactant, and their photocatalytic activity was evaluated using methyl orange and methylene blue dyes under UV light irradiation. XRD revealed the formation of CuO–ZnO nanocomposites, composing of monoclinic CuO and hexagonal ZnO. XPS analysis revealed that CuO–ZnO nanocomposites are made up of Cu(II), Zn(II) and O. FESEM and TEM images showed that pure CuO exhibit 3D flower-like microstructure, while the CuO–ZnO nanocomposites prepared for different Zn{sup 2+} concentrations have 3D flower-like CuO, microstructure adorned with rod-like ZnO particles. UV–Vis DRS showed absorption bands corresponding to CuO and ZnO around 960 nm and 395 nm, respectively. PL spectra of CuO–ZnO nanocomposites exhibited reduced PL emissions compared to pure CuO, indicating the low recombination rate of photogenerated electrons and holes. Photodegradation assay revealed that catalytic activity of CuO–ZnO nanocomposites increased with Zn{sup 2+} concentration, and also effectively degrade methyl orange and methylene blue dyes when compared to pure CuO. The enhanced photocatalytic activity of CuO–ZnO nanocomposites were mainly ascribed to the reduced recombination and efficient separation of photogenerated charge carriers. The possible mechanism for the improved photocatalytic activity of CuO–ZnO nanocomposites was proposed.

  17. Cu2ZnSnSe4 thin films prepared by selenization of one-step electrochemically deposited Cu-Zn-Sn-Se precursors

    Science.gov (United States)

    Meng, Mingming; Wan, Lei; Zou, Peng; Miao, Shiding; Xu, Jinzhang

    2013-05-01

    In this research a non-vacuum strategy was reported in facile preparation of kesterite-type Cu2ZnSnSe4 (CZTSe) thin films via selenization of one-step electrochemically prepared Cu-Zn-Sn-Se precursors. The Cu-Zn-Sn-Se precursor films were prepared by electrochemical deposition from electrolytes containing CuSO4, ZnSO4, SnCl4 and H2SeO3, and the substrate is a Mo coated soda-lime glass. The CZTSe thin films were obtained by annealing the electrochemically deposited films in the selenium vapors at the temperature of 550 °C. The crystal phases, micro-structures, chemical compositions and optical properties of CZTSe films have been studied by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma optical emission spectrometer (ICP-OES), Raman scattering spectrum, and UV-vis absorption spectroscopic means. The results revealed that the electrolytes with Cu:Zn:Sn:Se molar ratio of 3:70:20:3 yields nearly pure phase of kesterite, and a band gap of 0.94 eV was determined by spectroscopic measurements.

  18. Phytoremediation of Cu and Zn by vetiver grass in mine soils amended with humic acids.

    Science.gov (United States)

    Vargas, Carmen; Pérez-Esteban, Javier; Escolástico, Consuelo; Masaguer, Alberto; Moliner, Ana

    2016-07-01

    Phytoremediation of contaminated mine soils requires the use of fast-growing, deep-rooted, high-biomass, and metal-tolerant plants with the application of soil amendments that promote metal uptake by plants. A pot experiment was performed to evaluate the combined use of vetiver grass (Chrysopogon zizanioides) and humic acid for phytoremediation of Cu and Zn in mine soils. Vetiver plants were grown in soil samples collected from two mine sites of Spain mixed with a commercial humic acid derived from leonardite at doses of 0, 2, 10, and 20 g kg(-1). Plant metal concentrations and biomass were measured and metal bioavailability in soils was determined by a low molecular weight organic acid extraction. Results showed that humic acid addition decreased organic acid-extractable metals in soil. Although this extraction method is used to estimate bioavailability of metals, it was not a good estimator under these conditions due to competition with the strong chelators in the added humic acid. High doses of humic acid also promoted root growth and increased Cu concentrations in plants due to formation of soluble metal-organic complexes, which enhanced removal of this metal from soil and its accumulation in roots. Although humic acid was not able to improve Zn uptake, it managed to reduce translocation of Zn and Cu to aerial parts of plants. Vetiver resulted unsuitable for phytoextraction, but our study showed that the combined use of this species with humic acid at 10-20 g kg(-1) could be an effective strategy for phytostabilization of mine soils.

  19. Cu-Zn-Pb multi isotopic characterization of a small watershed (Loire river basin, France)

    Science.gov (United States)

    Desaulty, A. M.; Millot, R.; Perret, S.; Bourrain, X.

    2015-12-01

    Combating metal pollution in surface water is a major environmental, public health and economic issue. Knowledge of the behavior of metals, such as copper (Cu), zinc (Zn) and lead (Pb) in sediments and dissolved load, is a key factor to improve the management of rivers. Recent advances in mass spectrometry related to the development of MC-ICPMS allow to analyze the isotopic composition of these elements, and previous studies show the effectiveness of isotopic analyses to determine the anthropogenic sources of pollution in environment. The goal of this study is to use the Cu-Zn-Pb multi-isotopic signature to track the pollutions in surface water, and to understand the complex processes causing the metals mobilization and transport in environment. More particularly we investigate the mechanisms of distribution between the dissolved load and particulate load, known to play an important role in the transport of metals through river systems. As case study, we chose a small watershed, poorly urbanized in the Loire river basin. Its spring is in a pristine area, while it is only impacted some kilometers further by the releases rich in metals coming from a hospital water treatment plant. First a sampling of these liquid effluents as well as dissolved load and sediment from upstream to downstream was realized and their concentrations and isotopic data were determined. Then to simulate a lot of potential natural and anthropogenic modifications of environmental conditions, we made sequential extraction protocol using various reagents on the sediments. Isotopic analyzes were performed also on the various extracting solutions. Isotopic ratios were measured using a Neptune MC-ICPMS at the BRGM, after a protocol of purification for Zn and Cu. The results showed that, these isotopic systematics reveal important informations about the mechanists of mobilization and transport of metals through river systems. However experiments performed under laboratory conditions will be necessary

  20. Concentrations of Pb, Zn, and Cu in Taraxacum spp. in relation to urban pollution

    Energy Technology Data Exchange (ETDEWEB)

    Cook, C.M.; Lanaras, T.; Sgardelis, S.P.; Pantis, J.D. (Univ. of Thessaloniki (Greece))

    1994-08-01

    The combustion of petroleum fuel and exhaust emissions are major sources of atmospheric pollution in cities which result in the deposition of toxic substances, particularly heavy metals, in the surface layers of soils. Lead in particular enters the environment from the use of tetraethyl lead as an antiknock agent for petrol engines constituting 21% of fine particles emitted from cars burning leaded petrol. Antiwear protectants incorporated in lubricants often contain Cd, Cr, Cu, Hg, Ni, Pb and/or Zn which are also released into the environment by inefficient engines and irresponsible dumping of engine oils. Zn from tyre wear and Cu from diesel engines also add considerably to the environmental metal burden. Lowering of the permitted lead content of petrol and the growing use of unleaded fuel are expected to lead to reductions in the environmental lead burden, however, until unleaded fuel becomes universally accepted lead contamination, particularly of roadside soils and vegetation is a major cause for concern. A direct relationship between car exhaust, the Pb content of needles of Abies alba and reduced growth has been observed and can extend hundreds of metres from major highways. Lead tolerance has been observed in higher plants growing mine waste soils and to a lesser extent on lead-contaminated roadside soils. Automobiles which are responsible for line sources of pollution emissions in rural and suburban areas have a more far-reaching impact on roadside vegetation, already under considerable stress, in urban areas. Information on heavy metal effects on vegetation in urban environments however, are scarce. Modeling and multivariate analysis of a few of the factors involved have provided only limited data related to plant performance in these complex environments. Therefore in this study, the extent of heavy metal pollution by Pb, Zn, Cu and Cd in soils and in dandelion plants in the city of Thessaloniki has been examined. 20 refs., 2 figs., 3 tabs.

  1. Template Synthesis, Characterization and Biological Activity of Cu(II, Ni(II, Co(II, Zn(IIComplexes with Isonicotinoylhydrazone--2-aldehydefluorene Ligand

    Directory of Open Access Journals (Sweden)

    2010-01-01

    Full Text Available This is about synthesizing new complex combinations of Cu(II, Ni(II,Co(II, Zn(II with aroylhydrazone ligand isonicotinoylhydrazone-2-aldehydefluorene (INHAF made by condensation of isonicotinoylhydrazine with 2-aldehydefluorene. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility values, thermal analysis and for the Cu(II complex the ESR spectrum has been registered. For all complexes the biological activity against the Staphylo-coccus aureus, Escherichia coli, Klebssiella pneumoniae bacteria has been investigated. The experimental data sustain stoichiometry of 1:2 (metal/ligand for the Cu(II, Ni(II, Zn(II complexes and of 1:1 for the complex with Co(II. The electronic spectra and the magnetic moments suggest octahedral stereochemistry at the complexes with Cu(II, Ni(II and the tetrahedral geometry for the Co(II complex. The INHAF ligand is coordinated bidentate by the O=C amide oxygen and the azomethine nitrogen in the complexes of Cu(II, Ni(II, Co(II and monodentate by the azomethine nitrogen in the complex of Zn(II.

  2. Facile synthesis of Zn doped CuO hierarchical nanostructures: Structural, optical and antibacterial properties

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Javed, E-mail: tariqjan84@gmail.com, E-mail: javed.suggau@iiu.edu.pk; Jan, Tariq, E-mail: tariqjan84@gmail.com, E-mail: javed.suggau@iiu.edu.pk; Ul-Hassan, Sibt; Umair Ali, M.; Abbas, Fazal [Laboratory of Nanoscience and Technology, Department of Physics, International Islamic University, H-10, Islamabad (Pakistan); Ahmed, Ishaq [Experimental Physics Labs, National Center for Physics, Islamabad (Pakistan); Mansoor, Qaisar; Ismail, Muhammad [Institute of Biomedical and Genetic Engineering (IBGE), Islamabad (Pakistan)

    2015-12-15

    Zn{sub x}Cu{sub 1−x}O (where x= 0, 0.01, 0.03, 0.05, 0.07 and 0.1 mol%) hierarchical nanostructures have been prepared via soft chemical route. X-ray diffraction (XRD) results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases. The micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zn doping. Scanning electron microscope (SEM) analyses depict the formation of hierarchical nanostructures having average particle size in the range of 26-43 nm. The surface area of CuO nanostructures has been reduced systematically with the increase in Zn content which is linked with the variations in particle size. An obvious decrease in the optical band gap energy of the synthesized CuO hierarchical nanostructures has been observed with Zn doping which is assigned to the formation of shallow levels in the band gap of CuO and combined transition from oxygen 2p states to d sates of Cu and Zn ions. The bactericidal potency of the CuO hierarchical nanostructures have been found to be enhanced remarkably with Zn doping.

  3. ZnO:Cu nanorods with visible luminescence: copper induced defect levels and its luminescence dynamics

    Science.gov (United States)

    Raji, R.; Gopchandran, K. G.

    2017-02-01

    In this work, we report the synthesis of ZnO:Cu nanoparticles with rod-like morphology using co-precipitation method. X-ray diffraction analysis indicated that these ZnO:Cu nanoparticles has wurtzite structure with preferential growth along (1 0 1) crystal plane. The formation of additional defect levels in these particles on doping with Cu was investigated using Raman and fluorescence spectroscopy. The increase in intensity of E 1 (LO) mode observed at ~580 cm-1 in the Raman spectra of ZnO:Cu nanoparticles, confirmed the formation of additional defect levels in these nanoparticles on doping with Cu. The doping concentration was evident in the intensity of the additional Raman mode observed at ~280 cm-1 for the Cu doped nanoparticles. Photoluminescence spectra of Cu doped ZnO nanoparticles shows three visible emission peaks at 413, 435 and 531 nm along with a UV emission peak at 390 nm, whereas undoped ZnO nanoparticles showed only two peaks, at 389 and 582 nm. The shrinkage in band gap causing the emission of violet, blue and green colors on doping with Cu are attributed to the s-d and p-d exchange interactions between conduction band electrons of ZnO and localized d electrons of Cu ions, resulting in renormalization of band gap. The emission bands observed in these ZnO:Cu nanoparticles has been illustrated with a schematic energy level diagram.

  4. Cu{sub 2}ZnSnSe{sub 4} thin films prepared by selenization of co-electroplated Cu-Zn-Sn precursors

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhesheng, E-mail: zheshengchen@gmail.com [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Han Lei; Wan Lei [Research center for Photovoltaic System Engineering Ministry of Education, Hefei University of Technology, Hefei 230009 (China); Zhang Chunhui; Niu Haihong [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Xu Jinzhang, E-mail: xujz@lzu.edu.cn [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Research center for Photovoltaic System Engineering Ministry of Education, Hefei University of Technology, Hefei 230009 (China)

    2011-08-01

    A novel technique for growth of high quality Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin films is reported in our work. The CZTSe thin films were fabricated onto Mo layers by co-electroplating Cu-Zn-Sn precursors followed by annealing in the selenium vapors at the substrate temperature of 550 deg. C. The morphology and structure of CZTSe thin films were characterized using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Raman scattering spectrum, respectively. The results revealed that the single phase was in the CZTSe thin films, and the other impurities such as ZnSe and Cu{sub 2}SnSe{sub 3} were not existed though they were difficult to distinguish both from EDS and XRD.

  5. Cu 2ZnSnSe 4 thin films prepared by selenization of co-electroplated Cu-Zn-Sn precursors

    Science.gov (United States)

    Chen, Zhesheng; Han, Lei; Wan, Lei; Zhang, Chunhui; Niu, Haihong; Xu, Jinzhang

    2011-08-01

    A novel technique for growth of high quality Cu 2ZnSnSe 4 (CZTSe) thin films is reported in our work. The CZTSe thin films were fabricated onto Mo layers by co-electroplating Cu-Zn-Sn precursors followed by annealing in the selenium vapors at the substrate temperature of 550 °C. The morphology and structure of CZTSe thin films were characterized using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Raman scattering spectrum, respectively. The results revealed that the single phase was in the CZTSe thin films, and the other impurities such as ZnSe and Cu 2SnSe 3 were not existed though they were difficult to distinguish both from EDS and XRD.

  6. Selective hydrogenolysis of glycerol to propylene glycol on Cu-ZnO composite catalysts: structural requirements and reaction mechanism.

    Science.gov (United States)

    Wang, Shuai; Zhang, Yichi; Liu, Haichao

    2010-05-03

    Cu-ZnO catalysts were prepared by homogeneous coprecipitation with varying Cu/Zn atomic ratios (0.4-2:1). The catalysts were examined in selective hydrogenolysis of glycerol to propylene glycol. Although propylene glycol selectivities remained essentially constant (over 93%) on the different Cu-ZnO catalysts, the turnover frequencies changed markedly with the Cu/Zn ratio, and reached the greatest value at the ratio of 1:1. Such activity dependence on the Cu/Zn ratio was in parallel with the change in the interaction between Cu and ZnO and in the Cu microstrain, as a consequence of the effects on the crystalline phases of hydroxycarbonate precursors for the Cu-ZnO catalysts, reflecting the structural requirements for glycerol hydrogenolysis. The hydrogenolysis mechanism was also examined and apparently involves kinetically relevant glycerol dehydrogenation to glyceraldehyde on Cu-ZnO and subsequent glyceraldehyde dehydration and hydrogenation to propylene glycol. The mechanism is consistent with the observed superior activities of the more strained Cu particles, and the higher propylene glycol selectivities obtained at higher glycerol and hydrogen concentrations. These findings provide a rationale for the design of more effective Cu-based catalysts in selective hydrogenolysis of glycerol and other biomass-derived polyols, for example, by synthesis of highly strained Cu particles strongly interacting with ZnO or other oxide supports.

  7. Nanoparticles from Cu-Zn-Al shape memory alloys physically synthesized by ion milling deposition

    Energy Technology Data Exchange (ETDEWEB)

    Pavon, Luis Alberto Lopez [Universidad Autonoma de Nuevo Leon (UANL), Nuevo Leon (Mexico); Cuellara, Enrique Lopez; Castro, Alejandro Torres; Cruza, Azael Martinez de la [Universidad Autonoma de Nuevo Leon (CIIDIT/UANL), Nuevo Leon (Mexico). Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia; Ballesteros, Carmen [Universidad Carlos III de Madrid, Madrid (Spain). Departamento de Fisica; Araujo, Carlos Jose de [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia Mecanica

    2012-05-15

    In this research, an ion milling equipment was used to elaborate nanoparticles from Cu-Zn-Al alloys with shape memory effect. Two different compositions were used, target A: 75.22Cu-17.12Zn-7.66Al at % with an Ms of -9 deg C and target B: 76.18Cu-15.84Zn-7.98Al with an Ms of 20 degree C. Nanoparticles were characterized by High Resolution Transmission Electron Microscopy, Electron Diffraction and Energy Dispersive X-ray Spectroscopy. The obtained nanoparticles showed a small dispersion, with a size range of 3.2-3.5 nm. Their crystal structure is in good agreement with the bulk martensitic structure of the targets. In this sense, results on morphology, composition and crystal structure have indicated that it is possible to produce nanoparticles of CuZnAl shape memory alloys with martensitic structure in a single process using Ion Milling. (author)

  8. Toxicity of Nanoscale CuO and ZnO to Daphnia magna

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-zhou; LU Guang-hua; XIA Jun; JIN Shao-ge

    2012-01-01

    The potential effects of nanoscale CuO(nCuO),nanoscale ZnO(nZnO)and their mixtures on Daphnia magna were investigated,including 48-h acute toxicity and 21-d chronic toxicity tests as well as a feeding experiment.The results of acute toxicity show that nCuO/nZnO mixture was the most toxic followed by nCuO and nZnO.The nanoparticles(NPs)inhibited both the growth and reproduction of Daphnia magna during the testing period.Concentration dependence was apparent in all the cases and the intrinsic rate of natural increase was confirmed to be a very sensitive parameter to NPs exposure.Binary mixture appeared to be more toxic than the corresponding individual exposures at most cases except for the feeding behavior.

  9. Enhanced Solar Photoelectrochemical Conversion Efficiency of ZnO:Cu Electrodes for Water-Splitting Application

    Directory of Open Access Journals (Sweden)

    Rekha Dom

    2013-01-01

    Full Text Available n-type ZnO:Cu photoanodes were fabricated by simple spray pyrolysis deposition technique. Influence of low concentration (range ~10−4–10−1% of Cu doping in hexagonal ZnO lattice on its photoelectrochemical performance has been investigated. The doped photoanodes displayed 7-time enhanced conversion efficiencies with respect to their undoped counterpart, as estimated from the photocurrents generated under simulated solar radiation. This is the highest enhancement in the solar conversion efficiency reported so far for the Cu-doped ZnO. This performance is attributed to the red shift in the band gap of the Cu-doped films and is in accordance with the incident-photon-current-conversion efficiency (IPCE measurements. Electrochemical studies reveal an n-type nature of these photoanodes. Thus, the study indicates a high potential of doped ZnO films for solar energy applications, in purview of the development of simple nanostructuring methodologies.

  10. Predictive GIS Model for Potential Mapping of Cu, Pb, Zn Mineralization

    Institute of Scientific and Technical Information of China (English)

    Tarik. B. Benomar; BIAN Fuling

    2006-01-01

    The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensing imagery (Landsat TM5). The mineral potential of the study area is assessed by means of GIS based geodata integration techniques for generating predictive maps. GIS predictive model for Cu, Pb, Zn potential was carried out in this study area (Weixi) using weight of evidence. The weights of evidence modeling techniques is the data driven method in which the spatial associations of the indicative geologic features with the known mineral occurrences in the area are quantified, and weights statistically assigned to the geologic features. The best predictive map generated by this method defines 24% the area having potential for Cu, Pb, Zn mineralization further exploration work.

  11. Pitting Corrosion of Cu-Zn-Al Shape Memory Alloy in Simulated Uterine Fluid

    Institute of Scientific and Technical Information of China (English)

    Bangyi CHEN; Chenghao LIANG; Daojun FU

    2005-01-01

    Electrochemical test technology and surface analysis method were employed to investigate the pitting corrosion of Cu-Zn-Al shape memory alloy in simulated uterine fluid. The results showed that the breakage of the breakingrenovating equilibrium of surface layers resulted in the pitting corrosion of Cu-Zn-Al shape memory alloy in simulated uterine fluid. The development of pitting corrosion was controlled by dissolution of surface layers. The critical pitting corrosion potential was 1.70 VsCE. The kinetics equation for the development of pitting corrosion for Cu-Zn-Al shape memory alloy in simulated uterine fluid was i0=465.68 t-0.5+1.5. Pitting appearances of pits could be two types: tortoise-shell, and anomaly abscess. Cl- ion facilitated the pitting corrosion of Cu-Zn-Al shape memory alloy by competing adsorption and concentrating on alloy surface at high positive potential.

  12. Understanding the activity of Zn-Cu sites in methanol synthesis

    NARCIS (Netherlands)

    Batyrev, E.D.

    2013-01-01

    This thesis deals with the Cu/ZnO interaction in activated methanol synthesis catalysts. A combination of classical characterization techniques and surface science techniques was applied to probe the dynamic modification of catalyst structure upon the activation in hydrogen.

  13. Effect of precipitation on elastic modulus of Al-Zn-Mg-Cu-Li alloys

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhong-kui; ZHOU Tie-tao; LIU Pei-ying; LI Huan-xi; CHEN Chang-qi

    2006-01-01

    Al-5.6Zn-3.0Mg-1.6Cu-1.1Li-0.24Cr alloys and Al-8.0Zn-2.4Mg-2.4Cu-1.1Li-0.18Zr alloys (mass fraction, %) were aged by different processes. The microstructure and mechanical properties were determined by transmission electron microscopy(TEM),tensile test and Vicker's hardness test. The experimental results show that the most signified hardening is obtained by double-ageing or multi-ageing for the Al-Zn-Mg-Cu-Li alloys. The yield strength and the elastic modulus of the Li-containing alloys have relationships with ageing processes. The elastic modulus of Li-containing alloys decreases with the increment of precipitates though it is higher than that of Al-Zn-Mg-Cu alloy.

  14. Characterization of Cu-Zn Alloy Nanocrystalline Powders Prepared by Wire Electrical Explosion

    Institute of Scientific and Technical Information of China (English)

    WANG Qun; YANG Hai-Bin; GUO Wei-Li; ZOU Guang-Tian

    2000-01-01

    Nanocrystalline powders of Cu-Zn alloy in size ranging from 10 to 140nm was prepared from α-Cu-Zn alloy wire containing 39.8at.% Zn by an electrical explosion method. The particles are identified from x-ray diffraction as a mixture of the α,β,γ, and ε phases of Cu-Zn alloy. Most of the particles are hexagonal in shape, with only a small part being spherical and cubic. The composition of Zn in the explosion products varied from 6.9 to 45.2 at.% in different particles as determined by energy dispersive x-ray spectrometer. A possible mechanism for the formation of the alloy nanocrystalline powders is proposed, in which a redistribution process occurred caused by strong collision and diffusion between the two kinds of atoms during the powder formation.

  15. Enhanced wetting of Cu on ZnO by migration of subsurface oxygen vacancies

    DEFF Research Database (Denmark)

    Beinik, Igor; Helström, Matti; Jensen, Thomas Nørregaard

    2015-01-01

    Metal adhesion on metal oxides is strongly controlled by the oxide surface structure and composition, but lack of control over the surface conditions often limits the possibilities to exploit this in opto- and micro-electronics applications and heterogeneous catalysis where nanostructural control...... is of utmost importance. The Cu/ZnO system is among the most investigated of such systems in model studies, but the presence of subsurface ZnO defects and their important role for adhesion on ZnO have been unappreciated so far. Here we reveal that the surface-directed migration of subsurface defects affects...... the Cu adhesion on polar ZnO(0001) in the technologically interesting temperature range up to 550 K. This leads to enhanced adhesion and ultimately complete wetting of ZnO(0001) by a Cu overlayer. On the basis of our experimental and computational results we demonstrate a mechanism which implies...

  16. Design, synthesis, characterization and antibacterial and antifungal activity of a new 2-{(E-[(4-aminophenylimino]-methyl}-4,6-dichlorophenol and its complexes with Co(II, Ni(II, Cu(II and Zn(II: An experimental and DFT study

    Directory of Open Access Journals (Sweden)

    Bakirdere Emine Gulhan

    2016-01-01

    Full Text Available In this study, the complexes of Co (II, Ni (II, Cu (II and Zn (II with 2-(E-(4-aminophenyliminomethyl-4,6-dichlorophenol were prepared and characterized by physical, spectral and analytical data. The metal: ligand stoichiometric ratio is 1:2 in all the complexes. The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Their structures were elucidated on the basis of elemental analysis, IR, 1H and 13C NMR spectra, UV-VIS, magnetic susceptibility measurements and thermogravimetric analyses. Both the antibacterial and antifungal activities and MIC values of compounds were reported. Among the tested compounds, the most effective compound providing a MIC value of 64 μg/mL is Zn(L2 against C. tropicalis and B. subtilis. The theoretically optimized geometries of complexes have tetrahedral structures. The computed stretching frequencies of C=N, C-O and N-H bonds were found to be in good agreement with experimental data. All calculated frequencies fall within about 5% of the experimental frequency regions.

  17. Physical characterization of Cu{sub 2}ZnGeSe{sub 4} thin films from annealing of Cu-Zn-Ge precursor layers

    Energy Technology Data Exchange (ETDEWEB)

    Buffière, M., E-mail: buffiere@imec.be [Imec—Partner in Solliance, Leuven (Belgium); Department of Electrical Engineering (ESAT), KU Leuven, Heverlee (Belgium); ElAnzeery, H. [Imec—Partner in Solliance, Leuven (Belgium); KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Microelectronics System Design department, Nile University, Cairo (Egypt); Oueslati, S.; Ben Messaoud, K. [Imec—Partner in Solliance, Leuven (Belgium); KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Department of Physics, Faculty of Sciences of Tunis, El Manar (Tunisia); Brammertz, G.; Meuris, M. [Imec Division IMOMEC — Partner in Solliance, Diepenbeek (Belgium); Institute for Material Research (IMO) Hasselt University, Diepenbeek (Belgium); Poortmans, J. [Imec—Partner in Solliance, Leuven (Belgium); Department of Electrical Engineering (ESAT), KU Leuven, Heverlee (Belgium)

    2015-05-01

    Cu{sub 2}ZnGeSe{sub 4} (CZGeSe) can be considered as a potential alternative for wide band gap thin film devices. In this work, CZGeSe thin films were deposited on Mo-coated soda lime glass substrates by sequential deposition of sputtered Cu, Zn and e-beam evaporated Ge layers from elemental targets followed by annealing at high temperature using H{sub 2}Se gas. We report on the effect of the precursor stack order and composition and the impact of the annealing temperature on the physical properties of CZGeSe thin films. The optimal layer morphology was obtained when using a Mo/Cu/Zn/Ge precursor stack annealed at 460 °C. We have observed that the formation of secondary phases such as ZnSe can be prevented by tuning the initial composition of the stack, the stack order and the annealing conditions. This synthesis process allows synthesizing CZGeSe absorber with an optical band gap of 1.5 eV. - Highlights: • Cu{sub 2}ZnGeSe{sub 4} (CZGeSe) thin films were deposited using a two-step process. • CZGeSe dense layers were obtained using a Mo/Cu/Zn/Ge precursor annealed at 460 °C. • Formation of ZnSe can be avoided by tuning the composition and order of the initial stack. • P-type CZGeSe absorber with an optical band gap of 1.5 eV was obtained.

  18. Cu/Zn superoxide dismutase expression in the postnatal rat brain following an excitotoxic injury

    Directory of Open Access Journals (Sweden)

    Faiz Maryam

    2005-06-01

    Full Text Available Abstract Background In the nervous system, as in other organs, Cu/Zn superoxide dismutase (Cu/Zn SOD is a key antioxidant enzyme involved in superoxide detoxification in normal cellular metabolism and after cell injury. Although it has been suggested that immature brain has a different susceptibility to oxidative damage than adult brain, the distribution and cell-specific expression of this enzyme in immature brain and after postnatal brain damage has not been documented. Methods In this study, we used immunohistochemistry and western blot to analyze the expression of Cu/Zn SOD in intact immature rat brain and in immature rat brain after an NMDA-induced excitotoxic cortical injury performed at postnatal day 9. Double immunofluorescence labelling was used to identify Cu/Zn SOD-expressing cell populations. Results In intact immature brain, Cu/Zn SOD enzyme was widely expressed at high levels in neurons mainly located in cortical layers II, III and V, in the sub-plate, in the pyriform cortex, in the hippocampus, and in the hypothalamus. Glial fibrillary acidic protein-positive cells only showed Cu/Zn SOD expression in the glia limitans and in scattered cells of the ventricle walls. No expression was detected in interfascicular oligodendroglia, microglia or endothelial cells. Following excitotoxic damage, neuronal Cu/Zn SOD was rapidly downregulated (over 2–4 hours at the injection site before neurodegeneration signals and TUNEL staining were observed. Later, from 1 day post-lesion onward, an upregulation of Cu/Zn SOD was found due to increased expression in astroglia. A further increase was observed at 3, 5 and 7 days that corresponded to extensive induction of Cu/Zn SOD in highly reactive astrocytes and in the astroglial scar. Conclusion We show here that, in the intact immature brain, the expression of Cu/Zn SOD was mainly found in neurons. When damage occurs, a strong and very rapid downregulation of this enzyme precedes neuronal degeneration

  19. Tracing contamination sources in soils with Cu and Zn isotopic ratios

    Energy Technology Data Exchange (ETDEWEB)

    Fekiacova, Z.; Cornu, S. [INRA, UR 1119 Géochimie des Sols et des Eaux, F-13100 Aix en Provence (France); Pichat, S. [Laboratoire de Géologie de Lyon (LGL-TPE), Ecole Normale Supérieure de Lyon, CNRS, UMR 5276, 69007 Lyon (France)

    2015-06-01

    Copper (Cu) and zinc (Zn) are naturally present and ubiquitous in soils and are important micronutrients. Human activities contribute to the input of these metals to soils in different chemical forms, which can sometimes reach a toxic level for soil organisms and plants. Isotopic signatures could be used to trace sources of anthropogenic Cu and Zn pollution. The aim of this paper is to determine whether it is possible to identify (i) Cu and Zn contamination in soils and their sources, on the basis of their isotopic signatures, and (ii) situations that are a priori favorable or not for tracing Cu and Zn pollution using the isotopic approach. Therefore, we compiled data from the literature on Cu and Zn isotopes in soils, rocks and pollutants and added to this database the results of our own research. As only a few studies have dealt with agricultural contamination, we also studied a soil toposequence from Brittany, France, that experienced spreading of pig slurry for tens of years. In the surface horizons of the natural soils, the δ{sup 65}Cu values vary from − 0.15 to 0.44‰ and the δ{sup 66}Zn from − 0.03 to 0.43‰. Furthermore, vertical variations along soil profiles range from − 0.95 to 0.44‰ for δ{sup 65}Cu and from − 0.53 to 0.64‰ for δ{sup 66}Zn values. We concluded that pedogenetic processes can produce isotopic fractionation, yet, it is not always discernible and can be overprinted by an exogenous isotopic signature. Furthermore, some contaminants are enriched in heavy Cu or in light Zn compared to the rock or soil, but no generalization can be made. The anthropogenic inputs can be identified based on stable Cu and Zn isotope ratios if the isotope ratios of the sources are different from those of the soil, which needs to be tested for each individual case. - Highlights: • Pedogenetic processes produce some Cu and Zn isotope fractionation. • Pollution with distinct isotopic signatures can be traced using Cu and Zn isotopes. • Tracing

  20. In Vitro Degradation Behavior of Ternary Mg-Zn-Se and Mg-Zn-Cu Alloys as Biomaterials

    Science.gov (United States)

    Persaud-Sharma, Dharam; Budiansky, Noah

    2013-01-01

    In this study, the corrosion behavior of Mg-Zn-Se and Mg-Zn-Cu alloys was investigated to evaluate their corrosion behavior related to use as implantable biomaterials. The corrosion behavior of these alloys and a commercially available Mg-Zn alloy were examined using static solution electrochemical testing, dynamic solution gravimetric testing, ion leaching testing, and microscopic evaluation. Fluctuations in the pH of the Dulbecco’s Modified Eagles Medium (DMEM) used for the gravimetric and ion leaching immersion testing were also recorded over the 30-day duration to assess whether the media conditions induced by the alloy degradation would permit for cellular survival. Weight loss experimentation and electrochemical tests revealed the Mg-Zn-Cu alloy to have the greatest corrosion rate. PMID:24465245

  1. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Khelfane, A.; Tarzalt, H.; Sebboua, B.; Zerrouki, H.; Kesri, N., E-mail: kesri5n@gmail.com [Faculty of Physics, University of Science and Technology of Houari Boumediene, Algiers (Algeria)

    2015-12-31

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO{sub 2} and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient.

  2. Cu-implanted ZnO nanorods array film: An aqueous synthetic approach

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ajaya Kumar, E-mail: ajayaksingh_au@yahoo.co.in [Department of Chemistry, Govt. VYT PG. Autonomous College Durg, Chhattisgarh (India); Thool, Gautam Sheel [Department of Chemistry, Govt. VYT PG. Autonomous College Durg, Chhattisgarh (India); Singh, R.S. [Department of Physics, Govt. D.T. College, Utai, Durg, Chhattisgarh (India); Singh, Surya Prakash, E-mail: spsingh@iict.res.in [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Uppal road, Tarnaka, Hyderabad 500007 (India)

    2015-01-05

    Highlights: • Cu doped ZnO nanorods were synthesized using low temperature aqueous solution method. • We demonstrated the capping action of TEA via theoretical simulation. • Raman analysis revealed the presence of tensile strain in Cu doped ZnO nanorods. • Growth rate was found to be high in Cu doped ZnO nanorods. - Abstract: Pure and Cu doped ZnO nanorods array are synthesized via two step chemical bath deposition method. The seed layer is prepared by successive ionic layer adsorption reaction (SILAR) method. The synthesized materials have been systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and photoluminescence (PL) spectroscopy. SEM pictures show the existence of vertically well aligned hexagonal ZnO nanorods. EDAX spectrum confirms the presence of Cu in ZnO nanorods. High intense peak of (0 0 2) plane and E{sub 2}{sup high} mode for XRD and Raman spectrum respectively, suggest the ZnO nanorods are adopted c-axis orientation perpendicular to substrate. XRD and Raman analysis shows the presence of tensile strain in Cu doped ZnO nanorods. Effect of Cu doping on lattice constants, unit cell volume and Zn–O bond length of ZnO nanorods have also been studied. Room temperature PL measurement exhibits two luminescence bands in the spectra i.e. UV emission centered at 3.215 eV and a broad visible band. Theoretical investigation for capping action of triethanolamine is done by Hartree–Fock (HF) method with 3-21G basis set using Gaussian 09 program package.

  3. The Influences of CuO/ZnO Ratios on the Crystallization Characteristics Electrical and Magnetic Properties of CuxZn1−xO Powders

    Directory of Open Access Journals (Sweden)

    Kuan-Jen Chen

    2013-01-01

    Full Text Available This study synthesizes CuxZn1−xO powders using an aqueous solution method. The CuxZn1−xO powders with different content ratios of CuO and ZnO (CuO : ZnO = 1 : 2, 1 : 1, and 2 : 1 were formed. The crystalline characteristics and electrical and magnetic properties depended primarily on the mixing effect and oxygenation. The electrical resistance of C0.5Z0.5O (1.5×105 Ω/□ powder was lower than that of CuO (5.82×105 Ω/□ powder after ZnO mixing in CuO. This reduction was attributed to the substitution of Cu+ ions at Zn2+ sites or the formation of electron trapping defect centers. The concentration ratio of Cu2O phase in CuxZn1−xO powder mainly dominated the electrical resistance. The CuxZn1−xO has a diluted ferromagnetism (DFM and paramagnetism (PM. The electrical resistance of CuxZn1−xO decreased; the magnetic behavior increased instead. This study also analyzes the chemical binding of Cu0.5Zn0.5O powders to confirm the contribution of Cu+ ions to the electrical and magnetic properties.

  4. Growth and Raman scattering characterization of Cu2ZnSnS4 thin films

    OpenAIRE

    Fernandes, P. A.; Salomé, P M P; Cunha, A. F. da

    2009-01-01

    In the present work we report the results of the growth, morphological and structural characterization of Cu2ZnSnS4 (CZTS) thin films prepared by sulfurization of DC magnetron sputtered Cu/Zn/Sn precursor layers. The adjustment of the thicknesses and the properties of the precursors were used to control the final composition of the films. Its properties were studied by SEM/EDS, XRD and Raman scattering. The influence of the sulfurization temperature on the morphology, composition ...

  5. One-pot synthesis of Cu/ZnO/ZnAl2O4 catalysts and their catalytic performance in glycerol hydrogenolysis

    KAUST Repository

    Tan, Hua

    2013-01-01

    In this work, a series of Cu/ZnO/ZnAl2O4 catalysts with different metal molar fractions (Cu:Zn:Al) were successfully prepared using a one-pot method via the evaporation-induced self-assembly (EISA) of Pluronic P123 and the corresponding metal precursors. The catalysts were characterized using N2 adsorption, H2 temperature-programmed reduction (H2-TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). The catalytic properties of the resulting Cu/ZnO/ZnAl2O4 with different molar fractions of metals were investigated for the selective hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO). It was observed that the ZnAl2O 4 support exerts a strong positive effect on the catalytic activity of the copper-based catalysts, and the presence of ZnO further improves the catalytic activity of the Cu/ZnAl2O4 catalysts. The Cu/ZnO/ZnAl2O4 catalyst (Cu10Zn 30Al60, Cu/Zn/Al molar ratio is 10:30:60), which was the best catalyst, exhibited the highest yield (79%) of 1,2-PDO with 85.8% glycerol conversion and 92.1% 1,2-PDO selectivity at 180 °C reaction temperature in 80 wt% glycerol aqueous solution over 10 h reaction time. The high catalytic activity was attributed to the presence of the ZnAl2O4 support, the strong interaction between ZnO and Cu nanoparticles and the small particle size of ZnO and Cu. Moreover, the Cu/ZnO/ZnAl2O4 catalysts exhibited higher stability than Cu/ZnO and Cu/ZnO/Al2O 3 catalysts prepared by a co-precipitation method during consecutive cycling experiments, which is due to the high chemical and thermal stability of crystalline ZnAl2O4 under harsh reaction conditions. This journal is © The Royal Society of Chemistry.

  6. Solution-processed highly efficient Cu2ZnSnSe4 thin film solar cells by dissolution of elemental Cu, Zn, Sn, and Se powders.

    Science.gov (United States)

    Yang, Yanchun; Wang, Gang; Zhao, Wangen; Tian, Qingwen; Huang, Lijian; Pan, Daocheng

    2015-01-14

    Solution deposition approaches play an important role in reducing the manufacturing cost of Cu2ZnSnSe4 (CZTSe) thin film solar cells. Here, we present a novel precursor-based solution approach to fabricate highly efficient CZTSe solar cells. In this approach, low-cost elemental Cu, Zn, Sn, and Se powders were simultaneously dissolved in the solution of thioglycolic acid and ethanolamine, forming a homogeneous CZTSe precursor solution to deposit CZTSe nanocrystal thin films. Based on high-quality CZTSe absorber layer, pure selenide CZTSe solar cell with a photoelectric conversion efficiency of 8.02% has been achieved without antireflection coating.

  7. Double junction photoelectrochemical solar cells based on Cu2ZnSnS4/Cu2ZnSnSe4 thin film as composite photocathode

    Science.gov (United States)

    Zhu, L.; Qiang, Y. H.; Zhao, Y. L.; Gu, X. Q.

    2014-02-01

    A solvothermal method was used to synthesize Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) nanoparticles. CZTS/CZTSe bilayer films have been fabricated via a layer-by-layer blade coating process on the fluorine dope tin oxide (FTO) substrates. We converted conventional dye-sensitized solar cells (DSSCs) into double junction photoelectrochemical solar cells with the replacement of the Pt-coated counter electrode with the as-prepared films as composite photocathodes. Compared with conventional DSSCs, the cells show an increased short circuit current and power conversion efficiency.

  8. Non-blinking (Zn)CuInS/ZnS Quantum Dots Prepared by In Situ Interfacial Alloying Approach

    Science.gov (United States)

    Zhang, Aidi; Dong, Chaoqing; Li, Liang; Yin, Jinjin; Liu, Heng; Huang, Xiangyi; Ren, Jicun

    2015-10-01

    Semiconductor quantum dots (QDs) are very important optical nanomaterials with a wide range of potential applications. However, blinking behavior of single QD is an intrinsic drawback for some biological and photoelectric applications based on single-particle emission. Herein we present a rational strategy for fabrication of non-blinking (Zn)CuInS/ZnS QDs in organic phase through in situ interfacial alloying approach. This new strategy includes three steps: synthesis of CuInS QDs, eliminating the interior traps of QDs by forming graded (Zn)CuInS alloyed QDs, modifying the surface traps of QDs by introducing ZnS shells onto (Zn)CuInS QDs using alkylthiols as sulfur source and surface ligands. The suppressed blinking mechanism was mainly attributed to modifying QDs traps from interior to exterior via a step-by-step modification. Non-blinking QDs show high quantum yield, symmetric emission spectra and excellent crystallinity, and will enable applications from biology to optoelectronics that were previously hindered by blinking behavior of traditional QDs.

  9. Antiferromagnetism in YBa sub 2 Cu sub 3 O sub 6+x : Ga and Zn substitutions. Pt. 2. Zero field NMR of the Cu magnetic sites. [YBaCuGaO; YBaCuZnO

    Energy Technology Data Exchange (ETDEWEB)

    Mendels, P.; Alloul, H.; Arabski, J.; Collin, G. (Lab. de Physique des Solides, Univ. Paris Sud, 91 - Orsay (France)); Marucco, J.F. (Lab. des Composes Non Stoechiometriques, Univ. Paris Sud, 91 - Orsay (France))

    1990-11-15

    We present an extensive study of the antiferromagnetic state of YBa{sub 2}Cu{sub 3}O{sub 6+x} (0Cu zero field nuclear magnetic resonance (ZFNMR). Our experiments clearly demonstrate that hole doping in the CuO{sub 2} planes occurs only for x>0.2 and that the nuclear spin T{sub 1} is very short nearby doped holes. As for static magnetic disorder, we show that ZFNMR is a very local in-plane probe nearly insensitive to the stacking of the CuO{sub 2} antiferromagnetic sheets. No magnetic disorder occurs for x<0.2 within CuO{sub 2} planes. For x>0.2 a comparison with muon and neutron results is presented. Cu substitution by Ga and Zn do not affect markedly the AF order of the CuO{sub 2} sheet while intensity measurements clearly demonstrate that Zn does not substitute appreciably on the Cu(2) site. (orig.).

  10. Ca, Mg, Zn, Fe, Cu and Mn content of ass’s milk

    Directory of Open Access Journals (Sweden)

    Elisabetta Salimei

    2010-01-01

    Full Text Available The aim of this study was to determine Ca, Mg, Zn, Fe, Cu and Mn content of ass’s milk. Twenty four individual milk samples were collected from 4 lactating asses. During the experi- mental period milk samples were collected every 3 weeks interval, using a milking machine; asses were housed with the foals that were separated from the jennets 3 hours before milking. Milk was analysed for Ca, Mg, Zn, Fe, Cu and Mn content by atomic absorption spectrometry. The concentration mean (±SD of Ca Mg, Zn, Fe, and Cu were respectively 334.61±39.80, 58.46±8.43, 1.99±0.51, 1.15±0.52, 0.16±0.06 mg/kg. Mn was found only at trace level. Iron content of ass’s milk was the most variable ranging from 0.43 to 1.88 mg/kg. Correlation coefficients were positive and significant between Ca and Mg (r=0.63, Zn and Mg (r=0.45, Zn and Fe (r=0.49 and Zn and Cu (r=0.50. In this study, except for Fe, mean concentration of Ca, Mg, Zn, and Cu in ass’s milk was similar to those reported in literature for human milk.

  11. Chemical bath deposition of CdS thin films doped with Zn and Cu

    Indian Academy of Sciences (India)

    A I Oliva; J E Corona; R Patiño; A I Oliva-Avilés

    2014-04-01

    Zn- and Cu-doped CdS thin films were deposited onto glass substrates by the chemical bath technique. ZnCl2 and CuCl2 were incorporated as dopant agents into the conventional CdS chemical bath in order to promote the CdS doping process. The effect of the deposition time and the doping concentration on the physical properties of CdS films were investigated. The morphology, thickness, bandgap energy, crystalline structure and elemental composition of Zn- and Cu-doped CdS films were investigated and compared to the undoped CdS films properties. Both Zn- and Cu-doped CdS films presented a cubic crystalline structure with (1 1 1) as the preferential orientation. Lower values of the bandgap energy were observed for the doped CdS films as compared to those of the undoped CdS films. Zn-doped CdS films presented higher thickness and roughness values than those of Cu-doped CdS films. From the photoluminescence results, it is suggested that the inclusion of Zn and Cu into CdS crystalline structure promotes the formation of acceptor levels above the CdS valence band, resulting in lower bandgap energy values for the doped CdS films.

  12. Modification and inactivation of Cu,Zn-superoxide dismutase by the lipid peroxidation product, acrolein

    Directory of Open Access Journals (Sweden)

    Jung Hoon Kang

    2013-11-01

    Full Text Available Acrolein is the most reactive aldehydic product of lipidperoxidation and is found to be elevated in the brain whenoxidative stress is high. The effects of acrolein on the structureand function of human Cu,Zn-superoxide dismutase (SOD wereexamined. When Cu,Zn-SOD was incubated with acrolein, thecovalent crosslinking of the protein was increased, and the loss ofenzymatic activity was increased in a dose-dependent manner.Reactive oxygen species (ROS scavengers and copper chelatorsinhibited the acrolein-mediated Cu,Zn-SOD modification and theformation of carbonyl compound. The present study shows thatROS may play a critical role in acrolein-induced Cu,Zn-SODmodification and inactivation. When Cu,Zn-SOD that has beenexposed to acrolein was subsequently analyzed by amino acidanalysis, serine, histidine, arginine, threonine and lysine residueswere particularly sensitive. It is suggested that the modificationand inactivation of Cu,Zn-SOD by acrolein could be produced bymore oxidative cell environments. [BMB Reports 2013; 46(11:555-560

  13. Modification and inactivation of Cu,Zn-superoxide dismutase by the lipid peroxidation product, acrolein.

    Science.gov (United States)

    Kang, Jung Hoon

    2013-11-01

    Acrolein is the most reactive aldehydic product of lipid peroxidation and is found to be elevated in the brain when oxidative stress is high. The effects of acrolein on the structure and function of human Cu,Zn-superoxide dismutase (SOD) were examined. When Cu,Zn-SOD was incubated with acrolein, the covalent crosslinking of the protein was increased, and the loss of enzymatic activity was increased in a dose-dependent manner. Reactive oxygen species (ROS) scavengers and copper chelators inhibited the acrolein-mediated Cu,Zn-SOD modification and the formation of carbonyl compound. The present study shows that ROS may play a critical role in acrolein-induced Cu,Zn-SOD modification and inactivation. When Cu,Zn-SOD that has been exposed to acrolein was subsequently analyzed by amino acid analysis, serine, histidine, arginine, threonine and lysine residues were particularly sensitive. It is suggested that the modification and inactivation of Cu,Zn-SOD by acrolein could be produced by more oxidative cell environments.

  14. Damping performance of Cu-Zn-Al shape memory alloys in engineering structures

    Institute of Scientific and Technical Information of China (English)

    司乃潮; 孙克庆; 孙少纯; 刘海霞

    2004-01-01

    The stress strain curves of two CuZnAl shape memory alloys which have the martensitic transformation temperatures of 50 ℃ and -10 ℃ respectively, were measured by using electronic material tester after treated by different heat-treatment conditions. The results show that the area enclosed by hysteresis loop of the CuZnAl shape memory alloy in martensitic state is much larger than that of the alloy in austenitic state with super-elasticity at room temperature. Therefore, the former has better vibration attenuation effect. After being oil-quenched, waterquenched, and step-quenched, the CuZnAl alloy takes on more stable shape memory effect, better super-plasticity and superelasticity (pseudoelasticity). A CuZnAl shape memory alloy damper was designed, produced and installed to a 2-layer frame structure. In addition, the vibration experiments were made by dynamic data collecting analysis meter. The velocity of vibration attenuation of frame structure with CuZnAl shape memory alloy damper is much faster than that without it. And with the help of CuZnAl shape memory alloy damper, the attenuation period reduces to 1/10 of the original.

  15. Science Letters:Preparation of high-permeability NiCuZn ferrite

    Institute of Scientific and Technical Information of China (English)

    HU Jun; YAN Mi

    2005-01-01

    Appropriate addition of CuO/V2O5 and the reduction of the granularity of the raw materials particle decrease the sintering temperature ofNiZn ferrite from 1200 ℃ to 930 ℃. Furthermore, the magnetic properties of the NiZn ferrite prepared at low temperature of 930 ℃ is superior to that of the NiZn ferrite prepared by sintering at high temperature of 1200 ℃ because the microstructure of the NiZn ferrite sintered at 930 ℃ is more uniform and compact than that of the NiZn ferrite sintered at 1200 ℃.The high permeability of 1700 and relative loss coefficient tanδ//μi of 9.0×10-6 at 100 kHz was achieved in the (Ni0.17Zn0.63Cu0.20)Fe1.915O4 ferrite.

  16. Spectroscopic ellipsometry study of Cu{sub 2}ZnSnSe{sub 4} bulk crystals

    Energy Technology Data Exchange (ETDEWEB)

    León, M., E-mail: maximo.leon@uam.es; Lopez, N.; Merino, J. M.; Caballero, R. [Department of Applied Physics M12, Universidad Autónoma de Madrid, Madrid (Spain); Levcenko, S.; Gurieva, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany); Serna, R. [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain); Bodnar, I. V. [Department of Chemistry, Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus); Nateprov, A.; Guc, M.; Arushanov, E. [Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau MD 2028 (Moldova, Republic of); Schorr, S. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany); Institute of Geological Sciences, Free University Berlin, Malteserstr. 74-100, Berlin (Germany); Perez-Rodriguez, A. [IREC, Catalonia Institute for Energy Research, C. Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs (Barcelona) (Spain); IN2UB, Departament d' Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain)

    2014-08-11

    Using spectroscopic ellipsometry we investigated and analyzed the pseudo-optical constants of Cu{sub 2}ZnSnSe{sub 4} bulk crystals, grown by the Bridgman method, over 0.8–4.5 eV photon energy range. The structures found in the spectra of the complex pseudodielectric functions were associated to E{sub 0}, E{sub 1A}, and E{sub 1B} interband transitions and were analyzed in frame of the Adachi's model. The interband transition parameters such as strength, threshold energy, and broadening were evaluated by using the simulated annealing algorithm. In addition, the pseudo-complex refractive index, extinction coefficient, absorption coefficient, and normal-incidence reflectivity were derived over 0.8–4.5 eV photon energy range.

  17. A valence bond model for aqueous Cu(II) and Zn(II) ions in the AMOEBA polarizable force field.

    Science.gov (United States)

    Xiang, Jin Yu; Ponder, Jay W

    2013-04-05

    A general molecular mechanics (MM) model for treating aqueous Cu(2+) and Zn(2+) ions was developed based on valence bond (VB) theory and incorporated into the atomic multipole optimized energetics for biomolecular applications (AMOEBA) polarizable force field. Parameters were obtained by fitting MM energies to that computed by ab initio methods for gas-phase tetra- and hexa-aqua metal complexes. Molecular dynamics (MD) simulations using the proposed AMOEBA-VB model were performed for each transition metal ion in aqueous solution, and solvent coordination was evaluated. Results show that the AMOEBA-VB model generates the correct square-planar geometry for gas-phase tetra-aqua Cu(2+) complex and improves the accuracy of MM model energetics for a number of ligation geometries when compared to quantum mechanical (QM) computations. On the other hand, both AMOEBA and AMOEBA-VB generate results for Zn(2+)-water complexes in good agreement with QM calculations. Analyses of the MD trajectories revealed a six-coordination first solvation shell for both Cu(2+) and Zn(2+) ions in aqueous solution, with ligation geometries falling in the range reported by previous studies. Copyright © 2012 Wiley Periodicals, Inc.

  18. Cu,Zn superoxide dismutase: cloning and analysis of the Taenia solium gene and Taenia crassiceps cDNA.

    Science.gov (United States)

    Parra-Unda, Ricardo; Vaca-Paniagua, Felipe; Jiménez, Lucia; Landa, Abraham

    2012-01-01

    Cytosolic Cu,Zn superoxide dismutase (Cu,Zn-SOD) catalyzes the dismutation of superoxide (O(2)(-)) to oxygen and hydrogen peroxide (H(2)O(2)) and plays an important role in the establishment and survival of helminthes in their hosts. In this work, we describe the Taenia solium Cu,Zn-SOD gene (TsCu,Zn-SOD) and a Taenia crassiceps (TcCu,Zn-SOD) cDNA. TsCu,Zn-SOD gene that spans 2.841 kb, and has three exons and two introns; the splicing junctions follow the GT-AG rule. Analysis in silico of the gene revealed that the 5'-flanking region has three putative TATA and CCAAT boxes, and transcription factor binding sites for NF1 and AP1. The transcription start site was a C, located at 22 nucleotides upstream of the translation start codon (ATG). Southern blot analysis showed that TcCu,Zn-SOD and TsCu,Zn-SOD genes are encoded by a single copy. The deduced amino acid sequences of TsCu,Zn-SOD gene and TcCu,Zn-SOD cDNA reveal 98.47% of identity, and the characteristic motives, including the catalytic site and β-barrel structure of the Cu,Zn-SOD. Proteomic and immunohistochemical analysis indicated that Cu,Zn-SOD does not have isoforms, is distributed throughout the bladder wall and is concentrated in the tegument of T. solium and T. crassiceps cysticerci. Expression analysis revealed that TcCu,Zn-SOD mRNA and protein expression levels do not change in cysticerci, even upon exposure to O(2)(-) (0-3.8 nmol/min) and H(2)O(2) (0-2mM), suggesting that this gene is constitutively expressed in these parasites.

  19. Electromigration of Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn solder joints with Au/Ni(P)/Cu and Ag/Cu pads

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.-J., E-mail: HJLin@itri.org.t [Institute of Materials Science and Engineering, National Taiwan University, 1 Roosevelt St. Sec. 4, Taipei 106, Taiwan (China); Industrial Technology Research Institute, Mechanical and Systems Research Laboratories, Hsinchu 310, Taiwan (China); Lin, J.-S., E-mail: JohnnyLin@itri.org.t [Industrial Technology Research Institute, Mechanical and Systems Research Laboratories, Hsinchu 310, Taiwan (China); Department of Mechanical Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan); Chuang, T.-H., E-mail: tunghan@ntu.edu.t [Institute of Materials Science and Engineering, National Taiwan University, 1 Roosevelt St. Sec. 4, Taipei 106, Taiwan (China)

    2009-11-13

    It has previously been established that adding 0.2 wt.% Zn into a Sn-3Ag-0.5Cu-0.5Ce alloy improves the mechanical properties and eliminates the problem of rapid whisker growth. However, no detailed studies have been conducted on electromigration behavior of Sn-3Ag-0.5Cu-0.5Ce-0.2Zn alloy. The electromigration damage in solder joints of Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn with Ag/Cu pads and Au/Ni(P)/Cu pads was studied after current stressing at room temperature with an average current density of 3.1 x 10{sup 4} A/cm{sup 2}. With additions of 0.5 wt.% Ce and 0.2 wt.% Zn, the electromigration processes of Sn-Ag-Cu solder joints were accelerated due to refinement of the solder matrix when joint temperature was around 80 deg. C. Since Ni is more resistant than Cu to diffusion driven by electron flow, solder joints of both alloys (Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn) with Au/Ni(P)/Cu pads possess longer current-stressing lifetimes than those with Ag/Cu pads.

  20. Re-partitioning of Cu and Zn isotopes by modified protein expression

    Directory of Open Access Journals (Sweden)

    Ragnarsdottir K Vala

    2008-10-01

    Full Text Available Abstract Cu and Zn have naturally occurring non radioactive isotopes, and their isotopic systematics in a biological context are poorly understood. In this study we used double focussing mass spectroscopy to determine the ratios for these isotopes for the first time in mouse brain. The Cu and Zn isotope ratios for four strains of wild-type mice showed no significant difference (δ65Cu -0.12 to -0.78 permil; δ66Zn -0.23 to -0.48 permil. We also looked at how altering the expression of a single copper binding protein, the prion protein (PrP, alters the isotope ratios. Both knockout and overexpression of PrP had no significant effect on the ratio of Cu isotopes. Mice brains expressing mutant PrP lacking the known metal binding domain have δ65Cu isotope values of on average 0.57 permil higher than wild-type mouse brains. This implies that loss of the copper binding domain of PrP increases the level of 65Cu in the brain. δ66Zn isotope values of the transgenic mouse brains are enriched for 66Zn to the wild-type mouse brains. Here we show for the first time that the expression of a single protein can alter the partitioning of metal isotopes in mouse brains. The results imply that the expression of the prion protein can alter cellular Cu isotope content.

  1. Characteristics Of Sn-Zn Cast Alloys With The Addition Of Ag And Cu

    Directory of Open Access Journals (Sweden)

    Gancarz T.

    2015-09-01

    Full Text Available The aim of this work was to study the effects of Ag and Cu on the thermal properties and microstructure of Sn-Zn-Ag-Cu cast alloys. Solders based on eutectic Sn-Zn containing 0.5 to 1.0 at.% of Ag and Cu were developed for wave soldering. DSC measurements were performed to determine the melting temperatures of the alloys. TMA and electrical resistivity measurements were performed between −50 and 150°C and between 30 and 150°C, respectively. Small precipitates of Cu5Zn8, CuZn4, and AgZn3 were observed in the microstructures, and their presence was confirmed by XRD measurements. The inclusion of Ag and Cu improved the electrical resistivity and increased the melting temperature, as well as the CTE, of the alloys. However, tests performed to measure the mechanical properties of the alloys demonstratedthat the addition of Ag and Cu caused the mechanical properties to decrease.

  2. Effects of Cu, Zn and Pb Combined Pollution on Soil Hydrolase Activities

    Directory of Open Access Journals (Sweden)

    FENG Dan

    2015-08-01

    Full Text Available To study the relations between soil enzyme activities and heavy metal pollution, the combined effects of Cu, Zn and Pb on the three hydrolase activities, including invertase(IN, urease(Uand alkaline phosphatase(ALPwere investigated via an orthogonal experiment. Results showed as the following: When the concentration of Cu was 400 mg·kg-1, the U and ALP activities were decreased 51% and 44%, separately; When Zn was at 500 mg·kg-1, IN and ALP activities were only decreased 3% and 9%, while U activity was increased; When Pb was at 500 mg·kg-1, IN and U activities were increased, while ALP activity was decreased 13%. As a whole, Cu was considered as the most remarkable influence factor for IN, U and ALP activity regardless of interactions among the heavy metals, Zn came second, and Pb mainly showed activation. Considering interactions, Cu×Zn could significantly influence U activity(P<0.05, effects of Cu×Pb and Cu×Zn on ALP activity were remarkable(95% confidence interval. The response of ALP activity was more sensitive than the other two enzymes. Soil ALP activity might be a sensitive tool for assessing the pollution degree of Cu.

  3. Chelation of Cu(II, Zn(II, and Fe(II by Tannin Constituents of Selected Edible Nuts

    Directory of Open Access Journals (Sweden)

    Magdalena Karamać

    2009-12-01

    Full Text Available The tannin fractions isolated from hazelnuts, walnuts and almonds were characterised by colorimetric assays and by an SE-HPLC technique. The complexation of Cu(II and Zn(II was determined by the reaction with tetramethylmurexide, whereas for Fe(II, ferrozine was employed. The walnut tannins exhibited a significantly weaker reaction with the vanillin/HCl reagent than hazelnut and almond tannins, but the protein precipitation capacity of the walnut fraction was high. The SE-HPLC chromatogram of the tannin fraction from hazelnuts revealed the presence of oligomers with higher molecular weights compared to that of almonds. Copper ions were most effectively chelated by the constituents of the tannin fractions of hazelnuts, walnuts and almonds. At a 0.2 mg/assay addition level, the walnut tannins complexed almost 100% Cu(II. The Fe(II complexation capacities of the tannin fractions of walnuts and hazelnuts were weaker in comparison to that of the almond tannin fraction, which at a 2.5 mg/assay addition level, bound Fe(II by ~90%. The capacity to chelate Zn(II was quite varied for the different nut tannin fractions: almond tannins bound as much as 84% Zn(II, whereas the value for walnut tannins was only 8.7%; and for hazelnut tannins, no Zn(II chelation took place at the levels tested.

  4. Study of Zn-Cu ferrite nanoparticles for LPG sensing.

    Science.gov (United States)

    Jain, Anuj; Baranwal, Ravi Kant; Bharti, Ajaya; Vakil, Z; Prajapati, C S

    2013-01-01

    Nanostructured zinc-copper mixed ferrite was synthesized using sol-gel method. XRD patterns of different compositions of zinc-copper ferrite, Zn(1-x)Cu(x)Fe2O4 (x = 0.0, 0.25, 0.50, 0.75), revealed single phase inverse spinel ferrite in all the samples synthesized. With increasing copper concentration, the crystallite size was found to be increased from 28 nm to 47 nm. The surface morphology of all the samples studied by the Scanning Electron Microscopy there exhibits porous structure of particles throughout the samples. The pellets of the samples are prepared for LPG sensing characteristics. The sensing is carried out at different operating temperatures (200, 225, and 250°C) with the variation of LPG concentrations (0.2, 0.4, and 0.6 vol%). The maximum sensitivity of 55.33% is observed at 250°C operating for the 0.6 vol% LPG.

  5. Preparation and Characterization of Cu2ZnSnS4 Thin Films and Solar Cells Fabricated from Quaternary Cu-Zn-Sn-S Target

    OpenAIRE

    2013-01-01

    CZTS thin films were fabricated through sputtering from a quaternary Cu-Zn-Sn-S target, followed by a sulfurization process. CZTS thin-film solar cells were also fabricated and a highest efficiency of 4.04% was achieved. It has been found that obvious Zn loss occurs during the sputtering and poorly crystallized CZTS are formed in the sputtered films. The Zn loss leads to the appearance of SnS. A sulfurization process can obviously improve the crystallinity of CZTS and films with grain size of...

  6. Kesterite thin-film solar cells: advances in materials modelling of Cu{sub 2}ZnSnS{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Aron [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath (United Kingdom); Chen, Shiyou [Key Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai (China); Surface Physics Laboratory, Fudan University, Shanghai (China); Key Laboratory of Polar Materials and Devices (MOE), East China Normal University, Shanghai (China); Wei, Su-Huai [National Renewable Energy Laboratory, Golden, Colorado (United States); Gong, Xin-Gao [Key Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai (China); Surface Physics Laboratory, Fudan University, Shanghai (China)

    2012-04-15

    Quaternary semiconducting materials based on the kesterite (A{sub 2}BCX{sub 4}) mineral structure are the most promising candidates to overtake the current generation of light-absorbing materials for thin-film solar cells. Cu{sub 2}ZnSnS{sub 4} (CZTS), Cu{sub 2}ZnSnSe{sub 4} (CZTSe) and their alloy Cu{sub 2}ZnSn(Se,S){sub 4} consist of abundant, low-cost and non-toxic elements, unlike current CdTe and Cu(In,Ga)Se{sub 2} based technologies. Zinc-blende related structures are formed by quaternary compounds, but the complexity associated with the multi-component system introduces difficulties in material growth, characterization, and application. First-principles electronic structure simulations, performed over the past five years, that address the structural, electronic, and defect properties of this family of compounds are reviewed. Initial predictions of the bandgaps and crystal structures have recently been verified experimentally. The calculations highlight the role of atomic disorder on the cation sub-lattice, as well as phase separation of Cu{sub 2}ZnSnS{sub 4} into ZnS and CuSnS{sub 3}, on the material performance for light-to-electricity conversion in photovoltaic devices. Finally, the current grand challenges for materials modeling of thin-film solar cells are highlighted. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Removal of Cd, Cu, Pb, and Zn from aqueous solutions by biochars.

    Science.gov (United States)

    Doumer, M E; Rigol, A; Vidal, M; Mangrich, A S

    2016-02-01

    Sorption and desorption of heavy metals (Cd, Cu, Pb, and Zn) was evaluated in biochars derived from sugarcane bagasse (SB), eucalyptus forest residues (CE), castor meal (CM), green coconut pericarp (PC), and water hyacinth (WH) as candidate materials for the treatment of contaminated waters and soils. Solid-liquid distribution coefficients depended strongly on the initial metal concentration, with K d,max values mostly within the range 10(3)-10(4) L kg(-1). For all biochars, up to 95 % removal of all the target metals from water was achieved. The WH biochar showed the highest K d,max values for all the metals, especially Cd and Zn, followed by CE (for Cd and Pb) and PC (for Cd, Pb, and Zn). Sorption data were fitted satisfactorily with Freundlich and linear models (in the latter case, for the low concentration range). The sorption appeared to be controlled by cationic exchange, together with specific surface complexation at low metal concentrations. The low desorption yields, generally less than 5 %, confirmed that the sorption process was largely irreversible and that the biochars could potentially be used in decontamination applications.

  8. Geogenic distribution and baseline concentrations of Cu and Zn in surficial soil of Guiyang, China

    Institute of Scientific and Technical Information of China (English)

    WANG Ji; WANG Shijie; OUYANG Ziyuan; LI Ruiling

    2006-01-01

    This paper describes the environmentally geochemical characteristics of heavy metal pollu tants such as Cu and Zn in the surficial soil of Guiyang, the capital city of Guizhou Province. The baseline concentrations of heavy metals in soil and the geochemical norms have been established to distinguish natural or artificial influence on the environment. Using the statistically analytical methods, we have established the baseline of Cu in Guiyang ( 18.8 mg/kg) and the soil ( over 68.4 mg/kg) may suffer Cu contamination. The data of Zn are 46.3 mg/kg and 112.0 mg/kg. Geoaccumulation index analysis indicated that the surficial soil that has suffered non-pollution to mid-pollution of Cu accounts for 38%, 38%, and 22% for mid-pollution, and only 2% between mid-pollution to severe pollution. Surficial soil that has suffered non-pollution to mid-pollution of Zn accounts for 41%, 50%, and 7% for mid-pollution, and only 2% between mid-pollution to severe pollution. The maximal degree of Cu contamination is 5.09 in the surficial soil of Guiyang. Surficial soil that has not suffered Cu pollution accounts for 53.2%. The total pollution degree of Cu is slightly over zero. So the surficial soil of Guiyang has suffered slight Cu pollution. The maximum value of Zn contamination degree is 2.85 in the surficial soil of Guiyang. 77.8% of the surficial soil has not yet suffered any Zn pollution. The total pollution degree of Zn is less than zero.So the surficial soil in Guiyang is free from pollution of Zn.

  9. Preparation of highly oriented Al:ZnO and Cu/Al:ZnO thin films by sol-gel method and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaprasath, G.; Murugan, R. [School of Physics, Alagappa University, Karaikudi 630 004, Tamil Nadu (India); Mahalingam, T. [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of); Hayakawa, Y. [Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011 (Japan); Ravi, G., E-mail: gravicrc@gmail.com [School of Physics, Alagappa University, Karaikudi 630 004, Tamil Nadu (India)

    2015-11-15

    Highly oriented thin films of Al doped ZnO (Al:ZnO) and Cu co-doped Al:ZnO (Cu/Al:ZnO) thin films were successfully deposited by sol–gel spin coating on glass substrates. The deposited films were characterized using X-ray diffraction analysis and found to exhibit hexagonal wurtzite structure with c-axis orientation. SEM images revealed that hexagonal rod shaped morphologies were grown perpendicular to the substrate surface due to repeated deposition process. High transmittance values were observed for pure ZnO compared to Al:ZnO and Cu/Al:ZnO thin films. The band gap widening is caused by the increase of carrier concentration, which is believed to be due to Burstein-Moss effect due to Al and Cu doping. PL spectra of Cu/Al:ZnO thin films indicate that the UV emission peaks slightly shifted towards lower energy side. XPS study was carried out for Zn{sub 0.80}Al{sub 0.10}Cu{sub 0.10}O thin films to analyze the binding energy of Al, Cu, Zn and O. Magnetic measurement studies exhibited ferromagnetic behavior at room temperature, which may be due to the increase in copper concentration in the doped films. The ferromagnetic behavior can be understood from the exchange coupling between localized ‘d’ spin of Cu ion mediated by free delocalized carriers. - Highlights: • High quality of Al:ZnO and Cu co-doped Al:ZnO thin films were fabricated by sol–gel method. • The XRD analyses revealed that the deposited thin films have hexagonal wurtzite structure. • XPS was carried out for Zn{sub 0.80}Al{sub 0.10}Cu{sub 0.10}O films to analyze the binding energy of Al, Cu, Zn and O. • SEM studies were made for Al:ZnO and Cu/Al:ZnO thin films. • RTFM was observed in Cu co-doped Al:ZnO thin films.

  10. [Speciation analysis of trace elements Cu, Fe and Zn in serum by flame atomic absorption spectrophotometry].

    Science.gov (United States)

    Hu, Jun; Chang, Yao-Ming; Gao, Shuang-Bin; Hai, Chun-Xu; Li, Jin-Sheng; Xie, Xiao-Ping

    2008-03-01

    Since biological functions of the elements are generally different, depending on their chemical forms, chemical speciation analysis is really important in metallomics research. Thus, multielement analysis and chemical speciation of the elements in serum were carried out in the present work. A hyphenated technique was developed for high-throughput speciation analysis of the copper, iron and zinc in serum by molecular biology technology and flame atomic absorption spectrophotometry (AAS). Here, Cu, Fe and Zn in serum were classifyied as the forms of combination and non-combination. The serum protein was precipitated by 60% concentration of ethanol under hypothermy. The forms of combination of Cu, Fe and Zn in serum which combined with proteins were in precipitations, and the forms of non-combination of Cu, Fe and Zn in serum, which were free ions, were in supernatant. The total amount of Cu, Fe and Zn in serum and the amount of the forms of non-combination of Cu, Fe and Zn were analyzed by AAS. The amount of the forms of combination of Cu, Fe and Zn was obtained by calculation. The detection limit of Cu in serum by the method is around and 9.84 x 10(-3) microg x mL(-1). For Fe and Zn, the detection limit is about 2.76 x 10(-2) microg x mL(-1) and 1.06 x 10(-3) microg x mL(-1), respectively. The percentage recovery of trace elements Cu, Fe and Zn by the proposed procedure is in the range 95.0%-101.0%, 95.0%-102.0% and 95.0%-103.0%, respectively. The relative standard deviation (RSD) of trace elements Cu, Fe and Zn in the serum is in the range 1.88%-2.26%, 0.56%-1.59% and 0.34%-1.36%, respectively. Speciation of trace elements Cu, Fe and Zn in the serum of SD rat were analyzed by the method.

  11. Atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging

    Institute of Scientific and Technical Information of China (English)

    LI Zhou; XIAO Zhu; BAO Ji-qing; XU Gen-ying; ZHENG Feng

    2006-01-01

    The bulk specimens with preferable orientation were utilized to investigate atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging by in-situ X-ray diffraction. It is found that the exchange of Zn atoms at position Ⅲ and Cu atoms at Ⅱ and the exchange of Zn atoms at position Ⅲ and Al atoms atⅠon the basal plane of martensite occur during heating at a heating rate of 5 ℃/min. 13% (2/25 ) of Al atoms transfer from positionⅠto position Ⅲ when temperature goes up to 160 ℃.

  12. Complete transformation of ZnO and CuO nanoparticles in culture medium and lymphocyte cells during toxicity testing.

    Science.gov (United States)

    Ivask, Angela; Scheckel, Kirk G; Kapruwan, Pankaj; Stone, Vicki; Yin, Hong; Voelcker, Nicolas H; Lombi, Enzo

    2017-03-01

    Here, we present evidence on complete transformation of ZnO and CuO nanoparticles, which are among the most heavily studied metal oxide particles, during 24 h in vitro toxicological testing with human T-lymphocytes. Synchrotron radiation-based X-ray absorption near edge structure (XANES) spectroscopy results revealed that Zn speciation profiles of 30 nm and 80 nm ZnO nanoparticles, and ZnSO4- exposed cells were almost identical with the prevailing species being Zn-cysteine. This suggests that ZnO nanoparticles are rapidly transformed during a standard in vitro toxicological assay, and are sequestered intracellularly, analogously to soluble Zn. Complete transformation of ZnO in the test conditions was further supported by almost identical Zn spectra in medium to which ZnO nanoparticles or ZnSO4 was added. Likewise, Cu XANES spectra for CuO and CuSO4-exposed cells and cell culture media were similar. These results together with our observation on similar toxicological profiles of ZnO and soluble Zn, and CuO and soluble Cu, underline the importance of dissolution and subsequent transformation of ZnO and CuO nanoparticles during toxicological testing and provide evidence that the nano-specific effect of ZnO and CuO nanoparticles is negligible in this system. We strongly suggest to account for this aspect when interpreting the toxicological results of ZnO and CuO nanoparticles.

  13. Effects of Cu2+ and Zn2+ on growth of Triticum aestivum seedling%Cu2+和Zn2+对普通小麦幼苗生长的影响

    Institute of Scientific and Technical Information of China (English)

    李进学; 曹虎; 张芬琴; 李彩霞

    2005-01-01

    The effects of Cu2+ and Zn2+ on growth and physiological characters of Triticum aestivum Linn. seedling were studied. The resultsindicatedthat the higherconcentration ofCu2+ andZn2+ hadobvious inhibition, showing that the content of chlorophyll was reduced, the content of MDA and electrical conductivity increased, the vigor of root reduced. It showed that the effect of Cu2+ on T. aestivum was more poisonous than that of Zn2+.

  14. The energies of formation and mobilities of Cu surface species on Cu and ZnO in methanol and water gas shift atmospheres studied by DFT

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Janssens, Ton V.W.; Temel, Burcin;

    2012-01-01

    ) species are investigated in relevant synthesis gas compositions. The CuCO and Cu2HCOO species are identified to be predominant for metal transport on Cu particles, which may contribute to sintering of Cu by particle migration and coalescence. Furthermore, transport of Cu on ZnO is found mostly to occur......Catalysts based on copper, such as the Cu/ZnO/Al2O3 system are widely used for industrial scale methanol synthesis and the low temperature water gas shift reaction. A common characteristic of these catalysts is that they deactivate quite rapidly during operation and therefore understanding...... through CuCO species, which indicates that CuCO is an important species for Ostwald ripening in a Cu/ZnO catalyst. These results provide atomistic perspective on the diffusion of the species that may contribute to catalyst sintering, therefore lending a valuable foundation for future investigations...

  15. Case study on the strategy and application of enhancement solutions to improve remediation of soils contaminated with Cu, Pb and Zn by means of electrodialysis

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul; Ribeiro, Alexandra B.;

    2005-01-01

    Numerous studies have been conducted with electrochemical removal of heavy metals from spiked kaolinite. Meanwhile, when moving from kaolinite to real soils, new factors must be taken into account-factors influencing, e.g., the buffering capacity of the soil against acidification and the adsorption...... soil, ammonia may be used as enhancement solution, due to the formation of charged complexes between ammonia and Cu. Thus, Cu is mobile at high pH when ammonia is added and Cu can be removed without dissolving the calcareous parts. Zn is also mobilized by ammonia, but to a lesser extent than Cu....... In the case of Cu, Zn and Pb at the same time, alkaline ammonium citrate may be a solution. It was shown that this enhancement solution could mobilize these three pollutants, but optimization of concentration and pH of the ammonium citrate is still needed. When choosing a remediation scheme...

  16. Comparative Study of the Defect Point Physics and Luminescence of the Kesterites Cu2ZnSnS4 and Cu2ZnSnSe4 and Chalcopyrite Cu(In,Ga)Se2: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M. J.; Repins, I.; Teeter, G.; Contreras, M.; Al-Jassim, M.; Noufi, R.

    2012-08-01

    In this contribution, we present a comparative study of the luminescence of the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) and their related chalcopyrite Cu(In,Ga)Se2 (CIGSe). Luminescence spectroscopy suggests that the electronic properties of Zn-rich, Cu-poor kesterites (both CZTS and CZTSe) and Cu-poor CIGSe are dictated by fluctuations of the electrostatic and chemical potentials. The large redshift in the luminescence of grain boundaries in CIGSe, associated with the formation of a neutral barrier is clearly observed in CZTSe, and, to some extent, in CZTS. Kesterites can therefore replicate the fundamental electronic properties of CIGSe.

  17. Heterojunction formation in (CdZn)S/CuInSe2 ternary solar cells

    Science.gov (United States)

    Ahrenkiel, R. K.; Kazmerski, L. L.; Matson, R. J.; Osterwald, C.; Massopust, T. P.; Mickelsen, R. A.; Chen, W. S.

    1983-10-01

    The electrical properties of (CdZn)S/CuInSe2 solar cells have been investigated by combining electron beam induced current measurements and capacitance-voltage measurements on the same device. In the as-grown device, the CuInSe2 is lightly doped n type. After baking to about 225 C in vacuum, the CuInSe2 converts to p type forming the heterojunction. Oxygen does not appear to be necessary for type conversion to occur.

  18. Study of polycrystalline Cu2ZnSnS4 films by Raman scattering

    OpenAIRE

    Fernandes, P. A.; Salomé, P M P; Cunha, A. F. da

    2011-01-01

    Cu2ZnSnS4 (CZTS) is a p-type semiconductor that has been seen as a possible low-cost replacement for Cu(In,Ga)Se2 in thin film solar cells. So far compound has presented difficulties in its growth, mainly, because of the formation of secondary phases like ZnS, CuxSnSx+1, SnxSy, Cu2−xS and MoS2. X-ray diffraction analysis (XRD), which is mostly used for phase identification cannot resolve some of these phases from the kesterite/stannite CZTS and thus the use of a complementary tech...

  19. ZnO/Cu nanocomposite: a platform for direct electrochemistry of enzymes and biosensing applications.

    Science.gov (United States)

    Yang, Chi; Xu, Chunxiang; Wang, Xuemei

    2012-03-06

    Unique structured nanomaterials can facilitate the direct electron transfer between redox proteins and the electrodes. Here, in situ directed growth on an electrode of a ZnO/Cu nanocomposite was prepared by a simple corrosion approach, which enables robust mechanical adhesion and electrical contact between the nanostructured ZnO and the electrodes. This is great help to realize the direct electron transfer between the electrode surface and the redox protein. SEM images demonstrate that the morphology of the ZnO/Cu nanocomposite has a large specific surface area, which is favorable to immobilize the biomolecules and construct biosensors. Using glucose oxidase (GOx) as a model, this ZnO/Cu nanocomposite is employed for immobilization of GOx and the construction of the glucose biosensor. Direct electron transfer of GOx is achieved at ZnO/Cu nanocomposite with a high heterogeneous electron transfer rate constant of 0.67 ± 0.06 s(-1). Such ZnO/Cu nanocomposite provides a good matrix for direct electrochemistry of enzymes and mediator-free enzymatic biosensors.

  20. Research on a Zn-Cu alloy as a biodegradable material for potential vascular stents application.

    Science.gov (United States)

    Niu, Jialin; Tang, Zibo; Huang, Hua; Pei, Jia; Zhang, Hua; Yuan, Guangyin; Ding, Wenjiang

    2016-12-01

    Zn-based alloys have been viewed as new potential materials for biodegradable implants, such as cardiovascular stents, mainly in consideration of their lower corrosion rate when compared with that of Mg alloys. In this study we developed a new Zinc-4wt.%Copper (Zn-4Cu) alloy as a biodegradable material. Hot extrusion was applied to Zn-4Cu to refine the microstructure and consequently improve its mechanical properties and corrosion resistance. After extrusion, dendritic CuZn5 phases were broken and distributed along the extrusion direction. The grains were refined obviously due to dynamical recrystallization. The yield strength (YS), ultimate tensile strength (UTS) and elongation of the as-extruded alloy are 250±10MPa, 270±10MPa and 51±2%, respectively. The corrosion rate of the as-extruded alloy in Hank's solution is about 9.41(±1.34)μmyear(-1). In vitro evaluation shows that Zn-4Cu presents acceptable toxicity to human endothelial cells, and could effectively inhibit bacteria adhesion and biofilm formation. The present study indicates that the as-extruded Zn-4Cu alloy exhibits excellent strength and ductility, uniform and slow degradation, good biocompatibility and significant antibacterial effect, which make it an excellent candidate material for biodegradable implants, especially for cardiovascular stents application.

  1. Facile synthesis of ZnO/CuInS2 nanorod arrays for photocatalytic pollutants degradation.

    Science.gov (United States)

    Yang, Yawei; Que, Wenxiu; Zhang, Xinyu; Xing, Yonglei; Yin, Xingtian; Du, Yaping

    2016-11-05

    Vertically-aligned ZnO nanorod arrays on a fluorine-doped tin oxide glass substrate were homogeneously coated with visible light active CuInS2 quantum dots by using a controllable electrophoretic deposition strategy. Compared with the pure ZnO nanorod arrays, the formation of high-quality ZnO/CuInS2 heterojunction with well-matched band energy alignment expanded the light absorption from ultraviolet to visible region and facilitated efficient charge separation and transportation, thus yielding remarkable enhanced photoelectrochemical performance and photocatalytic activities for methyl orange and 4-chlorophenol degradation. The ZnO/CuInS2 film with the deposition duration of 80min showed the highest degradation rate and photocurrent density (0.95mA/cm(2)), which was almost 6.33 times higher than that of the pure ZnO nanorod arrays film. The CuInS2 QDs sensitized ZnO nanorod arrays film was proved to be a superior structure for photoelectrochemical and photocatalytic applications due to the optimized CuInS2 loading and well-maintained one-dimensional nanostructure.

  2. Cu(I)/SO2-4/ZnO和Cu(I)/S2O2-8/ZnO催化剂的制备与表征%Preparation and Characterization of Cu(Ⅰ)/SO2-4/ZnO and Cu(Ⅰ)/S2O2-8/ZnO Catalysts

    Institute of Scientific and Technical Information of China (English)

    李忠; 黄海彬; 谢克昌

    2008-01-01

    采用浸渍法对无定形ZnO分别用稀H2SO4和(NH4)2S2O8溶液处理,制备了SO2-4/ZnO和S2O2-8/ZnO固体酸.通过固体离子交换法制备了Cu(Ⅰ)/SO2-4/ZnO和Cu(Ⅰ)/S2O2-8/ZnO两种催化剂,并采用XRD,FTIR,TPD和TPR等进行了表征.研究结果表明,用稀H2SO4和(NH4)2S2O8溶液分别浸渍处理无定形ZnO,经过500~600 ℃高温焙烧后得到的SO2-4/ZnO和S2O2-8/ZnO固体酸表面形成了Zn3O(SO4)2物种;py-FTIR结果表明,两者均具有B酸中心和L酸中心,进一步的NH3-TPD研究结果证明,制备的固体酸NH3脱附峰均出现在543 ℃附近,属于高强度固体酸.结构分析认为,由于SO2-4强烈的电子诱导作用,SO2-4和ZnO形成的桥式配位物种产生了B酸中心和L酸中心,而其螯合配位形成的物种没有酸性.SO2-4/ZnO和S2O2-8/ZnO固体酸与CuCl进行离子交换所制备的Cu(Ⅰ)/SO2-4/ZnO和Cu(Ⅰ)/S2O2-8/ZnO催化剂的Cu(Ⅰ)易于还原,对甲醇氧化羰基化合成碳酸二甲酯(DMC)表现出较高的活性和选择性,DMC选择性为98.3%,时空收率可达到1.9 g(g\\5h).

  3. Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Malte

    2012-03-28

    Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.

  4. Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhuo Shiyi; Xiong Yuying; Gu Min, E-mail: xiongyy@scnu.edu.c [Laboratory of Quantum Information Technology, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)

    2009-05-01

    ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn{sub 0.99}Cu{sub 0.01}O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1+. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.

  5. Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    Zhuo Shiyi; Xiong Yuying; Gu Min

    2009-01-01

    ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.

  6. Influence of Zn Addition on Microstructures and Martensitic Transformation in CuZr-based Alloys

    Institute of Scientific and Technical Information of China (English)

    Kai-kai SONG; Dian-yu WU; Feng WAN; Xiao-jun BAI; Chong-de CAO

    2016-01-01

    Compositional dependences on microstructures and martensitic transformation behaviors in (Cu0.5 Zr0.5 )100-x Znx (x =1.5,2.5,4.5,7.0,10.0,and 14.0 at.%)alloys were investigated.It was found that CuZr martensites were present in the present alloys.With increasing Zn content,the volume fractions of CuZr martensitic crystals and B2 CuZr phase gradually decrease and increase,respectively.With the addition of high Zn contents (i.e.,7.0,10.0, and 14.0 at.%),the matrix proves to be eutectic.Thermal analysis results show that the initial martensitic transfor-mation temperature (Ms)decreases from (412±5)K to (329±5)K as the Zn content increases from 1.5 at.% to 14.0 at.%.The values of Ms of Cu-Zr-Zn shape memory alloys are inversely proportional to the number and concen-trations of valence electrons (i.e.,e v/a and c v ),respectively,implying that the martensitic transformation in CuZr-Zn alloys could be of electronic nature.

  7. Thermoelectric Properties of In-Doped Cu2ZnGeSe4

    Science.gov (United States)

    Chetty, R.; Bali, A.; Femi, O. E.; Chattopadhyay, K.; Mallik, R. C.

    2016-03-01

    Recently, much research has been focused on finding new thermoelectric materials. Cu-based quaternary chalcogenides that belong to A2BCD4 (A = Cu; B = Zn, Cd; C = Sn, Ge; D = S, Se, Te) are wide band gap materials and one of the potential thermoelectric materials due to their complex crystal structures. In this study, In-doped quaternary compounds Cu2ZnGe1- x In x Se4 ( x = 0, 0.025, 0.05, 0.075, 0.1) were prepared by a solid state synthesis method. Powder x-ray diffraction patterns of all the samples showed a tetragonal crystal structure (space group I- 42m) of the main phase with a trace amount of impurity phases, which was further confirmed by Rietveld analysis. The elemental composition of all the samples showed a slight deviation from the nominal composition with the presence of secondary phases. All the transport properties were measured in the temperature range 373-673 K. The electrical resistivity of all the samples initially decreased up to ˜470 K and then increased with increase in temperature upto 673 K, indicating the transition from semiconducting to metallic behavior. Positive Seebeck coefficients for all the samples revealed that holes are the majority carriers in the entire temperature range. The substitution of In3+ on Ge4+ introduces holes and results in the decrease of resistivity as well as the Seebeck coefficient, thereby leading to the optimization of the power factor. The lattice thermal conductivity of all the samples decreased with increasing temperature, indicating the presence of phonon-phonon scattering. As a result, the thermoelectric figure of merit ( zT) of the doped sample showed an increase as compared to the undoped compound.

  8. Determination of the band offset for the heterostructure ZnO/Cu{sub 2}O and ZnS/Cu{sub 2}O via X-ray photoelectron spektroscopy (XPS)

    Energy Technology Data Exchange (ETDEWEB)

    Kramm, Benedikt; Laufer, Andreas; Kronenberger, Achim; Graubner, Swen; Reppin, Daniel; Seibert, Alba; Schurig, Philipp; Polity, Angelika; Meyer, Bruno K. [1. Physikalisches Institut, Justus-Liebig-Universitaet, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2011-07-01

    ZnO and Cu{sub 2}O are direct band-gap semiconductors. Both are promising materials for electronic devices like diodes, transistors or solar cells. Important is, that ZnO and Cu{sub 2}O contain only non toxic und sustainable elements. Due to a band-gap energy of 2.1 eV for Cu{sub 2}O a high absorption in the visible light spectrum could be obtained which is suitable for solar cells. We produced a heterojunction of intrinsic p-type Cu{sub 2}O and hydrogen doped n-type ZnO or ZnS on sapphire using sputter deposition. Investigating the energy band structure of the thin film heterojunction ZnO/Cu{sub 2}O via XPS yield to be a type II alignment with a valence-band offset between 2.4 - 2.7 eV. Furthermore the band offset between ZnS and Cu{sub 2}O, using ZnS as a buffer-layer for the heterostructure ZnO/ZnS/Cu{sub 2}O, was explored. For the band offset structure of the whole system the band offset values for ZnS/ZnO, determined by Persson, have been used.

  9. Ten metal complexes of vitamin B3/niacin: Spectroscopic, thermal, antibacterial, antifungal, cytotoxicity and antitumor studies of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II), Pt(IV) and Au(III) complexes

    Science.gov (United States)

    Al-Saif, Foziah A.; Refat, Moamen S.

    2012-08-01

    Ten coordination compounds, namely Mn(NA)2Cl2·4H2O (1), Fe(NA)Cl3(H2O)2 (2), Co(NA)2(NO3)2·6H2O (3), Ni(NA)Cl2·5H2O (4), Cu(NA)Cl2·3H2O (5), Zn(NA)(NO3)2·H2O (6), Pd(NA)2Cl2·H2O (7), Cd(NA)Cl2·H2O (8), Pt(NA)2Cl4·5H2O (9) and Au(NA)Cl3 (10) were obtained by the reactions of the corresponding transition metal salts with vitamin B3/niacin (NA) in the presence of 1:4 (v:v) distilled water: methanol solvent at 70 °C for about 30 min, and their suggested structures were determined by elemental analyses, molar conductivity, (infrared, UV-vis) spectra, effective magnetic moment in Bohr magnetons, electron spin resonance (ESR), thermal analysis (TG), X-ray powder diffraction (XRD) as well as scanning electron microscopy (SEM). The results revealed that in complexes 1, 3, 7, and 9 both of two NA ligand coordinates one metal ion to form four or six coordinated structures, while in compound 10, one NA ligand coordinate to Au+++ ion to form a square-planar geometry with N-bonded pyridine ligand is suggested, and (2, 4, 5, 6 and, 8) complexes have 1:1 structures. Antimicrobial and antitumor activities were assessment against some kind of (G+ and G-) bacteria, fungi and breast carcinoma cells (MCF-7-cell line).

  10. Catalytic properties of Cu/Co/Zn/Zr oxides prepared by various methods

    Institute of Scientific and Technical Information of China (English)

    Limin Shi; Wei Chu; Siyu Deng; Huiyuan Xu

    2008-01-01

    The new Cu-Co based (Cu/Co/Zn/Zr) catalysts for higher-alcohol synthesis were prepared using coprecipitation method, plasma enhanced method and reverse coprecipitation method under ultrasound irradiation. The catalysts were investi-gated by the means of BET, SEM, XRD, H2-TPR and XPS. Catalytic properties of the catalysts prepared by various methods were examined using CO hydrogenation reaction. It was found that plasma enhanced method and reverse coprecipitation method under ultrasound irradiation were both effective in enhancing the catalytic properties of Cu/Co/Zn/Zr mixed oxides. The small particle size, high dispersion of active components, the improvement of specific surface area and surface contents of active phases could account for the excellent performance of the experimental Cu/Co/Zn/Zr catalysts.

  11. Effect of the Zn(II) on the reduction of Cu(II) in natural clinoptilolite

    Science.gov (United States)

    Rodríguez Iznaga, I.; Petranovskii, V.; Castillon, F. F.; Farias, M. H.

    2006-10-01

    The [Cu(H 2O) n] 2+ reduction in the presence of Zn 2+, with both cations supported on natural clinoptilolite, has been studied using hydrogen flow at different reduction temperatures. The analysis of the obtained results allows to conclude that the Cu 2+ reduction process and the subsequent aggregation of the reduced species of copper forming particles of colloidal and nanometric size is sensitive to the presence of zinc and to the temperature of reduction. The presence of Zn 2+ diminishes the temperature of Cu 2+ reduction. The Cu 2+ reduction in the presence of Zn 2+ could constitute an alternative procedure to control the degree of aggregation of reduced copper species and, thus, to modify the size of the resultant copper nanoparticles in the clinoptilolite matrix.

  12. Probing the orientations of coordination complex molecules onto the surface of ZnO nanoparticles by means of surface enhanced Raman scattering, UV–vis and DFT methods

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Om; Gautam, Priyanka; Singh, Ranjan K., E-mail: ranjanksingh65@rediffmail.com

    2015-09-15

    Graphical abstract: - Highlights: • The adsorption geometry of three complex molecules onto the surface of ZnO nanoparticles is investigated by Raman, SERS and UV–vis techniques. • All the three complex molecules are adsorbed in flat-on geometry. • On the adsorption onto the ZnO NPs, the fluorescence background of Raman spectra of Zn complex is quenched. - Abstract: The surface enhanced Raman scattering (SERS) is a highly surface sensitive technique to study inter-surface properties of biological, organic, and inorganic materials. It is a precise technique to determine the adsorption geometry/orientation of the molecules as the intensity enhancement of the SERS bands depends on the adsorption geometry/orientation of molecules on SERS substrate. In the present work, Ni, Cu and Zn complexes of (Z)-N′(1,3,4-thiadiazol-2-yl) acetimidate were synthesized and adsorbed on ZnO nanoparticles. The surface enhanced Raman scattering (SERS), UV–vis and DFT techniques were applied to investigate the possible adsorption geometries of the complexes on ZnO. Consequently, it was found that the orientation of all three complex molecules is flat-on onto the surface of ZnO nanoparticles. The fluorescence background of Raman spectra of Zn complex is quenched and its geometry is isomerized after the adsorption onto the surface of ZnO nanoparticles. The adsorbed Cu complex on ZnO NPs absorbed UV radiations efficiently.

  13. A facile green antisolvent approach to Cu2+-doped ZnO nanocrystals with visible-light-responsive photoactivities.

    Science.gov (United States)

    Lu, Yi-Hsuan; Lin, Wei-Hao; Yang, Chao-Yao; Chiu, Yi-Hsuan; Pu, Ying-Chih; Lee, Min-Han; Tseng, Yuan-Chieh; Hsu, Yung-Jung

    2014-08-07

    An environmentally benign antisolvent method has been developed to prepare Cu(2+)-doped ZnO nanocrystals with controllable dopant concentrations. A room temperature ionic liquid, known as a deep eutectic solvent (DES), was used as the solvent to dissolve ZnO powders. Upon the introduction of the ZnO-containing DES into a bad solvent which shows no solvation to ZnO, ZnO was precipitated and grown due to the dramatic decrease of solubility. By adding Cu(2+) ions to the bad solvent, the growth of ZnO from the antisolvent process was accompanied by Cu(2+) introduction, resulting in the formation of Cu(2+)-doped ZnO nanocrystals. The as-prepared Cu(2+)-doped ZnO showed an additional absorption band in the visible range (400-800 nm), which conduced to an improvement in the overall photon harvesting efficiency. Time-resolved photoluminescence spectra, together with the photovoltage information, suggested that the doped Cu(2+) may otherwise trap photoexcited electrons during the charge transfer process, inevitably depressing the photoconversion efficiency. The photoactivity of Cu(2+)-doped ZnO nanocrystals for photoelectrochemical water oxidation was effectively enhanced in the visible region, which achieved the highest at 2.0 at% of Cu(2+). A further increase in the Cu(2+) concentration however led to a decrease in the photocatalytic performance, which was ascribed to the significant carrier trapping caused by the increased states given by excessive Cu(2+). The photocurrent action spectra illustrated that the enhanced photoactivity of the Cu(2+)-doped ZnO nanocrystals was mainly due to the improved visible photon harvesting achieved by Cu(2+) doping. These results may facilitate the use of transition metal ion-doped ZnO in other photoconversion applications, such as ZnO based dye-sensitized solar cells and magnetism-assisted photocatalytic systems.

  14. Characterization and photocatalytic activity of (ZnO–CuO)/SBA-15 nanocomposites synthesized by two-solvent method

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Peng; Zhang, Lili; Zhang, Gongtuo; Li, Guang; Sun, Zhaoqi [Key laboratory of Information Materials and Device, School of Physics and Materials Science, Anhui University, Hefei 230039 (China); Liu, Xiansong [Engineering Technology Research Center of Magnetic Materials, Hefei 230039 (China); Wu, Mingzai, E-mail: mingzaiwu@gmail.com [Key laboratory of Information Materials and Device, School of Physics and Materials Science, Anhui University, Hefei 230039 (China); Engineering Technology Research Center of Magnetic Materials, Hefei 230039 (China)

    2014-08-15

    Schematic between charge genenration and transfer for methylene orange degradation simulated by light. - Highlights: • Two-solvent method is used to prepare ZnO–CuO particles embedded in porous SBA-15. • The absorption edge of (ZnO–CuO)/SBA-15 composite is in the visible light regime. • The absorption intensity of the composite in visible light regime is enhanced. • The (ZnO–CuO)/SBA-15 composite has higher photocatalytic ability than Degussa P-25. - Abstract: Two-solvent method was employed to prepare ZnO–CuO nanoparticles embedded in mesoporous silica SBA-15 ((ZnO–CuO)/SBA-15). The as-obtained (ZnO–CuO)/SBA-15 nanocomposites were characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, N{sub 2} adsorption porosimetry, and diffusive reflective UV–vis spectroscopy. The photocatalytic activity of (ZnO–CuO)/SBA-15 nanocomposites toward methylene orange was investigated under simulated solar light irradiation, and the measurement results indicated that (ZnO–CuO)/SBA-15 nanocomposites exhibit higher photodegradation activity toward methylene orange than commercial TiO{sub 2} P-25. The photocatalytic activity of (ZnO–CuO)/SBA-15 nanocomposites were found to be dependent on both the adsorption ability of the nanocomposites and the loading dosage of ZnO–CuO nanoparticles in SBA-15. The optimal loading dosage of ZnO–CuO nanoparticles was determined. Too high or too low loading will lower the photodegradation ability of (ZnO–CuO)/SBA-15 nanocomposites.

  15. An optical study of the D-D neutron irradiation-induced defects in Co-and Cu-doped ZnO wafers

    Institute of Scientific and Technical Information of China (English)

    Wang Yun-Bo; Li Gong-Ping; Xu Nan-Nan; Pan Xiao-Dong

    2013-01-01

    Room-temperature photoluminescence and optical transmittance spectroscopy of Co-doped (1 × 1014,5 × 1016,and 1 × 1017 cm-2) and Cu-doped (5 × 1016 cm-2) ZnO wafers irradiated by D-D neutrons (fluence of 2.9 x 1010 cm-2) have been investigated.After irradiation,the Co or Cu metal and oxide clusters in doped ZnO wafers are dissolved,and the würtzite structure of ZnO substrate for each sample remains unchanged and keeps in high c-axis preferential orientation.The degree of irradiation-induced crystal disorder reflected from the absorption band tail parameter (E0) is far greater for doped ZnO than the undoped one.Under the same doping concentration,the Cu-doped ZnO wafer has much higher irradiation-induced disorder than the Co-doped one.Photoluminescence measurements indicate that the introduction rate of both the zinc vacancy and the zinc interstitial is much higher for the doped ZnO wafer with a high doping level than the undoped one.In addition,both crystal lattice distortion and defect complexes are suggested to be formed in doped ZnO wafers.Consequently,the Co-or Cu-doped ZnO wafer (especially with a high doping level) exhibits very low radiation hardness compared with the undoped one,and the Cu-doped ZnO wafer is much less radiation-hard than the Co-doped one.

  16. Defects related room temperature ferromagnetism in Cu-implanted ZnO nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Department of Physics and Development Center for New Materials Engineering and Technology in Universities of Guangdong, Zhanjiang Normal University, Zhanjiang 524048 (China); Li, D.K. [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 511400 (China); Wu, H.Z.; Liang, F.; Xie, W. [Department of Physics and Development Center for New Materials Engineering and Technology in Universities of Guangdong, Zhanjiang Normal University, Zhanjiang 524048 (China); Zou, C.W., E-mail: qingyihaiyanas@163.com [Department of Physics and Development Center for New Materials Engineering and Technology in Universities of Guangdong, Zhanjiang Normal University, Zhanjiang 524048 (China); Shao, L.X. [Department of Physics and Development Center for New Materials Engineering and Technology in Universities of Guangdong, Zhanjiang Normal University, Zhanjiang 524048 (China)

    2014-04-05

    Highlights: • Room temperature ferromagnetism was observed in Cu-implanted ZnO nanorod arrays. • Cu-implanted ZnO nanorods show a saturation magnetization value of 1.82 μ{sub B}/Cu. • The origin of ferromagnetism can be explained by the defects related bound magnetic polarons. -- Abstract: Room temperature ferromagnetism (FM) was observed in Cu-implanted ZnO nanorod arrays. The implantation dose for Cu ions was 1 × 10{sup 16} cm{sup −2} and the implantation energy was 100 keV. The ion implantation induced defects and disorder has been observed by the XRD, PL and TEM experiments. The PL spectrum revealed a dominant luminescence peaks at 390 nm and a broad and strong green emission at 500–700 nm, which is considered to be related to the ionized oxygen vacancy. Cu-implanted ZnO nanorods annealed at 500 °C show a saturation magnetization value of 1.82 μ{sub B}/Cu and a positive coercive field of 68 Oe. The carrier concentration is not much improved after annealing and in the order of 10{sup 16} cm{sup −3}, which suggests that FM does not depend upon the presence of a significant carrier concentration. The origin of ferromagnetism behavior can be explained on the basis of electrons and defects that form bound magnetic polarons, which overlap to create a spin-split impurity band.

  17. Substituent Effect on Proton Affinity of Imidazole in Cu,Zn-Superoxide Dismutase

    Institute of Scientific and Technical Information of China (English)

    JI Hong-Fang; ZHANG Hong-Yu

    2006-01-01

    To investigate whether the proton-accepting ability of imidazole in Cu,Zn-superoxide dismutase (SOD) was possibly modulated by Zn(Ⅱ) or not, the proton affinity (Ap) of N3 in imidazole group was calculated by density functional theory (DFF) with B3LYP functional. It was found that Zn(Ⅱ) attenuates the Ap, because of its electron-withdrawing effect, while the three ligands connected with Zn(Ⅱ) (residues of two His and one Asp) exert an opposite effect, owing to their electron-donating ability. This finding suggested that the three ligands should play a role in the normal function of Cu,Zn-SOD and should be taken into consideration in the future study.

  18. Catalytic and photoelectrochemical performances of Cu-Zn-Sn-Se thin films prepared using selenization of electrodeposited Cu-Zn-Sn metal precursors

    Science.gov (United States)

    Shao, Pin-Wen; Li, Chun-Ting; Ho, Kuo-Chuan; Cheng, Kong-Wei

    2015-07-01

    In this study, Cu2ZnSnSe4 (CZTSe) films are deposited onto the fluorine-doped-tin-oxide-coated glass substrate via the selenization of electrodeposited Cu-Zn-Sn metal precursors in an acidic solution with the applied potential of -0.9 V vs. an Ag/AgCl electrode. X-ray diffraction patterns reveal that the samples are the quaternary tetragonal CZTSe phase. The thicknesses and direct band gaps of the samples are in the ranges of 2.3 to 2.7 μm and 0.95 to 1.02 eV, respectively. All samples are p-type semiconductors with carrier density, mobility and flat-band potential in the ranges of 3.88 × 1017 to 1.37 × 1018 cm-3, 10.31 to 12.6 cm2 V-1 s-1 and -0.01 V to -0.08 V vs. Ag/AgCl reference electrode, respectively. The sample with [Cu]/[Zn + Sn] and [Zn]/[Sn] molar ratios of 0.87 and 0.66, respectively, has a maximum photo-enhanced current density of 0.41 mA cm-2 at an applied bias of -0.5 V vs. an Ag/AgCl electrode in 0.5 M H2SO4 solution under illumination. The best photo-conversion efficiency of dye-sensitized solar cells using CZTSe with [Cu]/[Zn + Sn] and [Zn]/[Sn] molar ratios of 0.87 and 0.66, respectively, as the counter electrode was 7.98%. The results show the high quality CZTSe films have potentials in applications of photoelectrochemical water splitting and dye-sensitized solar cells.

  19. Adsorption of multi-heavy metals Zn and Cu onto surficial sediments: modeling and adsorption capacity analysis.

    Science.gov (United States)

    Li, Shanshan; Zhang, Chen; Wang, Meng; Li, Yu

    2014-01-01

    Improved multiple regression adsorption models (IMRAMs) was developed to estimate the adsorption capacity of the components [Fe oxides (Fe), Mn oxides (Mn), organic materials (OMs), residuals] in surficial sediments for multi-heavy metal Zn and Cu. IMRAM is an improved version over MRAM, which introduces a computer program in the model developing process. As MRAM, Zn(Cu) IMRAM, and Cu(Zn) IMRAM again confirmed that there is significant interaction effects that control the adsorption of compounded Zn and Cu, which was neglected by additional adsorption model. The verification experiment shows that the relative deviation of the IMRAMs is less than 13%. It is revealed by the IMRAMs that Mn, which has the greatest adsorption capability for compounded Zn and Cu (54.889 and 161.180 mg/l, respectively), follows by interference adsorption capacity of Fe/Mn (-1.072 and -24.591 mg/l respectively). Zn and Cu influence each other through different mechanisms. When Zn is the adsorbate, compounded Cu mainly affects the adsorption capacities of Fe/Mn and Fe/Mn/OMs; while when Cu is the adsorbate, compounded Zn mainly exerts its effect on Mn, Fe/Mn, and Mn/OMs. It also shows that the compounded Zn or Cu weakened the interference adsorption of Fe/Mn, and meanwhile, strengthened the interference adsorption of Mn/OMs.

  20. Cu{sub 2}ZnSn(S,Se){sub 4} solar cells based on chemical bath deposited precursors

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Chao, E-mail: chao.gao@kit.edu [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Schnabel, Thomas; Abzieher, Tobias [Zentrum für Sonnenenergie-und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70565 Stuttgart (Germany); Krämmer, Christoph [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Powalla, Michael [Zentrum für Sonnenenergie-und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70565 Stuttgart (Germany); Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Kalt, Heinz; Hetterich, Michael [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany)

    2014-07-01

    A low-cost method has been developed to fabricate Cu{sub 2}ZnSn(S,Se){sub 4} solar cells. By this method, firstly SnS, CuS, and ZnS layers are successively deposited on a molybdenum/soda lime glass (Mo/SLG) substrate by chemical bath deposition. The Cu{sub 2}ZnSn(S,Se){sub 4} thin films are obtained by annealing the precursor in a selenium atmosphere utilizing a graphite box in the furnace. The obtained Cu{sub 2}ZnSn(S,Se){sub 4} thin films show large crystalline grains. By optimizing the preparation process, Cu{sub 2}ZnSn(S,Se){sub 4} solar cells with efficiencies up to 4.5% are obtained. The results imply that the Cu{sub 2}ZnSn(S,Se){sub 4}/CdS interface and the back contact may be limiting factors for solar cell efficiency. - Highlights: • A chemical bath deposition method is developed to prepare Cu{sub 2}ZnSn(S,Se){sub 4} thin films. • The Cu{sub 2}ZnSn(S,Se){sub 4} thin films show good crystallization. • Solar cells with efficiencies up to 4.5% can be prepared based on the Cu{sub 2}ZnSn(S,Se){sub 4} layer. • The limiting factors for the solar cell efficiency are analyzed.

  1. Visible-light-induced photocatalytic performances of ZnO-CuO nanocomposites for degradation of 2,4-dichlorophenol

    Institute of Scientific and Technical Information of China (English)

    E. D. Sherly; J. Judith Vijaya; L.John Kennedy

    2015-01-01

    Nanostructured ZnO and CuO, and coupled oxides, i.e., ZnCu, Zn2Cu, and ZnCu2, with ZnO:CuO molar ratios of 1:1, 2:1, and 1:2, respectively, were successfully prepared through a simple, one-step, mi-crowave-assisted urea–nitrate combustion synthesis, without the use of organic solvents or surfac-tants. The prepared samples were characterized using X-ray diffraction, X-ray photoelectron spec-troscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, diffuse reflectance spectroscopy, and photo-luminescence spectroscopy. The optical absorption of ZnO extended into the visible region after CuO loading. The photocatalytic activities of ZnO, CuO, and the coupled oxides were evaluated based on photodegradation of 2,4-dichlorophenol under visible-light irradiation. The coupled metal oxide Zn2Cu showed the best photocatalytic activity;this was mainly attributed to the extended photore-sponsive range and the increased charge separation rate in the nanocomposite. The photocatalytic degradation process obeyed pseudo-first-order kinetics. The results suggest that the coupled metal oxide Zn2Cu has potential applications as an efficient catalytic material with high efficiency and recyclability for the photocatalytic degradation of organic pollutants in aqueous solution under visible-light irradiation.

  2. Microstructure and properties of hot extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bao-sheng; Kuang, Ya-fei; Fang, Da-qing; Chai, Yue-sheng [Taiyuan Univ. of Science and Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Zhang, Yue-zhong [Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Taiyuan Univ. of Science and Technology (China). College of Chemical and Biological Engineering

    2017-04-15

    In petroleum drilling engineering, materials with high strength and rapid degradation are required for degradable fracturing ball applications. In this work, the microstructure, mechanical properties, and corrosion behavior of extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5 weight percent) alloys are investigated using optical microscopy, scanning electronic microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electronic microscopy, compression tests, electrochemical measurements, and hydrogen evolution tests, to explore their potential as excellent candidate alloys for degradable fracturing ball applications. It is found that the Mg-3Zn-Y alloy is mainly composed of α-Mg, Mg{sub 3}Zn{sub 3}Y{sub 2}, and Mg{sub 3}Zn{sub 6}Y phases. After Cu addition, a new MgZnCu phase is formed, while the Mg{sub 3}Zn{sub 3}Y{sub 2} phase disappears. The Mg-3Zn-Y-3Cu alloy shows the highest compressive strength (473 MPa) and yield strength (402 MPa), mainly attributed to the combined effect of the fine-grain and dispersed precipitation of Mg{sub 3}Zn{sub 6}Y and MgZnCu. The corrosion rate of Mg-3Zn-Y-3Cu reaches 0.41 mm day{sup -1} in 3.5 wt.% KCl solution. Consequently, Mg-3Zn-Y-3Cu alloy is a suitable degradable fracturing ball-seat material.

  3. Continuous production of Cu2ZnSnS4 nanocrystals in a flow reactor.

    Science.gov (United States)

    Shavel, Alexey; Cadavid, Doris; Ibáñez, Maria; Carrete, Alex; Cabot, Andreu

    2012-01-25

    A procedure for the continuous production of Cu(2)ZnSnS(4) (CZTS) nanoparticles with controlled composition is presented. CZTS nanoparticles were prepared through the reaction of the metals' amino complexes with elemental sulfur in a continuous-flow reactor at moderate temperatures (300-330 °C). High-resolution transmission electron microscopy and X-ray diffraction analysis showed the nanocrystals to have a crystallographic structure compatible with that of the kesterite. Chemical characterization of the materials showed the presence of the four elements in each individual nanocrystal. Composition control was achieved by adjusting the solution flow rate through the reactor and the proper choice of the nominal precursor concentration within the flowing solution. Single-particle analysis revealed a composition distribution within each sample, which was optimized at the highest synthesis temperatures used.

  4. Structure and age of the Cerro de Pasco Cu-Zn-Pb-Ag deposit, Peru

    Science.gov (United States)

    Cheney, E. S.

    1991-04-01

    The world-famous Cu-Zn-Pb-Ag deposit at Cerro de Pasco, Peru, consists of texturally massive pyrite, texturally massive sphalerite-galena-pyrite, and veins containing pyrite and enargite. Historically the deposit has been considered to be the hydrothermal product of the adjacent Miocene volcanic and intrusive complex (locally known as the “Vent”). However, both the texturally massive sulfides of the deposit and the pre-Miocene strata are cut by the Longitudinal fault, one of the largest faults in the district, but the Vent is not. Imbrication by the Longitudinal fault zone (duplex structures) has thickened the deposit so that it is amenable to open-pit mining. Dikes and pyrite-enargite veins pass from the Vent into the massive sulfides; fragments of massive pyrite occur in the Vent. Thus, no matter what their origin, the texturally massive sulfides are older and, therefore, genetically unrelated to the Vent.

  5. Pb, Cu, and Zn distributions at humic acid-coated metal-oxide surfaces

    Science.gov (United States)

    Wang, Yingge; Michel, F. Marc; Choi, Yongseong; Eng, Peter J.; Levard, Clement; Siebner, Hagar; Gu, Baohua; Bargar, John R.; Brown, Gordon E.

    2016-09-01

    Mineral surfaces are often coated by natural organic matter (NOM), which has a major influence on metal-ion sorption and sequestration because of the abundance of binding sites in such coatings and the changes they cause in local nanoscale environments. The effects of NOM coatings on mineral surfaces are, however, still poorly understood at the molecular level due to the complexity of these systems. In this study, we have applied long-period X-ray standing wave-fluorescence yield (LP-XSW-FY) spectroscopy to measure the partitioning of naturally present Cu(II) (0.0226%), Zn(II) (0.009%), and Pb(II) (∼0.0004%) between Elliott Soil Humic Acid (ESHA) coatings and three model single-crystal metal-oxide substrates: α-Al2O3 (0 0 0 1), α-Al2O3 (1 -1 0 2), and α-Fe2O3 (0 0 0 1). The competitive sorption effects among these metal ions for binding sites in the ESHA coatings and on the metal-oxide surfaces were investigated as a function of reaction time, calcium content, and solution pH. Pb(II) ions present in the ESHA coatings were found to redistribute to reactive α-Al2O3 (1 -1 0 2) and α-Fe2O3 (0 0 0 1) surfaces after 3 h of reaction (pH = 6.0, [Ca(II)] = 2 mM). Pb(II) partitioning onto these reactive metal-oxide surfaces increased with increasing reaction time (up to 7 d). In addition, the partitioning of Cu(II) and Zn(II) from the ESHA coating to the α-Fe2O3 (0 0 0 1) substrate increased slightly with reaction time (2.4% and 3.7% for Cu(II) and Zn(II), respectively, after 3 h and 6.4% and 7.7% for Cu(II) and Zn(II), respectively, after 72 h of reaction time). However, no changes in the partitioning of Cu(II) and Zn(II) onto the α-Al2O3 (1 -1 0 2) surface were observed with increasing reaction time, suggesting that these ions strongly complex with functional groups in the ESHA coatings. Similar results were obtained for Cu(II) and Zn(II) on the ESHA-coated α-Al2O3 (1 -1 0 2) surfaces in samples without the addition of calcium. However, the amounts of Pb

  6. Comparison of microstructure and corrosion properties of Al-Zn-Mg-Cu alloys 7150 and 7010

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-chang; FAN Xi-gang; REN Shi-yu; ZHANG Xin-mei; ZHANG Bao-you

    2006-01-01

    The influence of coarse Cu-bearing particles, matrix and subgrain boundary precipitates on the stress corrosion susceptibility of the Al-Zn-Mg-Cu alloys was investigated. The strength of 7150 alloy is about 15 MPa higher than that of 7010 alloy.The 7010 alloy exhibits higher resistance to stress corrosion cracking as compared with the 7150 alloy. The coarse Cu-bearing particles are detrimental to the resistance to stress corrosion cracking. The increase of size of matrix and subgrain boundary precipitates decreases the susceptibility of stress corrosion. The anodic dissolution and hydrogen embrittlement govern the cracking process. The severity of stress corrosion cracking is shown to be related to the coarse Cu-bearing particles, matrix and subgrain precipitates in Al-Zn-Mg-Cu alloys.

  7. Electrical Characterization of Cu Composition Effects in CdS/CdTe Thin-Film Solar Cells with a ZnTe:Cu Back Contact: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. V.; Duenow, J. N.; Kuciauskas, D.; Kanevce, A.; Dhere, R. G.; Young, M. R.; Levi, D. H.

    2012-07-01

    We study the effects of Cu composition on the CdTe/ZnTe:Cu back contact and the bulk CdTe. For the back contact, its potential barrier decreases with Cu concentration while its saturation current density increases. For the bulk CdTe, the hole density increases with Cu concentration. We identify a Cu-related deep level at {approx}0.55 eV whose concentration is significant when the Cu concentration is high. The device performance, which initially increases with Cu concentration then decreases, reflects the interplay between the positive influences and negative influences (increasing deep levels in CdTe) of Cu.

  8. An EXAFS and XANES study of MBE grown Cu-doped ZnO

    CERN Document Server

    Fons, P; Iwata, K; Matsubara, K; Niki, S; Nakahara, K; Takasu, H

    2003-01-01

    The wide bandgap semiconductor, ZnO, is intrinsically n-type and one of the remaining hurdles to be overcome before it can be used for optoelectronic applications is achieving p-type doping. A potential candidate for a p-type dopant is Cu. Towards this end, X-ray near-edge absorption (XANES) has been used to determine changes in valency of Cu in molecular beam epitaxial grown ZnO as a function of growth parameters. Growth parameters varied include the Cu flux which was varied over roughly three orders of magnitude T sub C sub u =800-1000 deg. C and two substrate temperatures: 300 and 600 deg. C. XANES measurements confirmed that Cu was in the +1 valence state for all as-grown samples. Preliminary EXAFS measurements also demonstrated that Cu incorporated into a Zn-atom position substitutionally. X-ray diffraction also indicated significant phase separation with the presence of both metallic Cu and CuO indicated for Cu concentrations >3x10 sup 2 sup 1 cm sup - sup 3.

  9. Delocalized mixed-valence bi- and trinuclear complexes with short Cu-Cu bonds.

    Science.gov (United States)

    Yang, Lei; Powell, Douglas R; Klein, Eric L; Grohmann, Andreas; Houser, Robert P

    2007-08-20

    Two mixed-valence copper complexes were synthesized with ligands N-(2-pyridylmethyl)acetamide (Hpmac) and N,N'-(2-methyl-2-pyridylpropan-1,3-diyl)bis(acetamide) (H2pp(ac)2). Dimer [Cu2(pmac)2]OTf and trimer [Cu3(pp(ac)2)2].NaOTf both contain fully delocalized, mixed-valence Cu(1.5)Cu(1.5) moieties.

  10. Discovery of Cu-Ni-Zn-Sn-Fe intermetallic compounds and S-bearing alloys in the Zhaishang gold deposit, southern Gansu Province and its geological significance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Examination of ores by optical microscope and EPMA from the Zhaishang gold deposit, southern Gansu Province, has revealed an abundance of rare minerals. These include native metals, Cu-Ni-Zn-Sn-Fe polymetallic compounds and S-bearing alloys of Ni, Fe, Zn, Cu and Sn, occurring as native nickel, Zn-Cu alloy, Ni-Zn-Cu alloy, Sn-Zn-Ni-Cu alloy, Zn-Cu-Ni alloy, Zn-Fe-Cu-Sn-Ni alloy, Fe-Ni-S alloy, Sn-Fe-Ni-S alloy, Fe-Zn-Cu-Ni-S alloy, Zn-Ni-Cu-Fe-S alloy and others. Compared with the Zn-Cu alloy minerals discovered previously, these Zn-Cu minerals fall in the α or α+β portion in Zn-Cu alloy phase diagram, and the α portion has higher Cu content. Cu-Ni-Zn-Sn-Fe intermetallic compounds and S-bearing alloy minerals have not been previously reported in the literature. These rare alloys formed in a strongly reducing environment with absent oxygen and low sulfur activities.

  11. Discovery of Cu-Ni-Zn-Sn-Fe intermetailic compounds and S-bearing alloys in the Zhaishang gold deposit,southern Gansu Province and its geological sisnificance

    Institute of Scientific and Technical Information of China (English)

    LIU JiaJun; MAO GuangJian; MA XingHua; LI LiXing; GUO YuQian; LIU GuangZhi

    2008-01-01

    Examination of ores by optical microscope and EPMA from the Zhaishang gold deposit, southern Gansu Province, has revealed an abundance of rare minerals. These include native metals, Cu-Ni-Zn-Sn-Fe polymetallic compounds and S-bearing alloys of Ni, Fe, Zn, Cu and Sn, occurring as native nickel, Zn-Cu alloy, Ni-Zn-Cu alloy, Sn-Zn-Ni-Cu alloy, Zn-Cu-Ni alloy, Zn-Fe-Cu-Sn-Ni alloy, Fe-Ni-S alloy, Sn-Fe-Ni-S alloy, Fe-Zn-Cu-Ni-S alloy, Zn-Ni-Cu-Fe-S alloy and others. Compared with the Zn-Cu alloy minerals discovered previously, these Zn-Cu minerals fall in the α or α+β portion in Zn-Cu alloy phase diagram, and the α portion has higher Cu content. Cu-Ni-Zn-Sn-Fe intermetallic compounds and S-bearing alloy minerals have not been previously reported in the literature. These rare alloys formed in a strongly reducing environment with absent oxygen and low sulfur activities.

  12. Detection of a ZnSe secondary phase in coevaporated Cu2ZnSnSe4 thin films

    Science.gov (United States)

    Redinger, Alex; Hönes, Katja; Fontané, Xavier; Izquierdo-Roca, Victor; Saucedo, Edgardo; Valle, Nathalie; Pérez-Rodríguez, Alejandro; Siebentritt, Susanne

    2011-03-01

    Cu2ZnSnSe4 (CZTSe) thin films are grown by coevaporation. Composition depth profiles reveal that a Zn rich phase is present at the CZTSe/Mo interface. Raman measurements on the as grown films are used to study the near surface region and the CZTSe/Mo interface, after mechanically removing the thin film from the Mo coated glass. These measurements provide direct experimental evidence of the formation of a ZnSe phase at the CZTSe/Mo interface. While the Raman spectra at the surface region are dominated by CZTSe modes, those measured at the CZTSe/Mo interface are dominated by ZnSe and MoSe2 modes.

  13. Electrical properties of Cu4ZnSnS2/ZnS heterojunction prepared by ultrasonic spray pyrolysis

    Science.gov (United States)

    Guitouni, S.; Khammar, M.; Messaoudi, M.; Attaf, N.; Aida, M. S.

    2016-12-01

    Cu2ZnSnS4 (CZTS)/ZnS heterojunctions have been prepared by a successive deposition of ZnS and CZTS thin films by ultrasonic spray pyrolysis technique on glass substrates. The cupric chloride concentration has been varied in the starting solution in order to investigate its influence on device properties. CZTS/ZnS heterojunctions were characterized by recording their current-voltage characteristics at different temperatures. The obtained results exhibit a good rectifying behavior of the realized heterojunction. Analysis of these results yields saturation current, series resistance and ideality factor determination. From the activation energy of saturation current we inferred that the thermal emission through the barrier height is the dominant mechanism of the reverse current rather than the defects contribution.

  14. Assessment of environmental loads of Cu and Zn from intensive inland shrimp aquaculture.

    Science.gov (United States)

    León-Cañedo, J A; Alarcón-Silvas, S G; Fierro-Sañudo, J F; Mariscal-Lagarda, M M; Díaz-Valdés, T; Páez-Osuna, F

    2017-02-01

    An experiment was developed to simulate inland shrimp farming using diluted seawater (1.9 g L(-1)) containing 75 shrimps (Litopenaeus vannamei) per square meter during a growth cycle of 120 days. In this study, the environmental loads of copper and zinc were estimated and compared to anthropogenic sources and shrimp aquacultures in other locations. Both metals resulted primarily from feeding, which accounted for 91.8% of Cu and 97.0% of Zn. Concentrations of Cu (110.8 ± 11.8 μg g(-1)) and Zn (69.0 ± 0.7 μg g(-1)) measured in the harvested shrimp had higher Cu and lower Zn concentrations compared to those reported for farmed shrimp from Brazil and Mexico. Clearly, organic sludge was the main route of removal for both metals (Cu 46.2%; Zn 92.6%). The annual environmental loads estimated for inland shrimp aquaculture were 598 ± 74 g Cu ha(-1) and 5080 ± 328 g Zn ha(-1).

  15. Salts affect the interaction of ZnO or CuO nanoparticles with wheat.

    Science.gov (United States)

    Stewart, Jacob; Hansen, Trevor; McLean, Joan E; McManus, Paul; Das, Siddhartha; Britt, David W; Anderson, Anne J; Dimkpa, Christian O

    2015-09-01

    Exposure to nanoparticles (NPs) that release metals with potential phytotoxicity could pose problems in agriculture. The authors of the present study used growth in a model growth matrix, sand, to examine the influence of 5 mmol/kg of Na, K, or Ca (added as Cl salts) and root exudates on transformation and changes to the bioactivity of copper(II) oxide (CuO) and zinc oxide (ZnO) NPs on wheat. These salt levels are found in saline agricultural soils. After 14 d of seedling growth, particles with crystallinity typical of CuO or ZnO remained in the aqueous fraction from the sand; particles had negative surface charges that differed with NP type and salt, but salt did not alter particle agglomeration. Reduction in shoot and root elongation and lateral root induction by ZnO NPs were mitigated by all salts. However, whereas Na and K promoted Zn loading into shoots, Ca reduced loading, suggesting that competition with Zn ions for uptake occurred. With CuO NPs, plant growth and loading was modified equally by all salts, consistent with major interaction with the plant with CuO rather than Cu ions. Thus, for both NPs, loading into plant tissues was not solely dependent on ion solubility. These findings indicated that salts in agricultural soils could modify the phytotoxicity of NPs.

  16. Changes of Cu, Zn, and Cd speciation in sewage sludge during composting

    Institute of Scientific and Technical Information of China (English)

    GAO Ding; ZHENG Guo-di; CHEN Tong-bin; LUO Wei; GAO Wei; ZHANG Yi-an; LI Yan-xia

    2005-01-01

    The potential toxicity risks from heavy metals depend on their chemical speciation. The four stages of the Tessier sequential extraction method were employed to investigate changes in heavy metal speciation(Cu, Zn, and Cd) of sewage sludge during forced aeration composting, and then to identify whether the composting process would reduce or enhance their toxicities. Throughout the composting process, the exchangeable, carbonate-bound, Fe-Mn oxide-bound, and organic matter-bound fractions of Cu were converted to the residual Cu fraction. The organic matter-bound Cu fraction greatly contributed to this transformation. Residual Zn fraction was transformed to the Fe-Mn oxide-bound and organic matter-bound fractions after composting. The residual Zn fraction was a major contributor to the organic matter-bound Zn fraction. The availability of Cu and Zn was reduced by composting such that the risk of heavy metal toxicity decreased with prolonged treatment times. Additionally, attention should be paid to the increased availability of Cd in sewage sludge after composting treatment.

  17. Chemical fractionation of Cu and Zn and their impacts on microbial properties in slightly contaminated soils

    Directory of Open Access Journals (Sweden)

    Liu Aiju

    2013-06-01

    Full Text Available Chemical fractionation of Cu and Zn in bulk soil and its effects on soil microbial properties were determined in Cu and Zn contaminated soils (Cu: 35.57~46.37 mg•kg-1, Zn: 74.33~127.20 mg•kg-1 sampled from an agricultural field in outskirts of Zibo, China during the month of September, 2011. A sequential extraction technique (SET was used for metals chemical fractionation analysis in soils and a correlation analysis was applied to determinate the effects of metal on soil microbial properties. Chemical speciation showed that Cu and Zn were mostly present in the residual fraction and their concentrations in the most labile fraction (acid soluble fraction were the lowest in the investigated soils. However, the correlation analysis indicated that the labile forms of Cu/Zn, such as its acid soluble, reducible or oxidizable fractions, were usually significantly negatively correlated with the tested microbial activities at 0.05 or 0.01 probability levels. These results indicate that the metal labile fractions could exert an inhibitory effect on the soil microbial parameters even in the minor contaminated soils.

  18. Effects of high pressure on the microstructure and hardness of a Cu-Zn alloy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; LIU Lin; YANG Jingru; PENG Guirong; LIU Jianhua; ZHANG Ruijun; XING Guangzhong

    2008-01-01

    The microstructure of a Cu-Zn alloy treated under different high pressures was investigated by means of metallographic,scanning electron microscope (SEM),energy dispersive spectrometer (EDS),and X-ray diffraction (XRD),and the hardness of the Cu-Zn alloy was also measured.The results show that the a phase with a smaller grain size,different shapes,and random distribution appears in the Cu-Zn alloy during the solid-state phase transformation generation in the temperature range of 25-750℃ and the pressure range of 0-6 GPa.The amount of residual α phase in the microstructure decreases and then increases with increasing pressure.Under a high pressure of 3 GPa,the least volume fraction of residual α phase was obtained,and under a high pressure of 6 GPa,the changes of the microstructure of the Cu-Zn alloy were not obvious.In addition,high pressure can increase the hardness of the Cu-Zn alloy,but it cannot generate any new phase.

  19. Determination of metals (As, Cu, Fe, and Zn in two fish species from the Miankaleh wetland

    Directory of Open Access Journals (Sweden)

    Alipour Hossein

    2016-06-01

    Full Text Available The objective of this study was to determine the concentrations As, Cu, Fe, and Zn in the livers, gills, and muscles of vobla or Caspian roach, Rutilus caspicus (Yakovlev, and bighead goby, Neogobius gorlap (Iljin, from the Miankaleh wetland. The results showed that metal accumulation in the liver tissues was higher than in the gills and muscles for all metals, and Fe concentration was higher than Zn, Cu, and As in all the tissues studied. The concentrations of As, Cu, Fe, and Zn in the livers, gills, and muscles of bighead goby were higher than in vobla tissues, except for concentrations of As in the muscles. Fe, Cu, and Zn concentrations in the muscles were below the maximum permissible limit of the WHO and the FAO for both species, but the concentration of As in the muscles of both species exceeded the permissible limit proposed by the FAO; thus, human consumption should be limited. The levels of the other metals (Fe, Cu and Zn were completely safe.

  20. Structural, magnetic and electrical properties of CuZn ferrite nanopowders

    Science.gov (United States)

    Li, Le-Zhong; Peng, Long; Zhong, Xiao-Xi; Wang, Rui; Tu, Xiao-Qiang

    2016-12-01

    Zn-substituted Cu ferrite nanopowders, Cu1-xZnxFe2O4 (0≤x≤1.0), were synthesized by the sol-gel auto-combustion method. The effect of Zn substitution on the structural, magnetic and electrical properties have been investigated. The DTA and TG results indicate that there are three steps of combustion process. The X-ray diffraction patterns show that there are Fe2O3, CuO and CuFeO2 secondary phases and tetragonal structure when x=0.0. Furthermore, the lattice parameter and the average crystallite size decrease, and the X-ray density increases with the increase of Zn substitution. The saturation magnetization increases with the increase of Zn substitution when x≤0.40, and decreases when x>0.40. Meanwhile, the coercivity monotonically decreases with the increase of Zn substitution. The polarization behavior for all the samples in the test frequency range of 100 Hz to 10 MHz obeys the charge polarization mechanism. Electrical transport behavior of the ferrites nanopowders is same with the impurity semiconductor, and the effect of Zn substitution on the temperature dependence of dc resistivity is observed.

  1. Selective precipitation of Cu from Zn in a pS controlled continuously stirred tank reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, R.M.M., E-mail: ricardo.sampaio@wur.nl [Sub-department of Environmental Technology, Wageningen University, ' Biotechnion' , Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen (Netherlands); Timmers, R.A., E-mail: ruud.timmers@wur.nl [Sub-department of Environmental Technology, Wageningen University, ' Biotechnion' , Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen (Netherlands); Xu, Y., E-mail: lucyxyzxyz@hotmail.com [Sub-department of Environmental Technology, Wageningen University, ' Biotechnion' , Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen (Netherlands); Keesman, K.J., E-mail: karel.keesman@wur.nl [Systems and Control Group, Wageningen University, Bornsesteeg 59, 6708 PD Wageningen (Netherlands); Lens, P.N.L., E-mail: piet.lens@wur.nl [Sub-department of Environmental Technology, Wageningen University, ' Biotechnion' , Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen (Netherlands)

    2009-06-15

    Copper was continuously and selectively precipitated with Na{sub 2}S to concentrations below 0.3 ppb from water containing around 600 ppm of both Cu and Zn in a Continuously Stirred Tank Reactor. The pH was controlled at 3 and the pS at 25 (pS = -log(S{sup 2-})) by means of an Ag{sub 2}S sulfide selective electrode. Copper's recovery and purity were about 100%, whereas the total soluble sulfide concentration was below 0.02 ppm. X-ray diffraction (XRD) analysis showed that copper precipitated as hexagonal CuS (covellite). The mode of the particle size distribution (PSD) of the CuS precipitates was around 36 {mu}m. The PSD increased by high pS values and by the presence of Zn. Depending on the turbulence, the CuS precipitates can grow up to 200 {mu}m or fragment in particles smaller than 3 {mu}m in a few seconds. Zn precipitation with Na{sub 2}S at pH 3 and 4, in batch, always lead to Zn concentrations above 1 ppm. Zn precipitated as cubic ZnS (spharelite).

  2. The case for metamorphic base metal mineralization: pyrite chemical, Cu and S isotope data from the Cu-Zn deposit at Kupferberg in Bavaria, Germany

    Science.gov (United States)

    Höhn, S.; Frimmel, H. E.; Debaille, V.; Pašava, J.; Kuulmann, L.; Debouge, W.

    2017-01-01

    The stratiform Cu-Zn sulfide deposit at Kupferberg in Germany represents Bavaria's largest historic base metal producer. The deposit is hosted by Early Paleozoic volcano-sedimentary strata at the margin of a high-grade allochthonous metamorphic complex. The present paper reports on the first Cu and S isotope data as well as trace element analyses of pyrite from this unusual deposit. The new data point to syn-orogenic mineralization that was driven by metamorphic fluids during nappe emplacement. Primary Cu ore occurs as texturally late chalcopyrite within stratiform laminated pyrite in black shale in two different tectonostratigraphic units of very low and low metamorphic grade, respectively, that were juxtaposed during the Variscan orogeny. Trace element contents of different pyrite types suggest the presence of at least one hydrothermal pyrite generation (mean Co/Ni = 35), with the other pyrite types being syn-sedimentary/early diagenetic (mean Co/Ni = 3.7). Copper isotope analyses yielded a narrow δ65Cu range of -0.26 to 0.36‰ for all ore types suggesting a hypogene origin for the principal chalcopyrite mineralization. The ore lenses in the two different tectonostratigraphic units differ with regard to their δ34S values, but little difference exists between poorly and strongly mineralized domains within a given locality. A genetic model is proposed in which syn-sedimentary/early diagenetic pyrite with subordinate chalcopyrite and sphalerite formed in black shale beds in the two different stratigraphic units, followed by late-tectonic strata-internal, hydrothermal mobilization of Fe, Cu, and Zn during syn-orogenic thrusting, which concentrated especially Cu to ore grade. In agreement with this model, Cu distribution in stream sediments in this region shows distinct enrichments bound to the margin of the allochthonous complex. Thus, Kupferberg can be considered a rare example of a syn-orogenic Cu deposit with the Cu probably being derived from syn

  3. Hume-Rothery electron concentration rule across a whole solid solution range in a series of gamma-brasses in Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga, Ni-Zn and Co-Zn alloy systems

    Science.gov (United States)

    Mizutani, U.; Noritake, T.; Ohsuna, T.; Takeuchi, T.

    2010-05-01

    The aim of the present work is to examine if the Hume-Rothery stabilisation mechanism holds across whole solid solution ranges in a series of gamma-brasses with especial attention to the role of vacancies introduced into the large unit cell. The concentration dependence of the number of atoms in the unit cell, N, for gamma-brasses in the Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga, Ni-Zn and Co-Zn alloy systems was determined by measuring the density and lattice constants at room temperature. The number of itinerant electrons in the unit cell, e/uc, is evaluated by taking a product of N and the number of itinerant electrons per atom, e/a, for the transition metal element deduced earlier from the full-potential linearised augmented plane wave (FLAPW)-Fourier analysis. The results are discussed within the rigid-band model using as a host the density of states (DOS) derived earlier from the FLAPW band calculations for the stoichiometric gamma-brasses Cu5Zn8, Cu9Al4 and TM2Zn11 (TM = Co and Ni). A solid solution range of gamma-brasses in Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga and Ni-Zn alloy systems is found to fall inside the existing pseudogap at the Fermi level. This is taken as confirmation of the validity of the Hume-Rothery stability mechanism for a whole solute concentration range of these gamma-brasses. An exception to this behaviour was found in the Co-Zn gamma-brasses, where orbital hybridisation effects are claimed to play a crucial role in stabilisation.

  4. Influence of Solution Heat Treatment on Structure and Mechanical Properties of ZnAl22Cu3 Alloy

    Directory of Open Access Journals (Sweden)

    Michalik R.

    2016-09-01

    Full Text Available The influence of solution heat treatment at 385°C over 10 h with cooling in water on the structure, hardness and strength of the ZnAl22Cu3 eutectoid alloy is presented in the paper. The eutectoid ZnAl22Cu3 alloy is characterized by a dendritic structure. Dendrites are composed of a supersaturated solid solution of Al in Zn. In the interdendritic spaces a eutectoid mixture is present, with an absence of the ε (CuZn4 phase. Solution heat treatment of the ZnAl22Cu3 alloy causes the occurrence of precipitates rich in Zn and Cu, possibly ε phase. Solution heat treatment at 385°C initially causes a significant decrease of the alloy hardness, although longer solution heat treatment causes a significant increase of the hardness as compared to the as-cast alloy.

  5. Ultrasensitive non-enzymatic glucose sensor based on three-dimensional network of ZnO-CuO hierarchical nanocomposites by electrospinning

    OpenAIRE

    2014-01-01

    Three-dimensional (3D) porous ZnO–CuO hierarchical nanocomposites (HNCs) nonenzymatic glucose electrodes with different thicknesses were fabricated by coelectrospinning and compared with 3D mixed ZnO/CuO nanowires (NWs) and pure CuO NWs electrodes. The structural characterization revealed that the ZnO–CuO HNCs were composed of the ZnO and CuO mixed NWs trunk (~200 nm), whose outer surface was attached with small CuO nanoparticles (NPs). Moreover, a good synergetic effect between CuO and ZnO w...

  6. Epitaxial Cu{sub 2}ZnSnSe{sub 4} layers by annealing of Sn/Cu/ZnSe(001) precursors on GaAs(001)

    Energy Technology Data Exchange (ETDEWEB)

    Krämmer, Christoph, E-mail: Christoph.Kraemmer@kit.edu [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Sachs, Johannes [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Pfaffmann, Lukas [Laboratory for Electron Microscopy, KIT (Germany); Musiol, Timo; Lang, Mario; Gao, Chao [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Gerthsen, Dagmar [Laboratory for Electron Microscopy, KIT (Germany); Kalt, Heinz [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Powalla, Michael [Light Technology Institute, KIT (Germany); Zentrum für Sonnenenergie-und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70565 Stuttgart (Germany); Hetterich, Michael [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany)

    2015-05-01

    We report on the fabrication of epitaxial Cu{sub 2}ZnSnSe{sub 4} films by a two-step fabrication approach. An epitaxial ZnSe(001) layer on GaAs(001) is grown by molecular-beam epitaxy followed by sequential deposition of Cu and Sn. The Sn/Cu/ZnSe(001) precursor is then thermally annealed in a selenium atmosphere. Raman spectroscopy confirms the presence of the kesterite phase. Electron microscopy shows that the films exhibit monocrystalline regions of several micrometers in size with inclusions of smaller grains with a different chemical composition. The latter is confirmed by electron backscatter diffraction measurements which prove the conservation of the crystal orientation defined by the cubic ZnSe/GaAs(001) precursor structure throughout the whole CZTSe film. - Highlights: • Two-step fabrication approach to obtain epitaxial kesterite layers is presented. • Kesterite phase formation is confirmed by Raman spectroscopy. • SnSe{sub x} compounds are identified to be the main secondary phase. • Electron backscatter diffraction proves epitaxial orientation of the films.

  7. Surface composition deviation of Cu2ZnSnS4 derivative powdered samples

    Science.gov (United States)

    Harel, S.; Guillot-Deudon, C.; Choubrac, L.; Hamon, J.; Lafond, A.

    2014-06-01

    Powdered samples of Cu2ZnSnS4 derivatives prepared through a solid-state route were investigated by both bulk (electron dispersive X-ray spectroscopy) and surface-sensitive (X-ray photoelectron spectroscopy) methods. We observe a deviation in composition between the surface and the bulk for all non-stoichiometric samples (both Cu-poor and Cu-rich). This behavior has already been observed for slightly Cu-poor CZTS thin films and is reminiscent of that of CIGSe compounds.

  8. Valence band offsets at Cu(In,Ga)Se{sub 2}/Zn(O,S) interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Tobias; Klein, Andreas [Surface Science Division, Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstrasse 32, 64287, Darmstadt (Germany); Botros, Miriam [Surface Science Division, Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstrasse 32, 64287, Darmstadt (Germany); Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Industriestrasse 6, 70565, Stuttgart (Germany); Witte, Wolfram; Hariskos, Dimitrios; Menner, Richard; Powalla, Michael [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Industriestrasse 6, 70565, Stuttgart (Germany)

    2014-09-15

    The energy band alignment at interfaces between Cu-chalcopyrites and Zn(O,S) buffer layers, which are important for thin-film solar cells, are considered. Valence band offsets derived from X-ray photoelectron spectroscopy for Cu(In,Ga)Se{sub 2} absorber layers with CdS and Zn(O,S) compounds are compared to theoretical predictions. It is shown that the valence band offsets at Cu(In,Ga)Se{sub 2}/Zn(O,S) interfaces approximately follow the theoretical prediction and vary significantly from sample to sample. The integral sulfide content of chemical bath deposited Zn(O,S) is reproducibly found to be 50-70%, fortuitously resulting in a conduction band offset suitable for solar cell applications with Cu(In,Ga)Se{sub 2} absorber materials. The observed variation in offset can neither be explained by variation of the Cu content in the Cu(In,Ga)Se{sub 2} near the interface nor by local variation of the chemical composition. Fermi level pinning induced by high defect concentrations is a possible origin of the variation of band offset. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Engineering of electronic and optical properties of ZnO thin films via Cu doping

    Institute of Scientific and Technical Information of China (English)

    Zhang Guo-Heng; Deng Xiao-Yan; Xue Hua; Xiang Gang

    2013-01-01

    ZnO thin films doped with different Cu concentrations are fabricated by reactive magnetron sputtering technique.XRD analysis indicates that the crystal quality of the ZnO:Cu film can be enhanced by a moderate level of Cu-doping in the sputtering process.The results of XPS spectra of zinc,oxygen,and copper elements show that Cu-doping has an evident and complicated effect on the chemical state of oxygen,but little effect on those of zinc and copper.Interestingly,further investigation of the optical properties of ZnO:Cu samples shows that the transmittance spectra exhibit both red shift and blue shift with the increase of Cu doping,in contrast to the simple monotonic behavior of the Burstein-Moss effect.Analysis reveals that this is due to the competition between oxygen vacancies and intrinsic and surface states of oxygen in the sample.Our result may suggest an effective way of tuning the bandgap of ZnO samples.

  10. Wetting Behavior and Interfacial Reactions in (Sn-9Zn)-2Cu/Ni Joints during Soldering and Isothermal Aging

    Institute of Scientific and Technical Information of China (English)

    Ning Zhao; Haitao Ma; Haiping Xie; Lai Wang

    2009-01-01

    The wetting property of (Sn-9Zn)-2Cu (wt pct) on Ni substrate and the evolution of interfacial microstructure in (Sn-9Zn)-2Cu/Ni joints during soldering as well as isothermal aging were studied.The wetting ability of eutectic Sn-9Zn solder on Ni substrate was markedly improved by adding 2 wt pct Cu into this solder alloy.Plate-like Cu5Zn8 intermetallic compounds (IMCs) were detected in (Sn-9Zn)-2Cu solder matrix.A continuous Ni5Zn21 IMC layer was formed at (Sn-9Zn)-2Cu/Ni interface after soldering.This IMC layer kept its type and integrality even after aging at 170℃ for up to 1000 h.At the early aging stage (before 500 h), the IMC layer grew fast and its thickness followed a linear relationship with the square root of aging time.Thereafter,however, the thickness increased very slowly with longer aging time.When the joints were aged for 1000 h,a new IMC phase, (Cu,Ni)5Zn8, was found in the matrix near the interface.The formation of (Cu,Ni)5Zn8phase can be attributed to the diffusion of Ni atoms into the solder matrix from the substrate.

  11. Atom probe study of Cu2ZnSnSe4 thin-films prepared by co-evaporation and post-deposition annealing

    Science.gov (United States)

    Schwarz, T.; Cojocaru-Mirédin, O.; Choi, P.; Mousel, M.; Redinger, A.; Siebentritt, S.; Raabe, D.

    2013-01-01

    We use atom probe tomography (APT) for resolving nanometer scale compositional fluctuations in Cu2ZnSnSe4 (CZTSe) thin-films prepared by co-evaporation and post-deposition annealing. We detect a complex, nanometer-sized network of CZTSe and ZnSe domains in these films. Some of the ZnSe domains contain precipitates having a Cu- and Sn-rich composition, where the composition cannot be assigned to any of the known equilibrium phases. Furthermore, Na impurities are found to be segregated at the CZTSe/ZnSe interface. The insights given by APT are essential for understanding the growth of CZTSe absorber layers for thin-film solar cells and for optimizing their optoelectronic properties.

  12. Acute toxicity of binary and ternary mixtures of Cd, Cu, and Zn to Daphnia magna.

    Science.gov (United States)

    Meyer, Joseph S; Ranville, James F; Pontasch, Mandee; Gorsuch, Joseph W; Adams, William J

    2015-04-01

    Standard static-exposure acute lethality tests were conducted with Daphnia magna neonates exposed to binary or ternary mixtures of Cd, Cu, and Zn in moderately hard reconstituted water that contained 3 mg dissolved organic carbon/L added as Suwannee River fulvic acid. These experiments were conducted to test for additive toxicity (i.e., the response to the mixture can be predicted by combining the responses obtained in single-metal toxicity tests) or nonadditive toxicity (i.e., the response is less than or greater than additive). Based on total metal concentrations (>90% dissolved) the toxicity of the tested metal mixtures could be categorized into all 3 possible additivity categories: less-than-additive toxicity (e.g., Cd-Zn and Cd-Cu-Zn mixtures and Cd-Cu mixtures when Cu was titrated into Cd-containing waters), additive toxicity (e.g., some Cu-Zn mixtures), or more-than-additive toxicity (some Cu-Zn mixtures and Cd-Cu mixtures when Cd was titrated into Cu-containing waters). Exposing the organisms to a range of sublethal to supralethal concentrations of the titrated metal was especially helpful in identifying nonadditive interactions. Geochemical processes (e.g., metal-metal competition for binding to dissolved organic matter and/or the biotic ligand, and possibly supersaturation of exposure waters with the metals in some high-concentration exposures) can explain much of the observed metal-metal interactions. Therefore, bioavailability models that incorporate those geochemical (and possibly some physiological) processes might be able to predict metal mixture toxicity accurately.

  13. Growth of Cu2ZnSnSe4 thin films by selenization of sputtered single-layered Cu-Zn-Sn metallic precursors from a Cu-Zn-Sn alloy target

    Science.gov (United States)

    Kim, Kyoo-Ho; Amal, Ikhlasul

    2011-09-01

    Cu2ZnSnSe4 (CZTSe) thin films were prepared by the simple process of selenization of single-layered metallic Cu-Zn-Sn precursors. These metallic precursors were deposited by radio frequency magnetron sputtering of a ternary Cu-Zn-Sn alloy target. Successive selenization was performed at various temperatures between 250°C and 500°C for 30 min. X-ray diffraction and Raman analysis showed that a single phase of the CZTSe compound can be obtained by selenization at 400°C, while increasing the selenization temperature to 500°C improves the grain size and crystal quality. The direct optical band gap of CZTSe films was calculated to be 1.06 eV to 1.09 eV with a high absorption coefficient on the order of 104 cm-1 for samples selenized at 400°C to 500°C. The obtained films are p-type semiconductors with bulk carrier concentrations of 2.41 to 7.96 × 1018 cm3, mobilities of 1.30 cm2 V-1 s-1 to 9.27 cm2 V-1 s-1, and resistivities of 0.20 Ωcm to 1.95 Ωcm.

  14. Syntheses, spectroscopic and thermal analyses of cyanide bridged heteronuclear polymeric complexes: [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine or N-ethylethylenediamine; Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II))

    Science.gov (United States)

    Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla

    2016-02-01

    Polymeric tetracyanonickelate(II) complexes of the type [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine (men) or N-ethylethylenediamine (neen); Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal and elemental analysis techniques. Additionally, FT-IR and Raman spectral analyses of men and neen have experimentally and theoretically investigated in the range of 4000-250 cm-1. The corresponding vibration assignments of men and neen are performed by using B3LYP density functional theory (DFT) method together with 6-31 G(d) basis set. The spectral features of the complexes suggest that the coordination environment of the M(II) ions are surrounded by the two symmetry related men and neen ligands and the two symmetry related N atom of cyanide groups, whereas the Ni(II) atoms are coordinated with a square-planar to four C atoms of the cyanide groups. Polymeric structures of the complexes consist of one dimensional alternative chains of [M(L)2]2+ and [Ni(CN)4]2- moieties. The thermal decompositions in the temperature range 30-700 °C of the complexes were investigated in the static air atmosphere.

  15. A role for Haemophilus ducreyi Cu,ZnSOD in resistance to heme toxicity.

    Science.gov (United States)

    Negari, Shahin; Sulpher, Jeff; Pacello, Francesca; Ingrey, Keely; Battistoni, Andrea; Lee, B Craig

    2008-06-01

    The Cu,Zn superoxide dismutase (Cu,ZnSOD) from Haemophilus ducreyi is the only enzyme of this class which binds a heme molecule at its dimer interface. To explore the role of the enzyme in this heme-obligate bacterium, a sodC mutant was created by insertional inactivation. No difference in growth rate was observed during heme limitation. In contrast, under heme rich conditions growth of the sodC mutant was impaired compared to the wild type strain. This growth defect was abolished by supplementation of exogenous catalase. Genetic complementation of the sodC mutant in trans demonstrated that the enzymatic property or the heme-binding activity of the protein could repair the growth defect of the sodC mutant. These results indicate that Cu,ZnSOD protects Haemophilus ducreyi from heme toxicity.

  16. Article Expression, Purification, and Characterization of Cu/ZnSOD from Panax Ginseng

    Directory of Open Access Journals (Sweden)

    Dayong Ding

    2014-06-01

    Full Text Available Superoxide dismutase (SOD has a strong antioxidant effect, but the traditional SOD extraction method is not the most efficient method of SOD amplification. In this study, we report the cloning of the Cu/ZnSOD gene from Panax ginseng into a temperature-regulated expression plasmid, pBV220. Cu/ZnSOD inclusion bodies were expressed in E. coli at a high level. Then, the inclusion bodies were purified by ion-exchange chromatography and molecular sieve chromatography. Finally, we obtained stable SOD in the bacterial broth, with a protein content of 965 mg/L and enzyme specific activity of 9389.96 U/mg. These results provide a foundation for future studies on the antioxidant mechanisms of ginseng and the development and application of ginseng Cu/ZnSOD.

  17. Epitaxial growth of magnetic ZnCuO thin films by pulsed laser deposition

    Science.gov (United States)

    Kim, Dong Hun; Kim, Tae Cheol; Lee, Seung Han; Jung, Hyun Kyu; Jeong, Jaeeun; Han, Seung Ho

    2017-02-01

    The crystal structure and magnetic properties of epitaxial ZnO thin films doped with 5 at% Cu on SrTiO3 (001) and (111) substrates were investigated. In the case of films deposited in oxygen, unique crystallographic growth directions on different substrates were observed, while a metallic phase was detected in films grown under vacuum. The Cu-doped ZnO thin films deposited on the SrTiO3 (111) substrates, with hexagonal structures, showed a single epitaxial relationship with the substrates, whereas those deposited on the SrTiO3 (001) substrates showed a double epitaxial growth mode. The epitaxial ZnCuO thin films deposited on the SrTiO3 (111) substrates under high vacuum exhibited a ferromagnetic signal at room temperature.

  18. The band gap of Cu2ZnSnSe4: Effect of order-disorder

    Science.gov (United States)

    Rey, G.; Redinger, A.; Sendler, J.; Weiss, T. P.; Thevenin, M.; Guennou, M.; El Adib, B.; Siebentritt, S.

    2014-09-01

    The order-disorder transition in kesterite Cu2ZnSnSe4 (CZTSe), an interesting material for solar cell, has been investigated by spectrophotometry, photoluminescence (PL), and Raman spectroscopy. Like Cu2ZnSnS4, CZTSe is prone to disorder by Cu-Zn exchanges depending on temperature. Absorption measurements have been used to monitor the changes in band gap energy (Eg) of solar cell grade thin films as a function of the annealing temperature. We show that ordering can increase Eg by 110 meV as compared to fully disordered material. Kinetics simulations show that Eg can be used as an order parameter and the critical temperature for the CZTSe order-disorder transition is 200 ± 20 °C. On the one hand, ordering was found to increase the correlation length of the crystal. But on the other hand, except the change in Eg, ordering did not influence the PL signal of the CZTSe.

  19. Electrical and gas sensing investigations on the sprayed ZnO:Cu thin films

    Science.gov (United States)

    Mhamdi, A.; Alkhalifah, Menea S.; Rajeh, S.; Labidi, A.; Amlouk, M.; Belgacem, S.

    2017-09-01

    The electrical and gas sensing properties of the sprayed Cu doped ZnO thin layers were investigated. The main study is an analysis of the conduction mechanism based on the measurement results of the frequency dispersion of the conductivity at different temperatures performed by impedance spectroscopy. It emerges from this study that the transport mechanism of charge carriers in such thin films is a thermally activated hopping mechanism. This process is confirmed by the obtained values of the maximum barrier height Wm deduced from the study of the frequency power law of the ac conductivity. Otherwise, we have studied the response evolution of ZnO: Cu sensors ethanol versus time, working temperature and relative doping. From the measurement results of gas sensing properties of ZnO:Cu thin film, we find that a good stability and response was observed for a doping of 2%.

  20. Effect of Sn on the Color and Tarnishing of Cu-Mn-Zn Alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect of Sn on the color and tarnishing of Cu-Mn-Zn alloys is investigated quantitatively. Using the CIE LAB color system,color parameters such as L*, a* and b* are selected to describe the surface color of alloys while the color difference (△E*)is used to evaluate the color stability. The results show that with the increase of Sn, the color change of Cu-Mn-Zn alloys is greatly reduced and the corrosion resistance in the synthetic sweat is improved dramatically. However, up to 4.4 wt pct Sn does not change the color of Cu-Mn-Zn alloys much. XPS and AES are employed to analyze the tarnished surface. It is proved that a Sn enriched film is formed and Sn takes the form of Sn oxide. This thin and protective oxide film can prevent alloy from further tarnishing.

  1. Novel inhibitors to Taenia solium Cu/Zn superoxide dismutase identified by virtual screening

    Science.gov (United States)

    García-Gutiérrez, P.; Landa-Piedra, A.; Rodríguez-Romero, A.; Parra-Unda, R.; Rojo-Domínguez, A.

    2011-12-01

    We describe in this work a successful virtual screening and experimental testing aimed to the identification of novel inhibitors of superoxide dismutase of the worm Taenia solium ( TsCu/Zn-SOD), a human parasite. Conformers from LeadQuest® database of drug-like compounds were selected and then docked on the surface of TsCu/Zn-SOD. Results were screened looking for ligand contacts with receptor side-chains not conserved in the human homologue, with a subsequent development of a score optimization by a set of energy minimization steps, aimed to identify lead compounds for in vitro experiments. Six out of fifty experimentally tested compounds showed μM inhibitory activity toward TsCu/Zn-SOD. Two of them showed species selectivity since did not inhibit the homologous human enzyme when assayed in vitro.

  2. Cumulation of Cu, Zn, Cd, and Mn in Plants of Gardno Lake

    Directory of Open Access Journals (Sweden)

    Trojanowski J.

    2013-04-01

    Full Text Available In the present paper there have been shown the results of research on yhe content of Zn, Cd, Cu, Mn and Pb in chosen plants of Lake Gardno.The biggest concentration of those metals has been observed in Potamogton natans and Elodea canadensis, on average Zn – 34.9, Pb -2.77, Cd – 0.62, Cu – 3.24 and Mn – 257.4 μg g-1. It has been found that the over-ground parts of the plants under analysis cumulate several times less of heavy metals than their roots. The determined enrichment factors enabled the researchers to state that Cu in the examined plants is of natural origin while Mn, Cd and Zn – of anthropogenic origin.

  3. Magneto-viscosity of hydrothermal synthesized Cu-Zn ferrite ferrofluids

    Directory of Open Access Journals (Sweden)

    Nisha Gautam

    2017-05-01

    Full Text Available The paraffin based ferrofluids were synthesized using the oleic acid coated Cu-Zn ferrite (CZF nanoparticles of compositions Cu0.6Zn0.4Fe2O4 (CZF1 and Cu0.4Zn0.6Fe2O4 (CZF2 synthesized by hydrothermal process. The transmission electron micrographs (TEM show the cubic shape particles of 4 to 10 nm and 4 to 18 nm size for CZF1 and CZF2 respectively. The nanoparticles show superparamagnetic behaviour. The viscosity increases with increase in magnetic field due to the formation of long chains of magnetic nanoparticles in ferrofluid. At higher flow rate, the magnetic chains break into smaller units and arrange along the flow direction. The flow curves show power law behavior. The size of magnetic nanoparticles influences the magneto-viscosity of the ferrofluids.

  4. Magneto-viscosity of hydrothermal synthesized Cu-Zn ferrite ferrofluids

    Science.gov (United States)

    Gautam, Nisha; Thirupathi, Gadipelly; Singh, Rajender

    2017-05-01

    The paraffin based ferrofluids were synthesized using the oleic acid coated Cu-Zn ferrite (CZF) nanoparticles of compositions Cu0.6Zn0.4Fe2O4 (CZF1) and Cu0.4Zn0.6Fe2O4 (CZF2) synthesized by hydrothermal process. The transmission electron micrographs (TEM) show the cubic shape particles of 4 to 10 nm and 4 to 18 nm size for CZF1 and CZF2 respectively. The nanoparticles show superparamagnetic behaviour. The viscosity increases with increase in magnetic field due to the formation of long chains of magnetic nanoparticles in ferrofluid. At higher flow rate, the magnetic chains break into smaller units and arrange along the flow direction. The flow curves show power law behavior. The size of magnetic nanoparticles influences the magneto-viscosity of the ferrofluids.

  5. Directed Evolution of Human Cu,Zn-SOD Under Artificial Oxidant Pressures

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cu,Zn-SOD is a highly conserved enzyme and the controversy about its evolutionary possibility in the near future has been lively. In order to further our understanding of the future fate of human Cu,Zn-SOD, we adopted a strategy relating to the directed evolution to study how the mutants of human Cu,Zn-SOD respond to different oxidative stress. After five rounds of screening, we found a mutant that can survive under harsh pressures and DNA sequencing proves that it shows a mutation responsible for the phenomenon. However, under natural pressure, our screening comes to nothing. Then we may draw the following conclusions: the evolution of biological macromolecules in some respect depends on their surroundings and if they are too familiar with a certain environment, they may embody evolutionary inertia.

  6. Recrystallization of the cold-deformed discontinuous precipitation microstructure in Al-Zn (-Cu) alloys

    Institute of Scientific and Technical Information of China (English)

    DING Hua; REN Yuping; HAO Shiming; WANG Dapeng; ZHAO Gang

    2004-01-01

    Recrystallization of cold-rolled discontinuous precipitation microstructure which has fine laminar structure in an Al-40% Zn (atom fraction) binary alloy is investigated by optical microscopy, SEM and TEM. It is found that there are two kinds of recrystallization mechanisms: continuous coarsening (CC) and discontinuous coarsening (DC). The latter can be divided into coarsening mainly driven by stored deformation energy at colony boundaries and slip bands and the one mainly driven by boundary energy in the area with little deformation. It is shown that the addition of Cu can retard the nucleation of coarsening cells and their growth. X-Ray diffraction analysis indicated the metastable phase CuZn4 transformed into equilibrium phase Al4Cu3Zn during the heating process.

  7. Effect of impurity concentration on optical and magnetic properties in ZnS:Cu nanoparticles

    Science.gov (United States)

    Chandra Patel, Prayas; Ghosh, Surajit; Srivastava, P. C.

    2017-09-01

    To obtain enhanced room temperature ferromagnetism (RTFM) along with the increase in optical bandgap in the compound semiconductors has been an interesting topic. Here, we report RTFM along with increase in energy bandgap in chemically synthesized Zn1-xCuxS (0 ≤ x ≤ 0.04) DMS nanoparticles. Structural properties of the synthesized samples studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show the formation of cubic phase Cu doped ZnS nanoparticles of 3-5 nm size. An intrinsic weak ferromagnetic behavior was observed in pure ZnS sample (at 300 K) which got increased in Cu doped samples and was understood due to defect induced ferromagnetism. UV-vis measurement showed increase in the energy bandgap with the increase in Cu doping. The PL study suggested the presence of sulfur and zinc vacancies and surface defects which were understood contributing to the intrinsic FM behavior.

  8. Cu and Zn uptake by Halimione portulacoides (L. ) Aellen. A long-term accumulation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Reboredo, F. (New Univ. of Lisbon (Portugal))

    1991-03-01

    Coastal areas and plant species colonizing salt-marshes are often exposed to a large diversity of pollutants, with emphasis on heavy metals. The important role of marsh vegetation in the accumulation of metals has been shown. Halimione portulacoides is one of the most representative halophytes of the salt-marshes of the river Sado estuary. In order to study the uptake and pattern of accumulation of Cu and Zn by the roots, stems and leaves of Halimione, plants were cultivated in vitro and treated daily with solutions containing 5, 25 and 50ppm Cu (as CuCl{sub 2}) and 50, 100 and 150ppm Zn (as ZnCl{sub 2}).

  9. Behavior and influence of Pb and Bi in Ag-Cu-Zn brazing alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of trace content of Pb and Bi elements on the spreading property and the strength of brazed joints of Ag-Cu-Zn filler metal have been studied. The results show that Pb has little effect on both above properties, and Bi has remarkable influence on the spreading property but little effect on the strength of brazed joint. Pb and Bi dissolve into the Ag-Cu-Zn matrix and will melt and gather at lower temperature when that alloy is being heated. Therefore a liquid forms on the surface of the Ag-Cu-Zn alloy and overlays the melting alloy, then keeps the filler metal away from the materials being joined, and so decreases the spreading property.

  10. Passivation for Cu2ZnSnS4/WZ-ZnO interface states: From the first principles calculations

    Science.gov (United States)

    Cheng, Yu-Wen; Tang, Fu-Ling; Xue, Hong-Tao; Liu, Hong-Xia; Gao, Bo

    2017-02-01

    We employed the first-principles calculations to investigate F, Cl and H's passivation effects for Cu2ZnSnS4 (102)/WZ-ZnO (110) interface, in which the interface states mainly originate from Sn atoms. The interface states peaks can be reduced more or less by introducing F, Cl and H around Sn atom. H and F have a more efficient passivation effect than Cl atoms. The charge density difference and Bader atomic charge analysis suggests that F, Cl and H can get part of the electrons leading to interface states and that the interface states can be passivated by F, Cl or H atoms.

  11. ANTIMICROBIAL ACTIVITY OF Ag+, Cu2+, Zn2+, Mg2+ IONS DOPED CHITOSAN NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Sukhodub LB

    2015-04-01

    Full Text Available Modification by polymers and inorganic ions of the bioactive materials for orthopedic implants with the purpose of initiating controlled reactions in tissues that surround the implant, is one of the modern approaches in medical materials. A key feature of functional polymers is their ability to form complexes with various metal ions in solution. Chitosan is natural biopolymer with pronounced affinity to transition metal ions. Some researches prove the higher antimicrobial activity of Chitosan-metal complexes compared with pure Chitosan. The purpose of this work was the study of antimicrobial activity of Chitosan nanoparticles modified by metal ions Ag+, Cu2+, Zn2+, Mg2+ against reference strains S. aureus 25923 ATSS, E. coli ATCC 25922, C. albicans ATCC 885653 for their further use as components of the composite biomaterials for medical purpose.Chitosan nanoparticles suspension was prepared by known method based on the ionotropic gelation between chitosan and sodium tripolyphosphate.To obtain Chitosan-metal nanoparticles to the Chitosan suspension were added the corresponding metal ions aqueous solutions in quantity to match the concentration of metal ions of 200 ppm . Antibacterial activities of Ag+, Cu2+, Zn2+, Mg2+ ions doped Chitosan nanoparticles, pure Chitosan nanoparticles, metal ions and 1% (v/v acetic acid solution (it was used as solvent for Chitosan against bacteria were evaluated by determination of minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC in vitro. Muller– Hinton (MH broth and MH agar (Russia were used as growth media. The bacteria suspension for further use was prepared with concentration that corresponded 0,5units by McFarland scale. The MIC was determined by a broth dilution method. The results were read after 24 hours of experimental tubes incubation at 37 oC as equivalent to the concentration of the tube without visible growth. To evaluate MBC, a sample of 0,1 ml was transferred from

  12. SOLID STATE SYNTHESIS,CHARACTERIZATION AND APPLICATIONS OF COPPER(Ⅱ),COBALT(Ⅱ),NICKEL(Ⅱ) AND ZINC(Ⅱ)WITH GLYCINE COMPLEXES UNDER MICROWAVE%微波辐射条件下Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)与甘氨酸配合物的固相合成、表征及应用

    Institute of Scientific and Technical Information of China (English)

    蒋才武; 陈超球; 梁利芳; 蒋治良

    2000-01-01

    该文研究了Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)的乙酸盐与甘氨酸在微波辐射及室温条件下的固--固相配位化学反应,通过固相反应一步合成了Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)与甘氨酸的配合物,经电导率、IR、UV及元素分析表征了产物,并用微波产物进行了植物助长试验.

  13. Immobilization of Zn, Cu, and Pb in contaminated soils using phosphate rock and phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xinde [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)] [Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Wahbi, Ammar [Soil Science Department, Faculty of Agriculture, University of Aleppo, Aleppo (Syrian Arab Republic); Ma, Lena, E-mail: lqma@ufl.edu [Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Li Bing; Yang Yongliang [National Research Center for Geoanalysis, Beijing 100037 (China)

    2009-05-30

    Considerable research has been done on P-induced Pb immobilization in Pb-contaminated soils. However, application of P to soils contaminated with multiple heavy metals is limited. The present study examined effectiveness of phosphoric acid (PA) and/or phosphate rock (PR) in immobilizing Pb, Cu, and Zn in two contaminated soils. The effectiveness was evaluated using water extraction, plant uptake, and a simple bioaccessibility extraction test (SBET) mimicking metal uptake in the acidic environment of human stomach. The possible mechanisms for metal immobilization were elucidated using X-ray diffraction, scanning electron microscopy, and chemical speciation program Visual MINTEQ. Compared to the control, all P amendments significantly reduced Pb water solubility, phytoavailability, and bioaccessibility by 72-100%, 15-86%, and 28-92%, respectively. The Pb immobilization was probably attributed to the formation of insoluble Pb phosphate minerals. Phosphorus significantly reduced Cu and Zn water solubility by 31-80% and 40-69%, respectively, presumably due to their sorption on minerals (e.g., calcite and phosphate phases) following CaO addition. However, P had little effect on the Cu and Zn phytoavailability; while the acid extractability of Cu and Zn induced by SBET (pH 2) were even elevated by up to 48% and 40%, respectively, in the H{sub 3}PO{sub 4} treatments (PA and PR + PA). Our results indicate that phosphate was effective in reducing Pb availability in terms of water solubility, bioaccessibility, and phytoavailability. Caution should be exercised when H{sub 3}PO{sub 4} was amended to the soil co-contaminated with Cu and Zn since the acidic condition of SBET increased Cu and Zn bioaccessibility though their water solubility was reduced.

  14. Immobilization of Zn, Cu, and Pb in contaminated soils using phosphate rock and phosphoric acid.

    Science.gov (United States)

    Cao, Xinde; Wahbi, Ammar; Ma, Lena; Li, Bing; Yang, Yongliang

    2009-05-30

    Considerable research has been done on P-induced Pb immobilization in Pb-contaminated soils. However, application of P to soils contaminated with multiple heavy metals is limited. The present study examined effectiveness of phosphoric acid (PA) and/or phosphate rock (PR) in immobilizing Pb, Cu, and Zn in two contaminated soils. The effectiveness was evaluated using water extraction, plant uptake, and a simple bioaccessibility extraction test (SBET) mimicking metal uptake in the acidic environment of human stomach. The possible mechanisms for metal immobilization were elucidated using X-ray diffraction, scanning electron microscopy, and chemical speciation program Visual MINTEQ. Compared to the control, all P amendments significantly reduced Pb water solubility, phytoavailability, and bioaccessibility by 72-100%, 15-86%, and 28-92%, respectively. The Pb immobilization was probably attributed to the formation of insoluble Pb phosphate minerals. Phosphorus significantly reduced Cu and Zn water solubility by 31-80% and 40-69%, respectively, presumably due to their sorption on minerals (e.g., calcite and phosphate phases) following CaO addition. However, P had little effect on the Cu and Zn phytoavailability; while the acid extractability of Cu and Zn induced by SBET (pH 2) were even elevated by up to 48% and 40%, respectively, in the H(3)PO(4) treatments (PA and PR+PA). Our results indicate that phosphate was effective in reducing Pb availability in terms of water solubility, bioaccessibility, and phytoavailability. Caution should be exercised when H(3)PO(4) was amended to the soil co-contaminated with Cu and Zn since the acidic condition of SBET increased Cu and Zn bioaccessibility though their water solubility was reduced.

  15. Biosolids conditioning and the availability of Cu and Zn for rice

    Directory of Open Access Journals (Sweden)

    Pires Adriana Marlene Moreno

    2003-01-01

    Full Text Available Sewage treatment process is a factor to be considered for biosolid use in agriculture. The greatest sewage treatment facility of São Paulo State (Barueri/SP altered in the year 2000 of its sludge treatment. The addition of ferric chloride and calcium oxide was substituted by the addition of polymers. This change can modify heavy metal phytoavailability. A green house experiment, using 2 soils treated with biosolids (three with and one without polymers with and without polymers was performed to evaluate Cu and Zn phytoavailability using rice (Oryza sativa L. as test plant. Three kilograms of two soils (Haphorthox abd Hapludox were placed in pots and the equivalent to 50 Mg ha-1 (dry basis of biosolid was added and incorporated. The statistical design adopted was completely randomized experiment, with five treatments (control plus four different biossolids each soil and four replications. Soil pH before and after harvesting, Cu and Zn concentrations in shoot were evaluated. Tukey (5% was used to compare the results. DTPA, HCl 0.1 mol L-1 and Mehlich 3 were used to estimate soil available Cu and Zn. Amounts extracted were correlated to those presented in rice shoot, to evaluate the efficiency of predicting Cu and Zn phytoavailabilities. Biosolids with polymers presented higher Cu and Zn phytoavailabilities, possibly due to the lower pH of these residues. In this case soil presented lowest values of pH and plant shoot had highest. All extractants were representative of Cu and Zn availability to rice plants.

  16. Biocompatibility Assessment of Novel Bioresorbable Alloys Mg-Zn-Se and Mg-Zn-Cu for Endovascular Applications: In- Vitro Studies

    OpenAIRE

    Persaud-Sharma, Dharam; Budiansky, Noah; McGoron, Anthony J

    2013-01-01

    Previous studies have shown that using biodegradable magnesium alloys such as Mg-Zn and Mg-Zn-Al possess the appropriate mechanical properties and biocompatibility to serve in a multitude of biological applications ranging from endovascular to orthopedic and fixation devices. The objective of this study was to evaluate the biocompatibility of novel as-cast magnesium alloys Mg-1Zn-1Cu wt.% and Mg-1Zn-1Se wt.% as potential implantable biomedical materials, and compare their biologically effecti...

  17. Cation/Anion Substitution in Cu2ZnSnS4 for Improved Photovoltaic Performance

    Science.gov (United States)

    Ananthoju, Balakrishna; Mohapatra, Jeotikanta; Jangid, Manoj K.; Bahadur, D.; Medhekar, N. V.; Aslam, M.

    2016-10-01

    Cations and anions are replaced with Fe, Mn, and Se in CZTS in order to control the formations of the secondary phase, the band gap, and the micro structure of Cu2ZnSnS4. We demonstrate a simplified synthesis strategy for a range of quaternary chalcogenide nanoparticles such as Cu2ZnSnS4 (CZTS), Cu2FeSnS4 (CFTS), Cu2MnSnS4 (CMTS), Cu2ZnSnSe4 (CZTSe), and Cu2ZnSn(S0.5Se0.5)4 (CZTSSe) by thermolysis of metal chloride precursors using long chain amine molecules. It is observed that the crystal structure, band gap and micro structure of the CZTS thin films are affected by the substitution of anion/cations. Moreover, secondary phases are not observed and grain sizes are enhanced significantly with selenium doping (grain size ~1 μm). The earth-abundant Cu2MSnS4/Se4 (M = Zn, Mn and Fe) nanoparticles have band gaps in the range of 1.04–1.51 eV with high optical-absorption coefficients (~104 cm‑1) in the visible region. The power conversion efficiency of a CZTS solar cell is enhanced significantly, from 0.4% to 7.4% with selenium doping, within an active area of 1.1 ± 0.1 cm2. The observed changes in the device performance parameters might be ascribed to the variation of optical band gap and microstructure of the thin films. The performance of the device is at par with sputtered fabricated films, at similar scales.

  18. Structural and optoelectronic properties of glucose capped Al and Cu doped ZnO nanostructures

    Directory of Open Access Journals (Sweden)

    Patwari Gunjan

    2016-03-01

    Full Text Available Al and Cu doped ZnO nanoparticles are considered as appropriate for modulation of structural and optoelectronic properties. Al atoms are found to substitute the host Zn whereas Cu dopants mainly segregate in grain boundaries and thereby determine the optical properties. The undoped as well as Al and Cu doped ZnO exhibit spherical well defined particles. The spherical nanoparticles change to rod type structures on co-doping. The average particle size decreases on doping what consequently results in an increment in band gap. Blue shift in UV absorption is governed by the functional group of glucose; further blue shift occurring on metal doping may be attributed to Burstein-Moss effect. PL spectra of doped and undoped ZnO show a dominant near band gap UV emission along with visible emission owing to the defects. The PL peak intensity increases on doping with Cu and Al. The linear I-V characteristics indicate the ohmic behavior of ZnO nanostructures.

  19. Structural, electronic and optical properties of Cu-doped ZnO: experimental and theoretical investigation

    Science.gov (United States)

    Horzum, S.; Torun, E.; Serin, T.; Peeters, F. M.

    2016-06-01

    Experiments are supplemented with ab initio density functional theory (DFT) calculations in order to investigate how the structural, electronic and optical properties of zinc oxide (ZnO) thin films are modified upon Cu doping. Changes in characteristic properties of doped thin films, that are deposited on a glass substrate by sol-gel dip coating technique, are monitored using X-ray diffraction (XRD) and UV measurements. Our ab initio calculations show that the electronic structure of ZnO can be well described by DFT+U/? method and we find that Cu atom substitutional doping in ZnO is the most favourable case. Our XRD measurements reveal that the crystallite size of the films decrease with increasing Cu doping. Moreover, we determine the optical constants such as refractive index, extinction coefficient, optical dielectric function and optical energy band gap values of the films by means of UV-Vis transmittance spectra. The optical band gap of ZnO the thin film linearly decreases from 3.25 to 3.20 eV at 5% doping. In addition, our calculations reveal that the electronic defect states that stem from Cu atoms are not optically active and the optical band gap is determined by the ZnO band edges. Experimentally observed structural and optical results are in good agreement with our theoretical results.

  20. Investigations on structural, vibrational and dielectric properties of nanosized Cu doped Mg-Zn ferrites

    Science.gov (United States)

    Yadav, Anand; Rajpoot, Rambabu; Dar, M. A.; Varshney, Dinesh

    2016-05-01

    Transition metal Cu2+ doped Mg-Zn ferrite [Mg0.5Zn0.5-xCuxFe2O4 (0.0 ≤ x ≤ 0.5)] were prepared by sol gel auto combustion (SGAC) method to probe the structural, vibrational and electrical properties. X-ray diffraction (XRD) pattern reveals a single-phase cubic spinel structure without the presence of any secondary phase corresponding to other structure. The average particle size of the parent Mg0.5Zn0.5Fe2O4 is found to be ~29.8 nm and is found to increase with Cu2+ doping. Progressive reduction in lattice parameter of Mg0.5Zn0.5Fe2O4 has been observed due to difference in ionic radii of cations with improved Cu doping. Spinel cubic structure is further confirmed by Raman spectroscopy. Small shift in Raman modes towards higher wave number has been observed in doped Mg-Zn ferrites. The permittivity and dielectric loss decreases at lower doping and increases at higher order doping of Cu2+.

  1. Leaching potential of pervious concrete and immobilization of Cu, Pb and Zn using pervious concrete.

    Science.gov (United States)

    Solpuker, U; Sheets, J; Kim, Y; Schwartz, F W

    2014-06-01

    This paper investigates the leaching potential of pervious concrete and its capacity for immobilizing Cu, Pb and Zn, which are common contaminants in urban runoff. Batch experiments showed that the leachability of Cu, Pb and Zn increased when pHconcrete might function to attenuate contaminant migration. A porous concrete block was sprayed with low pH water (pH=4.3±0.1) for 190 h. The effluent was highly alkaline (pH~10 to 12). In the first 50 h, specific conductance and trace-metal were high but declined towards steady state values. PHREEQC modeling showed that mixing of interstitial alkaline matrix waters with capillary pore water was required in order to produce the observed water chemistry. The interstitial pore solutions seem responsible for the high pH values and relatively high concentrations of trace metals and major cations in the early stages of the experiment. Finally, pervious concrete was sprayed with a synthetic contaminated urban runoff (10 ppb Cu, Pb and Zn) with a pH of 4.3±0.1 for 135 h. It was found that Pb immobilization was greater than either Cu or Zn. Zn is the most mobile among three and also has the highest variation in the observed degree of immobilization.

  2. A Novel Isoenzyme of CuZn-superoxide Dismutase from Nicotiana tobacum

    Institute of Scientific and Technical Information of China (English)

    Liang Quan SHENG; Shao Min LIU; Hou Rong XIAO; Bing Le XIA; Qing Liang LIU

    2004-01-01

    An isoenzyme of CuZn-superoxide dismutase, denoted as CuZnSODⅢ, has been separated and purified from Nicotiana Tobacum (tobacco) leaves to apparent homogeneity. Its molecular mass is 22976.6Da. It is composed of one subunit, which is consisted of 187 amine acid residues and contains 1 copper and 0.5 zinc atom. The activation energy of the thermal denaturation process has been obtained as about 143.5kJmol-1. Meanwhile, some properties of spectra were investigated.

  3. Cofiring behavior of NiCuZn ferrite/PMN ferroelectrics di-layer composites

    Institute of Scientific and Technical Information of China (English)

    MIAO Chun-lin; ZHOU Ji; YUE Zhen-xing; LI Long-tu

    2005-01-01

    The cofiring compatibility between ferrite and relaxor ferroelectrics materials is the key issue in the production of multilayer chip LC filters. The cofiring behavior, interfacial microstructure and diffusion of di-layer composites of NiCuZn ferrite/PMN relaxor ferroelectrics are studied. In order to analyze the matching condition of thermodynamic properties between ferrite and relaxor ferroelectric ceramics, TMA is performed on PMN ferroelectrics and NiCuZn ferrite with certain percentage of Bi2 O3, respectively. EDS results demonstrate that serious element diffusions exist at the interface, which is in accordance with the phase analysis based on XRD patterns.

  4. Quaternary Cu2ZnSnSe4 thin films for solar cells applications

    OpenAIRE

    Zoppi, Guillaume; Forbes, Ian; Miles, Robert; Dale, Phillip; Scragg, Jonathan; Peter, Laurence

    2009-01-01

    Polycrystalline thin films of Cu2ZnSnSe4 (CZTSe) were produced by selenisation of Cu(Zn,Sn) magnetron sputtered metallic precursors for solar cell applications. The p-type CZTSe absorber films were found to crystallize in the stannite structure (a = 5.684 Ã… and c = 11.353 Ã…) with an electronic bandgap of 0.9 eV. Solar cells with the structure were fabricated with device efficiencies up to 3.2%.

  5. Synthesis, surface characterization and optical properties of 3-thiopropionic acid capped ZnS:Cu nanocrystals

    Indian Academy of Sciences (India)

    Ashish Tiwari; S A Khan; R S Kher

    2011-08-01

    3-Thiopropionic acid (TPA) capped ZnS:Cu nanocrystals have been successfully synthesized by simple aqueous method. Powder X-ray diffraction (XRD) studies revealed the particle size to be 4.2 nm. Surface characterization of the nanocrystals by FTIR spectroscopy has been done and the structure for surface bound TPA based on spectral analysis was proposed. The optical studies were done using UV-VIS spectroscopy and particle size and diameter polydispersity index (DPI) were calculated. Photoluminescence (PL) spectrum reveals emission related to the transition from conduction band of ZnS to 2 level of Cu2+. Electron microscopy was also done by scanning electron microscopy (SEM).

  6. Prediction of Hardness of the Zn-Al-Cu Alloys of Agreement by Composition in Weight

    Directory of Open Access Journals (Sweden)

    Villegas-Cárdenas José David

    2013-06-01

    Full Text Available Ten alloys Zn – Al – Cu were developed in two parts, in agreement to two zones presented in the isopleth diagrams (Villas et al., 1995. The percentage of Cu and Al was systematically varied. Subsequently, hardness measurements were performed. These measurements allowed establishing two equations that predict the hardness with an error lower than 5%. With these equations, it is possible to obtain alloys that replace Al base alloys by a Zn base alloy, having the same hardness. This implicates also the elimination of the volumetric change in the presence of ε phase.

  7. HEAVY METALS (Ni, Cu, Zn AND Cd CONTENT IN SERUM OF RAT FED GREEN MUSSELS

    Directory of Open Access Journals (Sweden)

    Muhammad Yudhistira Azis

    2015-11-01

    Full Text Available Green mussel (Perna viridis can playing role as bio-indicator or biomonitoring agent for heavy-metalcontaminations in the sea. In this research, the concentrations of four elements Ni, Cu, Zn and Cd in P. viridis and in the serum of rat which orally feed by P. viridis were determined by Atomic Absorption Spectrometry (AAS following dry acid digestion. Parameter analysis was evaluated by determining confidence limit for the obtained results. The result showed that there was a sequence of heavy-metal content in green mussels sample and laboratory rats serum, such as Ni < Cd < Cu < Zn. Keywords: heavy metals, green mussels, laboratory rats serum, AAS

  8. Modeling and analysis of soybean (Glycine max. L Cu/Zn, Mn and Fe superoxide dismutases

    Directory of Open Access Journals (Sweden)

    V. Ramana Gopavajhula

    2013-01-01

    Full Text Available Superoxide dismutase (SOD, EC 1.15.1.1 is an important metal-containing antioxidant enzyme that provides the first line of defense against toxic superoxide radicals by catalyzing their dismutation to oxygen and hydrogen peroxide. SOD is classified into four metalloprotein isoforms, namely, Cu/Zn SOD, Mn SOD, Ni SOD and Fe SOD. The structural models of soybean SOD isoforms have not yet been solved. In this study, we describe structural models for soybean Cu/Zn SOD, Mn SOD and Fe SOD and provide insights into the molecular function of this metal-binding enzyme in improving tolerance to oxidative stress in plants.

  9. Effect of Deformation on Order-Disorder Phase Transformation in Cu-Zn Alloy

    Institute of Scientific and Technical Information of China (English)

    Zhang Ruijun; Xu Liang; Liu Jianhua

    2007-01-01

    The phase transformation temperature of ordered β' to disordered β in the Cu-Zn alloy was tested by DSC. The transformation activation energy was calculated and the effect of deformation of the phase transformation was discussed. The results show that the phase transformation temperature and activation energy of ordered β' to disordered β in the Cu-Zn alloy can be decreased going through deformation, and the phase transformation time can be also decreased. As a result, the order-disorder phase transformation occurs more easily.

  10. Analysis on Cu and Zn Concentrations in Agricultural Soils of Ili District, Xinjiang Autonomous Region, China

    Directory of Open Access Journals (Sweden)

    YANG Jing-na

    2015-02-01

    Full Text Available The aim of this work is mainly to investigate the contents of copper(Cuand zinc(Znin agricultural soils to provide basic infor-mation for the establishment of green and organic production base in Ili District, Xinjiang Autonomous Region. 600 topsoil samples of the a-gricultural land were collected from eight counties of Ili District, and the contents of Cu and Zn were determined by AAS after microwave di-gestion. The statistics analysis showed that the mean contents of Cu and Zn in the agricultural soils of Ili District were 28.68 mg·kg-1 and 83.17 mg·kg-1, respectively. The concentrations of Cu in the agricultural soils of Ili District ranged from 11.07 mg·kg-1 to 59.90 mg·kg-1, 85% of which ranged from 20 mg·kg-1 to 40 mg·kg-1; and the concentrations of Zn in the agricultural soils of Ili District ranged from 39.58 mg·kg-1 to 160.40 mg·kg-1, 90%of which ranged from 60 mg·kg-1 to 110 mg·kg-1. Furthermore, compared the Cu and Zn contents of the tested soils among the eight counties, Cu contents in Tekes County were higher than other counties, while Zn contents showed little difference. The con-tents of Cu and Zn in the tested soils were all below the threshold values that were established in the national environmental quality standard for soils(secondary standards, GB 15618-1995, but about 7% and 21% were higher than the Cu and Zn background values of soil in Ili District, respectively. Furthermore, the concentrations of Cu and Zn in soils of Ili District accord with the environmental requirements for or-ganic and green production base regulated by national standard of organic products(GB/T 19630-2011and industrial standard of green food(NY/T 391-2013.

  11. Structural and optical properties of Zn doped CuInS2 thin films

    Indian Academy of Sciences (India)

    Mahdi H Suhail

    2012-11-01

    Copper indium sulphide (CIS) films were deposited by spray pyrolysis onto glass substrates from aqueous solutions of copper (II) sulphate, indium chloride and thiourea using compressed air as the carrier gas. The copper/indium molar ratio (Cu/In) in the solution 1(1:1) and the sulphur/copper ratio (S/Cu) was fixed at 4. Structural properties of these films were characterized. The effects of Zn (0–5%)molecular weight compared with CuInS2 Source and different substrate temperatures on films properties were investigated using X-ray diffraction (XRD) and optical transmission spectra. Optical characteristics of the CuInS2 films have been analysed using spectrophotometer in the wavelength range 300–1100 nm. The absorption spectra of the films showed that this compound is a direct bandgap material and gap values varied between 1.55 and 1.57 eV, depending on the substrate temperatures. Zn-doped samples have a bandgap energy of 1.55–1.95 eV. It was observed that there is an increase in optical bandgap with increasing Zn % molecular weight. The optical constants of the deposited films were obtained from the analysis of the experimentally recorded transmission and absorption spectral data. The refractive index, n and dielectric constants, 1 and 2, were also discussed and calculated as a function of investigated wavelength range and found it dependent on Zn incorporation. We found that the Zn-doped CuInS2 thin films exhibit P-type conductivity and we predict that Zn species can be considered as suitable candidates for use as doped acceptors to fabricate CuInS2-based solar cells. The paper presents a study concerning the influence of deposition parameters (temperature of the substrate and concentration of Zn (1–5)% from 0.16 M ZnCl2) on the quality of CuInS2 thin films achieved by spray pyrolysis on glass substrate from solutions containing 0.02 M CuCl2.2H2O, 0.16 M thiourea and 0.08 M In2Cl3.5H2O.

  12. Magnetic properties of NiCuZn ferrites synthesized by oxalate precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Ghodake, S.A. [Department of Physics, Applied Electronics, Solapur University, Kegaon, Solapur 413 255 (India); Ghodake, U.R. [Department of Physics, Applied Electronics, Solapur University, Kegaon, Solapur 413 255 (India); Sawant, S.R. [Department of Electronics, Shivaji University, Kolhapur 416 004 (India); Suryavanshi, S.S. [Department of Physics, Applied Electronics, Solapur University, Kegaon, Solapur 413 255 (India)]. E-mail: sssuryavanshi@rediffmail.com; Bakare, P.P. [Centre for Material Characterization, National Chemical Laboratory, Pune 411008 (India)

    2006-10-15

    Ni-Cu-Zn ferrites have been synthesized by employing co-precipitation technique using oxalate precursors. X-ray diffractograms did not show impurity phases, indicating single-phase formation of the ferrites. The diffractograms of oxalate complex decomposed at 650 deg. C show that ferritization is complete up to 650 deg. C. Lattice parameter a (A) was found to decrease with the addition of Ni{sup 2+} which is attributed to ionic sizes of Ni{sup 2+} (0.69A), which replaces Cu{sup 2+} (0.72A). From the thermogravimetric studies it is observed that the experimentally observed total mass loss (%), agrees with theoretically calculated mass loss (%) indicating maintenance of requisite stoichiometry. Initial permeability ({mu}{sub i} ) shows increase when Ni{sup 2+} is added up to x=0.15 while for (x>0.15), it decreases. The increase in initial permeability ({mu}{sub i}) is attributed to monotonic increase in Ms, and K{sub 1} on addition of Ni{sup 2+}. However, the microstructure and density (porosity) also influence {mu}{sub i} variations. The decrease in {mu}{sub i} is attributable to increase of K{sub 1.} The composition with density 91.14% exhibits large {mu}{sub i} which also tends to increase with temperature up to 60 deg. C. Thus its usable range extends up to 60 deg. C. This samples has T{sub c} near to 160 deg. C.

  13. Room-temperature ferromagnetic properties of Cu-doped ZnO rod arrays

    Indian Academy of Sciences (India)

    C H Xia; C G Hu; C H Hu; Z Ping; F Wang

    2011-08-01

    We have investigated properties of the Cu-doped ZnO crystalline film synthesized by the hydrothermal method. X-ray diffraction and X-ray photoelectron spectroscopy results provide the evidence that Cu2+ is incorporated into the ZnO lattices. Photoluminescence spectrum of the rod arrays shows that the UV emission peak shifts a little to lower energy and its intensity decreased. There are another two emission peaks centred in blue and green regions because of the incorporation of Cu2+ ions. The rod arrays have exhibited room-temperature ferromagnetic behaviour with the remanence of 0.926 × 10-3 emu/cm3. We suggest that the exchange interaction between local spin-polarized electrons (such as the electrons of Cu2+ ions) and conductive electrons is the cause of room-temperature ferromagnetism.

  14. Fabrication of Cu2ZnSn(SxSe1 - x)4 solar cells by ethanol-ammonium solution process

    Science.gov (United States)

    Xue, Cong; Li, Jianmin; Wang, Yaguang; Jiang, Guoshun; Weifeng, Liu; Zhu, Changfei

    2016-10-01

    In this paper, Cu2ZnSn(SxSe1 - x)4 precursor films were produced by doctor blade process from SnS-Cu2O-ZnS slurry. To prepare the slurry, SnS, ZnS and Cu2O precipitates, which are outgrowths of stacked layer ZnS/Cu/SnS by CBD (chemical bath deposition)-annealing route, were dissolved in the mixture solvent of ethanol and NH3·H2O. Synthesized precursor films were then annealed at different conditions. The post-annealed films were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman measurements and UV-vis-NIR spectroscopy. SEM studies reveal that the rough and relatively compact absorber thin films are obtained via the sulfidation and sulfidation-selenization processes. X-ray diffraction and Raman spectrum results verify that the obtained films are composed of Cu2ZnSnS4 and Cu2ZnSnSe4 phases, which have high absorbance in visible range and direct band gap energy of 1.01-1.47 eV. The best devices yield total area power conversion efficiency of 1.99% and 2.95% corresponding to Cu2ZnSnS4 and Cu2ZnSn(SxSe1 - x)4 thin film solar cells under AM1.5 illumination without any anti-reflection layer.

  15. Overexpressing the Sedum alfredii Cu/Zn Superoxide Dismutase Increased Resistance to Oxidative Stress in Transgenic Arabidopsis

    Directory of Open Access Journals (Sweden)

    Zhen Li

    2017-06-01

    Full Text Available Superoxide dismutase (SOD is a very important reactive oxygen species (ROS-scavenging enzyme. In this study, the functions of a Cu/Zn SOD gene (SaCu/Zn SOD, from Sedum alfredii, a cadmium (Cd/zinc/lead co-hyperaccumulator of the Crassulaceae, was characterized. The expression of SaCu/Zn SOD was induced by Cd stress. Compared with wild-type (WT plants, overexpression of SaCu/Zn SOD gene in transgenic Arabidopsis plants enhanced the antioxidative defense capacity, including SOD and peroxidase activities. Additionally, it reduced the damage associated with the overproduction of hydrogen peroxide (H2O2 and superoxide radicals (O2•-. The influence of Cd stress on ion flux across the root surface showed that overexpressing SaCu/Zn SOD in transgenic Arabidopsis plants has greater Cd uptake capacity existed in roots. A co-expression network based on microarray data showed possible oxidative regulation in Arabidopsis after Cd-induced oxidative stress, suggesting that SaCu/Zn SOD may participate in this network and enhance ROS-scavenging capability under Cd stress. Taken together, these results suggest that overexpressing SaCu/Zn SOD increased oxidative stress resistance in transgenic Arabidopsis and provide useful information for understanding the role of SaCu/Zn SOD in response to abiotic stress.

  16. Microstructures and optical properties of Cu-doped ZnO films prepared by radio frequency reactive magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ma Ligang [College of physics and Electronics Engineering, Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu, 730070 (China); Ma Shuyi, E-mail: maligang186@163.com [College of physics and Electronics Engineering, Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu, 730070 (China); Chen Haixia; Ai Xiaoqian; Huang Xinli [College of physics and Electronics Engineering, Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu, 730070 (China)

    2011-09-15

    Pure and Cu-doped ZnO (ZnO:Cu) thin films were deposited on glass substrates using radio frequency (RF) reactive magnetron sputtering. The effect of substrate temperature on the crystallization behavior and optical properties of the ZnO:Cu films have been studied. The crystal structures, surface morphology and optical properties of the films were systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and a fluorescence spectrophotometer, respectively. The results indicated that ZnO films showed a stronger preferred orientation toward the c-axis and a more uniform grain size after Cu-doping. As for ZnO:Cu films, the full width at half maxima (FWHM) of (0 0 2) diffraction peaks decreased first and then increased, reaching a minimum of about 0.42 deg. at 350 deg. C and the compressive stress of ZnO:Cu decreased gradually with the increase of substrate temperature. The photoluminescence (PL) spectra measured at room temperature revealed two blue and two green emissions. Intense blue-green luminescence was obtained from the sample deposited at higher substrate temperature. Finally, we discussed the influence of annealing temperature on the structural and optical properties of ZnO:Cu films. The quality of ZnO:Cu film was markedly improved and the intensity of blue peak ({approx}485 nm) and green peak ({approx}527 nm) increased noticeably after annealing. The origin of these emissions was discussed.

  17. Inhibition effect of expression of Cu/Zn superoxide dismutase from rice on synthesis of Glutathione in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    AI Yu-zhuo; DU Ye-jie; ZU Yuan-gang; AN Zhi-gang

    2008-01-01

    The expression of a rice Cu/Zn superoxide dismutase (Cu/Zn-SOD) in Saccharomyces cerevisiae regulated by GAPDH promoter, involved in the inhibition of endogenous Glutathione (GSH) synthesis, and the competitive expression was detected by constructing the expression vector transferred Cu/Zn-SOD gene into wild-type S. Cerevisiae. Transcription and expression of the Cu/Zn-SOD gene in S. Cerevisiawere were confirmed by northern blot and SDS-PAGE, respectively, and activity of the Cu/Zn-SOD from crude extracts was enzymatically detected based on the effect of nitroblue tetrazolium (NBT) after running a native polyacrylamide gel. The GSH synthesis was also tested by DTNB (5, 5′-Dithiobis (2-nitrobenzoic acid)) method. Results showed that GSH synthesis was evidently suppressed by the expression of Cu/Zn-SOD gene in both control and heat shock strains. It implied that the expression of the Cu/Zn-SOD gene in S. Cerevisiae has more potential facility in response to oxidative exposure than that of endogenous GSH, although Cu/Zn-SOD and GSH were both contributed to the function of oxygen radical oxidoreduction.

  18. Band structures of Cu2ZnSnS4 and Cu2ZnSnSe4 from many-body methods

    Science.gov (United States)

    Botti, Silvana; Kammerlander, David; Marques, Miguel A. L.

    2011-06-01

    We calculate the band structures of kesterite and stannite Cu2ZnSnS4 and Cu2ZnSnSe4, using a state-of-the-art self-consistent GW approach. Our accurate quasiparticle states allow to discuss: the dependence of the gap on the anion displacement; the key-role of the nonlocality of the exchange-correlation potential to obtain good structural parameters; the reliability of less expensive hybrid functional and generalized gradient approximation+U approaches. In particular, we show that even if the band gap is correctly reproduced by hybrid functionals, the band-edge corrections are in disagreement with self-consistent GW results, which have decisive implications for the positioning of the defect levels in the band gap.

  19. Biosorption behaviors of Cu2+,Zn2+, Cd2+ and mixture by waste activated sludge

    Institute of Scientific and Technical Information of China (English)

    LUO Sheng-lian; YUAN Lin; CHAI Li-yuan; MIN Xiao-bo; WANG Yun-yan; FANG Yan; WANG Pu

    2006-01-01

    Biosorption of heavy metal ions, such as Cu2+, Cd2+ and Zn2+, was carried out using waste activated sludge from municipal sewage treatment plant as adsorption material, and the effects of parameters, such as pH value, temperature, reaction time and sorption duration, were studied in detail. The results indicate that the removal rates of Cu2+, Zn2+ and Cd2+ with low concentration are 96.47%, 80% and 90%, respectively, adsorbed by waste activated sludge. Little effect of dosage of activated sludge on the adsorption of Cu2+ and more effects on the adsorption of Zn2+ and Cd2+ are observed. Little effect oftemperature is observed, while pH value and adsorption time exert important influence on the sorption process. The adsorption behaviors of heavy metal ions all have parabolic relationships with pH value. The optimum pH value is between 6 and 10, and the optimum adsorption time is 1 h. In single heavy metal ion system, the sorption processes of Cu2+, Zn2+ and Cd2+ are in accordance with Freundlich model, which indicates that it is suitable for the treatment of these three heavy metal ions using intermittent operation. In addition, the sorption capacity of the sludge for Cu2+ is preferential to the other two ions.

  20. Cyclotron production of {sup 64}Cu by deuteron irradiation of {sup 64}Zn

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, K. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail: kamel.abbas@jrc.it; Kozempel, J. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Charles University Prague, Faculty of Science, Department of Organic and Nuclear Chemistry, 128 43 Prague (Czech Republic); Bonardi, M. [LASA, Radiochemistry Laboratory, University and INFN, via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Groppi, F. [LASA, Radiochemistry Laboratory, University and INFN, via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Alfarano, A. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Holzwarth, U. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Simonelli, F. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Hofman, H. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Horstmann, W. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy); Menapace, E. [ENEA, Applied Physics Division, Bologna (Italy); Leseticky, L. [Charles University Prague, Faculty of Science, Department of Organic and Nuclear Chemistry, 128 43 Prague (Czech Republic); Gibson, N. [Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 500, I-21020 Ispra (VA) (Italy)

    2006-09-15

    The short-lived (12.7 h half-life) {sup 64}Cu radioisotope is both a {beta} {sup +} and a {beta} {sup -} emitter. This property makes {sup 64}Cu a promising candidate for novel medical applications, since it can be used simultaneously for therapeutic application of radiolabelled biomolecules and for diagnosis with PET. Following previous work on {sup 64}Cu production by deuteron irradiation of natural zinc, we report here the production of this radioisotope by deuteron irradiation of enriched {sup 64}Zn. In addition, yields of other radioisotopes such as {sup 61}Cu, {sup 67}Cu, {sup 65}Zn, {sup 69m}Zn, {sup 66}Ga and {sup 67}Ga, which were co-produced in this process, were also measured. The evaporation code ALICE-91 and the transport code SRIM 2003 were used to determine the excitation functions and the stopping power, respectively. All the nuclear reactions yielding the above-mentioned radioisotopes were taken into account in the calculations both for the natural and enriched Zn targets. The experimental and calculated yields were shown to be in reasonable agreement. The work was carried out at the Scanditronix MC-40 Cyclotron of the Institute for Health and Consumer Protection of the Joint Research Centre of the European Commission (Ispra site, Italy). The irradiations were carried out with 19.5 MeV deuterons, the maximum deuteron energy obtainable with the MC-40 cyclotron.

  1. Trap and recombination centers study in sprayed Cu2ZnSnS4 thin films

    Science.gov (United States)

    Courel, Maykel; Vigil-Galán, O.; Jiménez-Olarte, D.; Espíndola-Rodríguez, M.; Saucedo, E.

    2014-10-01

    In this work, a study of trap and recombination center properties in polycrystalline Cu2ZnSnS4 thin films is carried out in order to understand the poor performance in Cu2ZnSnS4 thin film solar cells. Thermally stimulated current has been studied in Cu2ZnSnS4 deposited by pneumatic spray pyrolysis method using various heating rates, in order to gain information about trap centers and/or deep levels present within the band-gap of this material. A set of temperature-dependent current curves revealed three levels with activation energy of 126 ± 10, 476 ± 25, and 1100 ± 100 meV. The possible nature of the three levels found is presented, in which the first one is likely to be related to CuZn antisites, while second and third to Sn vacancies and SnCu antisites, respectively. The values of frequency factor, capture cross section, and trap concentration have been determined for each center.

  2. Ab initio investigation on hydrogen adsorption capability in Zn and Cu-based metal organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Tanuwijaya, V. V., E-mail: viny.veronika@gmail.com [Engineering Physics, Faculty of Industrial Technology, Institut Teknologi Bandung Jalan Ganeca 10 Gd. T.P. Rachmat, Bandung 40132 (Indonesia); Hidayat, N. N., E-mail: avantgarde.vee@gmail.com; Agusta, M. K., E-mail: kemal@fti.itb.ac.id; Dipojono, H. K., E-mail: dipojono@tf.itb.ac.id

    2015-09-30

    One of the biggest challenge in material technology for hydrogen storage application is to increase hydrogen uptake in room temperature and pressure. As a class of highly porous material, Metal-Organic Frameworks (MOF) holds great potential with its tunable structure. However, little is known about the effect of metal cluster to its hydrogen storage capability. Investigation on this matter has been carried out carefully on small cluster of Zn and Cu-based MOF using first principles method. The calculation of two distinct building units of MOFs, namely octahedral and paddle-wheel models, have been done with B3LYP density functional method using 6-31G(d,p) and LANL2DZ basis sets. From geometry optimization of Zn-based MOF linked by benzene-dicarboxylate (MOF-5), it is found that hydrogen tends to keep distance from metal cluster group and stays above benzene ring. In the other hand, hydrogen molecule prefers to stay atop of the exposed Cu atom in Cu-based MOF system linked by the same linker group (Cu-bdc). Calculated hydrogen binding enthalpies for Zn and Cu octahedral cages at ZnO{sub 3} sites are 1.64kJ/mol and 2.73kJ/mol respectively, while hydrogen binding enthalpies for Zn and Cu paddle-wheel cages calculated on top of metal atoms are found to be at 6.05kJ/mol and 6.10kJ/mol respectively. Major difference between Zn-MOF-5 and Cu-bdc hydrogen uptake performance might be caused by unsaturated metal sites present in Cu-bdc system and the influence of their geometric structures, although a small difference on binding energy in the type of transition metal used is also observed. The comparison between Zn and Cu-based MOF may contribute to a comprehensive understanding of metal clusters and the importance of selecting best transition metal for design and synthesis of metal-organic frameworks.

  3. Ab initio investigation on hydrogen adsorption capability in Zn and Cu-based metal organic frameworks

    Science.gov (United States)

    Tanuwijaya, V. V.; Hidayat, N. N.; Agusta, M. K.; Dipojono, H. K.

    2015-09-01

    One of the biggest challenge in material technology for hydrogen storage application is to increase hydrogen uptake in room temperature and pressure. As a class of highly porous material, Metal-Organic Frameworks (MOF) holds great potential with its tunable structure. However, little is known about the effect of metal cluster to its hydrogen storage capability. Investigation on this matter has been carried out carefully on small cluster of Zn and Cu-based MOF using first principles method. The calculation of two distinct building units of MOFs, namely octahedral and paddle-wheel models, have been done with B3LYP density functional method using 6-31G(d,p) and LANL2DZ basis sets. From geometry optimization of Zn-based MOF linked by benzene-dicarboxylate (MOF-5), it is found that hydrogen tends to keep distance from metal cluster group and stays above benzene ring. In the other hand, hydrogen molecule prefers to stay atop of the exposed Cu atom in Cu-based MOF system linked by the same linker group (Cu-bdc). Calculated hydrogen binding enthalpies for Zn and Cu octahedral cages at ZnO3 sites are 1.64kJ/mol and 2.73kJ/mol respectively, while hydrogen binding enthalpies for Zn and Cu paddle-wheel cages calculated on top of metal atoms are found to be at 6.05kJ/mol and 6.10kJ/mol respectively. Major difference between Zn-MOF-5 and Cu-bdc hydrogen uptake performance might be caused by unsaturated metal sites present in Cu-bdc system and the influence of their geometric structures, although a small difference on binding energy in the type of transition metal used is also observed. The comparison between Zn and Cu-based MOF may contribute to a comprehensive understanding of metal clusters and the importance of selecting best transition metal for design and synthesis of metal-organic frameworks.

  4. One-, Two-, and Three-Dimensional Heterospin Complexes Consisting of 4-(N-tert-Butyloxylamino)pyridine (4NOpy), Dicyanamide Ion (DCA), and 3d Metal Ions: Crystal Structures and Magnetic Properties of [M(II)(4NOpy)x(DCA)y(CH3CN)z]n (M = Mn, Co, Ni, Cu, Zn).

    Science.gov (United States)

    Ogawa, Hiraku; Mori, Koya; Murashima, Kensuke; Karasawa, Satoru; Koga, Noboru

    2016-01-19

    Solutions of 3d metal ion salts, M(NO3)2, 4-(N-tert-butyloxylamino)pyridine (4NOpy), and dicyanamide (DCA) in CH3CN were mixed to afford single crystals of the polymeric complexes [M(II)(4NOpy)x(DCA)y(CH3CN)z]n (M(II) = Mn (1), Co (2), Ni (3), Cu (4a and 4b), Zn (5)). X-ray crystallography revealed that the crystal structures are a three-dimensional (3-D) network for 1, 2-D networks for 2, 3, 4a, and 5, and a 1-D chain for 4b. Crystals of 2, 3, 4a, and 5 contained CH3CN molecules as crystal solvents, which were readily desorbed in the ambient atmosphere. After desorption of the CH3CN molecules, the crystal structures of 2 and 3 were confirmed to be slightly shrunk without destruction of the crystal lattice. Crystals of 2, 3, 4a, and 5 after desorption of crystal solvents were used for investigations of the magnetic properties. Complex 1 showed antiferromagnetic interactions to form a ferrimagnetic chain and exhibited the magnetic behavior of a 2-D (or 3-D) spin-canted antiferromagnet with TN = 12 K. Complex 2 containing anisotropic Co(II) ions also showed the behavior of a 1-D (or 2-D) spin-canted antiferromagnet with TN = 6 K. In 3, 4a, and 4b, the aminoxyl of 4NOpy ferromagnetically interacted with the metal ion with coupling constants of JM-NO/kB = 45, 45, and 43 K, respectively. In 5, the magnetic couplings between the aminoxyls in 4NOpy through the diamagnetic Zn(II) ion were weakly antiferromagntic (JNO-NO = -1.2 K). DCA might be a weak antiferromagnetic connector for the metal chains.

  5. Electrodeposited ZnO/Cu{sub 2}O heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, S.S.; Mittiga, A.; Salza, E.; Masci, A.; Passerini, S. [Agency for the New Technologies, Energy and the Environment (ENEA), Casaccia Research Center, Via Anguillarese 301, 00123 Rome (Italy)

    2008-01-01

    In this paper the fabrication and the characterization of heterojunction solar cells based on electrodeposited ZnO and Cu{sub 2}O is described. The effect of the electrodeposition conditions (pH and temperature) on the cell performance has been investigated. The cells made with a Cu{sub 2}O layer deposited at high pH (12) and moderate temperature (50 C) have shown conversion efficiency as high as 0.41%. (author)

  6. Intermetallic compound formation at Sn-3.0Ag-0.5Cu-1.0Zn lead-free solder alloy/Cu interface during as-soldered and as-aged conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng-Jiang [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)]. E-mail: wangfjy@yahoo.com.cn; Yu, Zhi-Shui [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Qi, Kai [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)

    2007-07-12

    Intermetallic formations of Sn-3.0Ag-0.5Cu solder alloy with additional 1.0 wt% Zn were investigated for Cu-substrate during soldering and isothermal aging. During soldering condition, the Cu{sub 5}Zn{sub 8} compound with granular-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu-1.0Zn solder, while the Cu{sub 6}Sn{sub 5} compound with scallop-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu solder. During thermal aging, the final interfacial structure for Sn-3.0Ag-0.5Cu-1.0Zn solder is solder/Cu{sub 5}Zn{sub 8}/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu, different from the solder/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu for Sn-3.0Ag-0.5Cu solder. The thickness of Cu-Sn IMC layers increases, while the thickness of Cu{sub 5}Zn{sub 8} compound layer decreases with increasing aging time due to the decomposition of the Cu{sub 5}Zn{sub 8} layer by the diffusion of Cu and Zn atoms into the solder and Cu{sub 6}Sn{sub 5} at higher aging temperature. For Sn-3.0Ag-0.5Cu-1.0Zn solder, at higher aging temperature of 150 or 175 {sup o}C, with the formation of Cu{sub 3}Sn at Cu{sub 6}Sn{sub 5}/Cu, Kirkendall voids can be observed at the interface of Cu{sub 3}Sn/Cu.

  7. EXAFS analysis of a human Cu,Zn SOD isoform focused using non-denaturing gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Chevreux, Sylviane; Roudeau, Stephane; Deves, Guillaume; Ortega, Richard [Laboratoire de Chimie Nucleaire Analytique et Bioenvironnementale, CNRS UMR5084, Universite Bordeaux 1, Chemin du Solarium, F-33175 Gradignan cedex (France); Solari, Pier Lorenzo [Synchrotron SOLEIL, L' Orme des Merisiers, BP 48, F-91192 Gif-sur-Yvette cedex, Saint-Aubin (France); Alliot, Isabelle; Testemale, Denis; Hazemann, Jean Louis, E-mail: ortega@cenbg.in2p3.f [FAME, ESRF, 6 rue Jules Horowitz, BP220, F-38043 Grenoble cedex (France)

    2009-11-15

    Isoelectric point isoforms of a metalloprotein, copper-zinc superoxide dismutase (CuZnSOD), separated on electrophoresis gels were analyzed using X-ray Absorption Spectroscopy. Mutations of this protein are involved in familial cases of amyotrophic lateral sclerosis. The toxicity of mutants could be relied to defects in the metallation state. Our purpose is to establish analytical protocols to study metallation state of protein isoforms such as those from CuZnSOD. We previously highlighted differences in the copper oxidation state between CuZnSOD isoforms using XANES. Here, we present the first results for EXAFS analyses performed at Cu and Zn K-edge on the majoritary expressed isoform of human CuZnSOD separated on electrophoresis gels.

  8. Pyrroloquinoline quinone from Gluconobacter oxydans fermentation broth enhances superoxide anion-scavenging capacity of Cu/Zn-SOD.

    Science.gov (United States)

    Ma, Ke; Cui, Jun-Zhu; Ye, Jian-Bin; Hu, Xian-Mei; Ma, Ge-Li; Yang, Xue-Peng

    2017-09-01

    A bioassay-guided fractionation of extract from Gluconobacter oxydans fermentation broth afforded Compound 1, which was identified as pyrroloquinoline quinone (PQQ) by spectroscopic methods. PQQ has been shown to enhance the superoxide anion-scavenging capacity significantly for Cu/Zn-SOD. To illustrate the mechanism, the interaction between PQQ and Cu/Zn-SOD was investigated. The multiple binding sites involving hydrogen bonds and van der Waals force between PQQ and Cu/Zn-SOD were revealed by isothermal titration calorimetry. The α-helix content was increased in the Cu/Zn-SOD structure with the addition of PQQ into the solution through ultraviolet (UV) spectroscopy. These results indicated that PQQ could change the conformation of Cu/Zn-SOD through interaction, which could enhance its superoxide anion-scavenging capacity. Therefore, PQQ is a potential natural antioxidant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Size-dependent dual emission of Cu,Mn:ZnSe QDs: Controlling both emission wavelength and intensity.

    Science.gov (United States)

    Xu, Shuhong; Jiang, Han; Dong, Renjie; Lv, Changgui; Wang, Chunlei; Cui, Yiping

    2017-06-01

    Cu,Mn:ZnSe quantum dots (QDs) of tunable size, controllable photoluminescence (PL) intensity ratio and PL range were prepared. A study of the experimental conditions confirmed that the size of Cu,Mn:ZnSe QDs is affected by the pH of the solution, the speed at which the Zn solution is injected and the reaction temperature. In general, high pH, low injection speed and high reaction temperature are optimal for preparing large QDs. Based on this knowledge, different sizes of Cu,Mn:ZnSe QDs were synthesized. Moreover, white emission Cu,Mn:ZnSe QDs were designed by controlling the experimental conditions and the feeding mole ratio of Mn:Cu. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Low-Temperature Sintering and Electromagnetic Properties of NiCuZn/CaTiO3 Composites

    Science.gov (United States)

    Yang, Haibo; Yang, Yanyan; Lin, Ying; Zhu, Jianfeng; Wang, Fen

    2012-04-01

    Dense CaTiO3/Ni0.37Cu0.20Zn0.43Fe1.92O3.88 (CTO/NiCuZn) composites were prepared by the conventional solid-state reaction method and sintered at 950°C. The phase compositions and surface morphologies of the composites were investigated using x-ray diffraction and scanning electron microscopy, respectively. The dielectric and magnetic properties of the composites were also investigated. The results show that the CTO/NiCuZn composites possess high dielectric constants and permeabilities, which can be used in high-frequency communications for capacitor-inductor integrating devices such as electromagnetic interference filters and antennas. With increasing NiCuZn concentration, the permeabilities of the CTO/NiCuZn composites increase, while the dielectric constants and cutoff frequencies decrease.

  11. Electrochemical behavior of Cu-Zn-Al shape memory alloy after surface modification by electroless plated Ni-P

    Institute of Scientific and Technical Information of China (English)

    LIANG Chenghao; CHEN Bangyi; CHEN Wan; WANG Hua

    2004-01-01

    The electrochemical behavior of Cu-Zn-Al shape memory alloy (SMA) with and without electroless plated Ni-P was investigated by electrochemical methods in artificial Tyrode's solution. The results showed that Cu-Zn-Al SMA engendered dezincification corrosion in Tyrode's solution. The anodic active current densities as well as electrochemical dissolution sensitivity of the electroless plated Ni-P Cu-Zn-Al SMA increased with NaCl concentration rising, pH of solution decreasing and environmental temperature uprising. X-ray diffraction analysis indicated that after surface modification by electroless plated Ni-P, an amorphous plated film formed on the surface of Cu-Zn-Al SMA. This film can effectively isolate matrix metal from corrosion media and significantly improve the electrochemical property of Cu-Zn-Al SMA in artificial Tyrode's solution.

  12. EXAFS analysis of a human Cu,Zn SOD isoform focused using non-denaturing gel electrophoresis

    Science.gov (United States)

    Chevreux, Sylviane; Solari, Pier Lorenzo; Roudeau, Stéphane; Deves, Guillaume; Alliot, Isabelle; Testemale, Denis; Hazemann, Jean Louis; Ortega, Richard

    2009-11-01

    Isoelectric point isoforms of a metalloprotein, copper-zinc superoxide dismutase (CuZnSOD), separated on electrophoresis gels were analyzed using X-ray Absorption Spectroscopy. Mutations of this protein are involved in familial cases of amyotrophic lateral sclerosis. The toxicity of mutants could be relied to defects in the metallation state. Our purpose is to establish analytical protocols to study metallation state of protein isoforms such as those from CuZnSOD. We previously highlighted differences in the copper oxidation state between CuZnSOD isoforms using XANES. Here, we present the first results for EXAFS analyses performed at Cu and Zn K-edge on the majoritary expressed isoform of human CuZnSOD separated on electrophoresis gels.

  13. Interface morphology and solute partition during directional soldification process of Al-1.5Cu-3Zn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fuyia Chen; Wanqib Jie [State Key Lab. of Solidification Processing, Northwestern Polytechnical Univ., Xian (China)

    2005-07-01

    Interface morphology and solute partition during directional solidification process of Al-1.5Cu-3.0Zn alloy were investigated at temperature gradient of 80 K/cm and growth rate between 0.1 and 7.1 {mu}m/s. The solid-liquid interface was quenched during directional solidification and the micromorphology at the longitudinal section was examined by optic microscopy and SEM. The cellular growth interface and dendritic growth interface were observed and characterized. The distribution of Cu and Zn was measured by EDS, the equilibrium solute partition coefficients for Cu and Zn in Al-1.5Cu-3.0Zn alloy were obtained to be 0.31 and 0.58. The activity model and concentration model, developed by present authors, were used to calculate the equilibrium solute partition coefficients in Al-1.5Cu-3Zn alloy. The model-calculated results were compared with experimental data. (orig.)

  14. Sb complexes and Zn interstitials in Sb-implanted ZnO epitaxial films

    Institute of Scientific and Technical Information of China (English)

    Liu Yao-Ping; Ying Min-Ju; Mei Zeng-Xia; Li Jun-Qianng; Du Xiao-Long; A.Yu.Kuznetsovc

    2011-01-01

    In the present work, post-annealing is adopted to investigate the formation and the correlation of Sb complexes and Zn interstitials in Sb-ion implanted ZnO films, by using Raman scattering technique and electrical characterizations.The damage of Zn sublattice, produced by ion bombardment process is discerned from the unrecovered E2 (L) peak in annealed high Sb+ dose implanted samples. It is suggested that the Zn sublattice may be strongly affected by the introduction of Sb dopant because of the formation of SbZn-2VZn complex acceptor. The appearance of a new peak at 510 cm-1 in the annealed high dose Sb+ implanted samples is speculated to result from (Zn interstitials-O interstitials)Zni-Oi complex, which is in a good accordance with the electrical measurement. The p-type ZnO is difficult to obtain from the Sb+ implantation, however, which can be realized by in-situ Sb doping with proper growth conditions instead.

  15. Cu2ZnSnSe4 Thin Films by Selenization of Simultaneously Evaporated Sn-Zn-Cu Metallic Lays for Photovoltaic Applications

    Science.gov (United States)

    Shao, Lexi; Zhang, Jun; Zou, Changwei; Xie, Wei

    Cu2ZnSnSe4 (CZTSe) thin films were prepared by selenization of simultaneously evaporated metallic Cu-Zn-Sn on soda lime glass (SLG) substrates. The selenization were performed in elemental selenium vapor ambient at 450 °C for 1.5 h using Argon as the carrier gas. The compositions and structural properties of the films were characterized by using EDS, XRD, and Raman, respectively. The results show that the synthesized CZTSe thin films are nearly stoichiometric and single-phase with a kesterite structure. The measurement for electrical and optical properties indicated that a high absorption coefficient of 104 cm-1 and a low resistivity of 30 Ωcm are obtained. The optical band-gap energy of the CZTSe thin film can be fitted to be as 1.52 eV, which closes to the optimum value for solar cell absorber. The preparation processing for CZTSe developed in this woek is more attractive than others reported in the industrialization applications because the atomic ratio of Cu:Sn:Zn in the precursor can be easily controlled by adjusting the ratio of the evaporation sources, meanwhile, it is more suitable for large-scale production.

  16. The remarkable activity and stability of a highly dispersive beta-brass Cu-Zn catalyst for the production of ethylene glycol

    OpenAIRE

    Molly Meng-Jung Li; Jianwei Zheng; Jin Qu; Fenglin Liao; Elizabeth Raine; Winson C. H. Kuo; Shei Sia Su; Pang Po; Youzhu Yuan; Shik Chi Edman Tsang

    2016-01-01

    Incorporation of Zn atoms into a nanosize Cu lattice is known to alter the electronic properties of Cu, improving catalytic performance in a number of industrially important reactions. However the structural influence of Zn on the Cu phase is not well studied. Here, we show that Cu nano-clusters modified with increasing concentration of Zn, derived from ZnO support doped with Ga3+, can dramatically enhance their stability against metal sintering. As a result, the hydrogenation of dimethyl oxa...

  17. Structural, magnetic and transport properties of CoZn/Cu electrodeposited multilayers

    Energy Technology Data Exchange (ETDEWEB)

    El Bahraoui, T.; Errahmani, H.; Berrada, A. E-mail: alamal29@hotmail.com; Dinia, A.; Schmerber, G.; Cherkaoui El Moursli, F.; Hajji, F.; Lassri, H

    2004-05-01

    We present experimental results of (Co{sub 9.7}Zn{sub 90.3}/Cu){sub 20} multilayers grown from electrochemical dual bath. X-ray diffraction patterns have shown that the CoZn structural lattice parameters are close to those of the monoclinic CoZn{sub 13} compound. The magnetic properties at room temperature reveal both superparamagnetic and ferromagnetic features. The magnetoresistance behaviour exhibits a broad, rounded maximum around H=0 and does not present any saturation.

  18. Preparation and Characterization of Cu2ZnSnS4 Thin Films and Solar Cells Fabricated from Quaternary Cu-Zn-Sn-S Target

    Directory of Open Access Journals (Sweden)

    Min Xie

    2013-01-01

    Full Text Available CZTS thin films were fabricated through sputtering from a quaternary Cu-Zn-Sn-S target, followed by a sulfurization process. CZTS thin-film solar cells were also fabricated and a highest efficiency of 4.04% was achieved. It has been found that obvious Zn loss occurs during the sputtering and poorly crystallized CZTS are formed in the sputtered films. The Zn loss leads to the appearance of SnS. A sulfurization process can obviously improve the crystallinity of CZTS and films with grain size of several hundred nanometers can be obtained after sulfurization. The optical band gap of the films is estimated to be 1.57 eV. The electrical properties of the 4.04% efficient solar cell were investigated and it has been found that cell has obvious deficiency in minority carrier lifetime. This deficiency should be responsible for the low Jsc and low Voc of our cell.

  19. Solid Liquid Interdiffusion Bonding of Zn4Sb3 Thermoelectric Material with Cu Electrode

    Science.gov (United States)

    Lin, Y. C.; Lee, K. T.; Hwang, J. D.; Chu, H. S.; Hsu, C. C.; Chen, S. C.; Chuang, T. H.

    2016-10-01

    The ZnSb intermetallic compound may have thermoelectric applications because it is low in cost and environmentally friendly. In this study, a Zn4Sb3 thermoelectric element coated with a Ni barrier layer and a Ag reaction layer was bonded with a Ag-coated Cu electrode using a Ag/Sn/Ag solid-liquid interdiffusion bonding process. The results indicated that a Ni5Zn21 intermetallic phase formed easily at the Zn4Sb3/Ni interface, leading to sound adhesion. In addition, Sn film was found to react completely with the Ag layer to form a Ag3Sn intermetallic layer having a melting point of 480°C. The resulting Zn4Sb3 thermoelectric module can be applied at the optimized operation temperature (400°C) of Zn4Sb3 material as a thermoelectric element. The bonding strengths ranged from 14.9 MPa to 25.0 MPa, and shear tests revealed that the Zn4Sb3/Cu-joints fractured through the interior of the thermoelectric elements.

  20. Application of 67Cu Produced by 68Zn(n,n'p+d)67Cu to Biodistribution Study in Tumor-Bearing Mice

    Science.gov (United States)

    Sugo, Yumi; Hashimoto, Kazuyuki; Kawabata, Masako; Saeki, Hideya; Sato, Shunichi; Tsukada, Kazuaki; Nagai, Yasuki

    2017-02-01

    67Cu produced by the 68Zn(n,n'p+d)67Cu reaction was used for the first time to determine the biodistribution of 67CuCl2 in colorectal tumor-bearing mice. A high uptake of 67Cu was observed in the tumor as well as in the liver and kidney, which are the major organs for copper metabolism. The result showing 67Cu accumulation in the tumor suggests that 67CuCl2 can be a potential radionuclide agent for cancer radiotherapy. It should also encourage further studies on the therapeutic effect on small animals using an increased dose of 67Cu produced by the 68Zn(n,n'p+d)67Cu reaction using presently available intense neutrons.

  1. Transient and modulated charge separation at CuInSe2/C60 and CuInSe2/ZnPc hybrid interfaces

    Science.gov (United States)

    von Morzé, Natascha; Dittrich, Thomas; Calvet, Wolfram; Lauermann, Iver; Rusu, Marin

    2017-02-01

    Spectral dependent charge transfer and exciton dissociation have been investigated at hybrid interfaces between inorganic polycrystalline CuInSe2 (untreated and Na-conditioned) thin films and organic C60 as well as zinc phthalocyanine (ZnPc) layers by transient and modulated surface photovoltage measurements. The stoichiometry and electronic properties of the bare CuInSe2 surface were characterized by photoelectron spectroscopy which revealed a Cu-poor phase with n-type features. After the deposition of the C60 layer, a strong band bending at the CuInSe2 surface was observed. Evidence for dissociation of excitons followed by charge separation was found at the CuInSe2/ZnPc interface. The Cu-poor layer at the CuInSe2 surface was found to be crucial for transient and modulated charge separation at CuInSe2/organic hybrid interfaces.

  2. Effect of the dietary oregano (Origanum vulgare) on Cu and Zn balance in weaned piglets.

    Science.gov (United States)

    Untea, Arabela; Criste, Rodica; Panaite, Tatiana; Costache, Iulian

    2011-01-01

    A 4-week study conducted on 20 weaned piglets (average initial weight 15 kg) evaluated the effects of dietary oregano (Origanum vulgare) used in the presence/absence of phytase on the Cu and Zn balance, while reducing/eliminating their inclusion in the diet as inorganic salts. Oregano was harvested from the wild flora. The Cu and Zn concentrations that were taken into consideration (9.85 ppm and 53.31 pmm, respectively) were the consensus values obtained in an interlaboratory study. The piglets were assigned to 4 groups (C, E1, E2, E3), housed in individual metabolic cages and fed on corn-soybean meal-based diets. The diet of the control group (C) with addition of 1% inorganic mineral premix (MP), contained: 40.92 ppm Cu, 144.96 ppm Zn. The experimental diets differed from the C diet as follows: E1--3% oregano, 0% phytase (5000 PU/g), 0% MP; E2--3% oregano, 0.01% phytase, 0% MP; E3--3% oregano, 0% phytase, 0.5% MP, E4--3% oregano, 0.01% phytase, 0,5% premix. For groups E1, E2, E3 and E4, 0.5% Zn of the MP were included in the diet, because the dietary oregano amount did not meet the requirements (NRC) for piglets. The mineral balance was determined during 3 periods of 5 days each. The levels of Cu and Zn were measured by FAAS in the samples (weekly samples/piglet) of ingesta, faeces and urine. It was noticed that although the dietary Cu ingested by the groups without MP was 75% (10.08 ppm) lower than C, the absorption coefficients were only 47% (28.83) lower than for group C (54.22%), while in the groups with 0.5% MP, the absorption was just 10% (48.86%) lower than for group C. For Zn, where the amount ingested by the experimental groups was 33% (97.62 ppm) lower than for group C, the absorption coefficients were just 20% (46.3%) lower than for group C (57.64%). No significant differences were noticed for Cu and Zn in terms of apparent absorption, between the groups with/without phytase. The deposits of Cu and Zn in the main organs and serum (from slaughtered

  3. Trace amounts of Cu²⁺ ions influence ROS production and cytotoxicity of ZnO quantum dots.

    Science.gov (United States)

    Moussa, Hatem; Merlin, Christophe; Dezanet, Clément; Balan, Lavinia; Medjahdi, Ghouti; Ben-Attia, Mossadok; Schneider, Raphaël

    2016-03-05

    3-Aminopropyltrimethoxysilane (APTMS) was used as ligand to prepare ZnO@APTMS, Cu(2+)-doped ZnO (ZnO:Cu@APTMS) and ZnO quantum dots (QDs) with chemisorbed Cu(2+) ions at their surface (ZnO@APTMS/Cu). The dots have a diameter of ca. 5 nm and their crystalline and phase purities and composition were established by X-ray diffraction, transmission electron microscopy, UV-visible and fluorescence spectroscopies and by X-ray photoelectron spectroscopy. The effect of Cu(2+) location on the ability of the QDs to generate reactive oxygen species (ROS) under light irradiation was investigated. Results obtained demonstrate that all dots are able to produce ROS (OH, O2(-), H2O2 and (1)O2) and that ZnO@APTMS/Cu QDs generate more OH and O2(-) radicals and H2O2 than ZnO@APTMS and ZnO:Cu@APTMS QDs probably via mechanisms associating photo-induced charge carriers and Fenton reactions. In cytotoxicity experiments conducted in the dark or under light exposure, ZnO@APTMS/Cu QDs appeared slightly more deleterious to Escherichia coli cells than the two other QDs, therefore pointing out the importance of the presence of Cu(2+) ions at the periphery of the nanocrystals. On the other hand, with the lack of photo-induced toxicity, it can be inferred that ROS production cannot explain the cytotoxicity associated to the QDs. Our study demonstrates that both the production of ROS from ZnO QDs and their toxicity may be enhanced by chemisorbed Cu(2+) ions, which could be useful for medical or photocatalytic applications.

  4. Antiproliferative effects of ZnO, ZnO-MTCP, and ZnO-CuMTCP nanoparticles with safe intensity UV and X-ray irradiation.

    Science.gov (United States)

    Sadjadpour, Susan; Safarian, Shahrokh; Zargar, Seyed Jalal; Sheibani, Nader

    2016-01-01

    In photodynamic therapy (PDT) of cancer both the light and the photosensitizing agent are normally harmless, but in combination they could result in selective tumor killing. Zinc oxide nanoparticles were synthesized and coated with the amino acid cysteine to provide an adequate arm for conjugation with porphyrin photosensitizers (meso-tetra (4-carboxyphenyl) porphyrin [MTCP] and CuMTCP). Porphyrin-conjugated nanoparticles were characterized by TEM, FTIR, and UV-vis, and fluorescence spectrophotometry. The 3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to measure cell viability in the presence or absence of porphyrin conjugates following UV and X-ray irradiation. The uptake of the porphyrin-conjugated ZnO nanoparticles by cells was detected using fluorescence microscopy. Our results indicated that the survival of T-47D cells was significantly compromised in the presence of ZnO-MTCP-conjugated nanostructures with UV light exposure. Exhibition of cytotoxic activity of ZnO-MTCP for human prostate cancer (Du145) cells occurred at a higher concentration, indicating the more resistant nature of these tumor cells. ZnO-CuMTCP showed milder cytotoxic effects in human breast cancer (T-47D) and no cytotoxic effects in Du145 with UV light exposure, consistent with its lower cytotoxic potency as well as cellular uptake. Surprisingly, none of the ZnO-porphyrin conjugates exhibited cytotoxic effects with X-ray irradiation, whereas ZnO alone exerted cytotoxicity. Thus, ZnO and ZnO-porphyrin nanoparticles with UV or X-ray irradiation may provide a suitable treatment option for various cancers.

  5. Responses of antioxidant defenses to Cu and Zn stress in two aquatic fungi.

    Science.gov (United States)

    Azevedo, Maria-Manuel; Carvalho, Agostinho; Pascoal, Cláudia; Rodrigues, Fernando; Cássio, Fernanda

    2007-05-15

    Aquatic hyphomycetes are fungi that play a key role in plant litter decomposition in streams. Even though these fungi occur in metal-polluted streams, the mechanisms underlying their tolerance to metals are poorly documented. We addressed the effects of Zn and Cu in Varicosporium elodeae and Heliscus submersus by examining metal adsorption to cell walls, plasma membrane integrity and production of reactive oxygen species at metal concentrations inhibiting biomass production in 50% or 80%. The activity of the enzymes catalase, superoxide dismutase and glucose-6-phosphate dehydrogenase was measured to elucidate their role in coping with oxidative stress induced by metals at short- (14 h) and long- (8 days) term exposure. Results show that V. elodeae was more susceptible to the toxic effects induced by Cu and Zn than H. submersus, as indicated by more extensive inhibition of biomass production. Both metals, particularly Cu, induced oxidative stress in the two fungal species, as shown by the noticeable recovery of biomass production in the presence of an antioxidant agent. In both fungi, Cu induced a more severe disruption of plasma membrane integrity than Zn. Our studies on antioxidant defenses showed that catalase had a greater role alleviating stress induced by Zn and Cu than superoxide dismutase. Chronic metal stress also stimulated the production of NADPH, via the pentose phosphate pathway by increasing the activity of glucose-6-phosphate dehydrogenase. Our results suggest that the tolerance of aquatic hyphomycetes to Cu and Zn is associated with the ability of these fungi to initiate an efficient antioxidant defense system.

  6. Morphology, electrical, and optical properties of heavily doped ZnTe:Cu thin films

    Energy Technology Data Exchange (ETDEWEB)

    El Akkad, Fikry [Physics Department, College of Science, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait); Abdulraheem, Yaser [Department of Electrical Engineering, College of Engineering and Petroleum, Kuwait University, Safat 13060 Kuwait (Kuwait)

    2013-11-14

    We report on a study of the physical properties of ZnTe:Cu films with Cu content up to ∼12 at. % prepared using rf magnetron sputtering. The composition and lateral homogeneities are studied using X-ray photoelectron spectroscopy (XPS). Atomic force microscopy measurements on films deposited at different substrate temperatures (up to 325 °C) yielded activation energy of 12 kJ/mole for the grains growth. The results of XPS and electrical and optical measurements provide evidence for the formation of the ternary zinc copper telluride alloy in films containing Cu concentration above ∼4 at. %. The XPS results suggest that copper is incorporated in the alloy with oxidation state Cu{sup 1+} so that the alloy formula can be written Zn{sub 1−y}Cu{sub y} Te with y = 2−x, where x is a parameter measuring the stoichiometry in the Cu site. The formation of this alloy causes appreciable shift in the binding energies of the XPS peaks besides an IR shift in the energy band gap. Detailed analysis of the optical absorption data revealed the presence of two additional transitions, besides the band gap one, originating from the Γ{sub 8} and Γ{sub 7} (spin-orbit) valence bands to a donor level at ∼0.34 eV below the Γ{sub 6} conduction band. This interpretation yields a value for the valence band splitting energy Δ≅ 0.87 eV independent of copper concentration. On the other hand, the mechanism of formation of the alloy is tentatively explained in terms of a point defect reaction in which substitutional Cu defect Cu{sub Zn} is also created. Assuming that substitutional Cu is the dominant acceptor in the Zn rich alloy as in ZnTe, its formation energy was determined to be 1.7 eV close to the theoretical value (1.41 eV) in ZnTe.

  7. Methanol synthesis over binary Cu/ZnO surfaces: exploration of energy surfaces for determining adsorption sites for CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Suarez, Luis; Frenzel, Johannes; Marx, Dominik [Ruhr University Bochum, Theoretical Chemistry, Bochum (Germany); Meyer, Bernd [Interdisziplinaeres Centrum fuer Molekulare Materialien (ICMM), ComputerChemieCentrum (CCC), Department Chemie und Pharmazie, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen (Germany)

    2011-07-01

    Methanol is synthesized from syngas over Cu/ZnO in a heterogeneous catalytic process with CO{sub 2} as carbon source. Atomistic insight into the strong metal substrate interaction (SMSI) effect in Cu/ZnO catalysts has been obtained in a static picture. Calculations of surface phase diagrams by ab initio-thermodynamics determined realistic structures of a small Cu{sub 8} cluster on ZnO(000 anti 1) in a hydrogen atmosphere with temperature and pressure conditions as required in the industrial process. These structures are stabilized by the interplay of structural changes as a result of redox properties of the syngas with realistic saturation of the catalyst surface by hydrogen interacting with defect sites. Herein the global energy landscape of the CO{sub 2} reactant over several thermodynamically relevant catalyst surface structures is explored with spatial resolution employing density functional theory. After having identified all possible adsorption sites on the complex Cu/ZnO surfaces the adsorption modes of the complexes are refined investigating their individual structures.

  8. Toxicity Evaluation of a New Zn-Doped CuO Nanocomposite With Highly Effective Antibacterial Properties.

    Science.gov (United States)

    Mantecca, Paride; Moschini, Elisa; Bonfanti, Patrizia; Fascio, Umberto; Perelshtein, Ilana; Lipovsky, Anat; Chirico, Giuseppe; Bacchetta, Renato; Del Giacco, Luca; Colombo, Anita; Gedanken, Aharon

    2015-07-01

    The increased resistances to conventional antibiotics determine a strong need for new antibacterials, and specific syntheses at the nanoscale promise to be helpful in this field. A novel Zinc-doped Copper oxide nanocomposite (nZn-CuO) has been recently sonochemically synthesized and successfully tested also against multi-drug resistant bacteria. After synthesis and characterization of the physicochemical properties, the new nZn-CuO is here evaluated by the Frog Embyo Teratogenesis Assay-Xenopus test for its toxicological potential and this compared with that of nCuO and nZnO synthesized under the same conditions. No lethal effects are observed, while malformations and growth retardation slightly increase after nZn-CuO exposure. Nevertheless, these effects are smaller than those of nZnO. NP uptake by embryo tissues increase significantly with increasing NP concentrations, while no significant accumulation and adverse effects are seen after exposure to soluble Cu(2+) and Zn(2+) at the concentrations dissolved from the NPs. Key oxidative response genes are upregulated by nZn-CuO, as well as by nCuO and nZnO, suggesting the common mechanism of action. Considering the enhanced biocidal activity shown by the nanocomposite, together with the results presented in this study, we can affirm that the doping of the metal oxide nanoparticles should be considered a useful tool to engineer a safer nano-antibacterial.

  9. Zn incorporation and (CuIn)1-xZn2xSe2 thin film formation during the selenization of evaporated Cu and In precursors on Al:ZnO coated glass substrates

    Science.gov (United States)

    Guillén, C.; Herrero, J.

    2011-11-01

    CuInSe2 thin films with typical 1.0 eV gap energy and tetragonal chalcopyrite structure have been obtained on soda-lime glass substrates by the reaction of sequentially evaporated Cu and In layers with elemental selenium vapor, at 500 °C in flowing Ar. When analogous deposition and reaction processes were performed on Al:ZnO coated glasses, some increment in the band gap energy and diminution in the crystalline interplanar spacings have been detected for the resulting films with an extent that depends on the Cu/In atomic ratio of the evaporated precursor layers. This fact has been related to Zn incorporation into the selenized film, with quaternary (CuIn)1-xZn2xSe2 compound formation that is influenced by the presence of copper selenide phases during the reaction process. Such deductions are supported by the optical, structural and compositional characterizations that have been performed comparatively on samples prepared by selenization of evaporated metallic precursors with two different Cu/In ratios (0.9 and 1.1) on bare and Al:ZnO coated glass substrates.

  10. First-principles study of defect formation in the photovoltaic semiconductor Cu2SnS3 for comparison with Cu2ZnSnS4 and CuInSe2

    Science.gov (United States)

    Nishihara, Hironori; Maeda, Tsuyoshi; Shigemi, Akio; Wada, Takahiro

    2016-04-01

    The formation energies of neutral Cu, Sn, and S vacancies in monoclinic Cu2SnS3 were calculated by first-principles pseudopotential calculations using plane-wave basis functions in typical points in a schematic ternary phase diagram of a Cu-Sn-S system. The formation energy of a Cu atom vacancy in Cu2SnS3 under the Cu-poor condition has been calculated to be 0.23 eV, which is considerably smaller than those of Sn and S vacancies in Cu2SnS3. The results have been compared with those in Cu2SnZnS4 and CuInSe2 calculated with the same version of program code. The formation energy of a Cu atom vacancy in Cu2SnS3 under the Cu-poor condition is smaller than those for Cu2SnZnS4 (0.40 eV) and CuInSe2 (0.50 eV). The results indicate that Cu vacancies are easily formed in Cu2SnS3 under the Cu-poor condition as is the case with Cu2ZnSnS4 and CuInSe2. In this respect, Cu2SnS3 has the appropriate character of a light-absorbing material for thin-film solar cells, as is the case with Cu2ZnSnS4 and CuInSe2.

  11. Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

    Science.gov (United States)

    Huang, Longbin; Li, Xiaofang; Nguyen, Tuan A H

    2015-01-01

    Elevated inorganic phosphate (Pi) concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu)-lead (Pb)-zinc (Zn) mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7), the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5), EHM-TD (fresh Cu-stream, high magnetite content) and local soil (weathered shale and schist), respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed), oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2), ankerite (Ca(Fe Mg)(CO3)2 and siderite (FeCO3), as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,Fe)S, ZnS, (Zn,Cd)S)) may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

  12. A chemosensor showing discriminating fluorescent response for highly selective and nanomolar detection of Cu²⁺ and Zn²⁺ and its application in molecular logic gate.

    Science.gov (United States)

    Fegade, Umesh A; Sahoo, Suban K; Singh, Amanpreet; Singh, Narinder; Attarde, Sanjay B; Kuwar, Anil S

    2015-05-04

    A fluorescent based receptor (4Z)-4-(4-diethylamino)-2-hydroxybenzylidene amino)-1,2dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (receptor 3) was developed for the highly selective and sensitive detection of Cu(2+) and Zn(2+) in semi-aqueous system. The fluorescence of receptor 3 was enhanced and quenched, respectively, with the addition of Zn(2+) and Cu(2+) ions over other surveyed cations. The receptor formed host-guest complexes in 1:1 stoichiometry with the detection limit of 5 nM and 15 nM for Cu(2+) and Zn(2+) ions, respectively. Further, we have effectively utilized the two metal ions (Cu(2+) and Zn(2+)) as chemical inputs for the manufacture of INHIBIT type logic gate at molecular level using the fluorescence responses of receptor 3 at 450 nm. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Fusion and characterization of an alloy Cu-Zn-Al-Ni of nuclear interest; Fusion y caracterizacion de una aleacion Cu-Zn-Al-Ni de interes nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Santana M, J.S

    2003-07-01

    The present work is the result of the study of a non ferrous quatenary alloy of Cu-Zn-Al-Ni (Foundry 3), it was chosen of a series of alloys to obtain so much information of its microstructural properties like mechanical, evaluating them and comparing them with the previously obtained ternary alloys of Cu-AI-Ni (Foundry 1) and Cu-Zn-AI (Foundry 2) identified as alloys of memory effect and superalloys. These were carried out starting from the foundry of their pure elements of Cu, Zn, Al, Ni. When physically having the ingot of each alloy, different techniques were used for their characterization. The used techniques were through the metallographic analysis, by scanning electron microscopy (SEM), X-ray dispersive energy spectroscopy (EDS), X-ray diffraction (XRD), mechanical essays and Rockwell hardness. The non ferrous quaternary alloy Cu-Zn-AI-Ni by means of the metallographic analysis didn't show significant differences in their three sections (superficial, longitudinal and transverse) since result an homogeneous alloy at the same that the both ternaries. The grain size of the quaternary alloy is the finest while the ternary alloy of Cu-AI-Ni is the one that obtained the biggest grain size. Through MEB together with the analysis by EDS and the mapping of the elements that constitute each alloy, show that the three foundries were alloyed, moreover the presence of aggregates was also observed in the Foundries 2 and 3. These results by means of the analysis of XRD corroborate that these alloys have more of two elements. Relating the microstructural properties with those mechanical show us that as minor was the grain size, better they were his mechanical properties, in this case that of the quaternary alloy. With regard to the test of Rockwell hardness the Foundry 1 were the softest with the temper treatment, while that the Foundries 2 and 3 were the hardest with this same treatment, being still harder the Foundry 2 but with very little difference, for what great