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Sample records for cupric oxide cuo

  1. Cupric Oxide (CuO) Oxidation Detects Pyrogenic Carbon in Burnt Organic Matter and Soils.

    Science.gov (United States)

    Hatten, Jeff; Goñi, Miguel

    2016-01-01

    Wildfire greatly impacts the composition and quantity of organic carbon stocks within watersheds. Most methods used to measure the contributions of fire altered organic carbon-i.e. pyrogenic organic carbon (Py-OC) in natural samples are designed to quantify specific fractions such as black carbon or polyaromatic hydrocarbons. In contrast, the CuO oxidation procedure yields a variety of products derived from a variety of precursors, including both unaltered and thermally altered sources. Here, we test whether or not the benzene carboxylic acid and hydroxy benzoic acid (BCA) products obtained by CuO oxidation provide a robust indicator of Py-OC and compare them to non-Py-OC biomarkers of lignin. O and A horizons from microcosms were burned in the laboratory at varying levels of fire severity and subsequently incubated for 6 months. All soils were analyzed for total OC and N and were analyzed by CuO oxidation. All BCAs appeared to be preserved or created to some degree during burning while lignin phenols appeared to be altered or destroyed to varying extents dependent on fire severity. We found two specific CuO oxidation products, o-hydroxybenzoic acid (oBd) and 1,2,4-benzenetricarboxylic acid (BTC2) that responded strongly to burn severity and withstood degradation during post-burning microbial incubations. Interestingly, we found that benzene di- and tricarboxylic acids (BDC and BTC, respectively) were much more reactive than vanillyl phenols during the incubation as a possible result of physical protection of vanillyl phenols in the interior of char particles or CuO oxidation derived BCAs originating from biologically available classes of Py-OC. We found that the ability of these compounds to predict relative Py-OC content in burned samples improved when normalized by their respective BCA class (i.e. benzene monocarboxylic acids (BA) and BTC, respectively) and when BTC was normalized to total lignin yields (BTC:Lig). The major trends in BCAs imparted by burning

  2. Magnetic disorder in cupric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, S.J.; Borzi, R.A.; Mercader, R.C. [Universidad Nacional de La Plata, C.C. 67, Departamento de Fisica, Facultad de Ciencias Exactas (Argentina)

    1999-11-15

    Investigations of the abnormal magnetic properties of cupric oxide reveal discrepancies between both experimental results and theoretical explanations. Through iron-doping cupric oxide by ball-milling and thermal treatments we have been able to obtain Moessbauer results that are an experimental evidence of semi-disorder. The magnetic hyperfine field of the Cu{sub 0.995}Fe{sub 0.005}O solid solution displays a spin-glass-like thermal dependence that undergoes two transitions, one at about 150 K, that can be assigned to the long-range ordering of the cupric oxide spins, and the second one at some temperature between 4.2 and 15 K, that exposes either the freezing of the Fe{sup 3+} spins into a local canted state or of magnetic clusters in the CuO matrix.

  3. Long-term effects of cupric oxide nanoparticles (CuO NPs) on the performance, microbial community and enzymatic activity of activated sludge in a sequencing batch reactor.

    Science.gov (United States)

    Wang, Sen; Li, Zhiwei; Gao, Mengchun; She, Zonglian; Ma, Bingrui; Guo, Liang; Zheng, Dong; Zhao, Yangguo; Jin, Chunji; Wang, Xuejiao; Gao, Feng

    2017-02-01

    The long-term effects of cupric oxide nanoparticles (CuO NPs) on the performance, microbial activity and microbial community of activated sludge were investigated in a sequencing batch reactor (SBR). The SBR performance had no evident change at 0-10 mg/L CuO NPs, whereas the CuO NPs concentration at 30-60 mg/L affected the COD, NH4(+)-N and soluble orthophosphate (SOP) removal, nitrogen and phosphorus removal rate and microbial enzymatic activity of activated sludge. Some CuO NPs might be absorbed on the surface of activated sludge or penetrate the microbial cytomembrane into the microbial cell interior of activated sludge. Compared to 0 mg/L CuO NPs, the reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) release increased by 43.6% and 56.4% at 60 mg/L CuO NPs, respectively. The variations of ROS production and LDH release demonstrated that CuO NPs could induce the toxicity towards the microorganisms and destroy the integrity of microbial cytomembrane in the activated sludge. High throughput sequencing of 16S rDNA indicated that CuO NPs could evidently impact on the microbial richness, diversity and composition of activated sludge in the SBR.

  4. Stimulated low frequency Raman scattering in cupric oxide nanoparticles water suspension

    Science.gov (United States)

    Averyushkin, A. S.; Baranov, A. N.; Bulychev, N. A.; Kazaryan, M. A.; Kudryavtseva, A. D.; Strokov, M. A.; Tcherniega, N. V.; Zemskov, K. I.

    2017-04-01

    Cupric oxide nanoparticles with average size of 213.2 nm, were synthesized in acoustoplasma discharge for investigating their vibrational properties. The low-frequency acoustic mode in cupric oxide (CuO) nanoparticles has been studied by stimulated low-frequency Raman scattering (SLFRS). SLFRS conversion efficiency, threshold and frequency shift of the scattered light are measured.

  5. Cupric and cuprous oxide by reactive ion beam sputter deposition and the photosensing properties of cupric oxide metal–semiconductor–metal Schottky photodiodes

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    Hong, Min-Jyun; Lin, Yong-Chen; Chao, Liang-Chiun, E-mail: lcchao@mail.ntust.edu.tw; Lin, Pao-Hung; Huang, Bohr-Ran

    2015-08-15

    Highlights: • CuO and Cu{sub 2}O were deposited by reactive ion beam sputter deposition. • Single phase CuO thin film is obtained with Ar:O{sub 2} = 2:1. • CuO MSM PD shows photoresponse from 400 nm to 1.30 μm. • CuO MSM PD is RC limited with a decay time less than 1 μs. - Abstract: Cupric (CuO) and cuprous (Cu{sub 2}O) oxide thin films have been deposited by reactive ion beam sputter deposition at 400 °C with an Ar:O{sub 2} ratio from 2:1 to 12:1. With an Ar:O{sub 2} ratio of 2:1, single phase polycrystalline CuO thin films were obtained. Decreasing oxygen flow rate results in CuO + Cu{sub 2}O and Cu{sub 2}O + Cu mixed thin films. As Ar:O{sub 2} ratio reaches 12:1, Cu{sub 2}O nanorods with diameter of 250 nm and length longer than 1 μm were found across the sample. Single phase CuO thin film exhibits an indirect band gap of 1.3 eV with a smooth surface morphology. CuO metal–semiconductor–metal (MSM) Schottky photodiodes (PD) were fabricated by depositing Cu interdigitated electrodes on CuO thin films. Photosensing properties of the CuO PD were characterized from 350 to 1300 nm and a maximum responsivity of 43 mA/W was found at λ = 700 nm. The MSM PD is RC limited with a decay time constant less than 1 μs.

  6. Photoelectrochemical water splitting for hydrogen production with metal oxide (hematite and cupric oxide) based photocatalysts

    Science.gov (United States)

    Tang, Houwen

    Solar hydrogen is one ideal energy source to replace fossil fuel, as it is sustainable and environmentally friendly. Solar hydrogen can be generated in a number of ways. Photoelectrochemical (PEC) water splitting is one of the most promising methods for solar-to-chemical energy conversion. In this research project, metal oxide-based photocatalysts, especially hematite (α-Fe 2O3) and cupric oxide (CuO), were investigated for use as electrodes in PEC water splitting for solar hydrogen production. In our research project of hematite-based electrodes, we started with the incorporation of transition metal, particularly titanium (Ti), in hematite thin films to modify the valence and conduction band edges of hematite. We found that Ti impurities improve the electron conductivity of hematite and consequently lead to significantly enhanced photocurrents. We further investigated the Ti and Mg co-alloyed hematite. In this case, Ti is the donor and Mg is the acceptor in hematite. The co-alloying approach enhanced the solubility of Mg and Ti, which led to reduced electron effective mass and therefore increased electron mobility. Also, co-alloying tunes the carrier density and therefore allows the optimization of electrical conductivity. The densities of charged defects were found to be reduced, and therefore carrier recombinations were reduced. As a result, the Ti and Mg co-alloyed hematite thin films exhibited much improved performance in PEC water splitting as compared to pure hematite thin films. For the study of cupric oxide-based electrodes, we first investigated the possibility of reducing the electrode corrosion of cupric oxide in aqueous solutions by incorporating Ti as an electrode corrosion inhibitor. We found that Ti alloying can enhance the stability of cupric oxide in base solutions at the cost of reducing its crystallinity and optical absorption, and consequently lowering its photon-to-electron conversion efficiency. In order to balance the stability and the

  7. In-vacuum scattered light reduction with cupric oxide surfaces for sensitive fluorescence detection

    CERN Document Server

    Norrgard, Eric B; Barry, John F; McCarron, Daniel J; Steinecker, Matthew H; DeMille, David

    2016-01-01

    We demonstrate a simple and easy method for producing low-reflectivity surfaces that are ultra-high vacuum compatible, may be baked to high temperatures, and are easily applied even on complex surface geometries. Black cupric oxide (CuO) surfaces are chemically grown in minutes on any copper surface, allowing for low-cost, rapid prototyping and production. The reflective properties are measured to be comparable to commercially available products for creating optically black surfaces. We describe a vacuum apparatus which uses multiple blackened copper surfaces for sensitive, low-background detection of molecules using laser-induced fluorescence.

  8. High-temperature electromagnons in the magnetically induced multiferroic cupric oxide driven by intersublattice exchange.

    Science.gov (United States)

    Jones, S P P; Gaw, S M; Doig, K I; Prabhakaran, D; Hétroy Wheeler, E M; Boothroyd, A T; Lloyd-Hughes, J

    2014-04-29

    Magnetically induced ferroelectric multiferroics present an exciting new paradigm in the design of multifunctional materials, by intimately coupling magnetic and polar order. Magnetoelectricity creates a novel quasiparticle excitation--the electromagnon--at terahertz frequencies, with spectral signatures that unveil important spin interactions. To date, electromagnons have been discovered at low temperature (domain spectroscopy that intersublattice exchange in the improper multiferroic cupric oxide (CuO) creates electromagnons at substantially elevated temperatures (213-230 K). Dynamic magnetoelectric coupling can therefore be achieved in materials, such as CuO, that exhibit minimal static cross-coupling. The electromagnon strength and energy track the static polarization, highlighting the importance of the underlying cycloidal spin structure. Polarized neutron scattering and terahertz spectroscopy identify a magnon in the antiferromagnetic ground state, with a temperature dependence that suggests a significant role for biquadratic exchange.

  9. One-Step Synthesis of Copper and Cupric Oxide Particles from the Liquid Phase by X-Ray Radiolysis Using Synchrotron Radiation

    Directory of Open Access Journals (Sweden)

    Akinobu Yamaguchi

    2016-01-01

    Full Text Available The deposition of copper (Cu and cupric oxide (Cu4O3, Cu2O, and CuO particles in an aqueous copper sulfate (CuSO4 solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin.

  10. Effect of Deposition Time on the Photoelectrochemical Properties of Cupric Oxide Thin Films Synthesized via Electrodeposition Method

    Directory of Open Access Journals (Sweden)

    Yaw Chong Siang

    2016-01-01

    Full Text Available The main aim of this study was to investigate the effect of deposition time on the physicochemical and photoelectrochemical properties of cupric oxide (CuO thin films synthesized via electrodeposition method. Firstly, the electrodeposition of amorphous CuO films on fluorine-doped tin oxide (FTO working electrodes with varying deposition time between 5 and 30 min was carried out, followed by annealing treatment at 500 °C. Resultant nanocrystalline CuO thin films were characterised using field emission-scanning electron microscopy (FE-SEM, photocurrent density, and photoluminescence measurements. Through FE-SEM analysis, it was observed that the surface of thin films was composed of irregular-sized CuO nanocrystals. A smaller CuO nanocrystals size will lead to a higher photoactivity due to the increase in overall catalytic surface area. In addition, the smaller CuO nanocrystals size will prolongs the electron-hole recombination rate due to the increase in copious amount of surface defects. From this study, it was revealed that the relationship between deposition time and CuO film thickness was non-linear. This could be due to the detachment of CuO thin films from the FTO surface at an increasing amount of CuO mass being deposited. It was observed that the amount of light absorbed by CuO thin films increased with film thickness until a certain extent whereby, any further increase in the film thickness will result in a reduction of light photon penetration. Therefore, the CuO nanocrystals size and film thickness have to be compromised in order to yield a higher catalytic surface area and a lower rate of surface charge recombination. Finally, it was found that the deposition time of 15 min resulted in an average CuO nanocrystals size of 73.7 nm, optimum film thickness of 0.73 μm, and corresponding photocurrent density of 0.23 mA/cm2 at the potential bias of - 0.3 V (versus Ag/AgCl. The PL spectra for the deposition time of 15 min has the lowest

  11. Peroxidase-like activity of water-soluble cupric oxide nanoparticles and its analytical application for detection of hydrogen peroxide and glucose.

    Science.gov (United States)

    Chen, Wei; Chen, Juan; Feng, Ye-Bin; Hong, Lei; Chen, Qi-Ying; Wu, Ling-Feng; Lin, Xin-Hua; Xia, Xing-Hua

    2012-04-07

    Water-soluble cupric oxide nanoparticles are fabricated via a quick-precipitation method and used as peroxidase mimetics for ultrasensitive detection of hydrogen peroxide and glucose. The water-soluble CuO nanoparticles show much higher catalytic activity than that of commercial CuO nanoparticles due to their higher affinity to hydrogen peroxide. In addition, the as-prepared CuO nanoparticles are stable over a wide range of pH and temperature. This excellent stability in the form of aqueous colloidal suspensions makes the application of the water-soluble CuO nanoparticles easier in aqueous systems. A colorimetric assay for hydrogen peroxide and glucose has been established based on the catalytic oxidation of phenol coupled with 4-amino-atipyrine by the action of hydrogen peroxide. This analytical platform not only confirms the intrinsic peroxidase-like activity of the water-soluble cupric oxide nanoparticles, but also shows its great potential applications in environmental chemistry, biotechnology and medicine.

  12. Structural, morphological, electrical, and optical properties of silver thin films of varying thickness deposited on cupric oxide

    Science.gov (United States)

    Hajakbari, Fatemeh; Shafieinejad, Farzaneh

    2016-03-01

    In this investigation, silver (Ag) films of varying thickness (25-100 nm) were grown on cupric oxide (CuO) on silicon and quartz. The CuO preparation was carried out by the thermal oxidation annealing of copper (Cu) thin films deposited by DC magnetron sputtering. The physical properties of the prepared films were studied by different techniques. Rutherford backscattering spectroscopy (RBS) analysis indicated that the Ag film thickness was about 25-100 nm. X-ray diffraction (XRD) results showed that by increasing Ag thickness, the film crystallinity was improved. Also, atomic force microscopy (AFM) and scanning electron microscopy (SEM) results demonstrated that the surface morphology and the grain size were affected by the Ag film thickness. Furthermore, the electrical resistivity of films determined by four-point probe measurements versus the Ag film thickness was discussed. A reduction in the optical band gap energy of CuO is observed from 1.51 to 1.42 eV with an increase in Ag film thickness to 40 nm in Ag/CuO films.

  13. Orbital driven impurity spin effect on the magnetic order of quasi-3D cupric oxide

    Science.gov (United States)

    Ganga, B. G.; Santhosh, P. N.; Nanda, B. R. K.

    2017-04-01

    Density functional calculations are performed to study the magnetic order of the severely distorted square planar cupric oxide (CuO) and local spin disorder in it in the presence of the transition metal impurities M (=Cr, Mn, Fe, Co and Ni). The distortion in the crystal structure, arisen to reduce the band energy by minimizing the covalent interaction, creates two crisscrossing zigzag spin-1/2 chains. From the spin dimer analysis we find that while the spin chain along ≤ft[1 0 \\bar{1}\\right] has strong Heisenberg type antiferromagnetic coupling (J ~ 127 meV), along ≤ft[1 0 1\\right] it exhibits weak, but robust, ferromagnetic coupling (J ~ 9 meV) mediated by reminiscent p-d covalent interactions. The impurity effect on the magnetic ordering is independent of M and purely orbital driven. If the given spin-state of M is such that the {{d}{{x2}-{{y}2}}} orbital is spin-polarized, then the original long-range ordering is maintained. However, if {{d}{{x2}-{{y}2}}} orbital is unoccupied, the absence of corresponding covalent interaction breaks the weak ferromagnetic coupling and a spin-flip takes place at the impurity site leading to breakdown of the long range magnetic ordering.

  14. Oxide Nanotube Analogues: CuO Nanobarrels

    Energy Technology Data Exchange (ETDEWEB)

    H. H. Farrell; R. D. Parra

    2011-11-01

    The principle 'form follows function' which dominated much of twentieth century architechture and industrial design has its parallel on the nanolevel in the concept of 'function follows form'. This has been realized in many technologically valuable ways on this level via nanoparticles such as nanotubes and quantum dots, for example. Now, a new material, copper oxide (CuO) nanobarrels, offers still another opportunity to exploit unusual form to obtain new functionality. Recently, CuO 'rings' on the order of 100 nm diameter have been observed experimentally by El-Azab and Liang (2003). In a separate effort, we have used first principles density functional calculations to investigate smaller, single walled CuO structures that appear to be nanotubes or nanobarrels with a square unit mesh rather than the hexagonal mesh of carbon nanotubes. These structures are unique and novel, and almost certainly will yield fascinating results when studied experimentally.

  15. Tailoring oxides of copper-Cu{sub 2}O and CuO nanoparticles and evaluation of organic dyes degradation

    Energy Technology Data Exchange (ETDEWEB)

    Raghav, Ragini; Aggarwal, Priyanka; Srivastava, Sudha, E-mail: sudha.srivastava@jiit.ac.in [Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307,Uttar Pradesh (India)

    2016-04-13

    We report a simple one-pot colloidal synthesis strategy tailoring cuprous or cupric nano-oxides in pure state. NaOH provided alkaline conditions (pH 12.5 -13) for nano-oxides formation, while its concentration regulated the oxidation state of the nano-oxides. The morphological, structural and optical properties of synthesized Cu{sub 2}O and CuO nanoparticles were studied by transmission electron microscopy (TEM), X-Ray diffraction (XRD) and UV-vis spectroscopy. Dye degradation capability of CuO and Cu2O nanoparticles was evaluated using four organic dyes - Malachite green, Methylene blue, Methyl orange and Methyl red. The results demonstrate effective degradation of all four dyes employing with almost comparable activity both Cu{sub 2}O and CuO nanoparticles.

  16. Tailoring oxides of copper-Cu2O and CuO nanoparticles and evaluation of organic dyes degradation

    Science.gov (United States)

    Raghav, Ragini; Aggarwal, Priyanka; Srivastava, Sudha

    2016-04-01

    We report a simple one-pot colloidal synthesis strategy tailoring cuprous or cupric nano-oxides in pure state. NaOH provided alkaline conditions (pH 12.5 -13) for nano-oxides formation, while its concentration regulated the oxidation state of the nano-oxides. The morphological, structural and optical properties of synthesized Cu2O and CuO nanoparticles were studied by transmission electron microscopy (TEM), X-Ray diffraction (XRD) and UV-vis spectroscopy. Dye degradation capability of CuO and Cu2O nanoparticles was evaluated using four organic dyes - Malachite green, Methylene blue, Methyl orange and Methyl red. The results demonstrate effective degradation of all four dyes employing with almost comparable activity both Cu2O and CuO nanoparticles.

  17. The Synthesis of Highly Aligned Cupric Oxide Nanowires by Heating Copper Foil

    Directory of Open Access Journals (Sweden)

    Jianbo Liang

    2011-01-01

    Full Text Available We have investigated the effects of grain size and orientation of copper substrates for the growth of cupric oxide nanowires by thermal oxidation method. Long, less-roughness, high-density, and aligned cupric oxide nanowires have been synthesized by heating (200 oriented copper foils with small grain size in air gas. Long and aligned nanowires of diameter around 80 nm can only be formed within a short temperature range from 400 to 700°C. On the other hand, uniform, smooth-surface, and aligned nanowires were not formed in the case of larger crystallite size of copper foils with (111 and (200 orientation. Smaller grain size of copper foil with (200 orientation is favorable for the growth of highly aligned, smooth surface, and larger-diameter nanowires by thermal oxidation method.

  18. The copper recovery from cupric oxide catalysts by plasma reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Imris, I.; Klenovcanova, A. [Technical Univ. of Kosice, Kosice (Slovakia). Dept. of Power Engineering

    2007-07-01

    A plasma reduction process was used to recover copper from cupric oxide catalysts. Two types of plasma reduction smelting tests were conducted to verify the thermodynamic calculations. The plasma reactor consisted of a cylindrical steel shell lined with a castable alumina and a graphite crucible. Cupric oxide catalyst ESM 461 was mixed with stoichiometric amounts of carbon reductant and a 10 per cent addition of calcium oxide flux. Results of the experimental tests and the thermodynamic analysis showed that the copper can be extracted from cupric oxide using the plasma reduction process. Copper recovery was limited by physico-chemical copper losses. Copper oxide solubility was relatively high, so that copper recovery was low in their first series of plasma tests. The addition of calcium oxide flux improved copper recovery rates when dicalcium silicate was formed in the slag. The offgas samples indicated that concentrations of carbon monoxide (CO) in the gas phase was very high. It was concluded that the process is both commercially feasible and does not produce liquid or solid wastes. 7 refs., 2 tabs., 4 figs.

  19. Thermodynamics of interface formation between Hexa-Peri Hexabenzocoronene and Cupric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Manwani, Krishna; Panda, Emila, E-mail: emila@iitgn.ac.in

    2015-02-27

    A thermodynamic formalism has been developed to predict the formation of an ultra-thin interfacial layer at a solid–solid interface. To derive the thermodynamic expressions at crystalline–crystalline as well as crystalline–amorphous interfaces, as used in this study, Miedema's semi-empirical approach is used. This formalism is then applied to understand the interfacial layer formation between the organic Hexa-Peri Hexabenzocoronene and inorganic Cupric oxide layers at room temperature. It is found that, graphene interfacial layer formation is thermodynamically favorable. This prediction is in agreement with the experimental observations from literature. - Highlights: • Formalism was developed to predict ultra-thin interfacial layer between solids. • This is unique to similar and dissimilar systems with scarce thermodynamic data. • Applicability was tested to Hexa-Peri Hexabenzocoronene–Cupric oxide interface. • Model predicted graphene interfacial layer is concurrent with experimental results.

  20. High gradient magnetic filtration of cupric oxide and fly ash particles

    Energy Technology Data Exchange (ETDEWEB)

    Lua, A.C. [Nanyang Technological University (Singapore). School of Mechanical and Production Engineering

    1996-12-31

    High gradient magnetic filtration (HGMF) tests have been carried out on cupric oxide particles and power plant fly ash which were dispersed in air streams. An experimental test rig was set up to conduct these tests. Results showed that for cupric oxide particles, filtration efficiencies of up to 95% were obtained for submicron sizes with dust loadings of up to 0.36 time the matrix volume. For fly ash, filtration efficiencies of up to 65% were obtained for submicron particles. However, all particle sizes showed progressive deterioration in efficiencies with loading. At the end of the test, the matrix had collected 0.52 times its own mass of fly ash. 2 refs., 7 figs.

  1. Substrate effects on SILAR route synthesized CuO thin films

    Science.gov (United States)

    Dhanasekaran, V.; Mahalingam, T.; Ravi, G.; Rhee, Jin-Koo

    2012-06-01

    Cupric oxide (CuO) thin films are deposited using SILAR method onto various substrates. The X-ray diffraction patterns revealed that the deposited films are polycrystalline in nature with monoclinic structure. The microstructural parameters of chemical bath deposited CuO thin films are calculated using the structural studies. The optical band gap value is determined using transmission spectrum of CuO thin films and the results are discussed.

  2. Thermal stimulated current response in cupric oxide single crystal thin films over a wide temperature range

    Science.gov (United States)

    Yang, Kungan; Wu, Shuxiang; Yu, Fengmei; Zhou, Wenqi; Wang, Yunjia; Meng, Meng; Wang, Gaili; Zhang, Yueli; Li, Shuwei

    2017-01-01

    Cupric oxide single crystal thin films (~26 nm) were grown by plasma-assisted molecular beam epitaxy. X-ray diffraction, Raman spectra and in situ reflection high-energy electron diffraction show that the thin films are 2  ×  2 reconstructed with an in-plane compression and out-of-plane stretching. A thermal stimulated current measurement indicates that the electric polarization response is shown in the special 2D cupric oxide single crystal thin film over a wide temperature range from 130 K to near-room temperature. We infer that the abnormal electric response involves the changing of phase transition temperature induced by structure distortion, the spin frustration and the magnetic fluctuation effect of a short-range magnetic order, or the combined action of both of the two factors mentioned above. This work suggests a promising clue for finding new room temperature single phase multiferroics or tuning phase transition temperatures.

  3. Effectiveness of orally administered cupric oxide needles in alleviating hypocupraemia in sheep and cattle.

    Science.gov (United States)

    Suttle, N F

    1981-05-09

    The oral administration of a small dose of cupric oxide "needles" (CuOn), providing 0.5 g copper, to hypocupraemic ewes maintained on a copper-deficient diet alleviated hypocupraemia for 111 days when the diet was supplemented with molybdenum and sulphate and for 301 days when the diet was not supplemented. The same amount of copper given as cupric sulphate was approximately half as effective. The administration of a large dose of CuOn, providing 40 g copper, to hypocupraemic steers and heifers alleviated hypocupraemia for not less than 41 days, at which time a substantial reserve of copper (428 mg) remained in the liver. The absorbability of copper in CuOn was estimated to be 8.3 per cent and 3.8 per cent (depending on diet) for sheep. It was calculated that enough absorbable copper could be provided in a single dose to meet the net copper requirements of ewes for several years. This new form of copper therapy demands a totally different approach from that associated with parenteral copper usage.

  4. CATALYTIC HYDROGENATION AND OXIDATION OF BIOMASS-DERIVED LEVULINIC ACID

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    Yan Gong

    2011-02-01

    Full Text Available Levulinic acid (LA, 4-oxo-pentanoic acid, is a new platform chemical with various potential uses. In this paper, catalytic hydrogenation and oxidation of levulinic acid were studied. It was shown from experiments that levulinic acid can be hydrogenated to γ-valerolactone (GVL over transition metal catalysts and oxidative-decarboxylated to 2-butanone (methyl-ethyl-ketone, MEK and methyl-vinyl-ketone (MVK by cupric oxide (CuO, cupric oxide/cerium oxide (CuO/CeO2, cupric oxide/ alumina (CuO/ Al2O3, and silver(I/ peroxydisulfate (Ag(I/S2O82-.

  5. Ultra-high performance supercritical fluid chromatography of lignin-derived phenols from alkaline cupric oxide oxidation.

    Science.gov (United States)

    Sun, Mingzhe; Lidén, Gunnar; Sandahl, Margareta; Turner, Charlotta

    2016-08-01

    Traditional chromatographic methods for the analysis of lignin-derived phenolic compounds in environmental samples are generally time consuming. In this work, an ultra-high performance supercritical fluid chromatography method with a diode array detector for the analysis of major lignin-derived phenolic compounds produced by alkaline cupric oxide oxidation was developed. In an analysis of a collection of 11 representative monomeric lignin phenolic compounds, all compounds were clearly separated within 6 min with excellent peak shapes, with a limit of detection of 0.5-2.5 μM, a limit of quantification of 2.5-5.0 μM, and a dynamic range of 5.0-2.0 mM (R(2) > 0.997). The new ultra-high performance supercritical fluid chromatography method was also applied for the qualitative and quantitative analysis of lignin-derived phenolic compounds obtained upon alkaline cupric oxide oxidation of a commercial humic acid. Ten out of the previous eleven model compounds could be quantified in the oxidized humic acid sample. The high separation power and short analysis time obtained demonstrate for the first time that supercritical fluid chromatography is a fast and reliable technique for the analysis of lignin-derived phenols in complex environmental samples.

  6. Contrasting effects of sulfur dioxide on cupric oxide and chloride during thermochemical formation of chlorinated aromatics.

    Science.gov (United States)

    Fujimori, Takashi; Nishimoto, Yoshihiro; Shiota, Kenji; Takaoka, Masaki

    2014-12-01

    Sulfur dioxide (SO2) gas has been reported to be an inhibitor of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation in fly ash. However, other research has suggested little or no inhibitory effect of SO2 gas. Although these studies focused on reactions between SO2 gas and gas-phase chlorine (Cl) species, no attention was paid to thermochemical gas-solid reactions. In this study, we found contrasting effects of SO2 gas depending on the chemical form of copper (CuO vs CuCl2) with a solid-phase inorganic Cl source (KCl). Chlorinated aromatics (PCDD/Fs, polychlorinated biphenyls, and chlorobenzenes) increased and decreased in model fly ash containing CuO + KCl and CuCl2 + KCl, respectively, with increased SO2 injection. According to in situ Cu K-edge and S K-edge X-ray absorption spectroscopy, Cl gas and CuCl2 were generated and then promoted the formation of highly chlorinated aromatics after thermochemical reactions of SO2 gas with the solid-phase CuO + KCl system. In contrast, the decrease in aromatic-Cls in a CuCl2 + KCl system with SO2 gas was caused mainly by the partial sulfation of the Cu. The chemical form of Cu (especially the oxide/chloride ratio) may be a critical factor in controlling the formation of chlorinated aromatics using SO2 gas.

  7. Determination of lignin in marine sediment using alkaline cupric oxide oxidation-solid phase extraction-on-column derivatization-gas chromatography

    Science.gov (United States)

    Zhang, Ting; Li, Xianguo; Sun, Shuwen; Lan, Haiqing; Du, Peirui; Wang, Min

    2013-03-01

    Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide (CuO) oxidation method, the modification consisting in a solid phase extraction (SPE) and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations (RSDs) ranging from 0.57% to 8.04% ( n=3), while those with traditional liquid-liquid extraction (LLE) are from 44.52% to 86.16% with RSDs being from 0.53% to 13.14% ( n=3). Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8% ± 0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents. Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxyben-zaldehyde. The lignin content Σ8 (produced from 10 g dry sediment) in the research area is between 0.231 and 0.587 mg. S/V and C/V ratios (1.028 ± 0.433 and 0.192 ± 0.066, respectively) indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values of (Ad/Al)v suggest that the TOMs has been highly degraded.

  8. Nanostructured cupric oxide electrode: An alternative to amperometric detection of carbohydrates in anion-exchange chromatography.

    Science.gov (United States)

    Barragan, José T C; Kubota, Lauro T

    2016-02-01

    In this paper, a new and low cost copper/cupric oxide nanostructured electrode is presented as an alternative to the amperometric detection of carbohydrates in high-performance anion exchange chromatography. The modified copper electrodes were prepared by a simple and fast method which resulted in the obtainment of homogeneously distributed nanostructures adhered to the surface with controlled chemical nature. The results, when compared to conventional copper electrodes, exhibited considerable improvements in analytical results, including: 1) Better repeatability in consecutive glucose detections, in which the percent relative standard deviation improved from 15.1% to 0.279%. 2) Significant improvements in the stability of the baseline and a decrease of the stabilization time, going from several hours to approximately 15 min. 3) Considerable increase in the sensitivity towards glucose, from 5.02 nA min mg L(-1) to 25.5 nA min mg L(-1). 4) Improvements in the detectability with limits as low as 1.09 pmol. 5) Wide working range of concentrations (1 × 10(-2) to 1 × 10(4) mg L(-1)). 6) Good linearity with correlation coefficients greater than 0.998. 7) Possibility of detecting different molecules of carbohydrates (lactose, maltose, sucrose cellobiose, sorbitol, fructose, glucose, galactose, manose, arabitol, xylose, ribose and arabnose). In comparison to the electrode that is more employed for this type of application (gold electrode), the low cost, the possibility of detection at constant potential and the equivalent detection limits presented by the new electrode material introduced in this work emerge as characteristics that make this material a powerful alternative considering the detection of carbohydrates in anion exchange chromatography.

  9. Large-scale and green synthesis of octahedral flower-like cupric oxide nanocrystals with enhanced photochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shi-Kuo; Pan, Yu-Yi; Wu, Mi; Huang, Fang-Zhi; Li, Chuan-Hao, E-mail: lichuanhao1983@163.com; Shen, Yu-Hua, E-mail: s_yuhua@163.com

    2014-10-01

    Graphical abstract: - Highlights: • A green method is reported for large-scale synthesis of CuO nanocrystals via a coordination-deposition technique. • Flower-like nanostructure can be rationally tailored by adjusting reaction parameters. • Flower-like nanostructure can be obtained in a wide reaction solution volume range. • Uniform flower-like nanocrystal film assembled by oil–water interfacial self-assembly method exhibits excellent PEC performance. - Abstract: In this work, a large-scale and green method is reported for the facile synthesis of octahedral flower-like CuO nanocrystals via a coordination-deposition route by using Fehling regents. Not any harmful organic chemicals were used during the reaction period. The obtained hierarchical nanostructure can be rationally tailored by varying the concentration of tartrate ions and reaction time. The typical flower-like CuO nanocrystals in the range of 200–250 nm are consisted of numerous small crystalline whiskers, which present a porous surface with a specific surface area of 32.12 m{sup 2}/g and a narrow band gap of 1.5 eV. Importantly, the flower-like CuO nanocrystals show an enhanced photocatalytic activity toward decomposing Rhodamine B (RhB) molecules. The degradation rate is about 87.9% in 40 min under visible light irradiation, which is about 2.5 times for the commercial CuO powers (35.2%). Moreover, the uniform flower-like monolayered CuO film exhibits an excellent photoelectrochemical (PEC) performance with a maximum photocurrent density of 58.8 μA/cm{sup 2}, which is nearly five times higher than the commercial CuO film. This novel synthesis approach provides a large-scale and green protocol for synthesizing hierarchical metal oxide nanocrystals that are useful for photocatalysis, PEC water splitting and photovoltaic device.

  10. Thermal conductivity enhancement in thermal grease containing different CuO structures.

    Science.gov (United States)

    Yu, Wei; Zhao, Junchang; Wang, Mingzhu; Hu, Yiheng; Chen, Lifei; Xie, Huaqing

    2015-01-01

    Different cupric oxide (CuO) structures have attracted intensive interest because of their promising applications in various fields. In this study, three kinds of CuO structures, namely, CuO microdisks, CuO nanoblocks, and CuO microspheres, are synthesized by solution-based synthetic methods. The morphologies and crystal structures of these CuO structures are characterized by field-emission scanning electron microscope and X-ray diffractometer, respectively. They are used as thermal conductive fillers to prepare silicone-based thermal greases, giving rise to great enhancement in thermal conductivity. Compared with pure silicone base, the thermal conductivities of thermal greases with CuO microdisks, CuO nanoblocks, and CuO microspheres are 0.283, 0256, and 0.239 W/mK, respectively, at filler loading of 9 vol.%, which increases 139%, 116%, and 99%, respectively. These thermal greases present a slight descendent tendency in thermal conductivity at elevated temperatures. These experimental data are compared with Nan's model prediction, indicating that the shape factor has a great influence on thermal conductivity improvement of thermal greases with different CuO structures. Meanwhile, due to large aspect ratio of CuO microdisks, they can form thermal networks more effectively than the other two structures, resulting in higher thermal conductivity enhancement.

  11. Isolation of copper oxide (CuO) nanoparticles resistant Pseudomonas strains from soil and investigation on possible mechanism for resistance.

    Science.gov (United States)

    Soltani Nezhad, Shahla; Rabbani Khorasgani, Mohammad; Emtiazi, Giti; Yaghoobi, Mohammad Mehdi; Shakeri, Shahryar

    2014-03-01

    The present study deals with isolation and characterization of copper oxide nanoparticles resistant Pseudomonas strains that were isolated from the soil collected from mining and refining sites of Sarcheshmeh copper mine in the Kerman Province of Iran. The three isolates were selected based on high level of copper oxide nanoparticles (CuO NPs) resistance. The isolates were authentically identified as Pseudomonas fluorescens CuO-1, Pseudomonas fluorescens CuO-2 and Pseudomonas sp. CuO-3 by morphological, biochemical and 16S rDNA gene sequencing analysis. The growth pattern of these isolates with all the studied CuO NPs concentrations was similar to that of control (without CuO NPs) indicating that CuO NPs would not affect the growth of isolated strains. A reduction in the amount of exopolysaccharides was observed after CuO NPs-P. fluorescens CuO-1 culture supernatant interaction. The Fourier transform infrared spectroscopy (FT-IR) peaks for the exopolysaccharides extracted from the bacterial culture supernatant and the interacted CuO NPs were almost similar. The exopolysaccharide capping of the CuO NPs was confirmed by FT-IR and X-ray diffraction analysis. The study of bacterial exopolysaccharides capped CuO NPs with E. coli PTCC 1338 and S. aureus PTCC 1113 showed less toxicity compared to uncoated CuO NPs. Our study suggests that the capping of nanoparticles by bacterially produced exopolysaccharides serve as the probable mechanism of tolerance.

  12. Tailored 3D CuO Nanogrid Formation

    Directory of Open Access Journals (Sweden)

    Jusang Lee

    2011-01-01

    Full Text Available This paper reports on the controlled synthesis of 3D CuO nanogrids by the combined use of electrospinning and thermal oxidation of a composite metal mesh/polymer mat architecture. The obtained nanogrids result from three steps encompassing: (i Cu atom clusters diffusing into the nanofibers producing polymer-metal “core-shell”-type fibers (ii decomposition of the polymeric shell; (iii oxidation of the metallic core of the nanofibers to form self-supported, open nanogrids consisting of continuous nanofibers of CuO nanoparticles with an average diameter of 20 nm. The calculated band gap energy of the cupric oxide nanogrids was determined from the UV-Vis spectrum to be 1.32 eV. The unique 3D CuO nanogrids may be used as key components of 3D nanobatteries, photocatalysts, and p-type chemosensors.

  13. Ultrathin willow-like CuO nanoflakes as an efficient catalyst for electro-oxidation of hydrazine

    Science.gov (United States)

    Ma, Yuanyuan; Li, Hao; Wang, Rongfang; Wang, Hui; Lv, Weizhong; Ji, Shan

    2015-09-01

    In this paper, preparation of ultrathin willow-like CuO nanoflakes via a one-step process was reported. X-ray diffraction pattern showed the formation of monoclinic CuO crystal, which was also confirmed by result of high resolution transmission electron microscopy. Scanning electron microscopy showed that ultrathin willow-like CuO nanoflakes were formed. Catalytic testing indicated that the ultrathin willow-like CuO nanoflakes exhibited high electrocatalytic activity and durability toward the electro-oxidation of hydrazine in alkaline medium. The results suggested that the as-prepared CuO nanoflakes were potential electrode materials for hydrazine fuel cell.

  14. Mechanistic insights into the oxidation of substituted phenols via hydrogen atom abstraction by a cupric-superoxo complex.

    Science.gov (United States)

    Lee, Jung Yoon; Peterson, Ryan L; Ohkubo, Kei; Garcia-Bosch, Isaac; Himes, Richard A; Woertink, Julia; Moore, Cathy D; Solomon, Edward I; Fukuzumi, Shunichi; Karlin, Kenneth D

    2014-07-16

    To obtain mechanistic insights into the inherent reactivity patterns for copper(I)-O2 adducts, a new cupric-superoxo complex [(DMM-tmpa)Cu(II)(O2(•-))](+) (2) [DMM-tmpa = tris((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)amine] has been synthesized and studied in phenol oxidation-oxygenation reactions. Compound 2 is characterized by UV-vis, resonance Raman, and EPR spectroscopies. Its reactions with a series of para-substituted 2,6-di-tert-butylphenols (p-X-DTBPs) afford 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) in up to 50% yields. Significant deuterium kinetic isotope effects and a positive correlation of second-order rate constants (k2) compared to rate constants for p-X-DTBPs plus cumylperoxyl radical reactions indicate a mechanism that involves rate-limiting hydrogen atom transfer (HAT). A weak correlation of (k(B)T/e) ln k2 versus E(ox) of p-X-DTBP indicates that the HAT reactions proceed via a partial transfer of charge rather than a complete transfer of charge in the electron transfer/proton transfer pathway. Product analyses, (18)O-labeling experiments, and separate reactivity employing the 2,4,6-tri-tert-butylphenoxyl radical provide further mechanistic insights. After initial HAT, a second molar equiv of 2 couples to the phenoxyl radical initially formed, giving a Cu(II)-OO-(ArO') intermediate, which proceeds in the case of p-OR-DTBP substrates via a two-electron oxidation reaction involving hydrolysis steps which liberate H2O2 and the corresponding alcohol. By contrast, four-electron oxygenation (O-O cleavage) mainly occurs for p-R-DTBP which gives (18)O-labeled DTBQ and elimination of the R group.

  15. Separation of Arsenic from the Antimony-Bearing Dust through Selective Oxidation Using CuO

    Science.gov (United States)

    Zhong, Da-Peng; Li, Lei; Tan, Cheng

    2017-04-01

    A pyrometallurgical process of selective oxidation roasting of the antimony-bearing dust using CuO is put forward, in which the antimony component is oxidized to Sb2O4 staying in the roasted residue, and arsenic is volatilized in the form of As2O3. The addition of CuO has an active effect on the arsenic volatilization, because structures of some complicated As-Sb phases in the dust are destroyed after the "Sb" component in them is oxidized to Sb2O4, and this part of arsenic might be transformed to As2O3, which continues to volatilize. However, the arsenic volatilization rate decreases with the CuO amount in a certain range, which is attributed to the greater formation of Cu3 (AsO4)2 and Cu3As. Under the conditions of roasting temperature of 673 K (400 °C), roasting time of 100 minutes, CuO amount of 34.54 mass pct, and N2 flow rate of 30 mL/min, 91.50 pct arsenic and only 8.63 pct antimony go into the smoke.

  16. Separation of Arsenic from the Antimony-Bearing Dust through Selective Oxidation Using CuO

    Science.gov (United States)

    Zhong, Da-Peng; Li, Lei; Tan, Cheng

    2017-01-01

    A pyrometallurgical process of selective oxidation roasting of the antimony-bearing dust using CuO is put forward, in which the antimony component is oxidized to Sb2O4 staying in the roasted residue, and arsenic is volatilized in the form of As2O3. The addition of CuO has an active effect on the arsenic volatilization, because structures of some complicated As-Sb phases in the dust are destroyed after the "Sb" component in them is oxidized to Sb2O4, and this part of arsenic might be transformed to As2O3, which continues to volatilize. However, the arsenic volatilization rate decreases with the CuO amount in a certain range, which is attributed to the greater formation of Cu3 (AsO4)2 and Cu3As. Under the conditions of roasting temperature of 673 K (400 °C), roasting time of 100 minutes, CuO amount of 34.54 mass pct, and N2 flow rate of 30 mL/min, 91.50 pct arsenic and only 8.63 pct antimony go into the smoke.

  17. Ammonia Vapor-Assisted Synthesis of Cu(OH)2 and CuO Nanostructures: Anionic (Cl-, NO3 -, SO4 2-) Influence on the Product Morphology

    Science.gov (United States)

    Mansournia, Mohammadreza; Arbabi, Akram

    2017-01-01

    Shape control of inorganic nanostructures generally requires using surfactants or ligands to passivate certain crystallographic planes. This paper describes a novel additive-free synthesis of cupric oxide nanostructures with different morphologies from the aqueous solutions of copper(II) with Cl-, NO3 -, and SO4 2- as counter ions. Through a one-step approach, CuO nanoleaves, nanoparticles and flower-like microspheres were directly synthesized at 80°C upon exposure to ammonia vapor using a cupric solution as a single precursor. Furthermore, during a two-step process, Cu(OH)2 nanofibers and nanorods were prepared under an ammonia atmosphere, then converted to CuO nanostructures with morphology preservation by heat treatment in air. The as-prepared Cu(OH)2 and CuO nanostructures are characterized using x-ray diffraction, scanning electron microscopy and Fourier transformation infrared spectroscopy techniques.

  18. Ammonia Vapor-Assisted Synthesis of Cu(OH)2 and CuO Nanostructures: Anionic (Cl-, NO3 -, SO4 2-) Influence on the Product Morphology

    Science.gov (United States)

    Mansournia, Mohammadreza; Arbabi, Akram

    2016-09-01

    Shape control of inorganic nanostructures generally requires using surfactants or ligands to passivate certain crystallographic planes. This paper describes a novel additive-free synthesis of cupric oxide nanostructures with different morphologies from the aqueous solutions of copper(II) with Cl-, NO3 -, and SO4 2- as counter ions. Through a one-step approach, CuO nanoleaves, nanoparticles and flower-like microspheres were directly synthesized at 80°C upon exposure to ammonia vapor using a cupric solution as a single precursor. Furthermore, during a two-step process, Cu(OH)2 nanofibers and nanorods were prepared under an ammonia atmosphere, then converted to CuO nanostructures with morphology preservation by heat treatment in air. The as-prepared Cu(OH)2 and CuO nanostructures are characterized using x-ray diffraction, scanning electron microscopy and Fourier transformation infrared spectroscopy techniques.

  19. Cumene Liquid Oxidation to Cumene Hydroperoxide over CuO Nanoparticle with Molecular Oxygen under Mild Condition

    Institute of Scientific and Technical Information of China (English)

    Meiying Zhang; Lefu Wang; Hongbing Ji; Bing Wu; Xiaoping Zeng

    2007-01-01

    CuO nanoparticle was synthesized via wet chemical method and was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, and scanning electron microscopy (SEM). Catalytic oxidation of cumene with molecular oxygen was studied over CuO nanoparticle. The catalysts showed markedly higher activities as compared to CuO prepared by conventional method, CUO/AI2O3, or homogeneous copper catalyst under comparable reaction conditions. The cumene conversion, cumene hydroperoxide (CHP) yield, and selectivity using 0.25 g CuO nanoparticle catalyst and 0.1 mol cumene at 358 K for 7 h were 44.2%, 41.2% and 93.2%, respectively. The catalyst can be recycled. After 6 recycled experiments, no loss of catalytic activity was observed.

  20. Green synthesis of copper oxide (CuO) nanoparticles using banana peel extract and their photocatalytic activities

    Science.gov (United States)

    Aminuzzaman, Mohammod; Kei, Leong Mei; Liang, Wong Hong

    2017-04-01

    Copper oxide nanoparticles (CuO NPs) are interesting class of materials having multifunctional properties with promising applications in the areas of catalysts, gas sensors, batteries, magnetic storage media, solar energy, superconductors etc. Thus synthesis of CuO NPs has attracted tremendous interest to scientists and researchers Herein, we reported a green and simple method for biosynthesizing CuO NPs using banana peel extract as reducing and stabilizing agent. XRD, EDX, FE-SEM, FTIR have been used for characterization of biosynthesized CuO NPs. The results indicating that the CuO NPs synthesized by banana peel extract have high purity and the average particles size is 60 nm. The photocatalytic activity of the CuO NPs has been investigated by degradation of Congo red (CR) dye under solar irradiation. The extent of CR dye degradation by CuO NPs is monitored by using a UV-visible spectrophotometer. Due to the smaller size and high purity, the biosynthesized CuO NPs showed an excellent photocatlytic activity.

  1. Catalysis of the rare earth containing mixed oxides Ln2CuO4 in phenol hydroxylation

    Institute of Scientific and Technical Information of China (English)

    刘持标; 赵震; 叶兴凯; 吴越

    1997-01-01

    Mixed oxides Ln2CuO4±λ(Ln=La,Pr,Nd,Sm,Gd) with K2NiF4 structure were prepared Their crystal structures were studied with XRD and IR spectra.Meanwhile,the average valence of Cu ions and non stoichiometric oxygen (λ) were determined through chemical analyses.Catalysis of the above-mentioned mixed oxides in the phenol hydroxylation was investigated.Results show that the catalysis of these mixed oxides has close relation with their structures and composition.Substitution of A site atom in Ln2CuO4λ has a great influence on then eatalysis in the phenol hydroxylation.

  2. Photoelectrochemical Properties of CuO Grown by Using a Modified Chemical Bath Deposition Method

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jin-wook; Ryu, Hyukhyun [Inje University, Gimhae (Korea, Republic of); Lee, Won-Jae [Dong-Eui University, Busan (Korea, Republic of)

    2016-06-15

    In this study, cupric oxide (CuO) nanorods were grown on the fluorine-doped tin oxide (FTO) glass substrate using a modified-chemical bath deposition (M-CBD) method. We investigated the morphology, structural, optical and photoelectrochemical properties of the cupric oxide nanorods with various growth durations by using field-emission scanning-electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis) and three-electrode potentiostat, respectively. In this work, we found that the morphologies, thickness, growth rate, crystallinities, grain sizes and optical bandgap were controllable on the growth duration, which affected photocurrent density and photo-stability. The highest growth rate of CuO nanorods was 126 nm/min. From the XRD measurement, we also confirmed that (020) directional growth affected the growth of the CuO nanorods. A maximum photocurrent density of-1.88 mA/cm² at -0.55 V (vs. SCE) and high photo-stability value about 40% was obtained with 10 minutes growth duration.

  3. CuO nanoparticles: Synthesis, characterization, optical properties and interaction with amino acids

    Energy Technology Data Exchange (ETDEWEB)

    El-Trass, A.; ElShamy, H.; El-Mehasseb, I. [Nanochemistry Laboratory, Chemistry Department, Faculty of Science, Kafrelsheikh, University, 33516 Kafr ElSheikh (Egypt); El-Kemary, M., E-mail: elkemary@yahoo.com [Nanochemistry Laboratory, Chemistry Department, Faculty of Science, Kafrelsheikh, University, 33516 Kafr ElSheikh (Egypt)

    2012-01-15

    Cupric oxide (CuO) nanoparticles with an average size of 6 nm have been successfully prepared by an alcothermal method. The prepared CuO nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) and UV-visible absorption spectroscopy. A strong sharp emission under UV excitation is reported from the prepared CuO nanoparticles. The results show that the CuO nanoparticles have high dispersion and narrow size distribution. The fluorescence emission spectra display an intense sharp emission at 365 nm and weak broad intensity emission at 470 nm. Picosecond fluorescence measurements of the nanoparticles suggest bi-exponential function giving time constants of {tau}{sub 1} (330 ps, 94.21%) and {tau}{sub 2} (4.69 ns, 5.79%). In neutral and alkaline solutions, Zeta potential values of CuO nanoparticles are negative, due to the adsorption of COO{sup -} group via the coordination of bidentate. At low pH the zeta potential value is positive due to the increased potential of H{sup +} ions in solution. Comparative UV-visible absorption experiments with the model amino acid compounds of positive and negative charges as arginine and aspartic acid, respectively confirmed the negative surface of CuO nanoparticles. The results should be extremely useful for understanding the mode of the interaction with biological systems. This binding process also affects the particle's behavior inside the body.

  4. Chemical Oxidation of La2CuO4 Epitaxial Thin Films Grown by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-Chang; YAN Yun-Jie; ZHU Jing

    2007-01-01

    Chemical oxidation is used to induce superconductivity in La2CuO4 expitaxial thin films fabricated by pulsed laser deposition technique. Details about the influence of oxidation time on structural, surface morphology, Raman spectra, and electrical properties have been investigated. The results convince that successful uptake of oxygen occurs in the oxidized films, and the content of the inserted oxygen increases with increasing oxidation interval. The possible mechanism for the excess oxygen insertion into the film is also discussed.

  5. Studies and correlation among the structural, electrical and gas response properties of aerosol spray deposited self assembled nanocrystalline CuO

    Science.gov (United States)

    Singh, Iqbal; Bedi, R. K.

    2011-06-01

    Nanostructured CuO films have been grown on to the glass substrate by varying the deposition time from 10 to 30 min and substrate temperature from 300 to 400 °C by a simple ultrasonic spray pyrolysis technique, using aqueous a cupric nitrate solution as precursor. The effect of the substrate temperature on the textural, structural, electrical, and gas sensing properties of CuO films was studied and correlated. Thermal analysis of the dried precursor shows the elimination of physisorbed and chemisorbed water. It suggests the formation of CuO phase on substrate at temperature of 300 °C. X-ray diffractograms of the films indicate the formation of polycrystalline monoclinic CuO having monoclinic with crystallite size around 18 nm. The texture coefficient finds the (0 0 2) plane as the preferred orientation in films. The microstrain and dislocation densities have been calculated and found to decreases with increase in substrate temperature. The scanning electron micrographs indicate the formation of trapezium like facet structures on the film surface. AFM analysis shows uniform deposition of the CuO film over the entire substrate surface. Observations reveal that the film deposited at 300 °C show comparatively higher activation energy and appreciable response to ammonia at room temperature. The use of aqueous cupric nitrate as precursor results in the deposition of single phase copper oxide films.

  6. ELECTROCHEMICAL OXIDATION OF La2CuO4 SINGLE CRYSTALS

    Institute of Scientific and Technical Information of China (English)

    Chen Ling; Huang Yu-zhen; Zhou Fang; Dong Cheng; Che Guang-can; Zhao Zhong-xian

    2000-01-01

    Bulk superconducting La2CuO4+ single crystals are obtained byusing electrochemical intercalation technique from the as-growninsulating samples. Oxidation is carried out by constant currentI=10 at temperature T=70 and room temperature, respectively. Structure and magnetic properties are studied by low-temperature X-ray diffraction and susceptibility measurements. A superconducting phase with Tc of 19K and -0.12 can be attributed to the formation of oxygen clusters. Room temperature oxidation is inhomogeneous: two superconducting phases with T c1 of 24K and Tc2 of 8K and an antiferromagnetic phase are coexisting in the crystal. It is found that the appearance of Tc in this system has the step tendency.

  7. Assessment of Ethidium bromide and Ethidium monoazide bromide removal from aqueous matrices by adsorption on cupric oxide nanoparticles.

    Science.gov (United States)

    Fakhri, Ali

    2014-06-01

    The present study was undertaken to develop an effective adsorbent and to study the adsorption of Ethidium bromide and Ethidium monoazide bromide from aqueous solution using the CuO nanoparticles. The characteristics of CuO nanoparticles were determined and found to have a surface area 89.59m(2)/g. Operational parameters such as pH, contact time and adsorbent concentration, initial concentration and temperature were also studied. The amount of removal increases with the increase in pH from one to seven and reaches the maximum when the pH is nine. Adsorption data fitted well with the Langmuir, Freundlich and Florry-Huggins models. The results show that the best fit was achieved with the Langmuir isotherm equation with maximum adsorption capacities of 0.868 and 0.662mg/g for Ethidium bromide and Ethidium monoazide bromide, respectively. The adsorption process was found to follow pseudo-second-order kinetics. The calculated thermodynamic parameters, namely ΔG, ΔH and ΔS showed that adsorption of Ethidium bromide and Ethidium monoazide bromide was spontaneous and endothermic under examined conditions.

  8. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters.

    Science.gov (United States)

    Nogueira, C A; Paiva, A P; Oliveira, P C; Costa, M C; da Costa, A M Rosa

    2014-08-15

    The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu(2+) concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4h, [HCl] = 6M, [Cu(2+)] = 0.3M).

  9. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

    2014-08-15

    Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

  10. Study of Optical Band Gap of CuO Using Fermi's Golden Rule

    Science.gov (United States)

    Nemade, K. R.; Waghuley, S. A.

    2012-05-01

    Quantum size effect where the electronic and optical properties of solids are altered due to changes in the band structures, enhanced the surface/volume ratio in nano dimensions forces more than 33% of the atoms to be on the surface (for 10nm dot 35), which drastically altering the physical properties such as having lower melting temperature and lower sintering temperature, and higher diffusion force at elevated temperatures. Consequently, its Fermi's golden rule analysis becomes crucial. Cupric oxide (CuO) is an important transition metal oxide with the basis of several high temperature superconductors and giant magnetoresistance materials. In present investigation, optical Band Gap from UV data using Fermi's golden rule for single step chemically synthesized CuO was computed.

  11. Kinetics of carbon monoxide oxidation over modified supported CuO catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Loc, Luu Cam; Tri, Nguyen; Cuong, Hoang Tien; Thoang, Ho Si [Vietnam Academy of Science and Technology (VAST), Ho Chi Minh City (Viet Nam). Inst. of Chemical Technology; Agafonov, Yu.A.; Gaidai, N.A.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry

    2013-11-01

    The following supported on {gamma}-Al{sub 2}O{sub 3} catalysts: 10(wt.)%CuO (CuAl), 10%CuO+10%Cr{sub 2}O{sub 3} (CuCrAl) and 10%CuO+20%CeO{sub 2} (CuCeAl) were under the investigation. Physico-chemical characteristics of the catalysts were determined by the methods of BET, X-ray Diffraction (XRD), and Temperature-Programmed Reduction (TPR). A strong interaction of copper with support in CuAl resulted in the formation of low active copper aluminates. The bi-oxide CuCrAl was more active than CuAl owing to the formation of high catalytically active spinel CuCr{sub 2}O{sub 4}. The fact of very high activity of the sample CuCeAl can be explained by the presence of the catalytically active form of CuO-CeO{sub 2}-Al{sub 2}O{sub 3}. The kinetics of CO total oxidation was studied in a gradientless flow-circulating system at the temperature range between 200 C and 270 C. The values of initial partial pressures of carbon monoxide (P{sup o}{sub CO}), oxygen (P{sup o}{sub O2}), and specially added carbon dioxide (P{sup o}{sub CO{sub 2}}) were varied in ranges (hPa): 10 / 45; 33 / 100, and 0 / 30, respectively. (orig.)

  12. Nanostructured CuO Thin Films Prepared through Sputtering for Solar Selective Absorbers

    Directory of Open Access Journals (Sweden)

    Senthuran Karthick Kumar

    2013-01-01

    Full Text Available Nanostructured cupric oxide (CuO thin films have been deposited on copper (Cu substrates at different substrate temperatures and oxygen to argon gas ratios through direct current (DC reactive magnetron sputtering. The deposited CuO thin films are characterized by using X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, profilometry, and spectrophotometry techniques. The crystalline phases, morphology, optical properties, and photothermal conversion efficiency of the CuO thin films are found to be significantly influenced by the change in substrate temperature and oxygen to argon gas ratio. The variations in the substrate temperature and oxygen to argon gas ratio have induced changes in Cu+ and Cu2+ concentrations of the CuO thin films that result in corresponding changes in their optical properties. The CuO thin film prepared at a substrate temperature of 30°C and O2 to Ar gas ratio of 1 : 1 has exhibited high absorptance and low emittance; thus, it could be used as a solar selective absorber in solar thermal gadgets.

  13. A simple, fast and cost-effective method of synthesis of cupric oxide nanoparticle with promising antibacterial potency: Unraveling the biological and chemical modes of action.

    Science.gov (United States)

    Chakraborty, Ruchira; Sarkar, Raj Kumar; Chatterjee, Arijit Kumar; Manju, Unnikrishnan; Chattopadhyay, Asoke Prasun; Basu, Tarakdas

    2015-04-01

    Gradual attainment of bacterial resistance to antibiotics led us to develop a robust method of synthesis of stable, colloidal cupric oxide nanoparticle of physiological pH with potential antibacterial action. Cu(II) oxide NP was synthesized by reduction-oxidation of CuCl2, using polyvinyl alcohol as stabilizer. Characteristics and antibacterial activity of the particles were investigated by techniques like UV-Vis spectrophotometry, DLS, AFM, TEM, EDS, FTIR, AAS, agar plating, FACS, gel electrophoresis and XPS. The NPs were about 50 nm in size and cubic in shape with two surface plasmon peaks at 266 and 370 nm and had semi-conducting behavior with a band gap of 3.40 and 3.96 eV. About 80% of precursor CuCl2 was converted to NP. The minimum inhibitory and the minimum bactericidal concentrations of CuO-NP were respectively 120 and 160 μg/mL for Escherichia coli and 180 and 195 μg/mL for Staphylococcus aureus in Luria-Bertani medium. In growth media, the NPs got modified by media organics with displacement of the stabilizer PVA molecules. This modified NP (around 240 nm) killed cells by generating ROS, which finally caused membrane lipid per-oxidation and chromosomal DNA degradation in NP-treated cells. Reports indicate that we are among the few who had prepared CuO-NP in colloidal form. The antibacterial potency of our particle in growth media was much promising than other reports. Our findings demonstrated that 'particle-specific' effect, not 'ion-specific' one, was responsible for the NP action. The NP may be used as a sterilizing agent in various bioprocesses and as substituent of antibiotics, after thorough toxicological study. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Synthesis and characterization of CuO nanoparticles using strong base electrolyte through electrochemical discharge process

    Indian Academy of Sciences (India)

    PURUSHOTTAM KUMAR SINGH; PANKAJ KUMAR; MANOWAR HUSSAIN; ALOK KUMAR DAS; GANESH CHANDRA NAYAK

    2016-04-01

    In the present study, cupric oxide (CuO) nanoparticles were synthesized by electrochemical discharge process using strong base electrolytes. The experiments were carried out separately using NaOH and KOH electrolytes.The mass output rate and the crystal size were obtained with variation of the rotation speed of magnetic stirrer for both types of electrolytes. The mass output rate of CuO nanoparticles increased with the increase in the speed of rotation, and, after an optimum speed, it started decreasing. However, the size of the particles reduced with the increase of the rotation speed. The crystal plane of the obtained CuO nanoparticles was similar for both the electrolytes whereas the yield of nanoparticles was higher in KOH as compared with NaOH under the sameexperiment conditions. In this set of experiments, the maximum output rates obtained were 21.66 mg h$^{−1}$ for NaOH and 24.66 mg h$^{−1}$ for KOH at 200 rpm for a single discharge arrangement. The average crystal size of CuO particles obtained was in the range of 13–18 nm for KOH electrolyte and 15–20 nm for NaOH electrolyte. Scanning electron microscopy images revealed that flower-like and caddice clew-shaped CuO nanocrystalline particles weresynthesized by the electrochemical discharge process. Fourier transform infrared spectrum showed that the CuO nanoparticles have a pure and monolithic phase. UV–vis–NIR spectroscopy was used to monitor oxidation course of Cu→CuO and the band gap energy was measured as 2 and 2.6 eV for CuO nanoparticle synthesized in NaOH and KOH solutions, respectively.

  15. Polyethylene glycol grafted flower-like cupric nano oxide for the hollow-fiber solid-phase microextraction of hexaconazole, penconazole, and diniconazole in vegetable samples.

    Science.gov (United States)

    Zendegi-Shiraz, Amene; Sarafraz-Yazdi, Ali; Es'haghi, Zarrin

    2016-08-01

    A simple, rapid, highly efficient, and reliable sample preparation method has been developed for the extraction and analysis of triazole pesticides from cucumber, lettuce, bell pepper, cabbage, and tomato samples. This new sorbent in the hollow-fiber solid-phase microextraction method is based on the synthesis of polyethylene glycol-polyethylene glycol grafted flower-like cupric oxide nanoparticles using sol-gel technology. Afterward, the analytes were analyzed by high-performance liquid chromatography with ultraviolet detection. The main parameters that affect microextraction efficiency were evaluated and optimized. This method has afforded good linearity ranges (0.5-50 000 ng/mL for hexaconazol, 0.012-50 000 ng/mL for penconazol, and 0.02-50 000 ng/mL for diniconazol), adequate precision (2.9-6.17%, n = 3), batch-to-batch reproducibility (4.33-8.12%), and low instrumental LODs between 0.003 and 0.097 ng/mL (n = 8). Recoveries and enrichment factors were 85.46-97.47 and 751-1312%, respectively.

  16. Honeycomb Cupric Oxide and Hematite Nanotubes Synergism Photoelectro-reduction CO2%蜂窝状CuO和Fe2O3纳米管协同光电还原CO2

    Institute of Scientific and Technical Information of China (English)

    王祜英; 徐金凤; 井华; 张军; 李培强; 路福绥

    2013-01-01

    采用阳极氧化法在Fe上原位生长直立有序的Fe2O3纳米管阵列,脉冲电沉积法将蜂窝状CuO组装到Fe2O3NTs上,得到CuO HCs/Fe2O3NTs催化剂.结果表明:Fe2O3NTs呈“火山状”规则生长,蜂窝状CuO均匀分布在Fe2O3 NTs表面.修饰后,材料的能隙由原来的2.03 eV窄化为1.84 eV.同时发现该催化剂具有优良的光催化还原性能和电催化还原性能,光电催化还原CO2的主要生成产物为甲醇,甲醇在6h时含量峰值为3.77 mmol/L.该研究对光电催化还原CO2有一定的指导和借鉴意义.%Vertically aligned Fe2O3 nanotubes (Fe2O3 NTs) arrays were prepared on the iron foil by potentiostatic anodization method.The anodization experiments were performed under 30 V for 2 h (20 ℃).The ferrous foil was working electrode and titanium foil was counter electrode.The electrolytes were consisted of 0.25 wt% NH4F in an aqueous solution (Volume of water:glycol=3.:97).After sonicating for 5 min,the samples were put under oxygen atmosphere with the flow rate of 60 seem (standard cubic centimeters/min) and heated to 500 ℃ with the rate of 3 ℃.min-1 and maintained at 500 ℃ for 2 h.Then cooled to room temperature with the rate of 3 ℃.min-1.Honeycomb structure cupric oxide (CuO HCs) were decorated on the surface of Fe2O3 NTs by the pulse electrochemical deposition method.This was done by CHI660D potentiostat in 1 mol.L-1 CuSO4 solution (40 ℃) in a three-electrode configuration.The Fe2O3 NTs electrode worked as counter electrode,Hg/Hg2Cl2 in saturated KCl solution as reference electrode,and platinum wire as working electrode,respectively.A 10 ms cathodic pulse with a current density of-70 mA.cm-2 was employed.After that followed by a 1 ms anodic pulse and its density was +70 mA.cm-2 to prevent damage of the Fe2O3 NTs structure.Finally was a 1000 ms rest time.The electrodeposition time was 36 s,with a forward duty cycle of 0.99% (considering cathodic,anodic and rest components).Then the samples were

  17. Characterization of lignin by gas chromatography and mass spectrometry using a simplified CuO oxidation method.

    Science.gov (United States)

    Kaiser, Karl; Benner, Ronald

    2012-01-03

    An efficient and high-throughput method to characterize lignin in environmental samples using alkaline CuO oxidation and capillary gas chromatography with mass detection is presented. Monomeric lignin phenols released during oxidation were selectively extracted using a polymer-based solid phase sorbent rather than liquid phase extraction. Sample size and matrix were found to influence lignin phenol yields. Increasing the sample size to an organic carbon content ≥1.5 mg of C minimizes phenol oxidation losses, and the addition of glucose as a sacrificial carbon source helped minimize oxidation losses in samples with <5 mg of organic carbon. © 2011 American Chemical Society

  18. Facile and Mild Strategy to Construct Mesoporous CeO2-CuO Nanorods with Enhanced Catalytic Activity toward CO Oxidation.

    Science.gov (United States)

    Chen, Guozhu; Xu, Qihui; Yang, Ying; Li, Cuncheng; Huang, Taizhong; Sun, Guoxin; Zhang, Shuxiang; Ma, Dongling; Li, Xu

    2015-10-28

    CeO2-CuO nanorods with mesoporous structure were synthesized by a facile and mild strategy, which involves an interfacial reaction between Ce2(SO4)3 precursor and NaOH ethanol solution at room temperature to obtain mesoporous CeO2 nanorods, followed by a solvothermal treatment of as-prepared CeO2 and Cu(CH3COO)2. Upon solvothermal treatment, CuO species is highly dispersed onto the CeO2 nanorod surface to form CeO2-CuO composites, which still maintain the mesoporous feature. A preliminary CO catalytic oxidation study demonstrated that the CeO2-CuO samples exhibited strikingly high catalytic activity, and a high CO conversion rate was observed without obvious loss in activity even after thermal treatment at a high temperature of 500 °C. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and hydrogen temperature-programmed reduction (H2-TPR) analysis revealed that there is a strong interaction between CeO2 and CuO. Moreover, it was found that the introduction of CuO species into CeO2 generates oxygen vacancies, which is highly likely to be responsible for high catalytic activity toward CO oxidation of the mesoporous CeO2-CuO nanorods.

  19. Electrical Conductivity of Sintered Chromia Mixed with TiO2,CuO and Mn-Oxides

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% (in molar fraction) TiO2 or CuO was investigated in the temperature range 500~900℃ in air and in Ar/4 vol. pct H2 atmospheres. The effect of different Mn-oxides on the electrical conductivity of Cr2O3 was also studied under the same conditions.From the conductivity measurements it is established that additions of TiO2 change the defect structure of Cr2O3 and the effect of TiO2 on the electrical conductivity is controlled by TiO2 concentration as well as temperature and O2 partial pressure of the surrounding atmosphere. The conductivity of Cr2O3 increased in air and decreased in the Ar/H2 atmosphere by CuO additions. The effect of CuO was discussed with possible changes in the defect concentration in Cr2O3. Mixing of Cr2O3 with different Mn-oxides at the same Mn to metal atom fraction decreased the conductivity in air and in Ar/H2 atmospheres. No clear correlation between the spinel fraction and the changes in conductivity could be found.

  20. Hetero-metal cation control of CuO nanostructures and their high catalytic performance for CO oxidation

    Science.gov (United States)

    Huang, Hongwen; Zhang, Liqiang; Wu, Kewei; Yu, Qing; Chen, Ru; Yang, Hangsheng; Peng, Xinsheng; Ye, Zhizhen

    2012-11-01

    A controllable synthesis of various morphologies of CuO nanostructures with tuning by hetero-metal cations has been developed in aqueous solution at room temperature. The morphologies of CuO can be engineered from nanosheets to nanoparticles with different length ratios of the long axis to the short axis. The formation of many metal-ion complexes plays an important role in slowing the release rate of OH- and affects the reaction kinetics further. We found that the effect of hetero-metal cations on the final morphology of the CuO nanostructures was the same as that of the cooling temperature. A series of temperature-controlled experiments demonstrated this. Furthermore, among all the synthesized CuO nanostructures, the fascinating colloidal mesoporous CuO quasi-monocrystalline nanosheets prepared at 25 °C with a thickness of ca. 10 nm and large specific surface area of 80.32 m2 g-1 is investigated intensively. These CuO nanosheets demonstrate a superior catalytic activity for CO oxidation, with features of high CO conversion efficiency (47.77 mmolCO g-1CuO h-1 at 200 °C), which is close to that reported for previously investigated supported-CuO catalysts, and a low apparent activation energy Ea (53.3 kJ mol-1).A controllable synthesis of various morphologies of CuO nanostructures with tuning by hetero-metal cations has been developed in aqueous solution at room temperature. The morphologies of CuO can be engineered from nanosheets to nanoparticles with different length ratios of the long axis to the short axis. The formation of many metal-ion complexes plays an important role in slowing the release rate of OH- and affects the reaction kinetics further. We found that the effect of hetero-metal cations on the final morphology of the CuO nanostructures was the same as that of the cooling temperature. A series of temperature-controlled experiments demonstrated this. Furthermore, among all the synthesized CuO nanostructures, the fascinating colloidal mesoporous CuO

  1. Room temperature chemically oxidized La2CuO4+y: Phase separation induced by thermal treatment

    DEFF Research Database (Denmark)

    Rial,C.; Moran, E.; Alario-Franco, M.A.

    1997-01-01

    for this material. The thermogravimetric analysis(TGA) of La2CuO4.103(4) evidences an unexplained two-step mass loss process. Based on this observation, three samples obtained by different thermal treatments of the fully oxidized material were studied by TGA, X-ray diffraction and AC magnetic susceptibility, After...... a short treatment at 433 K, La2CuO4.103(4) undergoes a phase separation into two phases: phase 1, with estimated y(1) = 0.086(4) and T-cl = 30 K, and phase 2, with estimated y(2) = 0.12(1) and T-c2 = 17 K. By increasing the annealing times, phase 2 transforms to phase I and finally disappears. Therefore...

  2. CexTi1-xO2 Mixed Oxides Supported CuO Catalyst for NO Reduction by CO

    Institute of Scientific and Technical Information of China (English)

    楼莉萍; 蒋晓原; 陈英旭; 吕光烈; 周仁贤; 郑小明

    2003-01-01

    CexTi1-xO2 mixed oxides of different mole ratios (x=0, 0.1, 0.2~0.9, 1.0) were prepared by co-precipitation of TiCl4 with Ce(NO3)3 and then loaded with different amounts of CuO. The effects of CuO on NO+CO reaction were investigated, and the structure and reductive properties of various CuO/CexTi1-xO2 were characterized by the methodologies of BET, TPR and XRD. The results show that different Ce/Ti mole ratios and calcination temperatures induce changes of structure and reductive properties of the CexTi1-xO2 mixed oxides. When x=0.1~0.5, amorphous CeTi2O6 phase mainly forms at 650 ℃ compared to the formation of CeTi2O6 which crystallizes at 800 ℃. When x>0.6, some TiO2 enters the CeO2 lattice and a CeO2-TiO2 solid solution is formed. The activity of 6%CuO/CexTi1-xO2 calcined at 650 ℃ is largely affected by the x values, which is the highest when x=0.3, 0.4 and 0.9. The NO conversion reaches 70% at a reaction temperature of 150 ℃. By comparison, the x values have little effect on the activity of 6%CuO/CexTi1-xO2 calcined at 800 ℃. There are strong interactions between CuO and CeTi2O6, I.e., formation of the CeTi2O6 phase shifts the CuO reduction peak temperature from 380 to 200 ℃, and CuO, in turn, shifts the CeTi2O6 reduction peak temperature from 600 to 300 ℃.

  3. Adsorptive Removal of Benzene and Toluene from Aqueous Environments by Cupric Oxide Nanoparticles: Kinetics and Isotherm Studies

    Directory of Open Access Journals (Sweden)

    Leili Mohammadi

    2017-01-01

    Full Text Available Removal of benzene and toluene, as the major pollutants of water resources, has attracted researchers’ attention, given the risk they pose to human health. In the present study, the potential of copper oxide nanoparticles (CuO-NPs in eliminating benzene and toluene from a mixed aqueous solution was evaluated. For this, we performed batch experiments to investigate the effect of solution pH (3–13, dose of CuO-NPs (0.1–0.8 g, contact time (5–120 min, and concentration of benzene and toluene (10–200 mg/l on sorption efficiency. The maximum removal was observed at neutral pH. By using the Langmuir model, we measured the highest adsorption capacity to be 100.24 mg/g for benzene and 111.31 mg/g for toluene. Under optimal conditions, adsorption efficiency was 98.7% and 92.5% for benzene and toluene, respectively. The sorption data by CuO-NPs well fitted into the following models: Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich model. The experimental information well fitted in the Freundlich for benzene and Langmuir for toluene. Based on the results, adsorption followed pseudo-second-order kinetics with acceptable coefficients. The findings introduced CuO-NPs as efficient compounds in pollutants adsorption. In fact, they could be used to develop a simple and efficient pollutant removal method from aqueous solutions.

  4. Synthesis of Cu/Cu2O nanoparticles by laser ablation in deionized water and their annealing transformation into CuO nanoparticles

    KAUST Repository

    Gondal, M. A.

    2013-08-01

    Nano-structured Cupric Oxide (CuO) has been synthesized using pulsed laser ablation of pure copper in water using Q-switched pulsed laser beam of 532 nm wavelength and, 5 nanosecond pulse duration and laser pulse energy of 100 mJ/pulse. In the initial unannealed colloidal suspension, the nanoparticles of Copper (Cu) and Cuprious oxide (Cu2O) were identified. Further the suspension was dried and annealed at different temperatures and we noticed the product (Cu/Cu2O) was converted predominantly into CuO at annealing temperature of 300 \\'C for 3 hours. As the annealing temperature was raised from 300 to 900 \\'C, the grain sizes of CuO reduced to the range of 9 to 26 nm. The structure and the morphology of the prepared samples were investigated using X-ray diffraction and Transmission Electron Microscope. Photoluminescence and UV absorption spectrometrystudies revealed that the band gap and other optical properties of nano-structured CuO were changed due to post annealing. Fourier transform spectrometry also confirmed the transformation of Cu/Cu2O into CuO. Copyright © 2013 American Scientific Publishers All rights reserved.

  5. Enhanced adhesion and field emission of CuO nanowires synthesized by simply modified thermal oxidation technique

    Science.gov (United States)

    Tang, C. M.; Wang, Y. B.; Yao, R. H.; Ning, H. L.; Qiu, W. Q.; Liu, Z. W.

    2016-09-01

    Metal oxide nanowires (NWs) can be easily grown by the thermal oxidation method, but the low adhesion between the NWs and the substrate restricts their practical applications in functional devices. In this work, the conventional hotplate technique is simply modified by introducing one or two stainless steel plates to supply a more stable oxidation environment, which is found to be beneficial to the growth and adhesion of CuO NWs on the Cu substrate. In detail, the Cu foils were heated on the hotplate directly, on one plate over the hotplate, and between two plates over the hotplate at 400 °C in ambient condition. It is found that the NWs obtained between two plates exhibit large length and diameter with moderate density. The sufficient activated oxygen, stable temperature, and proper temperature gradient configuration caused by the two plates accelerate the formation of CuO NWs, and result in the longest NWs with enhanced adhesion. The grain-boundary diffusion and Kirkendall effect are proposed to explain the mechanism of NWs growth and the formation of cracks. The NWs obtained between two plates also showed the best field emission properties, with lowest turn-on field (5.31 V μm-1) and threshold field (9.8 V μm-1). Excellent field emission properties and enhanced NW-substrate adhesion indicate that these NW arrays could be potentially used as the cathode of field emission displays.

  6. Superconductivity of Nd1.85Ce0.15CuO4-y by Electrochemical Oxidation

    Institute of Scientific and Technical Information of China (English)

    CHEN Ling; CHE Guang-Can; LI Hong; DONG Cheng; ZHOU Fang; HUANG Yu-Zhen; ZHAO Zhong-Xian

    2000-01-01

    Superconductivity of n-type superconductor Nd1.85Ce0.15CuO4-y (NCCO) by electrochemical oxidation is re ported for the first time and the cyclic voltammogram curve for NCCO as working electrode is presented. In vestigations indicate that after oxidation, superconductivity of NCCO is improved: Tc is raised from 20 K up to 26 K, the superconducting volume fraction is increased also. The valence electronic states of oxygen and copper in NCCO are studied by x-ray photoelectron spectroscopy. It is found that the Cu-2ps/2 peak shifts to the higher binding energy side about 0.4 e V, which indicates that the valence-state of copper ions is risen up after oxidation. These results imply that hole-carriers exist in n-type superconductor.

  7. CO oxidation over CuO catalysts supported on CeO2-ZrO2 prepared by microwave-assisted co-precipitation:The influence of CuO content

    Institute of Scientific and Technical Information of China (English)

    杨志强; 毛东森; 郭晓明; 卢冠忠

    2014-01-01

    CeO2-ZrO2 mixed oxide (Ce0.6Zr0.4O2) prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.4O2 catalysts with various CuO contents (0 wt.%-15 wt.%) via the method of incipient-wetness im-pregnation. The obtained CuO/Ce0.6Zr0.4O2 samples were characterized by N2 adsorption, XRD, Raman, TEM and H2-TPR technolo-gies, and their catalytic activities for CO oxidation were investigated. The results showed that the activity of CuO/Ce0.6Zr0.4O2 catalyst was strongly influenced by the content of CuO, and the catalyst with 10 wt.%CuO exhibited the best catalytic activity in CO oxida-tion, which could be attributed to the high dispersion and reducibility of CuO, and high oxygen vacancy concentration in the catalyst.

  8. Charge transport in single CuO nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junnan; Yin, Bo; Wu, Fei; Myung, Yoon; Banerjee, Parag, E-mail: parag.banerjee@wustl.edu [Department of Mechanical Engineering and Materials Science, One Brookings Drive, Washington University, St. Louis, Missouri 63130 (United States)

    2014-11-03

    Charge transport in single crystal, p-type cupric oxide (CuO) nanowire (NW) was studied through temperature based (120 K–400 K) current-voltage measurements. CuO NW with a diameter of 85 nm was attached to Au electrodes 2.25 μm apart, using dielectrophoresis. At low electrical field (<0.89 × 10{sup 3 }V/cm), an ohmic conduction is observed with an activation energy of 272 meV. The injected electrons fill traps with an average energy, E{sub T} = 26.6 meV and trap density, N{sub T} = 3.4 × 10{sup 15 }cm{sup −3}. After the traps are saturated, space charge limited current mechanism becomes dominant. For 120 K ≤ T ≤ 210 K phonon scattering limits mobility. For T ≥ 220 K, a thermally activated mobility is observed and is attributed to small polaron hopping with an activation energy of 44 meV. This mechanism yields a hole mobility of 0.0015 cm{sup 2}/V s and an effective hole concentration of 4 × 10{sup 18 }cm{sup −3} at 250 K.

  9. Charge transport in single CuO nanowires

    Science.gov (United States)

    Wu, Junnan; Yin, Bo; Wu, Fei; Myung, Yoon; Banerjee, Parag

    2014-11-01

    Charge transport in single crystal, p-type cupric oxide (CuO) nanowire (NW) was studied through temperature based (120 K-400 K) current-voltage measurements. CuO NW with a diameter of 85 nm was attached to Au electrodes 2.25 μm apart, using dielectrophoresis. At low electrical field (conduction is observed with an activation energy of 272 meV. The injected electrons fill traps with an average energy, ET = 26.6 meV and trap density, NT = 3.4 × 1015 cm-3. After the traps are saturated, space charge limited current mechanism becomes dominant. For 120 K ≤ T ≤ 210 K phonon scattering limits mobility. For T ≥ 220 K, a thermally activated mobility is observed and is attributed to small polaron hopping with an activation energy of 44 meV. This mechanism yields a hole mobility of 0.0015 cm2/V s and an effective hole concentration of 4 × 1018 cm-3 at 250 K.

  10. One-step self-assembled synthesis of CuO with tunable hierarchical structures and their electrocatalytic properties for nitrite oxidation in aqueous media.

    Science.gov (United States)

    Zhao, Youcheng; Song, Xinyu; Yin, Zhilei; Song, Qisheng

    2013-04-15

    Controlled synthesis of CuO with various hierarchical structures consisting of self-organized nanoparticles is realized by using n-octylamine (OLA) as a structure inducing agent via a facile hydrothermal synthetic method. The growth and assemblage of CuO can be finely tuned by selecting the preparative parameters. In particular, it is found that the degree of the hierarchical organization can be modulated by simply changing the amount of the n-octylamine and CuO nanoparticles exhibit self-assembled two-dimensional (2D) sheet-like, three-dimensional (3D) disk-like and bowknot-like architectures, respectively. In the present case, OLA serves as a capping surfactant that can modulate growth of CuO nanocrystals via hydrophobic forces between the OLA molecules. CuO nanoparticles can be self-assembled into different complex architectures depending on the strength of hydrophobic forces. Hierarchical sphere-like CuO assembled from nanorods can also be easily fabricated by adjusting the starting NaOH to CuCl2 volume ratio, in which OLA serves not only as the structure-directing agent, but also as a weak base agent to produce hydroxyl anions. The electrochemical performances of the as-synthesized different products for sensing nitrite oxidation are evaluated. The results reveal that the electrocatalytic activity is related to the secondary nanostructures. Compared to the others, the bowknot-shaped and sphere-shaped CuO products exhibit excellent electrocatalytic activity toward nitrite oxidation and fast current response in nitrite sensing because of their peculiar hierarchical structures with high BET surface areas and well-ordered pores.

  11. Size-dependent antimicrobial properties of CuO nanoparticles against Gram-positive and -negative bacterial strains

    Directory of Open Access Journals (Sweden)

    Azam A

    2012-07-01

    Full Text Available Ameer Azam,1,2 Arham S Ahmed,2 M Oves,3 MS Khan,3 Adnan Memic11Center of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia; 2Center of Excellence in Materials Science (Nanomaterials, Department of Applied Physics, 3Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, IndiaBackground: CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species. Here we synthesized different sized CuO nanoparticles and explored the size-dependent antibacterial activity of each CuO nanoparticles preparation.Methods: CuO nanoparticles were synthesized using a gel combustion method. In this approach, cupric nitrate trihydrate and citric acid were dissolved in distilled water with a molar ratio of 1:1. The resulting solution was stirred at 100°C, until gel was formed. The gel was allowed to burn at 200°C to obtain amorphous powder, which was further annealed at different temperatures to obtain different size CuO nanoparticles. We then tested the antibacterial properties using well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration methods.Results: XRD spectra confirmed the formation of single phase CuO nanoparticles. Crystallite size was found to increase with an increase in annealing temperature due to atomic diffusion. A minimum crystallite size of 20 nm was observed in the case of CuO nanoparticles annealed at 400°C. Transmission electron microscopy results corroborate well with XRD results. All CuO nanoparticles exhibited inhibitory effects against both Gram-positive and -negative bacteria. The size of the particles was correlated with its antibacterial activity.Conclusion: The antibacterial activity of CuO nanoparticles

  12. Inverse CeO2/CuO catalyst as an alternative to classical direct configurations for preferential oxidation of CO in hydrogen-rich stream.

    Science.gov (United States)

    Hornés, A; Hungría, A B; Bera, P; López Cámara, A; Fernández-García, M; Martínez-Arias, A; Barrio, L; Estrella, M; Zhou, G; Fonseca, J J; Hanson, J C; Rodriguez, J A

    2010-01-13

    A novel inverse CeO(2)/CuO catalyst for preferential oxidation of CO in H(2)-rich stream (CO-PROX) has been developed on the basis of a hypothesis extracted from previous work of the group (JACS 2007, 129, 12064). Possible separation of the two competing oxidation reactions involved in the process (of CO and H(2), respectively) is the key to modulation of overall CO-PROX activity and is based on involvement of different sites as most active ones for each of the two reactions. Achievement of large size CuO particles and adequate CeO(2)-CuO interfacial configurations in the inverse catalyst apparently allows appreciable enhancement of the catalytic properties of this kind of system for CO-PROX, constituting an interesting alternative to classic direct configurations so far explored for this process. Reasons for such behavior are analyzed on the basis of operando-XRD, -XAFS, and -DRIFTS studies.

  13. Synthesis of metal oxide nanoparticles (CuO and ZnO NPs) via biological template and their optical sensor applications

    Science.gov (United States)

    Maruthupandy, Muthuchamy; Zuo, Yong; Chen, Jing-Shuai; Song, Ji-Ming; Niu, He-Lin; Mao, Chang-Jie; Zhang, Sheng-Yi; Shen, Yu-Hua

    2017-03-01

    The present study is focused on employing Camellia japonica leaf extract as inductive and stabilizing agent to synthesis CuO and ZnO nanoparticles (NPs). The chemicals, such as (Cu(NO3)2·3H2O) and (Zn(NO3)2·6H2O) were converted into copper and zinc ions, respectively because of the different natural products present in the C. japonica leaf extract. The UV-vis spectra of CuO and ZnO NPs showed absorption peak at 290 nm and 301 nm, respectively. The XRD result revealed crystalline nature of the metal oxide NPs and the TEM images indicated that average sizes of the synthesized CuO and ZnO NPs were ∼17 nm and ∼20 nm, respectively. The FTIR spectra of C. japonica leaf extract showed the presence of organic groups, such as, sbnd OH, sbnd Csbnd N, and N-H, which would be responsible for forming CuO and ZnO NPs. The synthesized CuO and ZnO NPs were tested for the optical sensing of metal ions, viz. Li+ and Ag+ that illustrated excellent outcome and hence this method offers a novel lane for the synthesis of metal oxide NPs, which can be used as optical sensor for the detection of metal ions.

  14. Catalytic Decomposition of Nitric Oxide over Nano-sized PbTiO3 Supported Cupric Oxide%纳米晶PbTiO3负载CuO催化NO分解

    Institute of Scientific and Technical Information of China (English)

    邢丽; 薛念华; 陈向科; 郭学锋; 丁维平; 陈懿

    2005-01-01

    A large specific surface area perovskite-type mixed oxide PbTiO3 supported cupric oxide was synthesized as a catalyst for NO decomposition and characterized by techniques such as XPS, XRD,H2-TPR before and after NO deconlposition reactions. The catalytic properties were tested with a fix-bed micro-reactor. The results showed that the PbTiO3 was inactive for the reactions, but 1wt % Cu/PbTiO3 catalyst gave fairly good activities for NO decomposition at temperature as low as 473K. Copper species were found well-dispersed but weakly interacted with the support before NO decomposition, and the NO decomposition caused significant change in the environment of the copper species, which became Cu(Ⅰ) and most probably incorporated into surface crystal lattice of the nano-sized PbTiO3. In NO reaction, a large amount of oxygen atoms from the decomposition of NO penetrated into the nano-sized PbTiO3 support and caused small expansion of crystal lattice. The transport of oxygen between the copper species and the catalyst support may be helpful to speed up the kinetic regeneration of active metal sites from oxygen occupancy and resulted in good catalytic performance.

  15. Indium oxide (In2O3) nanoparticles induce progressive lung injury distinct from lung injuries by copper oxide (CuO) and nickel oxide (NiO) nanoparticles.

    Science.gov (United States)

    Jeong, Jiyoung; Kim, Jeongeun; Seok, Seung Hyeok; Cho, Wan-Seob

    2016-04-01

    Indium is an essential element in the manufacture of liquid crystal displays and other electronic devices, and several forms of indium compounds have been developed, including nanopowders, films, nanowires, and indium metal complexes. Although there are several reports on lung injury caused by indium-containing compounds, the toxicity of nanoscale indium oxide (In2O3) particles has not been reported. Here, we compared lung injury induced by a single exposure to In2O3 nanoparticles (NPs) to that caused by benchmark high-toxicity nickel oxide (NiO) and copper oxide (CuO) NPs. In2O3 NPs at doses of 7.5, 30, and 90 cm(2)/rat (50, 200, and 600 µg/rat) were administered to 6-week-old female Wistar rats via pharyngeal aspiration, and lung inflammation was evaluated 1, 3, 14, and 28 days after treatment. Neutrophilic inflammation was observed on day 1 and worsened until day 28, and severe pulmonary alveolar proteinosis (PAP) was observed on post-aspiration days 14 and 28. In contrast, pharyngeal aspiration of NiO NPs showed severe neutrophilic inflammation on day 1 and lymphocytic inflammation with PAP on day 28. Pharyngeal aspiration of CuO NPs showed severe neutrophilic inflammation on day 1, but symptoms were completely resolved after 14 days and no PAP was observed. The dose of In2O3 NPs that produced progressive neutrophilic inflammation and PAP was much less than the doses of other toxic particles that produced this effect, including crystalline silica and NiO NPs. These results suggest that occupational exposure to In2O3 NPs can cause severe lung injury.

  16. A density functional theory study of partial oxidation of propylene on Cu{sub 2}O(0 0 1) and CuO(0 0 1) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Düzenli, Derya [Chemical Engineering Department, Middle East Technical University, 06800 Ankara (Turkey); Mineral Analysis and Technology, General Directorate of Mineral Research and Exploration, 06800 Ankara (Turkey); Atmaca, Deniz Onay; Gezer, Miray Gülbiter [Chemical Engineering Department, Middle East Technical University, 06800 Ankara (Turkey); Onal, Isik, E-mail: ional@metu.edu.tr [Chemical Engineering Department, Middle East Technical University, 06800 Ankara (Turkey)

    2015-11-15

    Graphical abstract: - Highlights: • Propylene epoxidation mechanism on Cu{sub 2}O(0 0 1) and CuO(0 0 1) surfaces is investigated using DFT method. • Acrolein is found to be a thermodynamically more favorable product for both surfaces especially over CuO surface. • The more basic property of the surface oxygen increases the probability of acrolein formation over CuO(0 0 1) surface. - Abstract: This work theoretically investigates propylene epoxidation reaction on Cu{sub 2}O(0 0 1) and CuO(0 0 1) surfaces using periodical DFT method to determine the active copper species within the reaction mechanism. The transition states and energy profiles are calculated for the formation of surface intermediates such as oxametallopropylene (OMP) over Cu{sub 2}O(0 0 1) and oxygen bridging (OB) over CuO(0 0 1) and allylic H-stripping reaction (AHS) over both surfaces as well as for formation of products. Propylene oxide (PO) and acetone are obtained through OMP and OB surface intermediates and acrolein generation is observed through allylic H-stripping reaction (AHS). The calculations revealed that the corresponding surface intermediates for epoxidation reaction need to overcome an activation barrier of 13 kcal/mol over CuO surface whereas they occur without an energy barrier over Cu{sub 2}O surface indicating the higher activity of Cu{sup +} species. Acrolein is also found to be a thermodynamically more favorable product for both surfaces especially over CuO surface due to the presence of more surface oxygen atoms on which the basicity has been evaluated by the adsorption of sulfur dioxide. This indicates that the lattice oxygen inherent in both surface types does not participate in PO production.

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

    Science.gov (United States)

    Dimkpa, Christian O.; McLean, Joan E.; Latta, Drew E.; Manangón, Eliana; Britt, David W.; Johnson, William P.; Boyanov, Maxim I.; Anderson, Anne J.

    2012-09-01

    Metal oxide nanoparticles (NPs) are reported to impact plant growth in hydroponic systems. This study describes the impact of commercial CuO (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.

  18. Aggregation and removal of copper oxide (CuO) nanoparticles in wastewater environment and their effects on the microbial activities of wastewater biofilms.

    Science.gov (United States)

    Miao, Lingzhan; Wang, Chao; Hou, Jun; Wang, Peifang; Ao, Yanhui; Li, Yi; Geng, Nan; Yao, Yu; Lv, Bowen; Yang, Yangyang; You, Guoxiang; Xu, Yi

    2016-09-01

    The transport behaviors of copper oxide (CuO) NPs in wastewater matrix and their possible impacts on microbial activities of stable wastewater biofilms cultivated in a lab scale rotating biological contactor (RBC) were investigated. Significant aggregation of CuO NPs was observed in the wastewater samples, depending on their mass concentrations. Extracellular polymeric substance (EPS)-adsorbed copper accounted for a large proportion of the total copper accumulated in biofilms. The microelectrode profiles showed that a single pulse exposure to 50mg/L CuO resulted in a deeper penetration depth of oxygen in biofilms compared to the CuO NP free biofilms. The maximum oxygen consumption rate shifted to the deeper parts of biofilms, indicating that the respiration activities of bacteria in the top region of the biofilms was significantly inhibited by CuO NPs. Biofilms secreted more EPS in response to the nano-CuO stress, with higher production of proteins compared to polysaccharides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Physical Properties and Selective CO Oxidation of Coprecipitated CuO/CeO2 Catalysts Depending on the CuO in the Samples

    Directory of Open Access Journals (Sweden)

    Akkarat Wongkaew

    2013-01-01

    Full Text Available This paper investigates the effects of CuO contents in the CuO-CeO2 catalysts to the variation in physical properties of CuO/CeO2 catalysts and correlates them to their catalytic activities on selective CO oxidation. The characteristic of crystallites were revealed by X-ray diffraction, and their morphological developments were examined with TEM, SEM, and BET methods. Catalytic performance of catalysts was investigated in the temperature range of 90–240°C. The results showed that the catalyst was optimized at CuO loading of 20 wt.%. This was due to the high dispersion of CuO, high specific surface area, small crystallite sizes, and low degree of CuO agglomeration. Complete CO conversion with near 100% selectivity was achieved at a temperature below 120°C. The optimal performance was seen as a balance between CuO content and dispersion observed with growth, morphology, and agglomeration of nanostructures.

  20. Effect of the loading content of CuO on the activity and structure of CuO/Ce-Mn-O catalysts for CO oxidation

    Institute of Scientific and Technical Information of China (English)

    赵福真; 龚渺; 张广营; 李金林

    2015-01-01

    A urea-nitrate combustion method was used to prepare Ce-Mn-O material, which was applied as the support for a series of CuO/Ce-Mn-O catalysts. The structure of the catalysts was characterized with N2 adsorption/desorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of the catalysts for the oxidation of CO was evaluated on a conventional fixed-bed quartz reactor. XRD results showed that the synergetic effect between manganese and cerium led to a little higher electron density of Ce3+ in the mixed oxides. When the CuO content was lower than 5 wt.%, Cu species were well dispersed onto the Ce-Mn-O support or/and they formed a solid solution with CeO2 (inside the fluorite lattice). At higher CuO content (CuO>5 wt.%), large CuO particles were observed. There was strong interaction among ceria, man-ganese and copper oxide because of the doping of Mn. This interplay changed the reducibility and the valence states of the compo-nents, leading to the improved activity of the CuO/Ce-Mn-O catalysts.

  1. Methane oxidation and abundance of methane oxidizers in tropical agricultural soil (vertisol) in response to CuO and ZnO nanoparticles contamination.

    Science.gov (United States)

    Mohanty, Santosh Ranjan; Rajput, Parul; Kollah, Bharati; Chourasiya, Dipanti; Tiwari, Archana; Singh, Muneshwar; Rao, A Subba

    2014-06-01

    There is worldwide concern over the increase use of nanoparticles (NPs) and their ecotoxicological effect. It is not known if the annual production of tons of industrial nanoparticles (NPs) has the potential to impact terrestrial microbial communities, which are so necessary for ecosystem functioning. Here, we have examined the consequences of adding the NPs particularly the metal oxide (CuO, ZnO) on CH4 oxidation activity in vertisol and the abundance of heterotrophs, methane oxidizers, and ammonium oxidizers. Soil samples collected from the agricultural field located at Madhya Pradesh, India, were incubated with either CuO and ZnO NPs or ionic heavy metals (CuCl2, ZnCl2) separately at 0, 10, and 20 μg g(-1) soil. CH4 oxidation activity in the soil samples was estimated at 60 and 100 % moisture holding capacity (MHC) in order to link soil moisture regime with impact of NPs. NPs amended to soil were highly toxic for the microbial-mediated CH4 oxidation, compared with the ionic form. The trend of inhibition was Zn 20 > Zn 10 > Cu 20 > Cu 10. NPs delayed the lag phase of CH4 oxidation to a maximum of 4-fold and also decreased the apparent rate constant k up to 50 % over control. ANOVA and Pearson correlation analysis (α = 0.01) revealed significant impact of NPs on the CH4 oxidation activity and microbial abundance (p Biplot indicated negative impact of NPs on CH4 oxidation and microbial abundance. Our result also confirmed that higher soil moisture regime alleviates toxicity of NPs and opens new avenues of research to manage ecotoxicity and environmental hazard of NPs.

  2. 3D hierarchical walnut-like CuO nanostructures: Preparation, characterization and their efficient catalytic activity for CO oxidation

    Science.gov (United States)

    Yao, Weitang; Zhang, Yujuan; Duan, Tao; Zhu, Wenkun; Yi, Zao; Cui, Xudong

    2016-07-01

    In this work, 3D hierarchical walnut-shaped, 2D nanosheet and 3D microspheres single phase CuO nanostructures are functioning as catalysts and supporting materials, differing from the conventional ways. The novel nanostructures were synthesized via hydrothermal method under a stainless steel autoclave. The as-prepared materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and H2 temperature-programmed reduction (H2-TPR). The walnut-shaped structures with high O/Cu atomic ratio (1.22) exhibit high oxygen adsorption capacity and greatly enhanced catalytic activity. These results will be enrich the techniques for tuning the morphologies of metal oxide micro/nanostructures and open a new field in catalytic applications.

  3. 3D hierarchical walnut-like CuO nanostructures: Preparation, characterization and their efficient catalytic activity for CO oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Weitang [Laboratory of Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010 (China); Zhang, Yujuan [Laboratory of Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010 (China); Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang, Sichuan 621900 (China); Duan, Tao, E-mail: duant@ustc.edu.cn [Laboratory of Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010 (China); Zhu, Wenkun; Yi, Zao [Laboratory of Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010 (China); Cui, Xudong, E-mail: xudcui@163.com [Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang, Sichuan 621900 (China)

    2016-07-15

    In this work, 3D hierarchical walnut-shaped, 2D nanosheet and 3D microspheres single phase CuO nanostructures are functioning as catalysts and supporting materials, differing from the conventional ways. The novel nanostructures were synthesized via hydrothermal method under a stainless steel autoclave. The as-prepared materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and H{sub 2} temperature-programmed reduction (H{sub 2}-TPR). The walnut-shaped structures with high O/Cu atomic ratio (1.22) exhibit high oxygen adsorption capacity and greatly enhanced catalytic activity. These results will be enrich the techniques for tuning the morphologies of metal oxide micro/nanostructures and open a new field in catalytic applications.

  4. Structural and dielectric properties of Mn doped copper oxide (CuO) nanostructure

    Science.gov (United States)

    Khan, Imran; Khan, Shakeel; Ahmed, Hilal; Nongjai, Razia

    2013-06-01

    Undoped and Mn doped CuO nanocrystalline powder samples were prepared through standard solid state reaction method. The crystal structures of the CuO nanoparticles were characterized by X-ray diffraction. Dielectric measurements were performed on samples as a function of frequency at room temperate to determine the dielectric behavior of the samples. XRD data exhibited the presence of monoclinic crystal structure similar to the parent compound in all samples, suggesting that doped Mn ions sit at the regular lattice sites. The average crystallite size, calculated using Scherrer formula from XRD data, is found within the range of 23-27 nm. The dielectric constant (ɛ'), imaginary part of dielectric constant (ɛ") and loss tangent (tanδ) were studied as a function of frequency and composition at room temperature. The dependence of dielectric constant (ɛ') on frequency suggests a conduction mechanism in terms of hopping. This behavior can be explained on the basis of space charge polarization according to Maxwell and Wagner's two-layer model.

  5. CuO and Ag2O/CuO Catalyzed Oxidation of Aldehydes to the Corresponding Carboxylic Acids by Molecular Oxygen

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-04-01

    Full Text Available Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag2O/CuO (92% or simply CuO (86.6%. When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under optimal conditions, a series of aromaticand aliphatic aldehydes were oxidized to the corresponding acids in good yields.

  6. 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.

  7. CuO impregnated activated carbon for catalytic wet peroxide oxidation of phenol.

    Science.gov (United States)

    Liou, Rey-May; Chen, Shih-Hsiung

    2009-12-15

    This paper presents an original approach to the removal of phenol in synthetic wastewater by catalytic wet peroxide oxidation with copper binding activated carbon (CuAC) catalysts. The characteristics and oxidation performance of CuAC in the wet hydrogen peroxide catalytic oxidation of phenol were studied in a batch reactor at 80 degrees C. Complete conversion of the oxidant, hydrogen peroxide, was observed with CuAC catalyst in 20 min oxidation, and a highly efficient phenol removal and chemical oxygen demand (COD) abatement were achieved in the first 30 min. The good oxidation performance of CuAC catalyst was contributed to the activity enhancement of copper oxide, which was binding in the carbon matrix. It can be concluded that the efficiency of oxidation dominated by the residual H2O2 in this study. An over 90% COD removal was achieved by using the multiple-step addition in this catalytic oxidation.

  8. Inverse CeO2/CuO Catalyst as an Alternative to Classical Direct Configurations for Preferential Oxidation of CO in Hydrogen-Rich Stream

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.A.; Hornes, A.; Hungría, A.B.; Bera, P.; Camara, A.L.; Fernandez-Garcia, M.; Martinez-Arias, A.; Barrio, L.; Estrella, M.; Zhou, G.; Fonseca, J.J.; Hanson, J.C.

    2010-01-13

    A novel inverse CeO{sub 2}/CuO catalyst for preferential oxidation of CO in H{sub 2}-rich stream (CO-PROX) has been developed on the basis of a hypothesis extracted from previous work of the group (JACS 2007, 129, 12064). Possible separation of the two competing oxidation reactions involved in the process (of CO and H{sub 2}, respectively) is the key to modulation of overall CO-PROX activity and is based on involvement of different sites as most active ones for each of the two reactions. Achievement of large size CuO particles and adequate CeO{sub 2}-CuO interfacial configurations in the inverse catalyst apparently allows appreciable enhancement of the catalytic properties of this kind of system for CO-PROX, constituting an interesting alternative to classic direct configurations so far explored for this process. Reasons for such behavior are analyzed on the basis of operando-XRD, -XAFS, and -DRIFTS studies.

  9. Inverse CeO2/CuO Catalyst as an Alternative to Classical Direct Configurations for Preferential Oxidation of CO in Rich Hydrogen Stream

    Energy Technology Data Exchange (ETDEWEB)

    Hornes, A.; Hungri, A; Bera, P; Lopez Camara, A; Fernandez-Garcia, M; Martinez-Arias, A; Barrio, L; Estrella, M; Zhou, G; et. al.

    2010-01-01

    A novel inverse CeO{sub 2}/CuO catalyst for preferential oxidation of CO in H{sub 2}-rich stream (CO-PROX) has been developed on the basis of a hypothesis extracted from previous work of the group (JACS 2007, 129, 12064). Possible separation of the two competing oxidation reactions involved in the process (of CO and H{sub 2}, respectively) is the key to modulation of overall CO-PROX activity and is based on involvement of different sites as most active ones for each of the two reactions. Achievement of large size CuO particles and adequate CeO{sub 2}-CuO interfacial configurations in the inverse catalyst apparently allows appreciable enhancement of the catalytic properties of this kind of system for CO-PROX, constituting an interesting alternative to classic direct configurations so far explored for this process. Reasons for such behavior are analyzed on the basis of operando-XRD, -XAFS, and -DRIFTS studies.

  10. Hydrothermal synthesis of CuO micro-/nanostructures and their applications in the oxidative degradation of methylene blue and non-enzymatic sensing of glucose/H2O2.

    Science.gov (United States)

    Prathap, M U Anu; Kaur, Balwinder; Srivastava, Rajendra

    2012-03-15

    In this paper, we report on the amino acids-/citric acid-/tartaric acid-assisted morphologically controlled hydrothermal synthesis of micro-/nanostructured crystalline copper oxides (CuO). These oxides were characterized by means of X-ray diffraction, nitrogen sorption, scanning electron microscopy, Fourier transform infrared, and UV-visible spectroscopy. The surface area of metal oxides depends on the amino acid used in the synthesis. The formation mechanisms were proposed based on the experimental results, which show that amino acid/citric acid/tartaric acid and hydrothermal time play an important role in tuning the morphology and structure of CuO. The catalytic activity of as-synthesized CuO was demonstrated by catalytic oxidation of methylene blue in the presence of hydrogen peroxide (H(2)O(2)). CuO synthesized using tyrosine was found to be the best catalyst compared to a variety of CuO synthesized in this study. CuO (synthesized in this study)-modified electrodes were used for the construction of non-enzymatic sensors, which displayed excellent electrocatalytic response for the detection of H(2)O(2) and glucose compared to conventional CuO. The high electrocatalytic response observed for the CuO synthesized using tyrosine can be correlated with the large surface area, which enhances the accessibility of H(2)O(2)/glucose molecule to the active site that results in high observed current. The methodology adopted in the present study provides a new platform for the fabrication of CuO-based high-performance glucose and other biosensors.

  11. Active sites over CuO/CeO2 and inverse CeO2/CuO catalysts for preferential CO oxidation

    Science.gov (United States)

    Zeng, Shanghong; Wang, Yan; Ding, Suping; Sattler, Jesper J. H. B.; Borodina, Elena; Zhang, Lu; Weckhuysen, Bert M.; Su, Haiquan

    2014-06-01

    A series of CuO/CeO2 and inverse CeO2/CuO catalysts are prepared by the surfactant-templated method and characterized via XRD, HRTEM, H2-TPR, SEM, XPS, in situ XRD, in situ UV-Vis and N2 adsorption-desorption techniques. It is found that there are two kinds of surface sites in the CuO-CeO2 system, including CuO surface sites for CO chemisorption and CeO2 surface sites with oxygen vacancies for oxygen sorption. The active sites for CO oxidation are located on the contact interface of two-kind surface sites and the lattice oxygen can make a significant contribution to the CO-PROX reaction. The resistance to H2O and CO2 is related to BET surface area, the crystallite sizes of CuO and the reduction behavior of catalysts. The Ce4Cu4 and Ce4Cu1 catalysts exhibit the best resistance against H2O and CO2.

  12. Preferential oxidation of CO in excess H2 over the CeO2/CuO catalyst:Effect of initial support

    Institute of Scientific and Technical Information of China (English)

    Zhiming Gao; Yuanyuan Gong; Qiang Zhang; Hao Deng; Yong Yue

    2014-01-01

    Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperature-programmed reduction (TPR), XPS and TEM techniques. In comparison with the samples prepared with CuO as initial support, the samples with Cu(OH)2 as initial support have higher reducibilities and smaller relative TPR peak areas, and also larger specific surface areas at calcina-tion temperatures of 400◦C-600◦C. As a result, Cu(OH)2 is better than CuO as initial support for preferential oxidation of CO in excess H2 (CO-PROX). The best catalytic performance was achieved on the sample calcined at 600◦C and with an atomic ratio of Ce/Cu at 40%. XPS analyses indicate that more interface linkages Ce-O-Cu could be formed when it was calcined at 600◦C. And the atomic ratio of Ce/Cu at 40%led to a proper reducibility for the sample as illustrated by the TPR measurements.

  13. 氯化铜脱除硫化氢气体制硫磺研究%H2S Removal with Cupric Chloride for Producing Sulfur

    Institute of Scientific and Technical Information of China (English)

    张俊丰; 童志权

    2006-01-01

    A novel technology of removing H2S with cupric chloride solution was developed in this paper. Cupric as the form of CuS deposition, the CuS produced was then oxidized by excessive cupric ion in another reactor meanwhile cupric ion that has been consumed can be recovered by the oxidization of CuCl2- with oxygen in air,and the solution can be circulated. Moreover, the leaching kinetics of CuS by cupric ion was studied. The removal efficiency of H2S is close to 100%, and the required operating condition is mild. Compared with other wet oxidization methods, no raw material is consumed except O2 in air, the process has no secondary pollution and no problem of degradation and scale, and the absorbent is much stable and reliable.

  14. Chemical bath deposited (CBD) CuO thin films on n-silicon substrate for electronic and optical applications: Impact of growth time

    Science.gov (United States)

    Sultana, Jenifar; Paul, Somdatta; Karmakar, Anupam; Yi, Ren; Dalapati, Goutam Kumar; Chattopadhyay, Sanatan

    2017-10-01

    Thin film of p-type cupric oxide (p-CuO) is grown on silicon (n-Si) substrate by using chemical bath deposition (CBD) technique and a precise control of thickness from 60 nm to 178 nm has been achieved. The structural properties and stoichiometric composition of the grown films are observed to depend significantly on the growth time. The chemical composition, optical properties, and structural quality are investigated in detail by employing XRD, ellipsometric measurements and SEM images. Also, the elemental composition and the oxidation states of Cu and O in the grown samples have been studied in detail by XPS measurements. Thin film of 110 nm thicknesses exhibited the best performance in terms of crystal quality, refractive index, dielectric constant, band-gap, and optical properties. The study suggests synthesis route for developing high quality CuO thin film using CBD method for electronic and optical applications.

  15. Dispersion state of CuO on CeO2——An incorporation model for the interaction between metal oxide and oxide support

    Institute of Scientific and Technical Information of China (English)

    董林; 金永漱; 陈懿

    1997-01-01

    XRD and XPS are used to study the dispersion state of CuO on ceria surface.The dispersion capacity values of CuO measured by the two methods are consistent,which are of 1.20 mmol CuO/100 m CeO2.In addition,the results reveal that highly dispersed Cu2 + ions are formed at low CuO loadings and that increasing the CuO content to a value higher than its dispersion capacity produces crystalline CuO after the surface vacant sites on CeO2 are filled.The atomic composition of the outermost layer of the CuO/CeO2 samples has been probed by using static secondary ion mass spectroscopy (SSIMS),and the ratios of Cu/Ce are found to be 0.93 and 0.46 for the 1.22 and 0 61 mmol CuO/CeO2 samples respectively.Temperature-programmed reduction (TPR) profile with two reduction peaks at 156 and 16513 suggests that the reduction of highly dispersed Cu2+ ions consists of two steps and is easier than that of CuO crystallites,in which the TPR profile has only one reduction peak at about 249℃.The above experimental results are in

  16. Characterization of CuO(1 1 1)/MgO(1 0 0) films grown under two different PLD backgrounds

    Science.gov (United States)

    Kawwam, M.; Alharbi, F. H.; Kayed, T.; Aldwayyan, A.; Alyamani, A.; Tabet, N.; Lebbou, K.

    2013-07-01

    Cupric oxide (CuO) films were deposited on MgO (1 0 0) substrates by two different pulsed laser deposition (PLD) configurations, molecular gas background and RF-plasma assisted, at temperatures over 250-450 °C range. The films were characterized by X-ray diffraction (XRD), reflection of high energy electron diffraction (RHEED), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometery, and four probe conductivity measurements. The heating temperature was found to have a limited effect on the structural properties of the films grown in RF-plasma assisted background while it has a significant effect in the case of the standard gas background. The structural observations revealed that RF-plasma background increased the possibility of Frank-van der Merwe or the initial stages of Stranski-Krastanov growth mode, leaving the CuO films highly textured in (1 1 1) direction, atomically smooth and chemically stoichiometric. Optoelectronic properties of best obtained CuO film are presented as well.

  17. Characterization of CuO(1 1 1)/MgO(1 0 0) films grown under two different PLD backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Kawwam, M., E-mail: Mohammad.kawwam@univ-lyon1.fr [Laboratoire de Physico Chimie des Matériaux Luminescents (LPCML) UMR 5620 CNRS Université de Lyon 1, 69622 Villeurbanne cedex, Lyon (France); King Abdullah Institute for Nanotechnology, King Saud University, Riyadh (Saudi Arabia); Alharbi, F.H. [Energy Research Institute, King Abdulaziz City for Science and Technology (KACST), Riyadh (Saudi Arabia); Qatar Environment and Energy Research Institute, Doha (Qatar); Kayed, T. [College of Engineering University of Dammam (Saudi Arabia); Aldwayyan, A. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh (Saudi Arabia); Alyamani, A. [Energy Research Institute, King Abdulaziz City for Science and Technology (KACST), Riyadh (Saudi Arabia); Tabet, N. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Lebbou, K. [Laboratoire de Physico Chimie des Matériaux Luminescents (LPCML) UMR 5620 CNRS Université de Lyon 1, 69622 Villeurbanne cedex, Lyon (France)

    2013-07-01

    Cupric oxide (CuO) films were deposited on MgO (1 0 0) substrates by two different pulsed laser deposition (PLD) configurations, molecular gas background and RF-plasma assisted, at temperatures over 250–450 °C range. The films were characterized by X-ray diffraction (XRD), reflection of high energy electron diffraction (RHEED), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometery, and four probe conductivity measurements. The heating temperature was found to have a limited effect on the structural properties of the films grown in RF-plasma assisted background while it has a significant effect in the case of the standard gas background. The structural observations revealed that RF-plasma background increased the possibility of Frank–van der Merwe or the initial stages of Stranski–Krastanov growth mode, leaving the CuO films highly textured in (1 1 1) direction, atomically smooth and chemically stoichiometric. Optoelectronic properties of best obtained CuO film are presented as well.

  18. PREPARATION OF BENZIL BY OXIDIZING BENZOIN WITH CUPRIC NITRATE%硝酸铜氧化安息香制备苯偶酰

    Institute of Scientific and Technical Information of China (English)

    文瑞明; 丁亮中; 罗新湘; 俞善信

    2003-01-01

    @@ INTRODUCTION Benzil is an important photosensitive initiator of organic synthesis intermediates, medicinal intermediates and ultraviolet solidified resin(UV resin), and is usually prepared by oxidizing benzoin. The oxidizers and methods reported are mainly: (PhCH2Et3N)+Br-/(PhCO)2O2/MeCN[1], DMSO/(COCl)2/CH2Cl2[2], CrO3*CH3NH2*HCl/Al2O3[3], the metallorganic compound[4], microwave radiation[5],etc.

  19. Enhanced bromate formation during chlorination of bromide-containing waters in the presence of CuO: Catalytic disproportionation of hypobromous acid

    KAUST Repository

    Liu, Chao

    2012-10-16

    Bromate (BrO3 -) in drinking water is traditionally seen as an ozonation byproduct from the oxidation of bromide (Br-), and its formation during chlorination is usually not significant. This study shows enhanced bromate formation during chlorination of bromide-containing waters in the presence of cupric oxide (CuO). CuO was effective to catalyze hypochlorous acid (HOCl) or hypobromous acid (HOBr) decay (e.g., at least 104 times enhancement for HOBr at pH 8.6 by 0.2 g L-1 CuO). Significant halate concentrations were formed from a CuO-catalyzed hypohalite disproportionation pathway. For example, the chlorate concentration was 2.7 ± 0.2 μM (225.5 ± 16.7 μg L-1) after 90 min for HOCl (Co = 37 μM, 2.6 mg L-1 Cl2) in the presence of 0.2 g L-1 CuO at pH 7.6, and the bromate concentration was 6.6 ± 0.5 μM (844.8 ± 64 μg L -1) after 180 min for HOBr (Co = 35 μM) in the presence of 0.2 g L-1 CuO at pH 8.6. The maximum halate formation was at pHs 7.6 and 8.6 for HOCl or HOBr, respectively, which are close to their corresponding pKa values. In a HOCl-Br--CuO system, BrO3 - formation increases with increasing CuO doses and initial HOCl and Br- concentrations. A molar conversion (Br - to BrO3 -) of up to (90 ± 1)% could be achieved in the HOCl-Br--CuO system because of recycling of Br - to HOBr by HOCl, whereas the maximum BrO3 - yield in HOBr-CuO is only 26%. Bromate formation is initiated by the formation of a complex between CuO and HOBr/OBr-, which then reacts with HOBr to generate bromite. Bromite is further oxidized to BrO3 - by a second CuO-catalyzed process. These novel findings may have implications for bromate formation during chlorination of bromide-containing drinking waters in copper pipes. © 2012 American Chemical Society.

  20. Lead Nitrate Titration Determination of Cupric Oxide in Extension of Delay Powder%硝酸铅滴定法测定延期药中氧化铜

    Institute of Scientific and Technical Information of China (English)

    王风清; 董男平; 崔丽梅; 国飞; 朱晓莉

    2014-01-01

    以硝酸和H2O2对延期药中铅化合物和氧化铜完成溶解,通过硫脲释放,采用硝酸铅滴定法测定延期药中的氧化铜。加入30 mL HNO3溶液(1+8)和15 mL六次甲基四胺控制样品溶液为pH 5~6。结果表明,方法的回收率为98.8%~99.9%,测定结果的相对标准偏差为0.12%~0.2%(n=6)。该方法准确可靠,可用于延期药中氧化铜分析。%Copper oxide and lead compounds in delay powder were dissolved by nitric acid and H2O2,and released by thiourea,then copper oxide was determined with lead nitrate titration method. Sample solution was controlled as pH 5-6 by adding 30 mL HNO3 solution (1+8) and 15 mL hexamethylenetetramine. The results showed that the recoveries were 98.8%-99.9%,and the relative standard deviations of determination results were 0.12%-0.2%(n=6). The method is accurate,reliable,and suitable to determine copper oxide in delay powder.

  1. Chlorination of bromide-containing waters: Enhanced bromate formation in the presence ofsynthetic metal oxides and deposits formed indrinking water distribution systems

    KAUST Repository

    Liu, Chao

    2013-09-01

    Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhanced the decay of hypobromous acid (HOBr), a requisite intermediate during the oxidation of bromide to bromate, via (i) disproportionation to bromate in the presence of nickel oxide (NiO) and cupric oxide (CuO), (ii) oxidation of a metal to a higher valence state in the presence of cuprous oxide (Cu2O) and (iii) oxygen formation by NiO and CuO. Goethite (α-FeOOH) did not enhance either of these pathways. Non-charged species of metal oxides seem to be responsible for the catalytic disproportionation which shows its highest rate in the pH range near the pKa of HOBr. Due to the ability to catalyze HOBr disproportionation, bromate was formed during chlorination of bromide-containing waters in the presence of CuO and NiO, whereas no bromate was detected in the presence of Cu2O and α-FeOOH for analogous conditions. The inhibition ability of coexisting anions on bromate formation at pH 8.6 follows the sequence of phosphate>>sulfate>bicarbonate/carbonate. A black deposit in a water pipe harvested from a drinking water distribution system exerted significant residual oxidant decay and bromate formation during chlorination of bromide-containing waters. Energy dispersive spectroscopy (EDS) analyses showed that the black deposit contained copper (14%, atomic percentage) and nickel (1.8%, atomic percentage). Cupric oxide was further confirmed by X-ray diffraction (XRD). These results indicate that bromate formation may be of concern during chlorination of bromide-containing waters in distribution systems containing CuO and/or NiO. © 2013 Elsevier Ltd.

  2. Chlorination of bromide-containing waters: enhanced bromate formation in the presence of synthetic metal oxides and deposits formed in drinking water distribution systems.

    Science.gov (United States)

    Liu, Chao; von Gunten, Urs; Croué, Jean-Philippe

    2013-09-15

    Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhanced the decay of hypobromous acid (HOBr), a requisite intermediate during the oxidation of bromide to bromate, via (i) disproportionation to bromate in the presence of nickel oxide (NiO) and cupric oxide (CuO), (ii) oxidation of a metal to a higher valence state in the presence of cuprous oxide (Cu2O) and (iii) oxygen formation by NiO and CuO. Goethite (α-FeOOH) did not enhance either of these pathways. Non-charged species of metal oxides seem to be responsible for the catalytic disproportionation which shows its highest rate in the pH range near the pKa of HOBr. Due to the ability to catalyze HOBr disproportionation, bromate was formed during chlorination of bromide-containing waters in the presence of CuO and NiO, whereas no bromate was detected in the presence of Cu2O and α-FeOOH for analogous conditions. The inhibition ability of coexisting anions on bromate formation at pH 8.6 follows the sequence of phosphate > sulfate > bicarbonate/carbonate. A black deposit in a water pipe harvested from a drinking water distribution system exerted significant residual oxidant decay and bromate formation during chlorination of bromide-containing waters. Energy dispersive spectroscopy (EDS) analyses showed that the black deposit contained copper (14%, atomic percentage) and nickel (1.8%, atomic percentage). Cupric oxide was further confirmed by X-ray diffraction (XRD). These results indicate that bromate formation may be of concern during chlorination of bromide-containing waters in distribution systems containing CuO and/or NiO. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Crystallization and electrical resistivity of Cu{sub 2}O and CuO obtained by thermal oxidation of Cu thin films on SiO{sub 2}/Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    De Los Santos Valladares, L., E-mail: ld301@cam.ac.uk [Cavendish Laboratory, University of Cambridge, J.J Thomson Av., Cambridge CB3 0HE (United Kingdom); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901, Recife-Pe (Brazil); Salinas, D. Hurtado [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Dominguez, A. Bustamante [Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Najarro, D. Acosta [Instituto de Fisica, Departamento de Materia Condensada, Universidad Nacional Autonoma de Mexico, Ap. Postal 20-364, CP 01000 (Mexico); Khondaker, S.I. [NanoScience Technology Centre and Department of Physics, University of Central Florida, Orlando, FL 32826 (United States); Mitrelias, T.; Barnes, C.H.W. [Cavendish Laboratory, University of Cambridge, J.J Thomson Av., Cambridge CB3 0HE (United Kingdom); Aguiar, J. Albino [Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901, Recife-Pe (Brazil); Majima, Y. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); CREST, Japan Science and Technology Agency (JST), 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan)

    2012-08-01

    In this work, we study the crystallization and electrical resistivity of the formed oxides in a Cu/SiO{sub 2}/Si thin film after thermal oxidation by ex-situ annealing at different temperatures up to 1000 Degree-Sign C. Upon increasing the annealing temperature, from the X ray diffractogram the phase evolution Cu {yields} Cu + Cu{sub 2}O {yields} Cu{sub 2}O {yields} Cu{sub 2}O + CuO {yields} CuO was detected. Pure Cu{sub 2}O films are obtained at 200 Degree-Sign C, whereas uniform CuO films without structural surface defects such as terraces, kinks, porosity or cracks are obtained in the temperature range 300-550 Degree-Sign C. In both oxides, crystallization improves with annealing temperature. A resistivity phase diagram, which is obtained from the current-voltage response, is presented here. The resistivity was expected to increase linearly as a function of the annealing temperature due to evolution of oxides. However, anomalous decreases are observed at different temperatures ranges, this may be related to the improvement of the crystallization and crystallite size when the temperature increases. - Highlights: Black-Right-Pointing-Pointer The crystallization and electrical resistivity of oxides in a Cu films are studied. Black-Right-Pointing-Pointer In annealing Cu films, the phase evolution Cu + Cu{sub 2}O {yields} Cu{sub 2}O {yields} Cu{sub 2}O + CuO {yields} CuO occurs. Black-Right-Pointing-Pointer A resistivity phase diagram, obtained from the current-voltage response, is presented. Black-Right-Pointing-Pointer Some decreases in the resistivity may be related to the crystallization.

  4. Influence of reduction energy match among CuO species in CuO-CeO2 catalysts on the catalytic performance for CO preferential oxidation in excess hydrogen

    Institute of Scientific and Technical Information of China (English)

    Zhigang Liu; Yunlong Xie; Wensheng Li; Renxian Zhou; Xiaoming Zheng

    2011-01-01

    In the present study,we have investigated the reducibility of CuO species on CuO-CeO2 catalysts and the influence of CuO species on the catalytic performance for CO preferential oxidation(CO PROX)in excess hydrogen.It is revealed that the smaller the difference of reduction temperature(denoted as △T)for two adjacent CuO species is,the higher the catalytic activity of CuO-CeO2 for the PROX in excess hydrogen may be obtained.It means that if the reduction energy of CuO-CU2+pairs matched better,the reduction-oxidation recycle of CuO-Cu2+pairs would go on more easily,then the transferring energy of CuO-Cu2+pairs would be lesser.Therefore,the CuO-CeO2 catalysts will be largely improved in their catalytic performance if the different CuO species on the catalysts have matched the reduction energy,which would allows them to cooperate effectively.

  5. Synthesis of Thermally Spherical CuO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nittaya Tamaekong

    2014-01-01

    Full Text Available Copper oxide (CuO nanoparticles were successfully synthesized by a thermal method. The CuO nanoparticles were further characterized by thermogravimetric analysis (TGA, differential thermal analysis (DTA, X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDS, and high resolution transmission electron microscopy (HRTEM, respectively. The specific surface area (SSABET of CuO nanoparticles was determined by nitrogen adsorption. The SSABET was found to be 99.67 m2/g (dBET of 9.5 nm. The average diameter of the spherical CuO nanoparticles was approximately 6–9 nm.

  6. Synthesis and Optical Properties of CuO Nanocrystals with Controllable Shapes and Size

    Directory of Open Access Journals (Sweden)

    Goraya Neelinder

    2016-01-01

    Full Text Available Highly dispersed copper oxide (CuO nanoparticles had been successfully prepared by a hydrothermal technique where different adding temperatures of NaOH were taken. The as-prepared CuO nanoparticles were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM and Raman spectroscopy. The results showed that the adding temperature of NaOH has an important influence on the shape and size of CuO nanocrystals The influence of reaction conditions on morphology of CuO nanocrystals was discussed. Furthermore, different shapes of obtained CuO nanocrystals exhibit different Raman properties.

  7. Composite plasma electrolytic oxidation to improve the thermal radiation performance and corrosion resistance on an Al substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Donghyun [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Sung, Dahye [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Korea Institute of Industrial Technology (KITECH), Busan 46742 (Korea, Republic of); Lee, Junghoon [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Kim, Yonghwan [Korea Institute of Industrial Technology (KITECH), Busan 46742 (Korea, Republic of); Chung, Wonsub, E-mail: wschung1@pusan.ac.kr [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of)

    2015-12-01

    Highlights: • Composite plasma electrolytic oxidation was performed using dispersed CuO particles in convectional PEO electrolyte. • Thermal radiation performance and corrosion resistance were examined by FT-IR spectroscopy and electrochemical methods, respectively. • Deposited copper oxide on the surface of the Al substrate was enhanced the corrosion resistance and the emissivity compared with the conventional PEO. - Abstract: A composite plasma electrolytic oxidation (PEO) was performed for enhancing the thermal radiation performance and corrosion resistance on an Al alloy by dispersing cupric oxide (CuO) particles in a conventional PEO electrolyte. Cu-based oxides (CuO and Cu{sub 2}O) formed by composite PEO increased the emissivity of the substrate to 0.892, and made the surface being dark color, similar to a black body, i.e., an ideal radiator. In addition, the corrosion resistance was analyzed using potentio-dynamic polarization and electrochemical impedance spectroscopy tests in 3.5 wt.% NaCl aqueous solution. An optimum condition of 10 ampere per square decimeter (ASD) current density and 30 min processing time produced appropriate surface morphologies and coating thicknesses, as well as dense Cu- and Al-based oxides that constituted the coating layers.

  8. Effect of alginate on the aggregation kinetics of copper oxide nanoparticles (CuO NPs): bridging interaction and hetero-aggregation induced by Ca(2.).

    Science.gov (United States)

    Miao, Lingzhan; Wang, Chao; Hou, Jun; Wang, Peifang; Ao, Yanhui; Li, Yi; Lv, Bowen; Yang, Yangyang; You, Guoxiang; Xu, Yi

    2016-06-01

    The stability of CuO nanoparticles (NPs) is expected to play a key role in the environmental risk assessment of nanotoxicity in aquatic systems. In this study, the effect of alginate (model polysaccharides) on the stability of CuO NPs in various environmentally relevant ionic strength conditions was investigated by using time-resolved dynamic light scattering. Significant aggregation of CuO NPs was observed in the presence of both monovalent and divalent cations. The critical coagulation concentrations (CCC) were 54.5 and 2.9 mM for NaNO3 and Ca(NO3)2, respectively. The presence of alginate slowed nano-CuO aggregation rates over the entire NaNO3 concentration range due to the combined electrostatic and steric effect. High concentrations of Ca(2+) (>6 mM) resulted in stronger adsorption of alginate onto CuO NPs; however, enhanced aggregation of CuO NPs occurred simultaneously under the same conditions. Spectroscopic analysis revealed that the bridging interaction of alginate with Ca(2+) might be an important mechanism for the enhanced aggregation. Furthermore, significant coagulation of the alginate molecules was observed in solutions of high Ca(2+) concentrations, indicating a hetero-aggregation mechanism between the alginate-covered CuO NPs and the unabsorbed alginate. These results suggested a different aggregation mechanism of NPs might co-exist in aqueous systems enriched with natural organic matter, which should be taken into consideration in future studies. Graphical abstract Hetero-aggregation mechanism of CuO nanoparticles and alginate under high concentration of Ca(2.)

  9. Water treatment with exceptional virus inactivation using activated carbon modified with silver (Ag) and copper oxide (CuO) nanoparticles.

    Science.gov (United States)

    Shimabuku, Quelen Letícia; Arakawa, Flávia Sayuri; Fernandes Silva, Marcela; Ferri Coldebella, Priscila; Ueda-Nakamura, Tânia; Fagundes-Klen, Márcia Regina; Bergamasco, Rosangela

    2017-08-01

    Continuous flow experiments (450 mL min(-1)) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼10(5) UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water.

  10. Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation.

    Science.gov (United States)

    Sankar, Renu; Manikandan, Perumal; Malarvizhi, Viswanathan; Fathima, Tajudeennasrin; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

    2014-01-01

    Copper oxide (CuO) nanoparticles were synthesized by treating 5 mM cupric sulphate with Carica papaya leaves extract. The kinetics of the reaction was studied using UV-visible spectrophotometry. An intense surface Plasmon resonance between 250-300 nm in the UV-vis spectrum clearly reveals the formation of copper oxide nanoparticles. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) exhibited that the green synthesized copper oxide nanoparticles are rod in shape and having a mean particle size of 140 nm, further negative zeta potential disclose its stability at -28.9 mV. The Fourier-transform infrared (FTIR) spectroscopy results examined the occurrence of bioactive functional groups required for the reduction of copper ions. X-ray diffraction (XRD) spectra confirmed the copper oxide nanoparticles crystalline nature. Furthermore, colloidal copper oxide nanoparticles effectively degrade the Coomassie brilliant blue R-250 dye beneath the sunlight.

  11. Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation

    Science.gov (United States)

    Sankar, Renu; Manikandan, Perumal; Malarvizhi, Viswanathan; Fathima, Tajudeennasrin; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

    2014-03-01

    Copper oxide (CuO) nanoparticles were synthesized by treating 5 mM cupric sulphate with Carica papaya leaves extract. The kinetics of the reaction was studied using UV-visible spectrophotometry. An intense surface Plasmon resonance between 250-300 nm in the UV-vis spectrum clearly reveals the formation of copper oxide nanoparticles. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) exhibited that the green synthesized copper oxide nanoparticles are rod in shape and having a mean particle size of 140 nm, further negative zeta potential disclose its stability at -28.9 mV. The Fourier-transform infrared (FTIR) spectroscopy results examined the occurrence of bioactive functional groups required for the reduction of copper ions. X-ray diffraction (XRD) spectra confirmed the copper oxide nanoparticles crystalline nature. Furthermore, colloidal copper oxide nanoparticles effectively degrade the Coomassie brilliant blue R-250 dye beneath the sunlight.

  12. Synthesis and characterization of composite polymer, polyethylene glycol grafted flower-like cupric nano oxide for solid phase microextraction of ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair and water samples.

    Science.gov (United States)

    Sarafraz-Yazdi, Ali; Zendegi-Shiraz, Amene; Es'haghi, Zarrin; Hassanzadeh-Khayyat, Mohammad

    2015-10-30

    In this research, poly (ethylene glycol)-poly (ethylene glycol) grafted flower-like cupric oxidenano particles (PEG-PEG-g-CuO NPs) as a novel fiber coating of solid-phase microextraction (SPME) were synthesized by using sol-gel technology. This fiber was successfully applied to extract and determine the ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair using head space-solid-phase microextraction (HS-SPME) coupled to gas chromatography-flame ionization detector. Characterization and chemical composition of the nano particle was performed by Fourier transform infrared spectroscopy (FT-IR), energy dispersion spectroscopy (EDS) and back scatter analysis (BSA). These methods confirmed the successful fabrication of PEG-g-CuO NPs. The surface morphology of the fibers were inspected by scanning electron microscopy. The scanning electron microscopy (SEM) revealed many "crack-like" features and highly porous structure on the surface of fiber. The synthesized nanocomposites were used for preconcentration and extraction of benzene, toluene, ethyl benzene and o-xylene (BTEX). The effects of operating parameters such as: desorption temperature and time, extraction temperature, extraction time, stirring speed and salt effect were investigated and optimized. Under the optimal conditions, the method detection limits and the limits of quantification were between 0.00025-50.00000pgmL(-1) and 0.00200-200.00000pgmL(-1), respectively. Linearity was observed over a range 0.00200-200000.00000pgmL(-1). The relative standard deviations for one fiber (repeatability; n=5) were obtained from 3.30 up to 5.01% and between fibers or batch to batch (n=3; reproducibility) in the range of 3.63-6.21%. The developed method was successfully applied to simultaneous determination of BTEX in human hairs, tap water and distillate water.

  13. Determination of the mechanism of photoinduced toxicity of selected metal oxide nanoparticles (ZnO, CuO, Co3O4 and TiO2) to E.coli bacteria

    Institute of Scientific and Technical Information of China (English)

    Thabitha P.Dasari; Kavitha Pathakoti; Huey-Min Hwang

    2013-01-01

    Cytotoxicity of selected metal oxide nanoparticles (MNPs) (ZnO,CuO,Co3O4 and TiO2) was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LCs0 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LCs0 values was in the order of ZnO < CuO < Co3O4 < TiO2 under dark condition and ZnO < CuO < TiO2 < Co3O4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.

  14. The influence of cupric ions on shape of potentiodynamic curves obtained on 18 K gold

    Directory of Open Access Journals (Sweden)

    Rajčić-Vujasinović Mirjana

    2002-01-01

    Full Text Available The shape of potentiodynamic curves depends mainly on the composition of investigated alloys, but also on the electrolyte used in experiments. In this work investigation were performed for pure gold, and pure silver and copper as alloying metals, then for binary alloys Au-Ag and Au-Cu containing gold as in 18 k gold (i.e. 75 % Au and Ag-Cu with mass ratio 1:1 and, finally, for three component 18 k gold. It was established a catalytic effect of cupric ions present in electrolyte on oxidation of gold and 18 k gold alloys.

  15. Preparation of CuO Quantum Dots by Cost-Effective Ultrasonication Technique

    Science.gov (United States)

    Rathod, K. N.; Savaliya, Chirag; Babiya, K. R.; Vasvani, S. H.; Ramani, Rupeshkumar V.; Ramani, Bharat M.; Joshi, Ashvini D.; Pandya, Dhiren; Shah, N. A.; Markna, J. H.

    Due to exciting size-dependent chemical and physical properties, nanoscale materials have extensive range of applications compared with microstructural particles. CuO nanoparticles are very important among transition metal oxides because of their large number of applications. Quantum dots (QDs) of CuO (copper oxide) were prepared by the innovative ultrasonication method. Ultrasonic sound is used in this synthesis method to synthesize QDs of copper oxide. Structural and optical properties were studied in this research work. X-ray diffraction was used to study the formation of structural phase CuO QDs and found to be single phasic without any impurity. Transmission electron microscopic measurements were performed to study the morphology of QDs of CuO, which confirms spherical QDs with an average diameter of ˜4nm. In optical studies, absorption spectra of the CuO were analyzed by using UV-visible spectroscopy.

  16. Plant Mediated Green Synthesis of CuO Nanoparticles: Comparison of Toxicity of Engineered and Plant Mediated CuO Nanoparticles towards Daphnia magna

    Directory of Open Access Journals (Sweden)

    Sadia Saif

    2016-11-01

    Full Text Available Research on green production methods for metal oxide nanoparticles (NPs is growing, with the objective to overcome the potential hazards of these chemicals for a safer environment. In this study, facile, ecofriendly synthesis of copper oxide (CuO nanoparticles was successfully achieved using aqueous extract of Pterospermum acerifolium leaves. P. acerifolium-fabricated CuO nanoparticles were further characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray (EDX, Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS and dynamic light scattering (DLS. Plant-mediated CuO nanoparticles were found to be oval shaped and well dispersed in suspension. XPS confirmed the elemental composition of P. acerifolium-mediated copper nanoparticles as comprised purely of copper and oxygen. DLS measurements and ion release profile showed that P. acerifolium-mediated copper nanoparticles were more stable than the engineered CuO NPs. Copper oxide nanoparticles are used in many applications; therefore, their potential toxicity cannot be ignored. A comparative study was performed to investigate the bio-toxic impacts of plant-synthesized and engineered CuO nanoparticles on water flea Daphnia. Experiments were conducted to investigate the 48-h acute toxicity of engineered CuO NPs and plant-synthesized nanoparticles. Lower EC50 value 0.102 ± 0.019 mg/L was observed for engineered CuO NPs, while 0.69 ± 0.226 mg/L was observed for plant-synthesized CuO NPs. Additionally, ion release from CuO nanoparticles and 48-h accumulation of these nano CuOs in daphnids were also calculated. Our findings thus suggest that the contribution of released ions from nanoparticles and particles/ions accumulation in Daphnia needs to be interpreted with care.

  17. Plant Mediated Green Synthesis of CuO Nanoparticles: Comparison of Toxicity of Engineered and Plant Mediated CuO Nanoparticles towards Daphnia magna.

    Science.gov (United States)

    Saif, Sadia; Tahir, Arifa; Asim, Tayyaba; Chen, Yongsheng

    2016-11-09

    Research on green production methods for metal oxide nanoparticles (NPs) is growing, with the objective to overcome the potential hazards of these chemicals for a safer environment. In this study, facile, ecofriendly synthesis of copper oxide (CuO) nanoparticles was successfully achieved using aqueous extract of Pterospermum acerifolium leaves. P. acerifolium-fabricated CuO nanoparticles were further characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS). Plant-mediated CuO nanoparticles were found to be oval shaped and well dispersed in suspension. XPS confirmed the elemental composition of P. acerifolium-mediated copper nanoparticles as comprised purely of copper and oxygen. DLS measurements and ion release profile showed that P. acerifolium-mediated copper nanoparticles were more stable than the engineered CuO NPs. Copper oxide nanoparticles are used in many applications; therefore, their potential toxicity cannot be ignored. A comparative study was performed to investigate the bio-toxic impacts of plant-synthesized and engineered CuO nanoparticles on water flea Daphnia. Experiments were conducted to investigate the 48-h acute toxicity of engineered CuO NPs and plant-synthesized nanoparticles. Lower EC50 value 0.102 ± 0.019 mg/L was observed for engineered CuO NPs, while 0.69 ± 0.226 mg/L was observed for plant-synthesized CuO NPs. Additionally, ion release from CuO nanoparticles and 48-h accumulation of these nano CuOs in daphnids were also calculated. Our findings thus suggest that the contribution of released ions from nanoparticles and particles/ions accumulation in Daphnia needs to be interpreted with care.

  18. Synthesis and Structural Investigations of Ag-Added Ba T i O -CuO Mixed Oxide for C O Gas Sensing

    OpenAIRE

    Ahmed Mohamed El-Sayed; Fathy Mohamed Ismail; Saad Mabrouk Yakout

    2011-01-01

    Compositions having the general formula BaTiO3- C u O +  wt% Ag, where = 0 , 1 , 1 . 5 , and 2 have been prepared by solid state ceramic processing and sintered at 500 and 7 0 0 ∘ C for 5 h. Thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), infrared absorption spectra (IR), and scanning electron microscopy (SEM) were used to characterize the obtained sensor pellets. It was found that no solid state reaction took place between BaTiO3 and CuO during sintering process. The se...

  19. Oxidation behavior of Cu nanoparticles embedded into semiconductive TiO{sub 2} matrix

    Energy Technology Data Exchange (ETDEWEB)

    Stranak, Vitezslav, E-mail: stranak@prf.jcu.cz [University of South Bohemia, Faculty of Science, Branisovska 31, 37005 Ceske Budejovice (Czech Republic); Drache, Steffen; Wulff, Harm [University of Greifswald, Institute of Physics, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Hubicka, Zdenek [Institute of Physics, Academy of Science of the Czech Republic, Na Slovance 2, 18221 Prague (Czech Republic); Tichy, Milan [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague (Czech Republic); Kruth, Angela [Leibniz Institute for Plasma Science and Technology, INP Greifswald e.V., Felix-Hausdorff-Straße 2, 17489 Greifswald (Germany); Helm, Christiane A.; Hippler, Rainer [University of Greifswald, Institute of Physics, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

    2015-08-31

    Metal nanoparticles embedded into a semiconductive matrix represent a promising material for widely sought advanced technological applications. We focused our interest on the preparation of TiO{sub 2} matrix with embedded Cu nanoparticles. In particular, we studied the effect of reactive discharge (Ar/O{sub 2}) exposition on copper oxidation, which can result in two stable forms: cuprous oxide (Cu{sub 2}O) and cupric oxide (CuO). Copper nanoparticles, of size in range 10–50 nm, were produced by magnetron sputtering in combination with gas aggregation. The beam of Cu nanoparticles was impinging onto a silicon substrate which was directly exposed to a reactive Ar/O{sub 2} magnetron discharge providing sputtering of Ti target at the same time. The properties of deposited nanocomposite Cu({sub x}O)–TiO{sub 2} were investigated by X-ray photoelectron spectroscopy, grazing incidence X-ray diffractometry, X-ray reflectometry and scanning electron microscopy techniques to reveal the nanocomposite properties and to understand the oxidation process of embedded Cu nanoparticles. It was found that CuO is preferentially formed if copper is exposed to active oxygen species (O{sup +}, O{sup −}, O{sup ⁎} etc.) produced in the reactive magnetron discharge. On the other hand, Cu{sub 2}O was observed in the case of copper reaction in ambient Ar/O{sub 2} atmosphere. As a result, two possible copper oxidation mechanisms are proposed, employing chemical kinetics. - Highlights: • Cu–TiO{sub 2} nanocomposite was prepared by plasma assisted methods. • Embedded Cu always occurs in oxidized phase depending on the way of oxidation. • CuO is formed if copper is exposed to active oxygen species produced in Ar/O{sub 2} discharge. • Cu{sub 2}O appears in the case of copper reaction in an ambient oxygen-based atmosphere. • Two possible copper oxidation mechanisms are proposed.

  20. SELDI-TOF MS-based discovery of a biomarker in Cucumis sativus seeds exposed to CuO nanoparticles.

    Science.gov (United States)

    Moon, Young-Sun; Park, Eun-Sil; Kim, Tae-Oh; Lee, Hoi-Seon; Lee, Sung-Eun

    2014-11-01

    Metal oxide nanoparticles (NPs) can inhibit plant seed germination and root elongation via the release of metal ions. In the present study, two acute phytotoxicity tests, seed germination and root elongation tests, were conducted on cucumber seeds (Cucumis sativus) treated with bulk copper oxide (CuO) and CuO NPs. Two concentrations of bulk CuO and CuO NPs, 200 and 600ppm, were used to test the inhibition rate of root germination; both concentrations of bulk CuO weakly inhibited seed germination, whereas CuO NPs significantly inhibited germination, showing a low germination rate of 23.3% at 600ppm. Root elongation tests demonstrated that CuO NPs were much stronger inhibitors than bulk CuO. SELDI-TOF MS analysis showed that 34 proteins were differentially expressed in cucumber seeds after exposure to CuO NPs, with the expression patterns of at least 9 proteins highly differing from those in seeds treated with bulk CuO and in control plants. Therefore, these 9 proteins were used to identify CuO NP-specific biomarkers in cucumber plants exposed to CuO NPs. A 5977-m/z protein was the most distinguishable biomarker for determining phytotoxicity by CuO NPs. Principal component analysis (PCA) of the SELDI-TOF MS results showed variability in the modes of inhibitory action on cucumber seeds and roots. To our knowledge, this is the first study to demonstrate that the phytotoxic effect of metal oxide NPs on plants is not caused by the same mode of action as other toxins.

  1. Determination of the mechanism of photoinduced toxicity of selected metal oxide nanoparticles (ZnO, CuO, Co3O4 and TiO2) to E. coli bacteria.

    Science.gov (United States)

    Dasari, Thabitha P; Pathakoti, Kavitha; Hwang, Huey-Min

    2013-05-01

    Cytotoxicity of selected metal oxide nanoparticles (MNPs) (ZnO, CuO, Co3O4 and TiO2) was investigated in Escherichia coli both under light and dark conditions. Cytotoxicity experiments were conducted with spread plate counting and the LC50 values were calculated. We determined the mechanism of toxicity via measurements of oxidative stress, reduced glutathione, lipid peroxidation, and metal ions. The overall ranking of the LC50 values was in the order of ZnO TiO2 under dark condition and ZnO TiO2 < Co3O4 under light condition. ZnO MNPs were the most toxic among the tested nanoparticles. Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress. Released metal ions were found to have partial effect on the toxicity of MNPs to E. coli. In summary, the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E. coli.

  2. Correlated barrier hopping of CuO nanoparticles

    Science.gov (United States)

    Koshy, Jiji; Soosen, Samuel. M.; Chandran, Anoop; George, K. C.

    2015-12-01

    The ac conduction mechanism in copper oxide nanoparticles with 8 nm size, synthesized by a precipitation method was studied by analyzing ac conductivity in the frequency range of 50 Hz-1 MHz and in the temperature range of 373-573 K. X-ray diffraction and transmission electron microscopy (TEM) were employed for the structural and morphological characterization of CuO nanoparticles. The experimental and theoretical investigations suggested that the ac conduction mechanism in CuO nanoparticles can be successfully explained by a correlated barrier hopping model, which provided reasonable values for the maximum barrier height and characteristic relaxation time. It was also found that bipolaron hopping become prominent up to a particular temperature and beyond that single polaron hopping predominates. Physical parameters such as hopping distance and density of defect states were also calculated. Photoluminescence studies confirm the presence of a surface defect in CuO nanoparticles.

  3. Promotion of hexadecyltrimethyleamine bromide to the damage of Alexandrium sp. LC3 by cupric glutamate

    Institute of Scientific and Technical Information of China (English)

    LI Hao; MIAO Jin-lai; CUI Feng-xia; LI Guang-you

    2006-01-01

    The effect of hexadecyltrimethyleamine bromide (HDTMAB) on the removal of A lexandrium sp. LC3 under cupric glutamate stress was investigated. Toxic effect of cupric glutamate on A lexandrium sp. LC3 was significantly promoted in the presence of HDTMAB, especially at 3.0 cmc of HDTMAB. It was found that the sulfhydryl group content of the cell decreased, while the malonaldehyde content and membrane permeability increased when Alexandrium sp. LC3 was treated with HDTMAB and cupric glutamate complex, compared with cupric glutamate alone. The data suggest that HDTMAB might stimulate the damage of A lexandrium sp. LC3 by enhancing the membrane permeability.

  4. Synergy of CuO and CeO2 combination for mercury oxidation under low-temperature selective catalytic reduction atmosphere

    KAUST Repository

    Li, Hailong

    2016-07-19

    Synergy for low temperature Hg0 oxidation under selective catalytic reduction (SCR) atmosphere was achieved when copper oxides and cerium oxides were combined in a CuO-CeO2/TiO2 (CuCeTi) catalyst. Hg0 oxidation efficiency as high as 99.0% was observed on the CuCeTi catalyst at 200 °C, even the gas hourly space velocity was extremely high. To analyze the synergistic effect, comparisons of catalyst performance in the presence of different SCR reaction gases were systematically conducted over CuO/TiO2 (CuTi), CeO2/TiO2 (CeTi) and CuCeTi catalysts prepared by sol-gel method. The interactions between copper oxides and cerium oxides in CuCeTi catalyst yielded more surface chemisorbed oxygen, and facilitated the conversion of gas-phase O2 to surface oxygen, which are favorable for Hg0 oxidation. Copper oxides in the combination interacted with NO forming more chemisorbed oxygen for Hg0 oxidation in the absence of gas-phase O2. Cerium oxides in the combination promoted Hg0 oxidation through enhancing the transformations of NO to NO2. In the absence of NO, NH3 exhibited no inhibitive effect on Hg0 oxidation, because enough Lewis acid sites due to the combination of copper oxides and cerium oxides scavenged the competitive adsorption between NH3 and Hg0. In the presence of NO, although NH3 lowered Hg0 oxidation rate through inducing reduction of oxidized mercury, complete recovery of Hg0 oxidation activity over the CuCeTi catalyst was quickly achieved after cutting off NH3. This study revealed the synergistic effect of the combination of copper oxides and cerium oxides on Hg0 oxidation, and explored the involved mechanisms. Such knowledge would help obtaining maximum Hg0 oxidation co-benefit from SCR units in coal-fired power plants.

  5. La_2CuO_4微晶的溶胶-凝胶法制备及合成活化能%Preparation and Activation Energy of La_2CuO_4 Micro-crystallites Synthesized by Sol–Gel Process

    Institute of Scientific and Technical Information of China (English)

    李意峰; 黄剑锋; 曹丽云; 吴建鹏

    2011-01-01

    以硝酸镧和硝酸铜为起始原料、水为溶剂、柠檬酸为络合剂,采用溶胶-凝胶法制备La2CuO4微晶。通过热重-差热分析、X射线衍射、红外光谱和透射电子显微镜等表征前驱物凝胶粉体及La2CuO4粉体的热性能、物相组成、官能团及显微结构,用Kissinger法研究La2CuO4微晶的合成活化能。结果表明采用溶胶-凝胶法可以成功制备La2CuO4微晶:600℃煅烧2h可获得单一物相的La2CuO4;煅烧温度升至700℃后,La2CuO4晶粒形状为正交晶型结构,晶粒尺寸100~120nm,晶粒分布比较均匀。计算得到La2CuO4微晶的合成活化能为147.0kJ/mol。%Micro-crystallite La2CuO4 was prepared via a sol–gel process using lanthanum nitrate and cupric nitrate as raw materials,distilled water as solvent,and citric acid as complexing agent.Thermal properties,phase composition,functional group,and micro-structure of the as-prepared La2CuO4 were characterized by thermogravimetric–differential thermal analysis,X-ray diffraction,infra-red spectroscopy,and transmission electron microscopy.Synthesis activation energy of La2CuO4 was investigated by Kissinger method.Results show that La2CuO4 can be successfully prepared by the sol–gel process,and pure La2CuO4 can be obtained by cal-cining at 600 ℃ for 2 h.When calcination temperature is increased to 700 ℃,the La2CuO4 exhibits an orthogonal structure,the grain distribution is uniform and the size is about 100–120 nm.The preparation activation energy of La2CuO4 is calculated to be 147.0 kJ/mol.

  6. Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions

    Directory of Open Access Journals (Sweden)

    Limpo, J. L.

    1995-06-01

    Full Text Available Cupric solubility in the CuCl2-NH4Cl-NH3-H2O system for chloride concentrations lower than 4 molal in the temperature range 25-60 °C was studied. The experimental results show that for chloride concentration between 3.0 and 1.0 molal the cupric solubility is determined by the solubility of the cupric hydroxychloride Cu(OH1.5Cl0.5. For a chloride concentration value of 4.0 molal, there are two cupric compounds, the hydroxychloride Cu(OH1.5Cl0.5 or the diammine chloride Cu(NH32Cl2, on which the solubility of Cu(II depends, according to the temperature and the value of the ratio [NH3]Total/[Cu]Total.

    Se estudia la solubilidad del Cu(II en el sistema CuCl2-NH4Cl-NH3-H2O para concentraciones de cloruro inferiores a 4 molal en el intervalo de temperaturas 25-60 °C. Los resultados experimentales muestran que, para concentraciones de cloruros comprendidas entre 3,0 y 1,0 molal, la solubilidad cúprica viene determinada por la solubilidad del hidroxicloruro cúprico, Cu(OH1.5Cl0.5. Para concentraciones de cloruro 4,0 molal, existen dos compuestos cúpricos, el hidroxicloruro, Cu(OH1.5Cl0.5 o el cloruro de diamina, Cu(NH32Cl2, de los que, de acuerdo con la temperatura y con el valor de la relación [NH3]Total/[Cu]Total depende la solubilidad del Cu(II.

  7. Enhanced reactive oxygen species overexpression by CuO nanoparticles in poorly differentiated hepatocellular carcinoma cells

    Science.gov (United States)

    Kung, Mei-Lang; Hsieh, Shu-Ling; Wu, Chih-Chung; Chu, Tian-Huei; Lin, Yu-Chun; Yeh, Bi-Wen; Hsieh, Shuchen

    2015-01-01

    Copper oxide nanoparticles (CuO NPs) are known to exhibit toxic effects on a variety of cell types and organs. To determine the oxidative impact of CuO NPs on hepatocellular carcinoma (HCC) cells, well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) cells were exposed to CuO NPs. Cell viability assay showed that the median inhibition concentration (IC50) for SK-Hep-1 and HepG2 cells was 25 μg ml-1 and 85 μg ml-1, respectively. Cellular fluorescence intensity using DCFH-DA staining analysis revealed significant intracellular reactive oxygen species (ROS) generation of up to 242% in SK-Hep-1 cells, compared with 86% in HepG2 cells. HPLC analysis demonstrated that a CuO NP treatment caused cellular GSH depletion of 58% and a GSH/GSSG ratio decrease to ~0.1 in SK-Hep-1 cells. The oxidative stress caused by enhanced superoxide anion production was observed in both HepG2 (146%) and SK-Hep-1 (192%) cells. The Griess assay verified that CuO NPs induced NO production (170%) in SK-Hep-1 cells. Comet assay and western blot further demonstrated that CuO NPs induced severe DNA strand breakage (70%) in SK-Hep-1 cells and caused DNA damage via increased γ-H2AX levels. These results suggest that well-differentiated HepG2 cells possess a robust antioxidant defense system against CuO NP-induced ROS stress and exhibit more tolerance to oxidative stress. Conversely, poorly differentiated SK-Hep-1 cells exhibited a deregulated antioxidant defense system that allowed accumulation of CuO NP-induced ROS and resulted in severe cytotoxicity.Copper oxide nanoparticles (CuO NPs) are known to exhibit toxic effects on a variety of cell types and organs. To determine the oxidative impact of CuO NPs on hepatocellular carcinoma (HCC) cells, well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) cells were exposed to CuO NPs. Cell viability assay showed that the median inhibition concentration (IC50) for SK-Hep-1 and HepG2 cells was 25 μg ml-1 and 85 μg ml-1, respectively

  8. Short-term effects on antioxidant enzymes and long-term genotoxic and carcinogenic potential of CuO nanoparticles compared to bulk CuO and ionic copper in mussels Mytilus galloprovincialis.

    Science.gov (United States)

    Ruiz, Pamela; Katsumiti, Alberto; Nieto, Jose A; Bori, Jaume; Jimeno-Romero, Alba; Reip, Paul; Arostegui, Inmaculada; Orbea, Amaia; Cajaraville, Miren P

    2015-10-01

    The aim of this work was to study short-term effects on antioxidant enzyme activities and long-term genotoxic and carcinogenic potential of CuO nanoparticles (NPs) in comparison to bulk CuO and ionic copper in mussels Mytilus galloprovincialis after 21 days exposure to 10 μg Cu L(-1). Then, mussels were kept for up to 122 days in clean water. Cu accumulation depended on the form of the metal and on the exposure time. CuO NPs were localized in lysosomes of digestive cells, as confirmed by TEM and X ray microanalysis. CuO NPs, bulk CuO and ionic copper produced different effects on antioxidant enzyme activities in digestive glands, overall increasing antioxidant activities. CuO NPs significantly induced catalase and superoxide dismutase activities. Fewer effects were observed in gills. Micronuclei frequency increased significantly in mussels exposed to CuO NPs and one organism treated with CuO NPs showed disseminated neoplasia. However, transcription levels of cancer-related genes did not vary significantly. Thus, short-term exposure to CuO NPs provoked oxidative stress and genotoxicity, but further studies are needed to determine whether these early events can lead to cancer development in mussels.

  9. Facile synthesis of Fe-incorporated CuO nanoarrays with enhanced electrochemical performance for lithium ion full batteries

    Energy Technology Data Exchange (ETDEWEB)

    Heng, Bojun [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China); Department of Applied Physics, Wuhan University of Science and Technology, Wuhan, 430065 (China); Qing, Chen; Wang, Hai; Sun, Daming; Wang, Bixiao [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China); Tang, Yiwen, E-mail: ywtang@phy.ccnu.edu.cn [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China)

    2015-11-15

    CuO nanoarrays (CNAs) and Fe-incorporated CuO nanoarrays (FCNAs) were fabricated by hydrothermal method. Addition of Fe salt to the reaction mixture allowed the introduction of iron oxide onto the CNAs surface, which was characterized by XPS and HRTEM. Introducing Fe ion into reaction precursor significantly affected not only the morphologies of as-prepared products but also their electrochemical performance as anode for lithium ion full battery. The FCNAs electrodes showed higher specific capacity and better capacity retention at different current densities than that of CNAs. - Highlights: • Fe-incorporated CuO nanoarrays were fabricated by hydrothermal method. • Fe salt in reaction mixture leads to iron oxides forming on the surface of CuO. • Fe-incorporating improves the lithium ion battery performance of CuO anodes.

  10. Leaching of complex sulphide concentrate in acidic cupric chloride solutions

    Institute of Scientific and Technical Information of China (English)

    M. TCHOUMOU; M. ROYNETTE

    2007-01-01

    The chemical analysis of a complex sulphide concentrate by emission spectrometry and X-ray diffraction shows that it contains essentially copper, lead, zinc and iron in the form of chalcopyrite, sphalerite and galena. A small amount of pyrite is also present in the ore but does not be detected with X-ray diffraction. The cupric chloride leaching of the sulphide concentrate at various durations and solid/liquid ratios at 100 ℃ shows that the rate of dissolution of the ore is the fastest in the first several hours, and after 12 h it does not evolve significantly. If oxygen is excluded from the aqueous cupric chloride solution during the leaching experiment at 100 ℃, the pyrite in the ore will not be leached. The determination of principal dissolved metals in the leaching liquor by flame atomic absorption spectrometry, and the chemical analysis of solid residues by emission spectrometry and X-ray diffraction allow to conclude that the rate of dissolution of the minerals contained in the complex sulphide concentrate are in the order of galena>sphalerite>chalcopyrite.

  11. Kinetics of coal desulfurization using cupric chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Ghazali, S.; Muharam, C.; Sani, S.A. [Bandung Inst. of Tech. (Indonesia)

    1995-12-31

    Coal desulfurization prior to combustion can be carried out either by physical or chemical methods. The physical methods, where the elimination of sulfur compounds is based on the difference of physical properties between pyritic sulfur and organic matrix, have progressed significantly and are currently used in commercial practice. These methods are, however, ineffective to remove organic sulfurs where S is attached chemically to carbon in the coal matrix. These compounds, presumed to be mercaptan, thyophene, organic sulfides or organic disulfide, could only be removed by chemical treatments. This paper describes the experimental study of coal beneficiation by chemical methods using cupric chloride solution. The results obtained showed that both organic and pyritic sulfurs were reduced significantly. It was also observed that cupric ions have reacted with in fraction of coal which was assumed to be some oxygenated carbon. The kinetics study has shown that the reaction rate of pyrite pseudo homogenous model and the reaction rates of organic sulfur generated coal fractions follow the power law models. (author). 5 tabs., 4 figs., 10 refs.

  12. Synthesis and concentration dependent antibacterial activities of CuO nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Pandiyarajan, T.; Udayabhaskar, R. [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India); Vignesh, S.; James, R. Arthur [Department of Marine Science, Bharathidasan University, Tiruchirappalli 620 024 (India); Karthikeyan, B., E-mail: balkarin@yahoo.com [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India)

    2013-05-01

    We report, synthesis and antibacterial activities of CuO nanoflakes. CuO nanoparticles are prepared at room temperature through sol–gel method. X-ray diffraction studies show the particles are monoclinic (crystalline) in nature. Scanning electron microscopy (SEM) images clearly show that the prepared particles are flake like in structure. Fourier transform infrared (FTIR) spectra exhibits three different bands that correspond to the A{sub u} and B{sub u} modes. Antibacterial studies were performed on Shigella flexneri, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella typhimurium, Bacillus subtilis, Escherichia coli, Vibrio cholera, Pseudomonas aeruginosa and Aeromonas liquefaciens bacterial strains. Among these bacterial strains, S. flexneri and B. subtilis are most sensitive to copper oxide nanoparticles than the positive control (Penicillin G) and S. typhimurium strain shows the less sensitive. Results show that sensitivity is highly dependent on the concentrations of CuO nanoflakes. - Highlights: ► CuO nanoflakes are prepared through simple sol–gel method at room temperature. ► Bacterial strains are highly affected by CuO nanoflakes than the positive control. ► Zone of inhibition increases with an increase of CuO concentrations. ► Sensitivity is highly dependent on the concentrations of CuO nanoflakes.

  13. Cutin-derived CuO reaction products from purified cuticles and tree leaves

    Science.gov (United States)

    Goñi, Miguel A.; Hedges, John I.

    1990-11-01

    Long chain (C 16-C 18) hydroxy fatty acids are obtained among the nonlignin-derived reaction products from the CuO oxidation of a variety of geochemical samples. In order to investigate the origin of these acids, the CuO reaction products of isolated cuticles and whole leaves were investigated. The reaction products from the CuO oxidation of purified apple ( Malus pumila) cuticle include 16-hydroxy-hexadecanoic acid, 10,16-dihydroxyhexadecanoic acid, 9,10,18-trihydroxyoctadec-12-enoic acid, and 9,10,18-trihydroxyoctadecanoic acid as major components. The distribution of these cutin-derived CuO reaction products is similar to the monomer compositions deduced from traditional methods of cutin analysis. Oxidation of whole English Holly ( Ilex aquifolium) leaves yields cutin-derived acidic reaction products (in addition to lignin-derived phenols) similar to those obtained from oxidation of the corresponding isolated cuticles, indicating that CuO oxidation of bulk plant tissue is a viable procedure of cutin analysis in geochemical applications.

  14. Cupric Hexacyanoferrate Nanoparticle Modified Carbon Ceramic Composite Electrodes

    Institute of Scientific and Technical Information of China (English)

    WANG,Peng(王鹏); ZHU,Guo-Yi(朱果逸)

    2002-01-01

    Graphite powder-supported cupric hexacyanoferrate (CuHCF)nanoparticles were dispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite, which was used as electrode material to fabricate surface-renewable CuHCF-modified electrodes. Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterized using cyclic and square-wave voitammetry.Cyclic voltammograms at various scan rates indicated that peak currents were surface-confined at low scan rates. In the presence of glutathione, a clear electrocatalytic response was observed at the CuHCF-modified composite electrodes. In addition, the electrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanical polishing on emery paper, as well as ease of preparation, and good chemical and mechanical stability in a flowing stream.

  15. Cupric Hexacyanoferrate Nanoparticle Modified Carbon Ceramic Composite Electrodes

    Institute of Scientific and Technical Information of China (English)

    WANG,Peng; ZHU,Guo-Yi

    2002-01-01

    Graphite powder-supported cupric hexacyanoferrate(CuHCF) nanoparticles were dispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite,which was used as electrode materials to fabricate surface-renewable CuHCF-modified electrodes.Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterized using cyclic and square-wave voltammetry. Cyclinc voltammograms at various scan rates indicated that peak currents were suface-confined at low scan rates.In the presence of glutathione,a clear electrocatalytic response was observed at the CuHCF-modified composite electrodes.In addition,the electrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanical polishing on emery paper,as well as ease of preparation,and good chemical and mechanical stability in a flowing stream.

  16. Chlorination of iodide-containing waters in the presence of CuO: Formation of periodate

    KAUST Repository

    Liu, Chao

    2014-11-18

    It has been shown previously that the disproportionation of halogen-containing oxidants (e.g., HOCl, HOBr, and ClO2) is enhanced by a CuO-catalyzed process. In this study, the transformation of iodine during chlorination in the presence of CuO was investigated. There is no significant enhancement of the disproportionation of hypoiodous acid (HOI) in the presence of CuO. The formation rate of iodate (IO3 -) in the CuO-HOCl-I- system significantly increased when compared to homogeneous solutions, which was ascribed to the activation of HOCl by CuO enhancing its reactivity toward HOI. In this reaction system, iodate formation rates increase with increasing CuO (0-0.5 g L-1) and bromide (0-2 μM) doses and with decreasing pH (9.6-6.6). Iodate does not adsorb to the CuO surfaces used in this study. Nevertheless, iodate concentrations decreased after a maximum was reached in the CuO-HOCl-I-(-Br-) systems. Similarly, the iodate concentrations decrease as a function of time in the CuO-HOCl-IO3 - or CuO-HOBr-IO3 - system, and the rates increase with decreasing pH (9.6-6.6) due to the enhanced reactivity of HOCl or HOBr in the presence of CuO. It could be demonstrated that iodate is oxidized to periodate by a CuO-activated hypohalous acid, which is adsorbed on the CuO surface. No periodate could be measured in filtered solutions because it was mainly adsorbed to CuO. The adsorbed periodate was identified by scanning electron microscopy plus energy dispersive spectroscopy and X-ray photoelectron spectroscopy.

  17. Chlorination of iodide-containing waters in the presence of CuO: formation of periodate.

    Science.gov (United States)

    Liu, Chao; Salhi, Elisabeth; Croué, Jean-Philippe; von Gunten, Urs

    2014-11-18

    It has been shown previously that the disproportionation of halogen-containing oxidants (e.g., HOCl, HOBr, and ClO2) is enhanced by a CuO-catalyzed process. In this study, the transformation of iodine during chlorination in the presence of CuO was investigated. There is no significant enhancement of the disproportionation of hypoiodous acid (HOI) in the presence of CuO. The formation rate of iodate (IO3(-)) in the CuO-HOCl-I(-) system significantly increased when compared to homogeneous solutions, which was ascribed to the activation of HOCl by CuO enhancing its reactivity toward HOI. In this reaction system, iodate formation rates increase with increasing CuO (0-0.5 g L(-1)) and bromide (0-2 μM) doses and with decreasing pH (9.6-6.6). Iodate does not adsorb to the CuO surfaces used in this study. Nevertheless, iodate concentrations decreased after a maximum was reached in the CuO-HOCl-I(-)(-Br(-)) systems. Similarly, the iodate concentrations decrease as a function of time in the CuO-HOCl-IO3(-) or CuO-HOBr-IO3(-) system, and the rates increase with decreasing pH (9.6-6.6) due to the enhanced reactivity of HOCl or HOBr in the presence of CuO. It could be demonstrated that iodate is oxidized to periodate by a CuO-activated hypohalous acid, which is adsorbed on the CuO surface. No periodate could be measured in filtered solutions because it was mainly adsorbed to CuO. The adsorbed periodate was identified by scanning electron microscopy plus energy dispersive spectroscopy and X-ray photoelectron spectroscopy.

  18. Multi-functional CuO nanowire/TiO2 nanotube arrays photoelectrode synthesis, characterization, photocatalysis and SERS applications.

    Science.gov (United States)

    Sheng, Pengtao; Li, Weili; Du, Pengwei; Cao, Kesheng; Cai, Qingyun

    2016-11-01

    Vertically aligned single crystalline CuO nanowire arrays (NWs) grown directly on TiO2 nanotube arrays (NTAs) supporting by Ti foil have been successfully fabricated using facile thermal oxidation of Cu nanocrystals in static air. CuO NWs growth behavior dependent on parent Cu nanocrystals sizes has been well investigated. Mass transport channel of Cu ions in horizontal and vertical for supporting CuO NWs diameter and length changes has been confirmed through a novel step-by-step surface diffusion process. CuO NWs, nano-mushrooms and nanosheets can be easily obtained by varying growth conditions. After photocatalytic synthesis of snow-like Ag nanocrystals upon CuO NWs/TiO2 NTAs, the hybrid photoelectrode exhibits superior catalytic property and detection sensitivity, which can clean themselves by photocatalytic degradation of RhB molecules adsorbed to the substrate under irradiation using surface enhanced Raman scattering (SERS) detection, a recycling can been achieved.

  19. Influence of thermal annealing on microstructural, morphological, optical properties and surface electronic structure of copper oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Department of Physics, Nigde University, 51240 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Akgul, Guvenc, E-mail: guvencakgul@gmail.com [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Yildirim, Nurcan [Department of Physics Engineering, Ankara University, 06100 Ankara (Turkey); Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Unalan, Husnu Emrah [Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Turan, Rasit [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15

    In this study, effect of the post-deposition thermal annealing on copper oxide thin films has been systemically investigated. The copper oxide thin films were chemically deposited on glass substrates by spin-coating. Samples were annealed in air at atmospheric pressure and at different temperatures ranging from 200 to 600°C. The microstructural, morphological, optical properties and surface electronic structure of the thin films have been studied by diagnostic techniques such as X-ray diffraction (XRD), Raman spectroscopy, ultraviolet–visible (UV–VIS) absorption spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The thickness of the films was about 520 nm. Crystallinity and grain size was found to improve with annealing temperature. The optical bandgap of the samples was found to be in between 1.93 and 2.08 eV. Cupric oxide (CuO), cuprous oxide (Cu{sub 2}O) and copper hydroxide (Cu(OH){sub 2}) phases were observed on the surface of as-deposited and 600 °C annealed thin films and relative concentrations of these three phases were found to depend on annealing temperature. A complete characterization reported herein allowed us to better understand the surface properties of copper oxide thin films which could then be used as active layers in optoelectronic devices such as solar cells and photodetectors. - Highlights: • Effect of post-deposition annealing on copper oxide thin films was investigated. • Structural, optical, and electronic properties of the thin films were determined. • Oxidation states of copper oxide thin films were confirmed by XPS analysis. • Mixed phases of CuO and Cu{sub 2}O were found to coexist in copper oxide thin films.

  20. Combination of CuO nanoparticles and fluconazole: preparation, characterization, and antifungal activity against Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Weitz, Iris S., E-mail: irisweitz@braude.ac.il; Maoz, Michal; Panitz, Daniel [ORT Braude College, Department of Biotechnology Engineering (Israel); Eichler, Sigal; Segal, Ester [Technion – Israel Institute of Technology, Department of Biotechnology and Food Engineering (Israel)

    2015-08-15

    Combination therapy becomes an important strategy in the management of invasive fungal infections and emergence of resistant fungi mutants. In this work, we examine the combination of copper oxide (CuO) nanoparticles (NPs) with fluconazole as potential treatment against the pathogenic fungi, Candidaalbicans. CuO NPs (∼7 nm in size) were synthesized with acetate ligands assembled on their surface, as shown by both thermal gravimetric analysis and FTIR spectroscopy. Unlike the commercial CuO (both bulk and 50 nm particles), that are poorly dispersed in water, the interaction with water allows the fine dispersion of the coated CuO NPs and their excellent colloidal stability. The addition of fluconazole to the aqueous CuO dispersion induced spontaneous self-assembly of the NPs into linear pearl-like chains network, shown by cryogenic transmission electron microscopy (cryo-TEM). The antifungal activity of the CuO NPs and their combination with fluconazole (fluconazole–CuO NPs) was studied against C. albicans. The best MIC values were obtained at concentrations as low as 0.2 and 0.3 mg/mL, respectively. The results suggest that fluconazole–CuO NPs can provide a potential alternative treatment for C. albicans infections.

  1. Combination of CuO nanoparticles and fluconazole: preparation, characterization, and antifungal activity against Candida albicans

    Science.gov (United States)

    Weitz, Iris S.; Maoz, Michal; Panitz, Daniel; Eichler, Sigal; Segal, Ester

    2015-08-01

    Combination therapy becomes an important strategy in the management of invasive fungal infections and emergence of resistant fungi mutants. In this work, we examine the combination of copper oxide (CuO) nanoparticles (NPs) with fluconazole as potential treatment against the pathogenic fungi, Candida albicans. CuO NPs ( 7 nm in size) were synthesized with acetate ligands assembled on their surface, as shown by both thermal gravimetric analysis and FTIR spectroscopy. Unlike the commercial CuO (both bulk and 50 nm particles), that are poorly dispersed in water, the interaction with water allows the fine dispersion of the coated CuO NPs and their excellent colloidal stability. The addition of fluconazole to the aqueous CuO dispersion induced spontaneous self-assembly of the NPs into linear pearl-like chains network, shown by cryogenic transmission electron microscopy (cryo-TEM). The antifungal activity of the CuO NPs and their combination with fluconazole (fluconazole-CuO NPs) was studied against C. albicans. The best MIC values were obtained at concentrations as low as 0.2 and 0.3 mg/mL, respectively. The results suggest that fluconazole-CuO NPs can provide a potential alternative treatment for C. albicans infections.

  2. Fabrication of CuO nanoplatelets for highly sensitive enzyme-free determination of glucose

    Energy Technology Data Exchange (ETDEWEB)

    Wang Juan [School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640 (China); Zhang Weide, E-mail: zhangwd@scut.edu.cn [School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640 (China)

    2011-09-01

    Highlights: > Adhered growth of CuO nanoplatelets on Cu foils. > Enzyme-free glucose sensor with very high sensitivity. > Excellent stability and good anti-interference ability. - Abstract: CuO nanoplatelets were grown on Cu foils by a one step, template free process. The structure and morphology of the CuO nanoplatelets were characterized by X-ray diffraction, scanning and transmission electron microscopy. The CuO nanoplatelets grown on Cu foil were integrated to be an electrode for glucose sensing. The electrocatalytic activity of the CuO nanoplatelets electrode for glucose in alkaline media was investigated by cyclic voltammetry and chronoamperometry. The electrode exhibits a sensitivity of 3490.7 {mu}A mM{sup -1} cm{sup -2} to glucose which is much higher than that of most reported enzyme-free glucose sensors and the linear range was obtained over a concentration up to 0.80 mM with a detection limit of 0.50 {mu}M (signal/noise = 3). Exhilaratingly, the electrode based on the CuO nanoplatelets is resistant against poisoning by chloride ion, and the interference from the oxidation of common interfering species, such as uric acid, ascorbic acid, dopamine and carbonhydrate compounds, can also be effectively avoided. Finally, the electrode was applied to analyze glucose concentration in human serum samples.

  3. Solution-dispersed CuO nanoparticles anode buffer layer: Effect of ultrasonic agitation duration on photovoltaic performance

    Science.gov (United States)

    Sabri, Nasehah Syamin; Yap, Chi Chin; Yahaya, Muhammad; Salleh, Muhamad Mat; Jumali, Mohammad Hafizuddin Haji

    2016-11-01

    The performance of inverted type hybrid organic solar cell based on poly(3-hexyltheopene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) can be improved by adding an anode buffer layer of copper oxide (CuO). CuO that serves as an electron blocking layer which could effectively reduce the charge recombination at the photoactive layer (P3HT:PCBM)/silver (Ag) interfaces. At the same time, Cuo anode buffer layer could accelerate the holes collection from the photoactive layer to the top electrode. In this study we investigated the effects of ultrasonic agitation duration in preparation of solution-dispersed CuO anode buffer layer on the performance of the devices with a configuration of fluorine tin oxide (FTO)/zinc oxide (ZnO) nanorod arrays/P3HT:PCBM/ CuO/Ag. Different durations of ultrasonic agitation (0, 5, 15 and 25 min) were used for CuO nanoparticles solution dispersion to obtain the optimum particle size distribution of CuO. It was found that the smallest average particle size of CuO was obtained by applying the ultrasonic agitation for longest duration of 25 min. The highest power conversion efficiency of 1.22% was recorded from the device incorporating with CuO anode buffer layer with the smallest average particle size. It is believed that CuO anode buffer layer with the smallest average particle size had the least agglomerates, thus leading to better film formation and contact surface area.

  4. Outcome of temperature variation on sol-gel prepared CuO nanostructure properties (optical and dielectric)

    Energy Technology Data Exchange (ETDEWEB)

    Bibi, Maryam [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan); Javed, Qurat-ul-Ain, E-mail: quratulain@sns.nust.edu.pk [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan); Abbas, Hussain [Institute of Avionics & Aeronautics (IAA), Air University, Islamabad (Pakistan); Baqi, Sabah [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan)

    2017-05-01

    The optical and dielectric properties of Copper Oxide (CuO) have made it a fascinating material to be used in solar energy harvesting, gas sensing, optoelectronics and catalytical applications. Focusing on the cost-effectiveness of Sol-gel method, it is employed for nanostructured CuO production. Effect of changing temperature is observed on the formation mechanism of CuO and its properties. The temperature range of 300 °C–500 °C was used in annealing of samples to produce defect free CuO nanomaterial. Prepared material was investigated using phase characterization (X-ray diffraction ‘XRD’) technique, scanning electron microscopy (SEM), UV–Visible absorption spectroscopy and LCR meter. A structural change in prepared CuO was observed from cluster formation to Nano-fibrils by increase in annealing temperature. 11.99 nm–29.17 nm crystallites of CuO were attained by using Debye Scherer formula. A large band gap of 3.15 eV was achieved by increasing the annealing temperature upto 400 °C. For better solar energy harvest, wide band gapped CuO structures are proved to be functional and practical materials. The fabricated CuO nanostructures were found suitable to be used in devices for stabilizing circuit designs for sensitive appliances as well as micro electromechanical systems (mems). - Highlights: • CuO was synthesized by using sol gel method post growth annealing process. • XRD and SEM characterizations confirm the successful synthesis of CuO. • Change in morphology was observed with varying annealing temperature. • Improved optical and dielectric properties were observed.

  5. Chamomile flower extract-directed CuO nanoparticle formation for its antioxidant and DNA cleavage properties

    Energy Technology Data Exchange (ETDEWEB)

    Duman, Fatih, E-mail: fduman@erciyes.edu.tr [Erciyes University, Science Faculty, Biology Department, Kayseri 38039, Kayseri (Turkey); Ocsoy, Ismail [Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes University, 38039, Kayseri (Turkey); Erciyes University, Nanotechnology Research Center, 38039, Kayseri (Turkey); Kup, Fatma Ozturk [Erciyes University, Science Faculty, Biology Department, Kayseri 38039, Kayseri (Turkey)

    2016-03-01

    In this study, we report the synthesis of copper oxide nanoparticles (CuO NPs) using a medicinal plant (Matricaria chamomilla) flower extract as both reducing and capping agent and investigate their antioxidant activity and interaction with plasmid DNA (pBR322).The CuO NPs were characterized using Uv–Vis spectroscopy, FT-IR (Fourier transform infrared spectroscopy), DLS (dynamic light scattering), XRD (X-ray diffraction), EDX (energy-dispersive X-ray) spectroscopy and SEM (scanning electron microscopy). The CuO NPs exhibited nearly mono-distributed and spherical shapes with diameters of 140 nm size. UV–Vis absorption spectrum of CuO NPs gave a broad peak around 285 and 320 nm. The existence of functional groups on the surface of CuO NPs was characterized with FT-IR analysis. XRD pattern showed that the NPs are in the form of a face-centered cubic crystal. Zeta potential value was measured as − 20 mV due to the presence of negatively charged functional groups in plant extract. Additionally, we demonstrated concentration-dependent antioxidant activity of CuO NPs and their interaction with plasmid DNA. We assumed that the CuO NPs both cleave and break DNA double helix structure. - Highlights: • The synthesis of microwave assisted green synthesis of CuO nanoparticles • The synthesized nanoparticles were analyzed by FT-IR, DLS, XRD, EDX and SEM. • Concentration-dependent antioxidant activity of CuO NPs was determined. • CuO NPs cause both cleavage in the DNA double helix structure and breaks as well.

  6. Direct electrochemistry of hemoglobin immobilized in CuO nanowire bundles.

    Science.gov (United States)

    Li, Yueming; Zhang, Qian; Li, Jinghong

    2010-11-15

    It is one of main challenges to find the suitable materials to enhance the direct electron transfer between the electrode and redox protein for direct electrochemistry field. Nano-structured metal oxides have attracted considerable interest because of unique properties, well biocompatibility, and good stability. In this paper, the copper oxide nanowire bundles (CuO NWBs) were prepared via a template route, and the bioelectrochemical performances of hemoglobin (Hb) on the CuO NWBs modified glass carbon electrodes (denoted as Hb-CuO NWBs/GC) were studied. TEM and XRD were used to characterize the morphology and structure of the as synthesized CuO NWBs. Fourier transform-infrared spectroscopy (FT-IR) proved that Hb in the CuO NWBs matrix could retain its native secondary structure. A pair of well-defined and quasi-reversible redox peaks at approximately -0.325 V (vs. Ag/AgCl saturated KCl) were shown in the cyclic voltammogram curve for the Hb-CuO NWBs/GC electrode, which indicated the direct electrochemical behavior. The Hb-CuO NWBs/GC electrode also displayed a good electrocatalytic activity toward the reduction of hydrogen peroxide. These results indicate that the CuO NWBs are good substrates for immobilization of biomolecules and might be promising in the fields of (bio) electrochemical analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Characterization and adsorption performance of Pb(II) on CuO nanorods synthesized by the hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Arfaoui, Lobna; Kouass, Salah [Laboratoire des matériaux utiles, Institut National de Recherche et d' Analyse Physico-Chimique (INRAP) Sidi Thabet, 2020 Tunis (Tunisia); Dhaouadi, Hassouna, E-mail: dhaouadihassouna@yahoo.fr [Laboratoire Matériaux Traitement et Analyse, Institut National de Recherche et d' Analyse Physico-Chimique (INRAP) Sidi Thabet, 2020 Tunis (Tunisia); Jebali, Raouf [Laboratoire des matériaux utiles, Institut National de Recherche et d' Analyse Physico-Chimique (INRAP) Sidi Thabet, 2020 Tunis (Tunisia); Touati, Fathi [Laboratoire Matériaux Traitement et Analyse, Institut National de Recherche et d' Analyse Physico-Chimique (INRAP) Sidi Thabet, 2020 Tunis (Tunisia)

    2015-10-15

    Highlights: • The nanorods of CuO were synthesized by a hydrothermal route without any surfactant. • X-ray diffraction showed monoclinic structure with space group C{sub 2/c}. • The nanorods show relatively high adsorption capacity for the removal of Pb(II). • The adsorption kinetics could be fitted well by the pseudo-second-order model. • The equilibrium data can be fitted well using the Langmuir isotherm model - Abstract: Copper oxide (CuO) nanorods were synthesized by hydrothermal method. The detailed structural, compositional and optical characterization of this material was also evaluated with XRD, FT-IR, EDS, and UV–vis spectroscopy, which confirmed that the obtained nanorods are well-crystallized CuO and possess good optical properties. SEM and TEM studies revealed that the as-synthesized CuO nanorods are uniform with an average diameter of 17 nm. The adsorption activity of the CuO nanostructures was studied. The adsorption results showed that the CuO nanorods are an effective and efficient adsorbent for the removal of Pb(II) ions. The influence of various operational parameters such as the pH of the solution, the contact time and the initial concentrations were also studied and the results were discussed. The estimated maximum lead ion adsorption capacity of the CuO nanorods was found to be 188.67 mg g{sup −1} at an optimum pH of 6.

  8. Preparation and characterization of nanocrystalline CuO powders with the different surfactants and complexing agent mediated precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, V.; Gajendiran, J., E-mail: gaja.nanotech@gmail.com

    2014-08-15

    Highlights: • CuO nanostructures by surfactants mediated method. • Structural and optical properties of CuO nanostructures changes under the effect of surface modifier. • Citric acid assisted is the best, in terms of size, morphology and optical properties than that of CTAB, SDS and PEG-400. - Abstract: Nanostructures of copper oxide (CuO) was synthesized into crystallite sized ranging from 20 to 50 nm in the presence of different surfactants, and complex agent such as cityl tri methyl ammonium bromide (CTAB), sodium do decyl sulfate (SDS), poly ethylene glycol (PEG-400) and citric acid via a precipitation route. Variations in several parameters and their effects on the structural and optical properties of CuO nanostructures (crystallite size, morphology and band gap) were investigated by XRD, FTIR, SEM and UV analysis. The UV–visible absorption spectra of the different surfactants and complexing agent assisted CuO nanostructures indicates that the estimated optical band gap energy value (1.94–1.98 eV) is higher than that of the bulk CuO value (1.4 eV), which is attributed to the quantum confinement effect. The formation mechanism of different surfactants and complexing agent assisted CuO nanostructures is also proposed.

  9. One dimensional CuO nanocrystals synthesis by electrical explosion: A study on structural, optical and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Shutesh, E-mail: shutesh.k@onsemi.com [Department of Mechanical Engineering University of Malaya, 50603 Kuala Lumpur (Malaysia); ON Semiconductor Package Innovation and Development Center, 70450 Seremban (Malaysia); Haseeb, A.S.M.A.; Johan, Mohd Rafie [Department of Mechanical Engineering University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-02-15

    Highlights: • One-dimensional CuO nanoflakes were synthesized by novel wire explosion technique. • A physical synthesis method capable of producing high aspect ratio (1:16) nanocrystals. • Most energy efficient and eco-friendly synthesis of low-dimensional transition metal oxide nanocrystals. -- Abstract: One-dimensional (1D) copper oxide (CuO) nanocrystals were synthesized using a novel wire explosion in de-ionized (DI) water without any chemical additives. Highly crystalline 1D CuO nanocrystals with 1:16 aspect ratio were successfully synthesized using this technique. The chemical nature and physical structure of the nanocrystals were controlled by simply modulating the exploding medium temperature. The results showed that nanocrystals produced at explosion temperatures 65 °C and 95 °C are pure CuO with optical band-gap energy of 2.38 eV. High Resolution Transmission Electron Microscope analysis (HRTEM) indicates that the CuO nanocrystals are with growth in [1{sup ¯}11] and [1 1 1] directions. The epitaxial crystal growth kinetics of the 1D nanostructure by aggregation was discussed. The incorporation of microstructural features like edge dislocations and porosity in the growth mechanism was examined. X-ray photoelectron spectroscopy (XPS) characterization indicates the formation of high purity CuO nanocrystals with valence state +2. This study provides an energy efficient and eco-friendly synthesis method of 1D transition metal oxide nanocrystals for electronic applications.

  10. Effects of copper(II) and copper oxides on THMs formation in copper pipe.

    Science.gov (United States)

    Li, Bo; Qu, Jiuhui; Liu, Huijuan; Hu, Chengzhi

    2007-08-01

    Little is known about how the growth of trihalomethanes (THMs) in drinking water is affected in copper pipe. The formation of THMs and chlorine consumption in copper pipe under stagnant flow conditions were investigated. Experiments for the same water held in glass bottles were performed for comparison. Results showed that although THMs levels firstly increased in the presence of chlorine in copper pipe, faster decay of chlorine as compared to the glass bottle affected the rate of THMs formation. The analysis of water phase was supplemented by surface analysis of corrosion scales using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDX). The results showed the scales on the pipe surface mainly consisted of Cu(2)O, CuO and Cu(OH)(2) or CuCO(3). Designed experiments confirmed that the fast depletion of chlorine in copper pipe was mainly due to effect of Cu(2)O, CuO in corrosion scales on copper pipe. Although copper(II) and copper oxides showed effect on THMs formation, the rapid consumption of chlorine due to copper oxide made THM levels lower than that in glass bottles after 4h. The transformations of CF, DCBM and CDBM to BF were accelerated in the presence of copper(II), cupric oxide and cuprous oxide. The effect of pH on THMs formation was influenced by effect of pH on corrosion of copper pipe. When pH was below 7, THMs levels in copper pipe was higher as compared to glass bottle, but lower when pH was above 7.

  11. Effects of sputtering power on properties of copper oxides thin films deposited on glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ooi, P. K.; Ng, S. S.; Abdullah, M. J. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-04-24

    Copper oxides are deposited by radio frequency sputtering using copper target in the mixture of argon and oxygen gasses. The structural and optical properties of the copper oxides deposited at different sputtering powers have been investigated. All the films are single phase polycrystalline. At low RF power (100 W), the film is monoclinic structure of cupric oxide (CuO). Meanwhile, the films are cubic structure of cuprous oxide (Cu2O) at higher RF power. Field emission scanning electron microscopy images show the films have different morphologies with small grain size and consist of a lot of voids. The analysis of energy dispersive X-ray spectroscopy shows that the ratio of Cu to O is increased as the RF power increased. From the ultraviolet–visible spectroscopy, the films have a broad absorption edge in the range of 300–500 nm. The band gap of the films grown at RF power of 100 W, and 120 W and above, were 1.18 eV and 2.16 eV, respectively.

  12. Morphology and gas sensing characteristics of density-controlled CuO nanostructures obtained by varying the oxygen partial pressure during growth

    Science.gov (United States)

    Lee, Dongjin; Jin, Changhyun; Noh, Youngwook; Park, Seokhyun; Choi, Sun-Woo

    2016-07-01

    By exerting different O2 partial pressures (0, 20, 40, and 60 sccm) onto copper substrates, we discovered that the growth parameter, namely, the O2 flow rate, affects the degree of nucleation, diameter, length, and crystalline quality of CuO nanowires (NWs). Scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to analyze the evolution of the morphological and the microstructural changes in the CuO nanostructures. The formation of a Cu2O interlayer between the Cu and the CuO layers could be adjusted by controlling more precisely the O2 flow rate. In addition, the reducing (H2S) and the oxidizing (O2, NO2, and SO2) gas sensing performances of these O2-assisted CuO NWs were compared with those of CuO NWs grown in static air. The response to the reducing H2S of the sensors based on CuO NWs grown using O2 at 40 sccm showed a higher electrical change and faster response and recovery times than the sensors based on CuO NWs grown using lower O2 flow rates, including the ones grown in static air and/or used for sensing oxidizing gases (O2, NO2, and SO2) did. On the basis of their growth and their gas-sensing applications, the possible mechanisms characteristic of the density-controlled CuO NWs grown using various O2 partial pressures are discussed.

  13. Fluorescence study on the interaction between apoCopC and cupric

    Institute of Scientific and Technical Information of China (English)

    PANG Erguo; ZHAO Yaqin; YANG Binsheng

    2005-01-01

    The interaction between apoCopC and cupric was investigated by fluorescence spectra, in phosphate (20 mmol/L) buffer at pH 6.0. Results suggest that the environment is measured to be hydrophobic completely around tryptophan (83). At the same time, apoCopC fluorescence at 320 nm was significantly quenched with the addition of cupric and the 1:1 stoichiometric ratio of apoCopC to cupric was confirmed by fluorescence. In addition, the conditional binding constants were calculated to be Kcu-Copc = (1.8(0.58)× 1013 mol-1 L on the basis of the results of fluorescence titration curves. The apoCopC has the ability to bind specifically cupricion.

  14. CHARACTERISATION OF Cr DOPED CuO NANOPARTICLES AND ITS PERFORMANCE IN SOLAR CELL

    OpenAIRE

    2016-01-01

    Pure and Cr2+doped Copper oxide (CuO) nanoparticles were synthesized by simple precipitation method and subjected to photovoltaic activity by forming nanopowder –thin film as light absorbing  layer  on an  indigenously fabricated heterojunction by Doctor-Blade method.  Effect of concentration of the dopant (2, 4, and 6 mol%)  on the properties of CuO was analyzed from X-Ray Diffraction pattern (XRD), Scanning Electron Microscopy(SEM) Energy Dispersive Analysis (EDAX), UV-Vis studies and Photo...

  15. Magnetoresistive study of the antiferromagnetic-weak ferromagnetic transition in single-crystal La2CuO4+δ

    Science.gov (United States)

    Belevtsev, B. I.; Dalakova, N. V.; Savitsky, V. N.; Panfilov, A. S.; Braude, I. S.; Bondarenko, A. V.

    2004-05-01

    Resistive measurements were made to study the magnetic field-induced antiferromagnetic (AF)—weak ferromagnetic (WF) transition in the La2CuO4 single crystal. The magnetic field (dc or pulsed) was applied normally to the CuO2 layers. The transition manifested itself in a drastic decrease of the resistance in critical fields of 5-7 T. The study is the first to display the effect of the AF-WF transition on the conductivity of the La2CuO4 single crystal in the direction parallel to the CuO2 layers. The results provide support for the three-dimensional nature of the hopping conduction of this layered oxide.

  16. CuO nanostructures: optical properties and morphology control by pyridinium-based ionic liquids.

    Science.gov (United States)

    Sabbaghan, Maryam; Shahvelayati, Ashraf Sadat; Madankar, Kamelia

    2015-01-25

    Copper oxide nanostructures have been synthesized by a simple reflux method in aqueous medium of pyridinium based ionic liquids. The structural and optical properties of CuO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and UV-visible. The morphologies of the nanostructures can be controlled by changing the amount of NaOH and ionic liquids. The results show that the use identical pyridinium based ionic liquids in ratio of 4:1 NaOH/Cu(OAc)2⋅H2O yield minor differences in morphology of CuO nanostructures. Different morphologies of CuO nanostructures were obtained by changing the ratio NaOH/Cu(OAc)2⋅H2O to 2:1. Ionic liquids play an important role on optical properties of CuO nanostructures. The results of optical measurements of the CuO nanostructures illustrate that band gaps are estimated to be 1.67-1.85 eV. PL patterns studies show that the ionic liquids can be effect on PL patterns of the samples. The reasons of these phenomena are discussed.

  17. Enhanced chlorine dioxide decay in the presence of metal oxides: Relevance to drinking water distribution systems

    KAUST Repository

    Liu, Chao

    2013-07-19

    Chlorine dioxide (ClO2) decay in the presence of typical metal oxides occurring in distribution systems was investigated. Metal oxides generally enhanced ClO2 decay in a second-order process via three pathways: (1) catalytic disproportionation with equimolar formation of chlorite and chlorate, (2) reaction to chlorite and oxygen, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly stronger abilities than goethite (α-FeOOH) to catalyze the ClO2 disproportionation (pathway 1), which predominated at higher initial ClO2 concentrations (56-81 μM). At lower initial ClO2 concentrations (13-31 μM), pathway 2 also contributed. The CuO-enhanced ClO2 decay is a base-assisted reaction with a third-order rate constant of 1.5 × 10 6 M-2 s-1 in the presence of 0.1 g L -1 CuO at 21 ± 1 C, which is 4-5 orders of magnitude higher than in the absence of CuO. The presence of natural organic matter (NOM) significantly enhanced the formation of chlorite and decreased the ClO 2 disproportionation in the CuO-ClO2 system, probably because of a higher reactivity of CuO-activated ClO2 with NOM. Furthermore, a kinetic model was developed to simulate CuO-enhanced ClO 2 decay at various pH values. Model simulations that agree well with the experimental data include a pre-equilibrium step with the rapid formation of a complex, namely, CuO-activated Cl2O4. The reaction of this complex with OH- is the rate-limiting and pH-dependent step for the overall reaction, producing chlorite and an intermediate that further forms chlorate and oxygen in parallel. These novel findings suggest that the possible ClO2 loss and the formation of chlorite/chlorate should be carefully considered in drinking water distribution systems containing copper pipes. © 2013 American Chemical Society.

  18. High-performance nanothermite composites based on aloe-vera-directed CuO nanorods.

    Science.gov (United States)

    Patel, Vinay Kumar; Bhattacharya, Shantanu

    2013-12-26

    In this work, we demonstrate the development of high-performance nanothermite composites derived from super-reactive CuO nanorods oxidizers fabricated by simple biogenic routes using Aloe vera plant extracts. Nanorods of various length scales have been realized via simple sonoemulsion and solid-state biosynthesis routes using Aloe vera gel as a green surfactant promoting the directional growth of CuO nanorods in both solid and emulsion phase. The biosynthesized CuO nanorods (oxidizers)/fuel (nanoaluminum) composites ignited vigorously with abundant gas generation, developing high heat of reaction of 1.66 kJ g(-1) and very high pressurization rate of around 1.09 MPa μs(-1) and peak pressure of 65.4 MPa when blasted inside a constant volume pressure cell with a charge density of 0.2 g cm(-3). The pressurization rates so obtained are four times higher with twice the peak pressure in comparison to such nanothermites formulated via other available state of the art wet-chemical techniques, which reflects the catalytic role of Aloe vera surface functional groups (A. vera-sfg) enhancing the reactivity of CuO oxidizers with excess gas release rate during exothermic reaction with nanoaluminum. Through this work, Aloe vera gel has for the first time been identified as a novel biotemplate for green synthesis of nanorod structures of metal oxides, and we have also studied the utility of A. vera-sfg in the creation of super-reactive CuO oxidizers producing excellent heat of reaction and dynamic pressure characteristics as demanded in propellants, explosives, and pyrotechnics.

  19. Synthesis and evaluation of bactericidal properties of CuO nanoparticles against Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Sayedeh Fatemeh Shaffiey

    2014-04-01

    Full Text Available   Objective(s: CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species.   Materials and Methods: Here, we synthesized CuO nanoparticles (NPs and explored the antibacterial activity of CuO NPs preparation. Results: Single crystalline nanoparticles of copper oxide having almost uniform particle size of 5-6 nm has been synthesized by a facile and versatile route. XRD spectra confirmed the formation of single phase CuO NPs. Transmission electron microscopy results corroborate well with XRD results. The technique employed is free from toxic solvents, organics and amines, is based on a simple reaction of copper sulfate and de-ionized water (DI, and their bactericidal effects against of Aeromonas hydrophila ATCC 7966T bacteria were investigated. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC with liquid culture for all of the Aeromonas hydrophila culture Medias was done. Conclusion: Present study confirms that Copper oxide nanoparticles have great promise as antimicrobial agent against Aeromonas hydrophila

  20. Waters of Hydration of Cupric Hydrates: A Comparison between Heating and Absorbance Methods

    Science.gov (United States)

    Barlag, Rebecca; Nyasulu, Frazier

    2011-01-01

    The empirical formulas of four cupric hydrates are determined by measuring the absorbance in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of absorbance versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…

  1. Archetypal sandwich-structured CuO for high performance non-enzymatic sensing of glucose.

    Science.gov (United States)

    Meher, Sumanta Kumar; Rao, G Ranga

    2013-03-07

    In the quest to enhance the selectivity and sensitivity of novel structured metal oxides for electrochemical non-enzymatic sensing of glucose, we report here a green synthesis of unique sandwich-structured CuO on a large scale under microwave mediated homogeneous precipitation conditions. The physicochemical studies carried out by XRD and BET methods show that the monoclinic CuO formed via thermal decomposition of Cu(2)(OH)(2)CO(3) possesses monomodal channel-type pores with largely improved surface area (~43 m(2) g(-1)) and pore volume (0.163 cm(3) g(-1)). The fascinating surface morphology and pore structure of CuO is formulated due to homogeneous crystallization and microwave induced self assembly during synthesis. The cyclic voltammetry and chronoamperometry studies show diffusion controlled glucose oxidation at ~0.6 V (vs. Ag/AgCl) with extremely high sensitivity of 5342.8 μA mM(-1) cm(-2) and respective detection limit and response time of ~1 μM and ~0.7 s, under a wide dynamic concentration range of glucose. The chronoamperometry measurements demonstrate that the sensitivity of CuO to glucose is unaffected by the absence of dissolved oxygen and presence of poisoning chloride ions in the reaction medium, which essentially implies high poison resistance activity of the sandwich-structured CuO. The sandwich-structured CuO also shows insignificant interference/significant selectivity to glucose, even in the presence of high concentrations of other sugars as well as reducing species. In addition, the sandwich-structured CuO shows excellent reproducibility (relative standard deviation of ~2.4% over ten identically fabricated electrodes) and outstanding long term stability (only ~1.3% loss in sensitivity over a period of one month) during non-enzymatic electrochemical sensing of glucose. The unique microstructure and suitable channel-type pore architecture provide structural stability and maximum accessible electroactive surface for unimpeded mobility of glucose

  2. Behavior of Aqueous Electrolytes in Steam Cycles - The Final Report on the Solubility and Volatility of copper(I) and Copper(II) Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Donald [ORNL; Benezeth, Pascale [Laboratoire des Mecanismes et Transferts en Geologie, Toulouse, France; Simonson, J Michael {Mike} [ORNL

    2004-05-01

    Measurements were completed on the solubility of cupric and cuprous oxides in liquid water and steam at controlled pH conditions from 25 to 400 C (77 to 752 F). The results of this study have been combined with those reported from this laboratory in two previous EPRI reports to provide a complete description of the solubility of these oxides and the speciation of copper dissolved in liquid water and steam as a function of oxidation state, temperature, pH, and in the case of steam, pressure. These constitute the first set of reliable data for cuprous oxide solubility over this range of conditions. For the more intensively studied CuO case, agreement was found between our results and those of previous studies of its solubility in steam, whereas only partial agreement was evident for its solubility in liquid water. For both oxides this disagreement often amounted to orders of magnitude. The solubility of cuprous oxide is somewhat lower than that of CuO at ambient conditions, except as very high pH. However, by 350 C (662 F), Cu{sub 2}O is the more soluble phase. At 100 C (212 F) and above, the logarithm of the solubility of both phases decreases linearly with increasing pH to a minimum value then sharply increases linearly with pH. In other words, above 100 C the solubility of both oxides become highly pH dependent. In fact at constant pH during startup, very high copper concentrations can be reached in the boiler water, more than an order of magnitude above those at ambient or operating temperatures. The enhancing effect of added ammonia on the solubility of both oxides is most significant at low temperatures and is much greater for cuprous oxide. Consequently, the mobility of copper is affected significantly under AVT startup conditions. The oxidation of copper metal and presumably cuprous oxide by addition of air-saturated makeup water can lead to much higher copper concentrations than equilibrium with cupric oxide would allow, but the presence of both copper metal

  3. Bioaccumulation and toxicity of CuO nanoparticles by a freshwater invertebrate after waterborne and dietborne exposures

    Science.gov (United States)

    Croteau, Marie-Noele; Misra, Superb K.; Luoma, Samuel N.; Valsami-Jones, Eugenia

    2014-01-01

    The incidental ingestion of engineered nanoparticles (NPs) can be an important route of uptake for aquatic organisms. Yet, knowledge of dietary bioavailability and toxicity of NPs is scarce. Here we used isotopically modified copper oxide (65CuO) NPs to characterize the processes governing their bioaccumulation in a freshwater snail after waterborne and dietborne exposures. Lymnaea stagnalis efficiently accumulated 65Cu after aqueous and dietary exposures to 65CuO NPs. Cu assimilation efficiency and feeding rates averaged 83% and 0.61 g g–1 d–1 at low exposure concentrations (–1), and declined by nearly 50% above this concentration. We estimated that 80–90% of the bioaccumulated 65Cu concentration in L. stagnalis originated from the 65CuO NPs, suggesting that dissolution had a negligible influence on Cu uptake from the NPs under our experimental conditions. The physiological loss of 65Cu incorporated into tissues after exposures to 65CuO NPs was rapid over the first days of depuration and not detectable thereafter. As a result, large Cu body concentrations are expected in L. stagnalis after exposure to CuO NPs. To the degree that there is a link between bioaccumulation and toxicity, dietborne exposures to CuO NPs are likely to elicit adverse effects more readily than waterborne exposures.

  4. Shape-controlled synthesis of Sn-doped CuO nanoparticles for catalytic degradation of Rhodamine B.

    Science.gov (United States)

    Vomáčka, Petr; Štengl, Václav; Henych, Jiří; Kormunda, Martin

    2016-11-01

    The uniform Sn-doped CuO nanoparticles were synthesized by a simple solution method at a low temperature. The prepared samples were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy techniques (HRSEM, HRTEM, SAED, STEM and EDS elemental mapping), atomic force microscopy (AFM), UV/Vis spectroscopy, nitrogen physisorption (BET) and by evaluation of the catalytic activity on the degradation of Rhodamine B. The tin doping had a considerable influence on the morphology of CuO. The gradual narrowing of the particles morphology in the crystallographic [010] direction was observed with increasing the dopant concentration. The plate-like, rectangularsquare and rod-like CuO nanoparticles were obtained. The mechanism of a crystal growth of CuO associated with doping is proposed. The tin doping also affected the structural and optical properties of CuO. Increasing the amount of a dopant led to a red-shift of a band gap from 1.33 to 1.18eV. The incorporation of tin into the structure of copper oxide was confirmed by XRD and distribution of tin mapped by EDS analysis. The good catalytic properties of the as-prepared doped material were demonstrated by the enhanced catalytic removal of Rhodamine B in the presence of H2O2. The undoped CuO nanosheets reached only 24% efficiency in the removal of Rhodamine B within two hours. The best result exhibited CuO_050Sn sample containing 4at.% of tin and the degradation of Rhodamine B reached 99% within the same time. We have demonstrated a simple, scalable process for the preparation of catalytically very active Sn-doped CuO nanoparticles with varying properties.

  5. 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.

  6. Preparation and Characterization of CuO Nanoparticles by Novel Sol-Gel Technique

    Directory of Open Access Journals (Sweden)

    Y. Aparna

    2012-10-01

    Full Text Available Recent developments of nanosize materials of metal and metal oxide particles are intensively pursued because of their prominence in different fields of applications. Among all the transition metal oxides, CuO is a potential candidate for the application of magnetic storage devices, solar energy transfer, sensors, and super capacitors etc. Moreover CuO nanoparticles act as a good catalyst in some of the chemical reactions. CuO nanoparticles were prepared by novel sol-gel method. In this technique CuCl2.6H2O is added with acetic acid and heated to 100 °C with continuous stirring. To control the ph of the above solution, NaOH is added to the solution till ph reached desired value. The color of the solution changed from blue to black with precipitation. The black precipitation was washed 3 – 4 times with distilled water. Finally the solution was centrifuged and dried in air for one day. The CuO nanoparticles were characterized by studying their structure with X-ray diffraction and composition by energy dispersive X-ray analysis. The size of the nanoparticles is estimated by particle size analyzer and transmission electron microscopy. The optical studies were carried out with Uv-Vis spectrophotometer.

  7. Monitoring a CuO gas sensor at work: an advanced in situ X-ray absorption spectroscopy study.

    Science.gov (United States)

    Volanti, D P; Felix, A A; Suman, P H; Longo, E; Varela, J A; Orlandi, M O

    2015-07-28

    X-ray absorption near edge structure (XANES) and electrical measurements were used to elucidate the local structure and electronic changes of copper(II) oxide (CuO) nanostructures under working conditions. For this purpose, a sample holder layout was developed enabling the simultaneous analysis of the spectroscopic and electrical properties of the sensor material under identical operating conditions. The influence of different carrier gases (e.g., air and N2) on the CuO nanostructures behavior under reducing conditions (H2 gas) was studied to analyze how a particular gas atmosphere can modify the oxidation state of the sensor material in real time.

  8. Nanostructured CuO thin film electrodes prepared by spray pyrolysis: a simple method for enhancing the electrochemical performance of CuO in lithium cells

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J.; Sanchez, L. [Cordoba Univ. (Spain). Departamento de Qumica Inorganica e Ingenieria Quimica; Martin, F.; Ramos-Barrado, J.R.; Sanchez, M. [Malaga Univ. (Spain). Lab. de Materiales y Superficie

    2004-10-15

    Nanostructured CuO thin films were prepared by using a spray pyrolysis method, copper acetate as precursor and stainless steel as substrate. The textural and structural properties of the films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed thorough coating of the substrate and thickness of 450-1250 nm; the average particle size as determined from the AFM images ranged from 30 to 160 nm. The XRD patterns revealed the formation of CuO alone and the XPS spectra confirmed the presence of Cu{sup 2+} as the main oxidation state on the surface. The films were tested as electrodes in lithium cells and their electrochemical properties evaluated from galvanostatic and step potential electrochemical spectroscopy (SPES) measurements. The discharge STEP curves exhibited various peaks consistent with the processes CuO {r_reversible} Cu{sub 2}O {r_reversible}Cu and with decomposition of the electrolyte, a reversible process in the light of the AFM images. The best electrode exhibited capacity values of 625 Ah kg{sup -1} over more than 100 cycles. This value, which involves a CuO {r_reversible} Cu reversible global reaction, is Ca. 50% higher than that reported for bulk CuO. The nanosize of the particles and the good adherence of the active material to the substrate are thought to be the key factors accounting for the enhanced electrochemical activity found. (author)

  9. Theoretical exploration of the oxidative properties of a [(tren Me1)CuO2]+ adduct relevant to copper monooxygenase enzymes: insights into competitive dehydrogenation versus hydroxylation reaction pathways.

    Science.gov (United States)

    de la Lande, Aurélien; Parisel, Olivier; Gérard, Hélène; Moliner, Vicente; Reinaud, Olivia

    2008-01-01

    Singlet and triplet H-transfer reaction paths from C-H and N-H bonds were examined by means of DFT and spin-flip TD-DFT computations on the [(tren Me1)CuO2]+ adduct. The singlet energy surfaces allow its evolution towards H2O2 and an imine species. Whereas N-H cleavage appears to be a radical process, C-H rupture results in a carbocation intermediate stabilized by an adjacent N atom and an electrostatic interaction with the [CuIOOH] metal core. Upon injection of an additional electron, the latter species straightforwardly forms a hydroxylated product. Based on these computational results, a new mechanistic description of the reactivity of copper monooxygenases is proposed.

  10. Subsolidus Phase Relations of the CaO-WO3-CuO System at 800 °C in Air

    DEFF Research Database (Denmark)

    Grivel, J. -C.

    2012-01-01

    The subsolidus phase relations of the CaO-WO3-CuO system were investigated in air. The samples were equilibrated at 800 degrees C. Under these conditions, five binary oxide phases are stable: Ca2CuO3, Cu3WO6, CuWO4, CaWO4 and Ca3WO6. The pseudo-ternary section is characterised by 6 three-phase re......The subsolidus phase relations of the CaO-WO3-CuO system were investigated in air. The samples were equilibrated at 800 degrees C. Under these conditions, five binary oxide phases are stable: Ca2CuO3, Cu3WO6, CuWO4, CaWO4 and Ca3WO6. The pseudo-ternary section is characterised by 6 three...

  11. Novel bamboo leaf shaped CuO nanorod@hollow carbon fibers derived from plant biomass for efficient and nonenzymatic glucose detection.

    Science.gov (United States)

    Li, Mian; Zhao, Zheng; Liu, Xiaotian; Xiong, Yueping; Han, Ce; Zhang, Yufan; Bo, Xiangjie; Guo, Liping

    2015-09-21

    The present paper reports on the preparation of novel bamboo leaf shaped CuO nanorod dispersed hollow carbon fibers (denoted as CuO NR@PCFs). Specially, the new-type hollow carbon fibers (containing abundant micro/meso/macropores and a large specific surface area) were prepared only by simple and fast pyrolysis of the natural product catkins without using any template or surfactant. Meanwhile, a facile method was used to prepare the bamboo leaf shaped CuO nanorod covered PCFs. Thanks to the abundant micro/meso/macropores, large specific surface area, and excellent electrical conduction efficiency of the PCF matrix, the as-prepared CuO NR@PCFs could also afford more catalytic sites, show more excellent reactant transport efficiency, and display more excellent electron transport rates compared with those for the pure CuO balls. Above all, these advantages will result in the excellent oxidation and detection efficiency of the CuO NR@PCF sample to glucose. Electrochemical measurements reveal that the CuO NR@PCF modified electrode can directly catalyze glucose oxidation and display an enhanced current response compared with the pure CuO balls (such as a response time within 4 s, wide linear ranges of 5 × 10(-3)-0.8 mM and 0.8-8.5 mM, good reproducibility, considerable stability, and excellent anti-interference to electroactive molecules and Cl(-)). The superior catalytic activity and selectivity make the CuO NR@PCF catalyst very promising for application in direct detection of glucose.

  12. Effect of triethanolamine:ethylenediamine ratios on CuO nanoparticles prepared by ultrasound irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ayob, M. T. M.; Ahmad, A. F.; Mohd, H. M. K.; Rahman, I. Abdul; Radiman, S. [School of Applied Physics, Faculty of Science and Technology (FST), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2014-09-03

    Coral-spherical-shaped of copper oxide nanoparticles have been successfully synthesized with different ratios of triethanolamine:ethylenediamine surfactant under ultrasonic condition. By controlling the amplitude of the ultrasonic radiation and concentration of metal salt precursors and surfactant, the formation of CuO nanospheres was obtained. Energy dispersive X-ray spectrum confirmed that Cu and O are the only elementary components present with a ratio of approximately 1:1. Furthermore, X-ray powder diffraction spectra for all the examined ratios of CuO showed well crystalline structures. UV-Vis spectroscopy was utilized to estimate the band gap energies of the CuO nanoparticles produced, which were found to be in the range of 2.74 eV to 2.95 eV. The field emission scanning electron micrographs of these nanospheres showed that their dimensions were in the range of 5-30 nm. These results indicate that the triethanolamine:ethylenediamine ratio plays an important role in the formation of different sized CuO nanoparticles, displaying a decrement in particle size with the increment in amount of triethanolamine ratios. This might be the key to synthesizing nanoparticles with specific sizes for various applications.

  13. Growth of Horizontal Nanopillars of CuO on NiO/ITO Surfaces

    Directory of Open Access Journals (Sweden)

    Siddharth Joshi

    2014-01-01

    Full Text Available We have demonstrated hydrothermal synthesis of rectangular pillar-like CuO nanostructures at low temperature (~60°C by selective growth on top of NiO porous structures film deposited using chemical bath deposition method at room temperature using indium tin oxide (ITO coated glass plate as a substrate. The growth of CuO not only filled the NiO porous structures but also formed the big nanopillars/nanowalls on top of NiO surface. These nanopillars could have significant use in nanoelectronics devices or can also be used as p-type conducting wires. The present study is limited to the surface morphology studies of the thin nanostructured layers of NiO/CuO composite materials. Structural, morphological, and absorption measurement of the CuO/NiO heterojunction were studied using state-of-the-art techniques like X-ray diffraction (XRD, transmission electron microscopy (SEM, atomic force microscopy (AFM, and UV spectroscopy. The CuO nanopillars/nanowalls have the structure in order of (5 ± 1.0 μm × (2.0 ± 0.3 μm; this will help to provide efficient charge transport in between the different semiconducting layers. The energy band gap of NiO and CuO was also calculated based on UV measurements and discussed.

  14. Releasing of Cupric Ion of Three types of Copper-bearing Intrauterine Contraceptive Device in Simulated Uterine Fluid

    Institute of Scientific and Technical Information of China (English)

    Jie GAO; Ying LI; Jian-ping LIU; Xuan GU

    2007-01-01

    Objective To compare the cupric ion releasing in vitro of the three IUDs.Methods The stability of cupric ion releasing of IUDs including TCu 380A IUD (TCu 380A), Multiload Cu375 IUD (MCu 375) and Yuangong 365 copper-bearing indomethacin-releasing IUD (Yuangong 365) by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometerResults The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71 -7.62±6.42 μg,4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 (P<0. 05).Conclusion TCu 380A and MCu 375 showed a "burst release" during the first few days and the former was of great significance(P<0. 05). The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order.

  15. Cupric natural zeolites as microbic ides;Zeolitas naturales cupricas como microbicidas

    Energy Technology Data Exchange (ETDEWEB)

    Contreras A, D.; Olguin G, M. T.; Alcantara D, D.; Burrola A, C., E-mail: teresa.olguin@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    The Escherichia coli and the Candida albicans are considered contamination indicators for what these organisms reflect the water quality. The natural zeolites by their characteristics and properties, they could incorporate to a waters treatment system, as ion exchange, adsorbents and/or microbiocid agents, representing an alternative method of low cost. Inside this investigation work was found that depending on the microorganism type, it varies the quantity of cupric zeolite that is required to carry out the water disinfection, being great for the case of yeasts than the bacteria s. In addition to that marked differences are presented in the required time to reach this process. The characterization of the natural zeolite material, sodium and cupric, was realized by means of scanning electron microscopy, determining the elementary composition (Energy Dispersive Spectroscopy) of each one of them, and by X-ray diffraction. (Author)

  16. Highly Efficient and Versatile Acetalization of Glycol Catalyzed by Cupric p-Toluenesulfonate

    Institute of Scientific and Technical Information of China (English)

    LIU,Cai-Hua; YU,Xin-Yu; LIANG,Xue-Zheng; WANG,Wen-Juan; YANG,Jian-Guo; HE,Ming-Yuan

    2007-01-01

    Acetalization of glycol with carbonyl compounds was carried out catalyzed by cupric p-toluenesulfonate. These carbonyl compounds included cyclohexanone, propionoaldehyde, n-butyraldehyde, iso-butyraldehyde, n-valeraldehyde, benzaldehyde and butanone. Satisfactory results were obtained: the conversions of these carbonyl compounds were more than 90%, the selectivities were higher than 99.1%, only 0.1% mole ratio of catalyst to substrate and 90 min were sufficient in most cases. The catalyst and products were separated easily by phase separation.

  17. Ferric and cupric ions requirement for DNA single-strand breakage by H2O2.

    Science.gov (United States)

    Tachon, P

    1989-01-01

    Hydrogen peroxide (H2O2), was able to nick the replicative form of the phage fd, without the addition of a reducing agent or of a metal. This DNA single-strand breakage decreased with an increase of the ionic strength, suggesting that H2O2 reacted with traces of metal bound to DNA. When cupric of ferric ions were added, the rate of DNA single-strand breakage by H2O2 greatly increased and it was 20-30 times faster with cupric than with ferric ions. The addition of EDTA at an equimolar ratio or in excess of metal prevented partially DNA single-strand cleavage by H2O2 in the presence of ferric ions and completely when cupric ions were used. Superoxide dismutase prevented DNA single-strand breakage by H2O2 and ferric ions. On the contrary, with cupric ions and H2O2, the addition of superoxide dismutase increased the rate of DNA single-strand breakage. That superoxide dismutase was acting catalytically was shown by the loss of its effects after heat inactivation of the enzyme. The results of the present study show that besides its involvement in the Fenton reaction, H2O2 is able to reduce the metal bound to DNA, generating the superoxide anion radical or/and its protonated form, the perhydroxyl radical involved in DNA nicking. On the other hand, the ability of cuprous ions unlike ferrous ions to dismutate the superoxide radical may explain some differences observed between iron and copper in the DNA single-strand breakage by H2O2.

  18. Preparation and characterization of nanostructured CuO thin films for photoelectrochemical splitting of water

    Indian Academy of Sciences (India)

    Diwakar Chauhan; V R Satsangi; Sahab Dass; Rohit Shrivastav

    2006-12-01

    Nanostructured copper oxide thin films (CuO) were prepared on conducting glass support (SnO2: F overlayer) via sol–gel starting from colloidal solution of copper (II) acetate in ethanol. Films were obtained by dip coating under room conditions (temperature, 25–32°C) and were subsequently sintered in air at different temperatures (400–650°C). The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and band gap energy were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated. Study suggests that thin films of CuO sintered at lower temperatures (≈ 400°C) are better for photoconversion than thick films or the films sintered at much higher temperatures. Plausible explanations have been provided.

  19. Free cupric ions in contaminated agricultural soils around a copper mine in eastern Nanjing City, China

    Institute of Scientific and Technical Information of China (English)

    LUO Xiao-san; ZHOU Dong-mei; WANG Yu-jun

    2006-01-01

    To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode (ISE) and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid (IDA), ethylenediamine (EN), and glycine (Gly)were compared for calibrating the Cu-ISE curves in the range of free cupric ions (pCu2+) 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu2+ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu2+ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu2+ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu2+ (with R2 value of 0.76), while not important for the soluble Cu concentration.

  20. Archetypal sandwich-structured CuO for high performance non-enzymatic sensing of glucose

    Science.gov (United States)

    Meher, Sumanta Kumar; Rao, G. Ranga

    2013-02-01

    In the quest to enhance the selectivity and sensitivity of novel structured metal oxides for electrochemical non-enzymatic sensing of glucose, we report here a green synthesis of unique sandwich-structured CuO on a large scale under microwave mediated homogeneous precipitation conditions. The physicochemical studies carried out by XRD and BET methods show that the monoclinic CuO formed via thermal decomposition of Cu2(OH)2CO3 possesses monomodal channel-type pores with largely improved surface area (~43 m2 g-1) and pore volume (0.163 cm3 g-1). The fascinating surface morphology and pore structure of CuO is formulated due to homogeneous crystallization and microwave induced self assembly during synthesis. The cyclic voltammetry and chronoamperometry studies show diffusion controlled glucose oxidation at ~0.6 V (vs. Ag/AgCl) with extremely high sensitivity of 5342.8 μA mM-1 cm-2 and respective detection limit and response time of ~1 μM and ~0.7 s, under a wide dynamic concentration range of glucose. The chronoamperometry measurements demonstrate that the sensitivity of CuO to glucose is unaffected by the absence of dissolved oxygen and presence of poisoning chloride ions in the reaction medium, which essentially implies high poison resistance activity of the sandwich-structured CuO. The sandwich-structured CuO also shows insignificant interference/significant selectivity to glucose, even in the presence of high concentrations of other sugars as well as reducing species. In addition, the sandwich-structured CuO shows excellent reproducibility (relative standard deviation of ~2.4% over ten identically fabricated electrodes) and outstanding long term stability (only ~1.3% loss in sensitivity over a period of one month) during non-enzymatic electrochemical sensing of glucose. The unique microstructure and suitable channel-type pore architecture provide structural stability and maximum accessible electroactive surface for unimpeded mobility of glucose as well as the

  1. Complete transformation of ZnO and CuO nanoparticles in culture medium and lymphocyte cells during toxicity testing

    Science.gov (United States)

    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 st...

  2. CuO and Co3O4 Nanoparticles: Synthesis, Characterizations, and Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Rashad

    2013-01-01

    Full Text Available Copper oxide and cobalt oxide (CuO, Co3O4 nanocrystals (NCs have been successfully prepared in a short time using microwave irradiation without any postannealing treatment. Both kinds of nanocrystals (NCs have been prepared using copper nitrate and cobalt nitrate as the starting materials and distilled water as the solvent. The resulted powders of nanocrystals (NCs were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and atomic force microscopy (AFM measurements. The obtained results confirm the presence of the both of oxides nanopowders produced during chemical precipitation using microwave irradiation. A strong emission under UV excitation is obtained from the prepared CuO and Co3O4 nanoparticles. The results show that the nanoparticles have high dispersion and narrow size distribution. The line scans of atomic force microscopy (AFM images of the nanocrystals (NCs sprayed on GaAs substrates confirm the results of both X-ray diffraction and transmission electron microscopy. Furthermore, vibrational studies have been carried out using Raman spectroscopic technique. Specific Raman peaks have been observed in the CuO and Co3O4 nanostructures, and the full width at half maximum (FWHM of the peaks indicates a small particle size of the nanocrystals.

  3. Electrochemical oxygen intercalation in La 2CuO 4 prepared by nitrates method: Microstructural effects

    Science.gov (United States)

    Michel, C. R.; Casan˜-Pastor, N.

    2000-11-01

    In order to determine microstructural effects in the electrochemical oxygen intercalation for La 2CuO 4, and the relative abundance of the two superconducting phases (T c = 33 and 44K), this oxide was prepared using the nitrates method, which involves the dissolution of La and Cu oxides in nitric acid. The product was pressed as pellets. A narrow grain size distribution and a density higher than 95% ϱ T was obtained. After electrochemical oxygen intercalation, at room temperature, this material gave a main superconducting phase with T c = 33K, whereas porous pellets obtaiined from the same oxide, with intermediate grinding, gave a T c = 44K.

  4. Superconductivity in Zigzag CuO Chains

    Energy Technology Data Exchange (ETDEWEB)

    Berg, E.

    2010-04-06

    Superconductivity has recently been discovered in Pr{sub 2}Ba{sub 4}Cu{sub 7}O{sub 15-{delta}} with a maximum T{sub c} of about 15K. Since the CuO planes in this material are believed to be insulating, it has been proposed that the superconductivity occurs in the double (or zigzag) CuO chain layer. On phenomenological grounds we propose a theoretical interpretation of the experimental results in terms of a new phase for the zigzag chain, labelled by C{sub 1}S{sub 3/2}. This phase has a gap in the relative charge mode and a partial gap in the relative spin mode. It has gapless uniform charge and spin excitations and can have a divergent superconducting susceptibility, even for repulsive interactions. A microscopic model for the zigzag CuO chain is proposed, and on the basis of density matrix renormalization group (DMRG) and bosonization studies, we adduce evidence that supports our proposal.

  5. Mesoscale organization of CuO nanoslices: Formation of sphere

    Indian Academy of Sciences (India)

    Jun Wang; Shunxiao Zhang; Zhanshuang Li; Jia You; Piaoping Yang; Xiaoyan Jing; Milin Zhang

    2008-04-01

    The nanocrystalline CuO powders were prepared by precipitation method using Cu(NO$_{3})_{2}$ as copper raw material, water and ethanol as dispersants, and NaOH and ammonia solution as precipitates. The structure, particle size and morphology of resulting CuO powders were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanism of CuO formation was discussed.

  6. Free-standing CuO nanoflake arrays coated Cu foam for advanced lithium ion battery anodes

    Science.gov (United States)

    Yang, Wanfeng; Wang, Jiawei; Ma, Wensheng; Dong, Chaoqun; Cheng, Guanhua; Zhang, Zhonghua

    2016-11-01

    For lithium ion batteries (LIBs), low electronic conductivity of CuO leads to rapid capacity decay and poor structural stability. Herein, we successfully fabricate three-dimensional CuO nanoflake arrays coated Cu foam by facile and efficient electrochemical oxidation. When being applied as anode material for LIBs, the CuO electrodes deliver stable reversible capacities of 523.9 mA h g-1 at 0.5 A g-1, 376.1 mA h g-1 at 1.0 A g-1 and 322.7 mA h g-1 at 2.0 A g-1 with high coulombic efficiency (>99%) after 100 cycles. A long cycle life of up to 400 cycles at 2.0 A g-1 is also achieved with the retention capacity of 193.5 mA h g-1. Moreover, the electrode exhibits excellent rate capability and can regain its original capacities as reversing to the low current densities. Noticeably, on-line differential electrochemical mass spectrometry and in situ Raman measurements confirm the formation of solid electrolyte interface film and the conversion mechanism for the CuO electrodes, respectively. The superior lithium storage performance can be attributed to the favorable nanoflake structures with high surface area and the perfect electrical contact between CuO and Cu substrate.

  7. Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers.

    Science.gov (United States)

    Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektaşoğlu, Burcu; Bener, Mustafa

    2010-01-01

    Tests measuring the combined antioxidant effect of the nonenzymatic defenses in biological fluids may be useful in providing an index of the organism's capability to counteract reactive species known as pro-oxidants, resist oxidative damage, and combat oxidative stress-related diseases. The selected chromogenic redox reagent for the assay of human serum should be easily accessible, stable, selective, and respond to all types of biologically important antioxidants such as ascorbic acid, alpha-tocopherol, beta-carotene, reduced glutathione (GSH), uric acid, and bilirubin, regardless of chemical type or hydrophilicity. Our recently developed cupric reducing antioxidant capacity (CUPRAC) spectrophotometric method for a number of polyphenols and flavonoids using the copper(II)-neocuproine reagent in ammonium acetate buffer is now applied to a complete series of plasma antioxidants for the assay of total antioxidant capacity of serum, and the resulting absorbance at 450 nm is recorded either directly (e.g., for ascorbic acid, alpha-tocopherol, and glutathione) or after incubation at 50 degrees C for 20 min (e.g., for uric acid, bilirubin, and albumin), quantitation being made by means of a calibration curve. The lipophilic antioxidants, alpha-tocopherol and beta-carotene, are assayed in dichloromethane. Lipophilic antioxidants of serum are extracted with n-hexane from an ethanolic solution of serum subjected to centrifugation. Hydrophilic antioxidants of serum are assayed in the centrifugate after perchloric acid precipitation of proteins. The CUPRAC molar absorptivities, linear ranges, and TEAC (trolox equivalent antioxidant capacity) coefficients of the serum antioxidants are established, and the results are evaluated in comparison with the findings of the ABTS/TEAC reference method. The intra- and inter-assay coefficients of variation (CVs) are 0.7 and 1.5%, respectively, for serum. The CUPRAC assay proved to be efficient for glutathione and thiol-type antioxidants

  8. Flexible 3D porous CuO nanowire arrays for enzymeless glucose sensing: in situ engineered versus ex situ piled

    Science.gov (United States)

    Huang, Jianfei; Zhu, Yihua; Yang, Xiaoling; Chen, Wei; Zhou, Ying; Li, Chunzhong

    2014-12-01

    Convenient determination of glucose in a sensitive, reliable and cost-effective way has aroused sustained research passion, bringing along assiduous investigation of high-performance electroactive nanomaterials to build enzymeless sensors. In addition to the intrinsic electrocatalytic capability of the sensing materials, electrode architecture at the microscale is also crucial for fully enhancing the performance. In this work, free-standing porous CuO nanowire (NW) was taken as a model sensing material to illustrate this point, where an in situ formed 3D CuO nanowire array (NWA) and CuO nanowires pile (NWP) immobilized with polymer binder by conventional drop-casting technique were both studied for enzymeless glucose sensing. The NWA electrode exhibited greatly promoted electrochemistry characterized by decreased overpotential for electro-oxidation of glucose and over 5-fold higher sensitivity compared to the NWP counterpart, benefiting from the binder-free nanoarray structure. Besides, its sensing performance was also satisfying in terms of rapidness, selectivity and durability. Further, the CuO NWA was utilized to fabricate a flexible sensor which showed excellent performance stability against mechanical bending. Thanks to its favorable electrode architecture, the CuO NWA is believed to offer opportunities for building high-efficiency flexible electrochemical devices.Convenient determination of glucose in a sensitive, reliable and cost-effective way has aroused sustained research passion, bringing along assiduous investigation of high-performance electroactive nanomaterials to build enzymeless sensors. In addition to the intrinsic electrocatalytic capability of the sensing materials, electrode architecture at the microscale is also crucial for fully enhancing the performance. In this work, free-standing porous CuO nanowire (NW) was taken as a model sensing material to illustrate this point, where an in situ formed 3D CuO nanowire array (NWA) and CuO nanowires

  9. Histopathological effects following short-term coexposure of Cyprinus carpio to nanoparticles of TiO2 and CuO.

    Science.gov (United States)

    Mansouri, Borhan; Maleki, Afshin; Davari, Behroz; Johari, Seyed Ali; Shahmoradi, Behzad; Mohammadi, Ebrahim; Shahsavari, Siros

    2016-10-01

    The aim of this research was to investigate the coexposure of nanoparticles of titanium dioxide (TiO2) and copper oxide (CuO) on the alterations of the gill, intestine, kidney, and liver tissues of carps (Cyprinus carpio). In this study, carps (length 23 ± 1.5 cm; weight 13 ± 1.3 g) were divided into six groups of 15 each and exposed to 2.5 and 5.0 mg L(-1) of CuO nanoparticles (NPs), 10.0 mg L(-1) of TiO2 NPs, and 2.5 and 5.0 mg L(-1) of CuO NPs + 10.0 mg L(-1) of TiO2 NP mixture. Fish were sampled for histopathological studies after hematoxylin-eosin staining. Results indicated that the more kinds of histopathology anomalies observed with CuO NP and TiO2 NP mixture were broadly of the same type as CuO NPs and TiO2 NPs alone, but the severity or incidence of injuries of gill, intestine, liver, and kidney of carps in the mixture of CuO NPs + TiO2 NPs was higher than that of each NP alone. Moreover, behavioral changes in carps exposed to CuO NP and TiO2 NP mixture such as hyperactivity, loss of balance, and convulsions were higher than those to CuO NPs and TiO2 NPs alone. In conclusion, the presence of TiO2 NPs enhanced the effects of NPs of copper oxide in terms of histopathological changes in carps.

  10. Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Pratibha, E-mail: rkpratibha@yahoo.com; Merwyn, S.; Agarwal, G. S.; Tripathi, B. K.; Pant, S. C. [Defence Research and Development Establishment (India)

    2012-01-15

    Copper (II) oxide multi-armed nanoparticles composed of 500-1000 nm long radiating nanospicules with 100-200 nm width near the base and 50-100 nm width at the tapered ends and {approx}25 nm thickness were synthesized by electrochemical deposition in the presence of an oxidant followed by calcination at 150 Degree-Sign C. The nanoparticles were characterized using SEM/EDX for morphology and composition, Raman spectroscopy for compound identification, and broth culture method for antibacterial efficacy. The CuO nanoparticles have shown remarkable bactericidal efficacy against Gram-positive and -negative waterborne disease causing bacteria like Escherichia coli, Salmonella typhi, staphylococcus aureus and Bacillus subtilis. E. coli has been chosen as representative species for waterborne disease causing bacteria. In antibacterial tests 500 {mu}g/mL nano CuO killed 3 Multiplication-Sign 10{sup 8} CFU/mL E. coli bacteria within 4 h of exposure. Moreover, 8.3 Multiplication-Sign 10{sup 6} CFU/mL E. coli were killed by 100 and 10 {mu}g/mL nano CuO within 15 min and 4 h of exposure, respectively. Antibacterial activity of nano CuO has been found many-fold compared with commercial bulk CuO. The fate of nanoparticles after antibacterial test has also been studied. The synthesized CuO nanoparticles are expected to have potential antibacterial applications in water purification and in paints and coatings used on frequently touched surfaces and fabrics in hospital settings.

  11. Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

    DEFF Research Database (Denmark)

    Poreddy, Raju; Engelbrekt, Christian; Riisager, Anders

    2015-01-01

    The oxidative dehydrogenation of alcohols to carbonyl compounds was studied using CuO nanoparticle catalysts prepared by solution synthesis in buffered media. CuO nanoparticles synthesized in N-cyclohexyl- 3-aminopropanesulfonic acid buffer showed high catalytic activity for the oxidation...

  12. Synthesis and structural characterization of ZnO and CuO nanoparticles supported mesoporous silica SBA-15

    Science.gov (United States)

    El-Nahhal, Issa M.; Salem, Jamil K.; Selmane, Mohamed; Kodeh, Fawzi S.; Ebtihan, Heba A.

    2017-01-01

    Zinc oxide (ZnO) and copper oxide (CuO) nanoparticles were loaded into mesoporous silica SBA-15 by post-synthesis and direct methods. The structural properties were characterized using wide and small angle X-ray diffraction (WXRD & SXRD), X-ray photoelectron spectroscopy (XPS) and N2-adsorption desorption (BET). The WXRD showed that, the loaded zinc and copper oxides were present in crystalline forms (impregnation). The mesoporosity properties of SBA-15 silica were well maintained even after the introduction of metal oxide nanoparticles. BET analysis indicate that the impregnated and condensed ZnO and CuO supported SBA-15 nanocomposites have a lower surface area than that of its parent SBA-15.

  13. Building Selectivity for NO Sensing in a NOx Mixture with Sonochemically Prepared CuO Structures

    Directory of Open Access Journals (Sweden)

    Max R. Mullen

    2015-12-01

    Full Text Available Several technologies are available for decreasing nitrogen oxide (NOx emissions from combustion sources, including selective catalytic reduction methods. In this process, ammonia reacts with nitric oxide (NO and nitrogen dioxide (NO2. As the stoichiometry of the two reactions is different, electrochemical sensor systems that can distinguish between NO and NO2 in a mixture of these two gases are of interest. Since NO and NO2 can be brought to equilibrium, depending on the temperature and the surfaces that they are in contact with, the detection of NO and NO2 independently is a difficult problem and has not been solved to date. In this study, we explore a high surface area sonochemically prepared CuO as the resistive sensing medium. CuO is a poor catalyst for NOx equilibration, and requires temperatures of 500 C to bring about equilibration. Thus, at 300 C, NO and NO2 retain their levels after interaction with CuO surface. In addition, NO adsorbs more strongly on the CuO over NO2. Using these two concepts, we can detect NO with minimal interference from NO2, if the latter gas concentration does not exceed 20% in a NOx mixture over a range of 100–800 ppm. Since this range constitutes most of the range of total NOx concentrations in diesel and other lean burn engines, this sensor should find application in selective detection of NO in this combustion application. A limitation of this sensor is the interference with CO, but with combustion in excess air, this problem should be alleviated.

  14. Cupric ion reducing antioxidant capacity assay for food antioxidants: vitamins, polyphenolics, and flavonoids in food extracts.

    Science.gov (United States)

    Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektas Oğlu, Burcu; Bener, Mustafa

    2008-01-01

    Antioxidants are health beneficial compounds through their combat with reactive oxygen and nitrogen species and free radicals that may cause tissue damage leading to various diseases. This work reports the development of a simple and widely applicable antioxidant capacity index for dietary polyphenols, vitamins C and E, and plasma antioxidants utilizing the copper(II)-neocuproine (Cu(II)-Nc) reagent as the chromogenic oxidizing agent. This novel method based on an electron-transfer mechanism was named by our research group as 'cupric reducing antioxidant capacity', abbreviated as the CUPRAC method. The method is comprised of mixing the antioxidant solution with aqueous copper(II) chloride, alcoholic neocuproine, and ammonium acetate aqueous buffer at pH 7, and subsequently measuring the developed absorbance at 450 nm after 30 min. Since the color development is fast for compounds like ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds are assayed after incubation at 50 degrees C on a water bath for 20 min. The flavonoid glycosides are hydrolyzed to their corresponding aglycones by refluxing in 1.2 M: HCl-containing 50% MeOH so as to exert maximal reducing power towards Cu(II)-Nc. The CUPRAC antioxidant capacities of synthetic mixtures are equal to the sum of individual capacities of antioxidant constituents, indicating lack of chemical deviations from Beer's law. Tests on antioxidant polyphenols demonstrate that the highest CUPRAC capacities are observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accord with the number and position of the -OH groups as well the conjugation level of the molecule. The parallelism of the linear calibration curves of pure antioxidants in water and in a given complex matrix (plant extract) demonstrates that there are no chemical interactions of interferent nature among the solution constituents

  15. 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.

  16. CuO nanoparticles supported on nitrogen and sulfur co-doped graphene nanocomposites for non-enzymatic glucose sensing

    Science.gov (United States)

    Li, Meixia; Guo, Qingbin; Xie, Juan; Li, Yongde; Feng, Yapeng

    2017-01-01

    Developing highly active catalysts to promote the electrocatalytic glucose oxidation (EGO) is a crucial demand for non-enzymatic glucose sensing. Herein, we reported the use of nitrogen and sulfur co-doped graphene (NSG) as a novel support material for anchoring CuO nanoparticles and obtained CuO/NSG was employed as an efficient EGO catalyst for non-enzymatic glucose sensing. The results showed that the NSG endowed the CuO/NSG with large surface area, increased structural defects, improved conductivity, and strong covalent coupling between NSG and CuO. Owing to the significant contribution of NSG and the synergistic effect of NSG and CuO, the CuO/NSG exhibited a remarkably higher EGO activity than CuO and CuO/reduced graphene oxide. The CuO/NSG-based sensor displayed excellent glucose sensing performances with a considerably low detection limit of 0.07 μM. These findings elucidate that the NSG is a promising support material for non-enzymatic glucose detection.

  17. Acute effects of Fe₂O₃, TiO₂, ZnO and CuO nanomaterials on Xenopus laevis.

    Science.gov (United States)

    Nations, Shawna; Wages, Mike; Cañas, Jaclyn E; Maul, Jonathan; Theodorakis, Chris; Cobb, George P

    2011-05-01

    Metal oxide nanomaterials have exhibited toxicity to a variety of aquatic organisms, especially microbes and invertebrates. To date, few studies have evaluated the toxicity of metal oxide nanomaterials on aquatic vertebrates. Therefore, this study examined effects of ZnO, TiO(2), Fe(2)O(3), and CuO nanomaterials (20-100 nm) on amphibians utilizing the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol, a 96 h exposure with daily solution exchanges. Nanomaterials were dispersed in reconstituted moderately hard test medium. These exposures did not increase mortality in static renewal exposures containing up to 1,000 mg L(-1) for TiO(2), Fe(2)O(3), CuO, and ZnO, but did induce developmental abnormalities. Gastrointestinal, spinal, and other abnormalities were observed in CuO and ZnO nanomaterial exposures at concentrations as low as 3.16 mg L(-1) (ZnO). An EC(50) of 10.3 mg L(-1) ZnO was observed for total malformations. The minimum concentration to inhibit growth of tadpoles exposed to CuO or ZnO nanomaterials was 10 mg L(-1). The results indicate that select nanomaterials can negatively affect amphibians during development. Evaluation of nanomaterial exposure on vertebrate organisms are imperative to responsible production and introduction of nanomaterials in everyday products to ensure human and environmental safety.

  18. Copper Oxide Thin Films through Solution Based Methods for Electrical Energy Conversion and Storage

    Science.gov (United States)

    Zhu, Changqiong

    basic lactate solution with a large lactate/Cu2+ molar ratio, are sodium-free. This finding stands in contrast to the observation that films grown in basic solution contain a significant amount of sodium impurity at their top surfaces. Therefore, it is concluded that the sodium impurities present in films grown from basic lactate solutions are detrimental to overall photovoltaic device performance by introducing interface traps and recombination centers for charge carriers, which suggests that removing these impurities may be a promising strategy for improving Cu2O based solar cells. It has been found that impurities at the surface of electrodeposited p-Cu2O films can be efficiently removed through the use of concentrated aqueous ammonia solution as a wet etching agent. The performance of Cu 2O homojunction photovoltaic devices incorporating etched p-Cu 2O as the bottom layer is higher compared to devices with as-deposited p-Cu2O layers due to an improvement of the homojunction interface quality. Reducing the density of defect states that act as carrier recombination centers is found to lead to larger open circuit voltages. Zinc-doped cuprous oxide (Zn:Cu2O) thin films have also been prepared via single step electrodeposition from an aqueous solution containing sodium perchlorate. The Zn/Cu molar ratio in the Cu2O films can be tuned by adjusting the magnitude of the applied potential and the sodium perchlorate concentration. Electrical characterization reveals that zinc dopants increase the Fermi level in Zn:Cu2O films, enabling a three-fold improvement in the power conversion efficiency of a fully electrodeposited Cu2O homojunction photovoltaic device. Complementary to the development of Cu2O based photovoltaic devices, the use of solution deposited cupric oxide (CuO) thin films for capacitive energy storage has also been investigated. A seed layer-assisted chemical bath deposition (SCBD) method has been developed to create high quality CuO thin films on transparent

  19. Uptake of iodide by a mixture of metallic copper and cupric compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, G.; Alnot, M.; Ehrhardt, J.J.; Bessiere, J. [Univ. Henri Poincare Nancy 1, Villers les Nancy (France). Lab. de Chimie Physique pour l`Environnement

    1999-05-15

    Environmental contaminants harmful to the health of present and future generations involve nuclear fission products as iodine radioisotopes. {sup 129}I is potentially one of the more mobile products because of its long half-life and its tendency to go into solution as an anion that is not retarded with silicate minerals. Ability of copper/cupric compound mixtures to remove iodide from solution was investigated to predict sorption of radioactive iodine in the environment and to assess their use in a nuclear reprocessing method. Thermodynamic calculations were performed to study the stability of such mixtures in solution and to obtain equilibrium constants of Cu(0)/Cu(II)/I{sup {minus}} and Cu(0)/Cu(II)/Cl{sup {minus}} systems. Both calculations and experimental results showed that a Cu(0)/Cu{sub 3}(OH){sub 2}(CO{sub 3}){sub 2} (azurite) mixture selectively uptakes iodide ions (initial concentrations: 10{sup {minus}2} and 10{sup {minus}1} M) in the presence of 10{sup {minus}1} M chloride ions. Reaction of iodide with copper powder and azurite crystal or copper plate and azurite powder have also been investigated, leading to precipitation of CuI onto massive copper phase. The different solids were separately analyzed by XPS and MEB-EDX, giving some insight in the uptake mechanism. It is proposed that soluble copper released by the cupric compound is reduced at the surface of metallic copper, leading to a preferential precipitation of CuI on copper surface.

  20. Spectral studies on CuO in sodium–calcium borophosphate glasses

    Indian Academy of Sciences (India)

    S SHAILAJHA; K GEETHA; P VASANTHARANI

    2016-08-01

    Transparent borophosphate glasses doped with CuO were prepared by melt quenching technique. X-ray diffraction (XRD), optical and luminescence properties of sodium–calcium borophosphate glasses doped with CuO have been studied. The XRD results showed the amorphous nature of the sample. The introduction of CuO was favourable for the colour changes from light blue to dark bluish green colour. Direct optical energy bandgaps before and after doping with different percents of copper oxide obtained in the range 4.81–2.99 eV indicated the role of copper in the glassy matrix by ultraviolet (UV) spectra. The glasses have more than 80% transparency for emission wavelength range, and strong absorption bands due to the charge transition of the Cu$^+$ and Cu$^{2+}$ ions were observed. The emission bands observed in the UV and blue regions are attributed to 3d$^9$4s–3d$^{10}$ triplet transition in Cu$^+$ ion.

  1. Extraction of important electrical parameters of CuO

    Energy Technology Data Exchange (ETDEWEB)

    Serin, T. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Ankara (Turkey); Yildiz, A., E-mail: yildizab@gmail.co [Department of Physics, Faculty of Science and Arts, Ahi Evran University, 40040 Kirsehir (Turkey); Horzum Sahin, S.; Serin, N. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Ankara (Turkey)

    2011-02-01

    Conductivity, X-ray diffraction (XRD), optical absorption and atomic force microscopy (AFM) measurements of CuO thin film were presented. Three distinct electrical conduction contributions with discrete characteristic activation energies were observed. The applicability of various theoretical models was considered to explain results on electrical transport. We extracted important electrical parameters of CuO, which might be useful for its gas sensor applications. -- Research Highlights: {yields} The important electrical parameters of CuO were extracted. Three distinct activation contributions were observed. {yields} Above 200 K, conductivity was controlled by potential barrier. {yields} Below 200 K, conductivity was described in terms of hopping conduction.

  2. Embedment of anodized p-type Cu₂O thin films with CuO nanowires for improvement in photoelectrochemical stability.

    Science.gov (United States)

    Wang, Peng; Ng, Yun Hau; Amal, Rose

    2013-04-01

    A highly stable p-type cuprous oxide (Cu2O) photoelectrode has been fabricated by direct anodization of the Cu foil, followed by a thermal treatment to introduce a protective layer of copper oxide (CuO) nanowires penetrating the surface of the Cu2O layer. The anodized Cu2O served as the seeding sites for the growth of CuO nanowires. The embedment of CuO nanowires within the Cu2O matrix enhanced the adhesion of the nanowires onto the Cu substrate. In addition, the presence of CuO nanowires on the outer layer of the composite film, in turn stabilized the Cu2O layer by passivating the redox activities of Cu2O when exposed to the environment. This nanostructured p-type Cu2O photoelectrode generated 360 μA cm(-2) of photocathodic current density upon visible light illumination and managed to retain its photocathodic current density after being used and kept for one month. The improvement in photoelectrochemical (PEC) stability by introducing a passive layer of CuO nanowires provides useful insights into the development of a Cu2O photoelectrode, as its stability remained as the main challenge.

  3. CuO nanoparticles incorporated in hierarchical MFI zeolite as highly active electrocatalyst for non-enzymatic glucose sensing.

    Science.gov (United States)

    Dong, Junping; Tian, Taolei; Ren, Linxiao; Zhang, Yuan; Xu, Jiaqiang; Cheng, Xiaowei

    2015-01-01

    A hierarchical MFI zeolite, with typical micro/meso bimodal pore structures, was prepared by desilication method. CuO nanoparticles (NPs) were incorporated into the hierarchical MFI zeolite by impregnation method. CuO/hierarchical zeolite composites were characterized by X-ray diffraction, transmission electron microscopy and nitrogen sorption. It is shown that the CuO nanoparticles are mostly dispersed in the mesopores with remaining of the crystallinity and morphology of the host zeolite. CuO nanoparticles located in hierarchical zeolite exhibit the excellent electrocatalytic performances to oxidation of glucose in alkaline media. The electrocatalytic activity enhances with increasing the loading content of CuO from 5% to 15%. The composites were fabricated for nonenzyme glucose sensing. Under the optimal conditions, the sensor shows a wide linear range from 5×10(-7) to 1.84×10(-2) M with a low detection limit of 3.7×10(-7) M. The sensor also exhibits good repeatability, long-term stability as well as high selectivity against interfering species.

  4. Preparation of Advanced CuO Nanowires/Functionalized Graphene Composite Anode Material for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jin Zhang

    2017-01-01

    Full Text Available The copper oxide (CuO nanowires/functionalized graphene (f-graphene composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH25COOH”, and the CuO nanowires (NWs were well dispersed in the f-graphene sheets. When used as anode materials in lithium-ion batteries, the composite exhibited good cyclic stability and decent specific capacity of 677 mA·h·g−1 after 50 cycles. CuO NWs can enhance the lithium-ion storage of the composites while the f-graphene effectively resists the volume expansion of the CuO NWs during the galvanostatic charge/discharge cyclic process, and provide a conductive paths for charge transportation. The good electrochemical performance of the synthesized CuO/f-graphene composite suggests great potential of the composite materials for lithium-ion batteries anodes.

  5. Preparation of Advanced CuO Nanowires/Functionalized Graphene Composite Anode Material for Lithium Ion Batteries

    Science.gov (United States)

    Zhang, Jin; Wang, Beibei; Zhou, Jiachen; Xia, Ruoyu; Chu, Yingli; Huang, Jia

    2017-01-01

    The copper oxide (CuO) nanowires/functionalized graphene (f-graphene) composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH2)5COOH”, and the CuO nanowires (NWs) were well dispersed in the f-graphene sheets. When used as anode materials in lithium-ion batteries, the composite exhibited good cyclic stability and decent specific capacity of 677 mA·h·g−1 after 50 cycles. CuO NWs can enhance the lithium-ion storage of the composites while the f-graphene effectively resists the volume expansion of the CuO NWs during the galvanostatic charge/discharge cyclic process, and provide a conductive paths for charge transportation. The good electrochemical performance of the synthesized CuO/f-graphene composite suggests great potential of the composite materials for lithium-ion batteries anodes. PMID:28772432

  6. Experimental study of enhanced heat transfer by addition of CuO nanoparticle

    Science.gov (United States)

    Jesumathy, Stella; Udayakumar, M.; Suresh, S.

    2012-06-01

    An energy storage system has been designed to study the thermal characteristics of paraffin wax with an embedded nano size copper oxide (CuO) particle. This paper presents studies conducted on phase transition times, heat fraction as well as heat transfer characteristics of paraffin wax as phase change material (PCM) embedded with CuO nanoparticles. 40 nm mean size CuO particles of 2, 5 and 10% by weight were dispersed in PCM for this study. Experiments were performed on a heat exchanger with 1.5-10 l/min of heat transfer fluid (HTF) flow. Time-based variations of the temperature distributions are revealed from the results of observations of melting and solidification curves. The results strongly suggested that the thermal conductivity enhances 6, 6.7 and 7.8% in liquid state and in dynamic viscosity it enhances by 5, 14 and 30% with increasing mass fraction of the CNEPs. The thermal conductivity ratio of the composites can be augmented by a factor up to 1.3. The heat transfer coefficient during solidification increased about 78% for the maximum flow rate. The analysis of experimental results reveals that the addition of copper oxide nanoparticles to the paraffin wax enhances both the conduction and natural convection very effectively in composites and in paraffin wax. The paraffin wax-based composites have great potential for energy storage applications like industrial waste heat recovery, solar thermal applications and solar based dynamic space power generation with optimal fraction of copper oxide nanoparticles.

  7. Syntheses of CuO nanostructures in ionic liquids

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.

  8. Syntheses of CuO nanostructures in ionic liquids

    Institute of Scientific and Technical Information of China (English)

    WANG Li; ZHAO Bin; YUAN ZhongYong; ZHANG XueJun; Wu QingDuan; CHANG LiXian; ZHENG WenJun

    2007-01-01

    A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route. Both nanoparticles (5 nm in size) and nanorods (5-10 nm in diameter and 50-100 nm in length) of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and nitrogen adsorption analysis. The morphologies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids. The growth mechanism of CuO nanostructures is investigated.

  9. Potentiostatic Deposition and Characterization of Cuprous Oxide Thin Films

    OpenAIRE

    2013-01-01

    Electrodeposition technique was employed to deposit cuprous oxide Cu2O thin films. In this work, Cu2O thin films have been grown on fluorine doped tin oxide (FTO) transparent conducting glass as a substrate by potentiostatic deposition of cupric acetate. The effect of deposition time on the morphologies, crystalline, and optical quality of Cu2O thin films was investigated.

  10. Long-term effects of CuO nanoparticles on the surface physicochemical properties of biofilms in a sequencing batch biofilm reactor.

    Science.gov (United States)

    Hou, Jun; You, Guoxiang; Xu, Yi; Wang, Chao; Wang, Peifang; Miao, Lingzhan; Li, Yi; Ao, Yanhui; Lv, Bowen; Yang, Yangyang

    2016-11-01

    In this study, we examined the long-term effects of copper oxide nanoparticles (CuO NPs) on the production and properties of EPS and the resulting variations in surface physicochemical characteristics of biofilms in a sequencing batch biofilm reactor. After exposure to 50 mg/L CuO NPs for 45 days, the protein (PRO) and polysaccharide (PS) contents in loosely bound EPS (LB-EPS) decreased as the production of LB-EPS decreased from 34.4 to 30 mg TOC/g EPS. However, the production of tightly bound EPS (TB-EPS) increased by 16.47 % as the PRO and PS contents increased. The content of humic-like substances (HS) increased significantly, becoming the predominant constituent in EPS with the presence of 50 mg/L CuO NPs. Furthermore, the results of three-dimensional excitation-emission fluorescence spectra confirmed the various changes in terms of the LB-EPS and TB-EPS contents after exposure to CuO NPs. Fourier transform infrared spectroscopy showed that the -OH and -NH2 groups of proteins in EPS were involved in the reaction with CuO NPs. Moreover, the chronic exposure to CuO NPs induced a negative impact on the flocculating efficiency of EPS and on the hydrophobicity and aggregation ability of microbial cells. The PRO/PS ratios of different EPS fractions were consistent with their hydrophobicities (R (2) >0.98) and bioflocculating efficiencies (R (2) >0.95); however, there was no correlation with aggregation ability. Additionally, the presence of bovine serum albumin (BSA) prevented the physical contact between CuO NPs and EPS as a result of NP aggregation and electrostatic repulsion.

  11. Theory and experiment on the cuprous-cupric electron transfer rate at a copper electrode.

    Energy Technology Data Exchange (ETDEWEB)

    Halley, J. W.; Smith, B. B.; Walbran, S.; Curtiss, L. A.; Rigney, R. O.; Sutjianto, A.; Hung, N. C.; Yonco, R. M.; Nagy, Z.; Univ. of Minnesota; NREL

    1999-04-01

    We describe results of experiment and theory of the cuprous-cupric electron transfer rate in an aqueous solution at a copper electrode. The methods are similar to those we reported earlier for the ferrous-ferric rate. The comparison strongly suggests that, in marked distinction to the ferrous-ferric case, the electron transfer reaction is adiabatic. The model shows that the activation barrier is dominated by the energy required for the ion to approach the electrode, rather than by the energy required for rearrangement of the solvation shell, also in sharp distinction to the case of the ferric-ferrous electron transfer at a gold electrode. Calculated activation barriers based on this image agree with the experimental results reported here.

  12. Theory and experiment on the cuprous{endash}cupric electron transfer rate at a copper electrode

    Energy Technology Data Exchange (ETDEWEB)

    Halley, J.W. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Smith, B.B. [National Renewable Energy Laboratory, Golden, Colorado (United States); Walbran, S. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Curtiss, L.A.; Rigney, R.O.; Sutjianto, A.; Hung, N.C.; Yonco, R.M.; Nagy, Z. [Argonne National Laboratory, Divisions of Materials Science, Chemistry and Chemical Technology, Argonne, Illinois 60439-4837 (United States)

    1999-04-01

    We describe results of experiment and theory of the cuprous{endash}cupric electron transfer rate in an aqueous solution at a copper electrode. The methods are similar to those we reported earlier for the ferrous{endash}ferric rate. The comparison strongly suggests that, in marked distinction to the ferrous{endash}ferric case, the electron transfer reaction is adiabatic. The model shows that the activation barrier is dominated by the energy required for the ion to approach the electrode, rather than by the energy required for rearrangement of the solvation shell, also in sharp distinction to the case of the ferric{endash}ferrous electron transfer at a gold electrode. Calculated activation barriers based on this image agree with the experimental results reported here. {copyright} {ital 1999 American Institute of Physics.}

  13. Preparation of solar selective absorbing CuO coating for medium temperature application

    Institute of Scientific and Technical Information of China (English)

    HUANG Qunwu; WANG Yiping; LI Jinhua

    2007-01-01

    A new method of preparing CuO solar selective absorbing coating for medium temperature is presented.After pretreatment,brass was overlaid with CuO by chemical plating.The effects of reactant concentration,reaction temperature and reaction time on the absorptivity of CuO coating were investigated.The optimized condition of preparing CuO coating was obtained.The CuO coating was analyzed with X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM).In order to prolong the period of use,the CuO coating was protected by TiO2.The experiment shows that the TiO2/CuO coating is more heat-resistant,acid-resistant,and wear resistant than CuO coating,without Iosing absorptivity markedly.The TiO2 coating can reduce emissivity and protect the CuO coating.

  14. Oxidation of Octopus vulgaris hemocyanin by nitrogen oxides

    Energy Technology Data Exchange (ETDEWEB)

    Salvato, B.; Giacometti, G.M.; Beltramini, M.; Zilio, F.; Giacometti, G.; Magliozzo, R.S.; Peisach, J.

    1989-01-24

    The reaction of Octopus vulgaris hemocyanin with nitrite was studied under a variety of conditions in which the green half-met derivative is formed. Analytical evidence shows that the amount of chemically detectable nitrite in various samples of the derivative is not proportional to the cupric copper detected by EPR. The kinetics of oxidation of hemocyanin as a function of protein concentration and pH, in the presence of nitrite and ascorbate, is consistent with a scheme in which NO/sub 2/ is the reactive oxidant. We suggest that the green half-methemocyanin contains a metal center with one cuprous and one cupric copper without an exogenous nitrogen oxide ligand.

  15. In-situ energy dispersive x-ray diffraction study of the growth of CuO nanowires by annealing method

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Himanshu; Ganguli, Tapas; Deb, S. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced technology, Indore-452013 (India); Sant, Tushar; Poswal, H. K.; Sharma, Surinder M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2013-10-14

    The in-situ growth of CuO nanowires was studied by Energy Dispersive X-ray Diffraction (EDXRD) to observe the mechanism of growth. The study was carried out for comparison at two temperatures—at 500 °C, the optimum temperature of the nanowires growth, and at 300 °C just below the temperature range of the growth. The in situ observation revealed the successive oxidation of Cu foil to Cu{sub 2}O layer and finally to CuO layer. Further analysis showed the presence of a compressive stress in CuO layer due to interface at CuO and Cu{sub 2}O layers. The compressive stress was found to increase with the growth of the nanowires at 500 °C while it relaxed with the growth of CuO layer at 300 °C. The present results do not support the existing model of stress relaxation induced growth of nanowires. Based on the detailed Transmission Electron Microscope, Scanning Electron Microscope, and EDXRD results, a microstructure based growth model has been suggested.

  16. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of catalytic ultrasound oxidation and membrane bioreactor.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Zhuang, Haifeng; Xu, Peng; Hou, Baolin

    2015-01-01

    Laboratorial scale experiments were conducted to investigate a novel system integrating catalytic ultrasound oxidation (CUO) with membrane bioreactor (CUO-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. Results indicated that CUO with catalyst of FeOx/SBAC (sewage sludge based activated carbon (SBAC) which loaded Fe oxides) represented high efficiencies in eliminating TOC as well as improving the biodegradability. The integrated CUO-MBR system with low energy intensity and high frequency was more effective in eliminating COD, BOD5, TOC and reducing transmembrane pressure than either conventional MBR or ultrasound oxidation integrated MBR. The enhanced hydroxyl radical oxidation, facilitation of substrate diffusion and improvement of cell enzyme secretion were the mechanisms for CUO-MBR performance. Therefore, the integrated CUO-MBR was the promising technology for advanced treatment in engineering applications.

  17. Electronic properties and morphology of copper oxide/n-type silicon heterostructures

    Science.gov (United States)

    Lindberg, P. F.; Gorantla, S. M.; Gunnæs, A. E.; Svensson, B. G.; Monakhov, E. V.

    2017-08-01

    Silicon-based tandem heterojunction solar cells utilizing cuprous oxide (Cu2O) as the top absorber layer show promise for high-efficiency conversion and low production cost. In the present study, single phase Cu2O films have been realized on n-type Si substrates by reactive magnetron sputtering at 400 °C. The obtained Cu2O/Si heterostructures have subsequently been heat treated at temperatures in the 400-700 °C range in Ar flow and extensively characterized by x-ray diffraction (XRD) measurements, transmission electron microscopy (TEM) imaging and electrical techniques. The Cu2O/Si heterojunction exhibits a current rectification of ~5 orders of magnitude between forward and reverse bias voltages. High resolution cross-sectional TEM-images show the presence of a ~2 nm thick interfacial SiO2 layer between Cu2O and the Si substrate. Heat treatments below 550 °C result in gradual improvement of crystallinity, indicated by XRD. At and above 550 °C, partial phase transition to cupric oxide (CuO) occurs followed by a complete transition at 700 °C. No increase or decrease of the SiO2 layer is observed after the heat treatment at 550 °C. Finally, a thin Cu-silicide layer (Cu3Si) emerges below the SiO2 layer upon annealing at 550 °C. This silicide layer influences the lateral current and voltage distributions, as evidenced by an increasing effective area of the heterojunction diodes.

  18. Hollow CuO nanospheres uniformly anchored on porous Si nanowires: preparation and their potential use as electrochemical sensors

    Science.gov (United States)

    Guo, Zheng; Seol, Myeong-Lok; Kim, Moon-Seok; Ahn, Jae-Hyuk; Choi, Yang-Kyu; Liu, Jin-Huai; Huang, Xing-Jiu

    2012-11-01

    Hollow CuO nanospheres have been prepared via a reduction reaction of copper ions on porous Si nanowires combined with calcination in air and uniformly anchored on their surfaces. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize and analyze as-synthesized samples. The results reveal that Si nanowires fabricated from heavily doped Si wafer are formed with a meso-porous structure by an Ag-assisted etching approach, and Cu nanoparticles are formed and uniformly decorated on the Si nanowires through a reaction of copper ions reduced by silicon. After annealing in air, Cu nanoparticles are in situ oxidized and transformed into CuO, leading to the formation of hollow nanospheres because of the Kirkendall effect. The diameter size of as-prepared CuO hollow spheres anchored on porous Si nanowires is mainly around 30 nm. Finally, in order to illuminate the advantages of this novel hybrid nanostructure of nanosized hollow spheres supported on porous nanowires, its electrochemical sensing performance to hydrazine as an example has been further investigated. The results confirm that it is a good potential application to detect hydrazine.Hollow CuO nanospheres have been prepared via a reduction reaction of copper ions on porous Si nanowires combined with calcination in air and uniformly anchored on their surfaces. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize and analyze as-synthesized samples. The results reveal that Si nanowires fabricated from heavily doped Si wafer are formed with a meso-porous structure by an Ag-assisted etching approach, and Cu nanoparticles are formed and uniformly decorated on the Si nanowires through a reaction of copper ions reduced by silicon. After annealing in air, Cu nanoparticles are in situ oxidized and transformed into CuO, leading to the

  19. Theoretical study of stability and reaction mechanism of CuO supported on ZrO{sub 2} during chemical looping combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Minjun; Liu, Jing, E-mail: liujing27@mail.hust.edu.cn; Shen, Fenghua; Cheng, Hao; Dai, Jinxin; Long, Yan

    2016-03-30

    Graphical abstract: - Highlights: • The stability and reaction mechanism of CuO supported on ZrO{sub 2} were studied by DFT. • ZrO{sub 2} provides a high resistance to CuO sintering. • ZrO{sub 2} promotes the activity of CuO for CO oxidation in fuel reactor. • The energy barriers are low enough for CuO/ZrO{sub 2} oxidation reaction in air reactor. - Abstract: The addition of inert support is important for the Cu-based oxygen carrier used in chemical looping combustion (CLC). The effects of the ZrO{sub 2} support on the stability and reactivity of Cu-based oxygen carrier were investigated using the density functional theory (DFT). First, the sintering inhibition mechanism of ZrO{sub 2} that support active CuO was investigated. The optimized Cu{sub 4}O{sub 4}/ZrO{sub 2} structure showed a strong interaction occurred between the Cu{sub 4}O{sub 4} cluster and ZrO{sub 2}(1 0 1) surface. The interaction prevented the migration and agglomeration of CuO. Next, the adsorption of CO on Cu{sub 4}O{sub 4}/ZrO{sub 2} and the mechanism of the CuO/ZrO{sub 2} reduction by CO were studied. CO mainly chemisorbed on the Cu site and ZrO{sub 2} acted as an electron donor in the adsorption system. The energy barrier of CuO/ZrO{sub 2} reduction by CO (0.79 eV) was much lower than that of the pure CuO cluster (1.44 eV), indicating that ZrO{sub 2} had a positive effect on CuO/ZrO{sub 2} reduction by CO. After CO was oxidized in the fuel reactor, the CuO was reduced into Cu. The adsorption of O{sub 2} on Cu{sub 2}/ZrO{sub 2} and the most likely pathway of Cu{sub 2}/ZrO{sub 2} oxidation by O{sub 2} were investigated. The adsorption of O{sub 2} was found a strong chemisorption behavior. The energy barriers were low enough for the Cu-based oxygen carrier oxidation reaction.

  20. In vitro release of cupric ion from intrauterine devices: influence of frame, shape, copper surface area and indomethacin.

    Science.gov (United States)

    Zhang, Shuangshuang; Li, Ying; Yu, Panpan; Chen, Tong; Zhou, Weisai; Zhang, Wenli; Liu, Jianping

    2015-02-01

    The release of cupric ion from copper intrauterine device (Cu-IUD) in human uterus is essential for contraception. However, excessive cupric ion will cause cytotoxic effect. In this paper, we investigated the influence of device characteristics (frame, copper surface area, shape, copper type and indomethacin) on copper release for the efficacy and adverse effects vary with IUD types which may correlate to their different release behaviors. Nine types of Cu-IUDs were selected and incubated in simulated uterine fluid. They were paired for comparison based on the device properties and the release of cupric ion was determined by flame atomic absorption spectrometer for about 160 days. The result showed that there was a burst release during the first month and the release rate tends to slow down and become steady afterwards. In addition, the copper release was mainly influenced by frame, indomethacin and copper type (copper wire and copper sleeve) while the shape variation had little effect on copper release throughout the experiment. Moreover, the influence of copper surface area was only noticeable during the first month. These findings were seldom reported before and may provide some useful information for the design of Cu-IUDs.

  1. Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats

    Directory of Open Access Journals (Sweden)

    Lee IC

    2016-06-01

    Full Text Available In-Chul Lee,1 Je-Won Ko,1 Sung-Hyeuk Park,1 Je-Oh Lim,1 In-Sik Shin,1 Changjong Moon,1 Sung-Hwan Kim,2 Jeong-Doo Heo,3 Jong-Choon Kim1 1College of Veterinary Medicine BK21 Plus Project Team, Chonnam National University, Gwangju, 2Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup, 3Gyeongnam Department of Environment and Toxicology, Korea Institute of Toxicology, Gyeongnam, Republic of Korea Abstract: Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs, their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5, vehicle (pH 6.5, and intestinal (pH 7.8 conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5% only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%–25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and

  2. Phytochemical profile and ABTS cation radical scavenging, cupric reducing antioxidant capacity and anticholinesterase activities of endemic Ballota nigra L. subsp. anatolica P.H. Davis from Turkey

    Institute of Scientific and Technical Information of China (English)

    Abdulselam Erta; Mehmet Boa; Yeter Yeil

    2014-01-01

    Objective: To evaluate the chemical compositions and biological activities of an endemic Ballotanigra Methods: Essential oil and fatty acid composition were determined by GC/MS analysis. ABTS cation radical decolourisation and cupric reducing antioxidant capacity assays were carried out to indicate the antioxidant activity. The anticholinesterase potential of the extracts were determined by Ellman method. L. subsp. anatolica P.H. Davis. Results: The major compounds in the fatty acid composition of the petroleum ether extract were identified as palmitic (36.0%) and linoleic acids (14.3%). The major components of essential oil were 1-hexacosanol (26.7%), germacrene-D (9.3%) and caryophyllene oxide (9.3%). The water extract indicated higher ABTS cation radical scavenging activity than α-tocopherol and BHT, at 100 µg/mL. The acetone extract showed 71.58 and 44.71% inhibitory activity against butyrylcholinesterase and acetylcholinesterase enzyme at 200 µg/mL, respectively. Conclusions: The water and acetone extracts of Ballota nigra subsp. anatolica can be investigated in terms of both phytochemical and biological aspects to find natural active compounds.

  3. Comparison of Antibacterial Effects of ZnO and CuO Nanoparticles Coated Brackets against Streptococcus Mutans

    Directory of Open Access Journals (Sweden)

    Baratali Ramazanzadeh

    2015-09-01

    Full Text Available Statement of the Problem: During the orthodontic treatment, microbial plaques may accumulate around the brackets and cause caries, especially in high-risk patients. Finding ways to eliminate this microbial plaque seems to be essential. Purpose: The aim of this study was to compare the antibacterial effects of nano copper oxide (CuO and nano zinc oxide (ZnO coated brackets against Streptococcus mutans (S.mutans in order to decrease the risk of caries around the orthodontic brackets during the treatment. Materials and Method: Sixty brackets were coated with nanoparticles of ZnO (n=20, CuO (n=20 and CuO-ZnO (n=20. Twelve uncoated brackets constituted the control group. The brackets were bonded to the crowns of extracted premolars, sterilized and prepared for antimicrobial tests (S.mutans ATCC35668. The samples taken after 0, 2, 4, 6 and 24 hours were cultured on agar plates. Colonies were counted 24 hours after incubation. One-way ANOVA and Tukey tests were used for statistical analysis. Results: In CuO and CuO-ZnO coated brackets, no colony growth was seen after two hours. Between 0-6 hours, the mean colony counts were not significantly different between the ZnO and the control group (p>0.05. During 6-24 hours, the growth of S.mutans was significantly reduced by ZnO nanoparticles in comparison with the control group (p< 0.001. However, these bacteria were not totally eliminated. Conclusion: CuO and ZnO-CuO nanoparticles coated brackets have better antimicrobial effect on S.mutans than ZnO coated brackets.

  4. Optical and other spectroscopic studies of lead, zinc bismuth borate glasses doped with CuO

    Science.gov (United States)

    Rajyasree, Ch.; Vinaya Teja, P. Michael; Murthy, K. V. R.; Krishna Rao, D.

    2011-12-01

    10MO·20Bi2O3·(70-x)B2O3·xCuO [M=Pb, Zn] with x=0, 0.4 and 0.8 (wt%) glasses were synthesized by the melt-quenching technique and were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Physical parameters, like density, and spectroscopic studies (optical absorption, EPR, FTIR and photoluminescence) were used to understand the role of modifier oxide and CuO in the glass matrix. A red shift of the absorption band corresponds to 2B1g→2B2g transition of Cu2+ ions from P2 to Z4 samples and the increase of hyperfine splitting factor (A‖) from P2 to Z2 shows that with the integration of PbO by ZnO the electron density around copper ion is increased. It is also supported by the gradual increase in theoretical optical basicity values of ZnO mixed glasses, as compared to that of PbO mixed glass matrix. Reduced bismuth radicals are found in undoped and 0.4% CuO doped glasses of both the series. Analysis of the absorption and emission studies indicates that the concentration of luminescence centers of bismuth ions (Bi3+ ions in UV region) is decreased by the integration of ZnO as well as by increasing the dopant concentration. In lead series PbO4 and BiO3 units are increased from P2 to P4 and in zinc series BiO3 units are decreased from Z0 to Z4. The conductivity of the glass matrices is increased in both the series with the dopant of CuO.

  5. Template free synthesis of mesoporous CuO nano architects for field emission applications.

    Science.gov (United States)

    Das, Swati; Maiti, Soumen; Saha, Subhajit; Das, Nirmalya Sankar; Chattopadhyay, Kalyan Kumar

    2013-04-01

    Cupric oxide mesospheres composed of its nanoparticles have been synthesized by a simple template free chemical route at different temperatures. Thermal aging followed by higher temperature (350 degrees C, 6 hours) annealing on these architects transformed them into hollow mesospheres consisting of sharp needle like structures with high aspect ratio (- 10(3)). A detailed analysis of field emission scanning electron microscopy confirmed a uniform registry of the prepared nanostructures. High resolution transmission electron microscopy showed that the as-grown mesospheres have hollow inner cavity with a thin outer shell. X-ray photoelectron spectroscopic analysis showed no obvious changes in the chemical composition of the nanostructures after annealing, confirming that the elements in the final products were in the proper oxidation states. Electron emission under electric field was investigated from these interesting structures. It was found that both of these nanostructures showed electron emission, but emission performance of the hollow mesospheres consisting of nanoneedles exhibited excellent performance with turn-on field as low as 2.8 V/microm and high enhancement factor (beta) - 5537.

  6. Rapid synthesis of three-dimensional network structure CuO as binder-free anode for high-rate sodium ion battery

    Science.gov (United States)

    Chen, Chengcheng; Dong, Yanying; Li, Songyue; Jiang, Zhuohan; Wang, Yijing; Jiao, Lifang; Yuan, Huatang

    2016-07-01

    We report on the preparation of the three dimensional (3D) network structure CuO by rapid and facile engraving method and their application as high rate anode for sodium ion battery. The CuO is rapidly synthesized by in-situ etched and oxidated the specified Cu foils within 15 min. It shows the 3D network architecture with flower-like nanosheets connected by nanowires, which provides the porous structure, short ion diffusion pathway and collaborative electronic transmission. Furthermore, the etched CuO can be directly used as anode for sodium ion battery without polymer additions or conductive agents. The electrodes exhibit excellent electrochemical performance with a high capacity of 680 mAh·g-1 at 50 mA g-1 and a reversible capacity of 280 mAh·g-1 at 1000 mA g-1. In addition, the electrochemical reaction and detail charge/discharge process are carefully explored to discover the conversion reaction routes and the recession reason. Thus, the 3D network structure CuO might open an insight for transition-metal oxides as energy storage materials.

  7. Study of structural and optical properties of Fe doped CuO nanoparticles

    Science.gov (United States)

    Rani, Poonam; Gupta, Ankita; Kaur, Sarabjeet; Singh, Vishal; Kumar, Sacheen; Kumar, Dinesh

    2016-05-01

    Iron doped Copper oxide nanoparticles were synthesized by the co-precipitation method at different concentration (3%, 6%, 9%) at 300-400° C with Copper Acetate and Ferric Chloride as precursors in presence of Polyethylene Glycol and Sodium Hydroxide as stabilizing agent. Effect of doping on the structural and optical properties is studied. The obtained nanoparticles were characterized by X-Ray Diffraction and UV-Visible Spectroscopy for examining the size and the band gap respectively. The X-Ray Diffraction plots confirmed the monoclinic structure of Copper oxide suggesting the Cu atoms replaced by Fe atoms and no secondary phase was detected. The indirect band gap of Fe doped CuO nanoparticles is 2.4eV and increases to 3.4eV as the concentration of dopant increases. The majority of particle size is in range 8 nm to 35.55 nm investigated by X-ray diffractometer.

  8. PdCl2-loading mesoporous copper oxide as a novel and environmentally friendly catalyst for diethyl carbonate synthesis

    Science.gov (United States)

    Zhang, Pingbo; Zhou, Yan; Fan, Mingming; Jiang, Pingping

    2015-03-01

    PdCl2-loading mesoporous copper oxide (PdCl2/mCuO) catalysts were successfully synthesized via a hard template with copper carbonate basic (Cu2(OH)2CO3), cupric nitrate (Cu(NO3)2·3H2O) and copper citrate (Cu2C6H4O7·2.5H2O) as the copper(II) precursors, respectively. Their catalytic performances were investigated in the synthesis of diethyl carbonate (DEC) by oxidative carbonylation of ethanol with CO and O2. The catalysts were characterized by TGA, XRD, nitrogen adsorption-desorption analysis and SEM with the aim of establishing their composition, morphology and structure. It was observed that the catalysts all showed a good selectivity to diethyl carbonate. However, due to a better mesoporous structure such as a bigger surface area, more uniform particle size and less agglomeration, the PdCl2/mCuO-1 catalyst prepared with Cu2(OH)2CO3 precursor showed a better catalytic activity that the conversion of EtOH was about 4.8% and the STY of DEC was 97.1 mg g-1 h-1. This was because the highly developed mesoporous structure could generate a bigger surface area, which benefited the contact between reactants and active sites, improved the conversion of ethanol, and thus enhanced the catalytic performance. Furthermore, a synthetic procedure diagram about "wet impregnation" method of mesoporous CuO prepared with Cu2(OH)2CO3 precursor was given to illustrate these results intuitively.

  9. Electron Doping by Charge Transfer at LaFeO 3 /Sm 2 CuO 4 Epitaxial Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Flavio Y. [Universidad Complutense, Spain; Schmidt, R [Universidad Complutense de Madrid, Spain; Varela, Maria [UCM, Dept Fis Aplicada 3, Madrid, Spain; Garcia-Barriocanal, Javier [Universidad Complutense, Spain; Rivera-Calzada, Alberto [Universidad Complutense, Spain; Cuellar, F. [Universidad Complutense de Madrid, Spain; Leon, Carlos [Universidad Complutense de Madrid, Spain; Thakur, P. [European Synchrotron Radiation Facility (ESRF); Cezar, J. C. [European Synchrotron Radiation Facility (ESRF); Brookes, N. B. [European Synchrotron Radiation Facility (ESRF); Garcia-Hernandez, M [Instituto de Ciencia de Materiales de Madrid (ICMM); Dagotto, Elbio R [ORNL; Pennycook, Stephen J [ORNL; Santamaria, J. [Universidad Complutense, Spain

    2013-01-01

    The breakdown of the lattice translational invariance symmetry that occurs at complex oxide interfaces may profoundly modify their electronic structure, leading to interfacial states with properties drastically different from those of the superlattice individual components. The appearance of a conducting two dimensional (2D) electron gas at the interface between two insulating oxides and induced magnetism in a non-magnetic material are just two among many fascinating examples. [ 1 8 ] One of the key factors underlying novel properties is the modifi cation of the doping and orbital occupancy near those interfaces, which may result from charge transfer processes. [ 3 , 9 11 ] If materials used in heterostructures have different work functions, a non-equilibrium situation will be created at the interface and charge will be transferred until the chemical potential levels off. [ 12 ] The use of such phenomena to modify doping in heterostructures has been proposed theoretically as a new route to avoid the quenched disorder that inevitably accompanies the chemical doping. At the interface between a Mott insulating parent compound of the high critical temperature superconductor (HTSC) family and a suitable material that would act as the charge donor, electron doped phases could be stabilized which would eventually turn metallic and perhaps superconducting. [ 12 , 13 ] Such charge transfer processes have been observed at interfaces involving copper oxides such as La 0.7 Ca 0.3 MnO 3 / YBa 2 Cu 3 O 7 , [ 14 ] La 2 x Sr x CuO 4 /La 2 CuO 4 [ 15 ] and SrTi 1 x Nb x O 3 / Sm 2 CuO 4 . [ 16 ] While a novel 2D superconducting state was found at the La 2-x Sr x CuO 4 /La 2 CuO 4 interface, [ 17 ] the effect of doping by charge transfer could not be examined in the other two cases due to the detrimental effect on the YBa 2 Cu 3 O 7 superconductivity of the spin polarized electrons from La 0.7 Ca 0.3 MnO 3 in one case and due to the conducting nature of the SrTi 1 x Nb x O 3 in the

  10. GMI effect in CuO coated Co-based amorphous ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Taysioglu, Asli Ayten [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Peksoz, Ahmet, E-mail: peksoz@uludag.edu.t [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaya, Yunus [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Derebasi, Naim [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Irez, Gazi [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaynak, Gokay [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey)

    2009-11-13

    A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

  11. Electrochemical fluorination of La(2)CuO(4): a mild "chimie douce" route to superconducting oxyfluoride materials.

    Science.gov (United States)

    Delville, M H; Barbut, D; Wattiaux, A; Bassat, J M; Ménétrier, M; Labrugère, C; Grenier, J C; Etourneau, J

    2009-08-17

    The fluorination of La(2)CuO(4) was achieved for the first time under normal conditions of pressure and temperature (1 MPa and 298 K) via electrochemical insertion in organic fluorinated electrolytes and led to lanthanum oxyfluorides of general formula La(2)CuO(4)F(x). Analyses showed that, underneath a very thin layer of LaF(3) (a few atomic layers), fluorine is effectively inserted in the material's structure. The fluorination strongly modifies the lanthanum environment, whereas very little modification is observed on copper, suggesting an insertion in the La(2)O(2) blocks of the structure. In all cases, fluorine insertion breaks the translation symmetry and introduces a long-distance disorder, as shown by electron spin resonance. These results highlight the efficiency of electrochemistry as a new "chimie douce" type fluorination technique for solid-state materials. Performed at room temperature, it additionally does not require any specific experimental care. The choice of the electrolytic medium is crucial with regard to the fluorine insertion rate as well as the material deterioration. Successful application of this technique to the well-known La(2)CuO(4) material provides a basis for further syntheses from other oxides.

  12. Proteomic response of mussels Mytilus galloprovincialis exposed to CuO NPs and Cu²⁺: an exploratory biomarker discovery.

    Science.gov (United States)

    Gomes, Tânia; Chora, Suze; Pereira, Catarina G; Cardoso, Cátia; Bebianno, Maria João

    2014-10-01

    CuO NPs are one of the most used metal nanomaterials nowadays with several industrial and other commercial applications. Nevertheless, less is known about the mechanisms by which these NPs inflict toxicity in mussels and to what extent it differs from Cu(2+). The aim of this study was to investigate changes in protein expression profiles in mussels Mytilus galloprovincialis exposed for 15 days to CuO NPs and Cu(2+) (10 μg L(-1)) using a proteomic approach. Results demonstrate that CuO NPs and Cu(2+) induced major changes in protein expression in mussels' showing several tissue and metal-dependent responses. CuO NPs showed a higher tendency to up-regulate proteins in the gills and down-regulate in the digestive gland, while Cu(2+) showed the opposite tendency. Distinctive sets of differentially expressed proteins were found, either common or specific to each Cu form and tissue, reflecting different mechanisms involved in their toxicity. Fifteen of the differentially expressed proteins from both tissues were identified by MALDI-TOF-TOF. Identified proteins indicate common response mechanisms induced by CuO NPs and Cu(2+), namely in cytoskeleton and cell structure (actin, α-tubulin, paramyosin), stress response (heat shock cognate 71, putative C1q domain containing protein), transcription regulation (zinc-finger BED domain-containing protein 1, nuclear receptor subfamily 1G) and energy metabolism (ATP synthase F0 subunit 6). CuO NPs alone also had a marked effect on other biological processes, namely oxidative stress (GST), proteolysis (cathepsin L) and apoptosis (caspase 3/7-1). On the other hand, Cu(2+) affected a protein associated with adhesion and mobility, precollagen-D that is associated with the detoxification mechanism of Cu(2+). Protein identification clearly showed that the toxicity of CuO NPs is not solely due to Cu(2+) dissolution and can result in mitochondrial and nucleus stress-induced cell signalling cascades that can lead to apoptosis. While the

  13. Thin films that consist of CuO mesocrystal nanosheets: an application of microbial-mineralization-inspired approaches to thin-film formation.

    Science.gov (United States)

    Ikeda, Tatsuya; Oaki, Yuya; Imai, Hiroaki

    2013-09-01

    Thin films of copper oxides can be synthesized on substrates by using approaches that are inspired by microbial mineralization processes. In nature, precipitates of manganese and iron oxides with controlled oxidation states and crystal phases are produced through biomineralization by microorganisms. We have previously reported microbial-mineralization-inspired approaches that are comprised of direct and intermediate routes for the controlled syntheses of transition-metal oxides. Herein, these approaches are applied to the thin-film formation and coating of copper oxides and a related compound with controlled crystal phases and morphologies. Thin films of CuO, Cu2O, and Cu2(OH)3Cl were selectively synthesized by using direct or intermediate routes. Notably, CuO mesocrystal nanosheets formed a thin film over the whole of the substrate. The resultant CuO mesocrystal nanosheets showed enhanced properties for the electrochemical detection of dopamine. This study shows the potential applicability of microbial-mineralization-inspired approaches to thin-film coatings.

  14. Measurement of the Cupric Ion Concentration in the Simulation of the Focusing effect

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Je-Young; Hong, Seung-Hyun; Chung, Bum-Jin [Kyung Hee University, Seoul (Korea, Republic of)

    2015-10-15

    The Rayleigh number and aspect ratio (H/R) ranged from 8.49x10{sup 7} to 5.43x10{sup 9} and 0.135 to 0.541 respectively. In order to simulate the different temperature conditions of top and side wall, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. A sulfuric acid-copper sulfate (H{sub 2}SO{sub 4} - CuSO{sub 4}) electroplating system was adopted as the mass transfer system. The experimental study was performed to investigate the focusing effect according to the different temperature conditions and the height in metallic layer. This work devised a method to simulate the different cooling conditions of the top and side walls and adopted an electrical resistance to the top plate. The electrical resistance was varied for the height of side wall. The experimental results agreed well with the Rayleigh-Benard convection correlations of Dropkin and Somerscales and Globe and Dropkin. The heat transfer was enhanced by increasing the electrical resistance and decreasing the height of side wall. The focusing effect at the side wall was improved by the hotter top wall condition. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP and PIV. The key of RGB, Brightness and PIV method is the clear images of the thermal boundary layer.

  15. Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats.

    Science.gov (United States)

    Lee, In-Chul; Ko, Je-Won; Park, Sung-Hyeuk; Lim, Je-Oh; Shin, In-Sik; Moon, Changjong; Kim, Sung-Hwan; Heo, Jeong-Doo; Kim, Jong-Choon

    2016-01-01

    Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs), their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions) after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5), vehicle (pH 6.5), and intestinal (pH 7.8) conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg) of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5%) only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%-25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen) of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and histopathology. Liver, kidney, and spleen were the major organs affected by Cu NPs. Collectively, the toxicity and kinetics of Cu NPs are most likely influenced by the release of Cu dissociated from Cu NPs under physiological conditions.

  16. The cupric ion reducing antioxidant capacity and polyphenolic content of some herbal teas.

    Science.gov (United States)

    Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Esin Karademir, Saliha; Erçağ, Erol

    2006-01-01

    The total antioxidant capacity of the aqueous extracts of some endemic herbs-prepared as infusions by steeping these herbs in hot water--was assayed with bis(neocuproine)copper(II) chloride, also known as the cupric ion reducing antioxidant capacity (CUPRAC) reagent, which was easily accessible, rapid, stable and responsive to both hydrophilic and lipophilic antioxidants. The highest antioxidant capacities of some herbal teas available in the Turkish market were observed for scarlet pimpernel (Anagallis arvensis), sweet basil (Ocimum basilicum), green tea (Camellia sinensis) and lemon balm (Melissa officinalis), in this order (1.63, 1.18, 1.07, and 0.99 mmol trolox equivalent (TR)/g, respectively). For infusions prepared from ready-to-use tea bags, the CUPRAC values were highest for Ceylon blended ordinary tea (4.41), green tea with lemon (1.61), English breakfast ordinary tea (1.26) and green tea (0.94), all of which were manufactured types of C. sinensis. Following the strongest antioxidant herbs with capacities close to or slightly exceeding 1.0 mmol TR/g, sage, thyme, coriander, coltsfoot, blackberry and immortelle (Helichrysum) exhibited capacities around 0.5 mmol TR/g. The correlation of the Folin total phenolic content of herbal teas with their CUPRAC and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) total antioxidant capacities gave linear curves with correlation coefficients of 0.966 and 0.936, respectively, showing that the CUPRAC assay results better correlated with total phenolic content of herbal teas. Absorbance versus concentration data at different dilutions and upon standard additions of model antioxidant compounds (trolox and quercetin) to herbal tea infusions showed that the absorbances (at 450 nm of the CUPRAC method) due to different antioxidant compounds in herbal tea infusions were additive; that is, the tested antioxidants did not chemically interact to cause apparent deviations from Beer's law.

  17. Decomposition dynamics of six salt marsh halophytes as determined by cupric oxide oxidation and direct temperature- resolved mass spectrometry

    NARCIS (Netherlands)

    Klap, V.A.; Louchouarn, P.; Boon, J.J.; Hemminga, M.A.; Van Soelen, J.

    1999-01-01

    This paper presents the results of a comparative study on the aerobic decomposition of six salt marsh plant species over a period of 2 yr. In addition to ash-free dry weight (AFDW) determination and elemental analysis (C and N), two analytic methods have been applied to obtain insight into the decom

  18. Visible light induced degradation of methylene blue using CeO2/V2O5 and CeO2/CuO catalysts.

    Science.gov (United States)

    Saravanan, R; Joicy, S; Gupta, V K; Narayanan, V; Stephen, A

    2013-12-01

    In the present study, the nanocatalysts CeO2, V2O5, CuO, CeO2/V2O5 and CeO2/CuO were synthesized by thermal decomposition method. This method is simple, fast and cost effective compared with other preparation methods. The synthesized catalysts were characterized by different techniques. The XRD and XPS results confirmed the structure and the oxidization states of the nanocomposite materials. DRS results suggested that the prepared CeO2/V2O5 and CeO2/CuO nanocomposites can generate more electrons and holes under visible light irradiation. The photocatalytic activities of prepared catalysts were evaluated using the degradation of aqueous methylene blue solution as a model compound under visible light irradiation. In addition, the nanocomposite (CeO2/V2O5 and CeO2/CuO) materials were employed to degrade the textile effluent under visible light condition.

  19. a Reexamination of the Red Band of CuO: Analysis of the [16.5] ^{2}Σ^{-} - X ^{2}Π_{i} Transition of ^{63}CuO and ^{65}CuO

    Science.gov (United States)

    Harms, Jack C.; Grames, Ethan M.; Yun, Sirkhoo; Ahmed, Bushra; O'Brien, Leah C.; O'Brien, James J.

    2017-06-01

    The red band of CuO has been observed at high resolution using Intracavity Laser Spectroscopy (ILS). The red band was rotationally analyzed in 1974 by Appelblad and Lagerqvist and a portion of the band structure was assigned as the spectrum of the [16.5] A ^{2}Σ^{+} - X ^{2}Π_{i} transition. Subsequent analyses of CuO showed that the character of the A state was ^{2}Σ^{-} in character, and thus the Λ-doubling parameter, p, was inverted, and the e/f parity assignments were reversed. In this study, the spectrum of CuO was recorded in the in the regions 16,150 \\wn - 16,270 \\wn and 16,405 \\wn - 16,545 \\wn. The CuO molecules were produced in the plasma discharge of a copper hollow cathode within the cavity of a tunable dye laser, using 0.6 torr of argon as the sputter gas and a trace amount of O_2 as the source of oxygen. The plasma spectra were recorded intermittently with spectra from an external I_2 cell, and line positions from the widely used Iodine Atlas were used for calibration. In uncongested regions of the spectrum, both ^{63}CuO and ^{65}CuO were observed with appreciable intensity. The resulting spectra were rotationally analyzed for both isotopologues, fitting the data as a ^{2}Σ^{-} - ^{2}Π_{i} transition using PGOPHER. Line positions from the millimeter wave and FTIR studies of ^{63}CuO performed in the late 1990s were included in the fit to overcome potential complications due to the ambiguous parity assignments prevalent in the CuO literature. Previously unreported molecular constants were obtained from the fit for ^{65}CuO, and the constants of ^{63}CuO are determined to at least an order of magnitude greater than the results of Appelblad and Lagerqvist. Results of this analysis will be presented.

  20. Cupric ion release and cytotoxicity for Yuangong Cu-IUDs and the release behavior of indomethacin for medicated 220 Cu-IUD

    Institute of Scientific and Technical Information of China (English)

    CAO BianMei; XI TingFei; ZHENG YuDong; YANG LiFeng; ZHENG Qi

    2009-01-01

    These years Yuangong copper-bearing intrauterine devices (Cu-IUDs) have been used because of less side effects in use. The corrosion of copper is essential to the success of contraception,and the release behavior of indomethacin from medicated Cu-IUD is related to its therapeutic effect. In this study,analytical methods were established to investigate the release behavior of cupric ion of three kinds of Yuangong Cu-IUDs and indomethacin of medicated Yuangong 220 Cu-IUD. Cu-IUDs were incubated in simulated uterine solution (SUS). The concentrations of cupric ion and indomethacin were analyzed by flame atomic absorption spectrometer (FAAS) for 60 days and UV/vis-3310 spectrophotometer for 60 days,respectively. The morphology of copper after corrosion was characterized by SEM. In addition,we detected cytotoxicity by MTT of L929 mouse fibroblasts cells caused by extracts of the three Yuangong Cu-IUDs. The release behavior of cupric ion for three kinds of Yuangong Cu-IUDs was biphasic,which consisted of the initial burst release and then slow and constant release. In vitro release experiment confirmed a biphasic release of indomethacin from Yuangong 220. The copper wire of Yuangong Cu-IUDs showed uneven corrosion. The RGR value of Yuangong 365 Cu-IUD was smaller than that of medicated Yuangong 220 Cu-IUD and RGR value of medicated Yuangong 220 Cu-IUD was smaller than that of Yuangong 300 Cu-IUD. The cupric ion release and indomethacin release showed biphasic. Indomethacin increased the cupric ion release rate and might diminish the adverse effects caused by burst release of cupric ion. The toxicity grade of these three Yuangong Cu-IUDs was 4. We should canvass the adverse events of Cu-IUDs based on practical experiments,and try our best to reduce the toxicity of Cu-IUDs.

  1. SnO2: CuO based hydrogen sulphide sensor on LTCC substrates

    Science.gov (United States)

    Kaur, Manmeet; Ganapathi, S. Kailasa; Chaware, Varsha; Rane, Vivek; Ramgir, Niranjan; Datta, Niyanta; Giramkar, Vijaya; Phatak, Girish; Aswal, D. K.; Gupta, S. K.

    2012-06-01

    Dependence of the resistance of metal-oxides thin films on environment is generally used to detect toxic gases at ppm levels. In order to obtain a fast response and recovery, sensing films are heated to high temperatures (upto 300°C). The heater assembly used to raise the film temperature not only makes the sensor bulky but also consumes high power. In our efforts to reduce the size of sensors, we have deposited SnO2: CuO thin film directly onto low-temperature co-fired ceramic (LTCC) substrates with integrated heater and temperature sensor. Sensor films were investigated for their compatibility with LTCC substrate and results show a stable response towards hydrogen sulphide gas for over a year. The stability of heater and thermistor embedded in LTCC substrate has also been monitored. The results of our study show films on LTCC substrate can be successfully applied in sensor technology.

  2. Photonic Sintering of Copper through the Controlled Reduction of Printed CuO Nanocrystals.

    Science.gov (United States)

    Paglia, Francesco; Vak, Doojin; van Embden, Joel; Chesman, Anthony S R; Martucci, Alessandro; Jasieniak, Jacek J; Della Gaspera, Enrico

    2015-11-18

    The ability to control chemical reactions using ultrafast light exposure has the potential to dramatically advance materials and their processing toward device integration. In this study, we show how intense pulsed light (IPL) can be used to trigger and modulate the chemical transformations of printed copper oxide features into metallic copper. By varying the energy of the IPL, CuO films deposited from nanocrystal inks can be reduced to metallic Cu via a Cu2O intermediate using single light flashes of 2 ms duration. Moreover, the morphological transformation from isolated Cu nanoparticles to fully sintered Cu films can also be controlled by selecting the appropriate light intensity. The control over such transformations enables for the fabrication of sintered Cu electrodes that show excellent electrical and mechanical properties, good environmental stability, and applications in a variety of flexible devices.

  3. Catalytic Oxidative Properties and Characterization of CuO/CeO2 Catalysts

    Institute of Scientific and Technical Information of China (English)

    蒋晓原; 周仁贤; 袁骏; 吕光烈; 郑小明

    2003-01-01

    The oxidative properties and characterization of CuO, CeO2 and CuO/CeO2 catalysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-ray diffraction Rietveld methods. The results show that either CuO or CeO2 activity is quite low for CO oxidation. However, when CuO and CeO2 are mixed, the oxidative activity of the catalyst increases significantly, probably owing to the valency status of copper species (Cu2+ and Cu+) on the CeO2 surface, the dispersion and reducibility. XPS surface analysis shows that CuO loading is very important in forming of either Cu2+ or Cu+. Rietveld analysis shows that some CuO, which has smaller ion radius than Ce4+, enters the CeO2 lattice after CuO and CeO2 are mixed. When the CuO loading reaches 5.0%, the size of CuO crystals is a minimum (6.1 nm) and the micro-strain value is a maximum (2.86×10-3), resulting in high surface energy and the best activity for CO oxidation.

  4. New modulation structures observed in Bi2.13Sr1.87CuO6+δ superconductors

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A new two-dimensional structure modulation along c-and b-axes has been discovered in superconducting single crystals of Bi2.13Sr1.87CuO6+δ(Bi2201)by x-ray scattering.Such modulation structure does not exist in non-superconducting Bi2201 single crystals.But instead lattice distortions are observed in the a-b-plane.This phenomenon may indicate that both strain relaxation and charge modulation in the a-b-plane are important to the occurrence of superconductivity in the copper oxides.

  5. In Vitro Sensitivity Research Concerning Some Microorganisms at Hydroxyquinoline and Cupric Derivatives Deposited onto Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Sorin Rapuntean

    2016-11-01

    Full Text Available ABSTRACT Introduction: The preparations based on hydroxyquinoline, in various combinations, are used in medicine, being shown to have an inhibitory effect against bacteria, molds, fungi, parasites, and viruses, but also having other beneficial effects mentioned in other medical conditions (anti-cancer, anti-degenerative, anti-inflammatory. Aims: In vitro susceptibility testing of microorganisms: bacteria (Gram positive and Gram negative, yeast (Candida spp., and unicellular algae (Prototheca spp. at the preparations based on hydroxyquinoline (HQ and its cupric derivatives deposited on hydroxyapatite (HAP. Materials and methods: There were tested microbial strains of the following genera: Escherichia, Staphylococcus, Micrococcus, Bacillus, Candida, and Prototheca. The tested products (developed in the Laboratory for Nanobiomaterials Synthesis, Center of Physical Chemistry, Faculty of Chemistry and Chemical Engineering, UBB Cluj-Napoca were developed in three versions: 1 HQ–Cu2+–HAP1; 2 HQ–Cu2+–HAP2; and 3 NHQ–Cu2+–HAP2, where NHQ stands for nitro hydroxyquinoline. Determination of the inhibitory effect was conducted by diffusion technique in nutrient agar, according to CLSI 2013 standards, with necessary adaptations for testing of products made in the form of suspensions. Results: Following interpretation, it was found that the inhibition zones, arising from the antimicrobial effect of the tested products showed variability in size, depending on the test product and the microbial strain: Escherichia coli (8-10 mm, Staphylococcus sp. (17.6 - 23.2 mm, Micrococcus spp. (24.4 - 27.6 mm, Bacillus spp. (14.0 - 16.0 mm, Candida spp. (20.4 - 25.2 mm, Prototheca spp. (20.8 - 30.0 mm. From the three tested products, the best efficacy was found at the product no. 3 (NHQ – Cu2+ – HAP2, followed by no. 1 (HQ– Cu2+–HAP1 and no. 2 (HQ–Cu2+–HAP2. Conclusions: The inhibitory effect was bactericidal, manifested more intensively against Gram

  6. Electrolytic regeneration of acid cupric chloride printed circuit board etchant. Final report, August 1, 1995--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Oxley, J.E.; Smialek, R.J.

    1997-04-18

    The overall objective of this ERIP program was to make substantial progress in further developing a process for electrolytic regeneration of acid cupric chloride etchant - a process which was initially demonstrated in in-house studies and EPA Phase I and Phase II SBIRs. Specific objectives of the work were: (1) to define optimum system operating conditions by conducting a systematic study of process parameters, (2) to develop or find a superior electrolyic cell separator material, (3) to determine an optimum activation procedure for the flow-through carbon/graphite felt electrodes which are so critical to process performance, (4) to demonstrate - on the pre-prototype scale - electrolytic compensation for oxygen ingress - which causes etchant solution growth, and (5) to begin engineering design work on a prototype-scale regeneration unit. Parametric studies looked at the effect that key plating parameters have on copper deposit quality. Parameters tested included (a) velocity past the plating cathodes, (b) copper concentration in the catholyte solution from which the copper is being plated, (c) plating current density, and (d) catholyte cupric ion concentration. The most significant effects were obtained for velocity changes. The work showed that catholyte velocities above 0.5 ft/sec were needed to get adequate plating at 77.5 mA/cm{sup 2} and higher currents, and that even higher flow was better.

  7. Characterization of Doped and Undoped CuO Nanoparticles

    Science.gov (United States)

    Gazioǧlu, Dilek Taşkin; Dumludaǧ, Fatih; Altindal, Ahmet

    2010-01-01

    Undoped and doped with Ti, Cd and Zn CuO nanoparticles were obtained by precipitation method. The crystal structures of the CuO nanoparticles were characterized by X-ray diffraction. Impedance spectroscopy (IS) and d.c conductivity (σd.c) measurements were performed on samples as a function of temperature and frequency (40-105 Hz.) to determine the electrical behavior of the nano powder. It was found that the Arrhenius graph of the samples consist of two linear regions and corresponding activation energies. The dependency of frequency exponent s on temperature and frequency suggests a conduction mechanism which is indication of hopping. The measured impedance spectra showed a furher semicircle at low frequencies for all temperatures. The low frequency semicirles in impedance spectra are attributted to the garin boundry effects.

  8. Investigation on CuO Dispersed PVA Polymer Films

    Directory of Open Access Journals (Sweden)

    R. Divya

    2015-05-01

    Full Text Available Addition of inorganic nanoparticles to polymers allows the modification of physical properties of polymers as well as the implementation of new features in polymer matrix. In the present work, we have made an attempt to disperse CuO nanoparticles in the polyvinyl alcohol (PVA and to understand the change in structural, optical and electrical properties of the polymer film. CuO nanoparticles were added in four different concentrations, viz. 2.5, 5.0, 7.5 and 10 wt%. A total of 5 films were prepared (including the pure PVA film, for comparison.The prepared films were subjected to XRD, FESEM, UV-Vis spectral, PL spectral and electrical analyses. The results obtained are reported.

  9. Exchange bias effect in composites of cuo nanoparticles and nanosilica glass

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan Saha, Dhriti [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Kumar Nandi, Arun [Polymer Science Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Chakravorty, Dipankar, E-mail: mlsdc@iacs.res.in [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India)

    2014-04-15

    Nanodimensional silica based glass containing iron ions was prepared within the compressed pellet of CuO nanoparicles. The nanocomposite material showed exchange bias effect. This effect arose due to ferromagnetic iron doped CuO phase and antiferromagnetic CuO interface formation within the nanocomposite during the synthesis process. Coercive field as a function of temperature was fitted with Arhenius–Neel equation and extracted blocking temperature was 511 K. The value of effective anisotropy constant for the nanocomposite was found to be 3.64x10{sup 5} erg/cc. - Highlights: • Nanoglass comprising SiO{sub 2} and Fe{sub 2}O{sub 3} was grown with pores of CuO nanoparticle compacts. • CuO (AFM)-core and Fe doped CuO (FM) shell were formed during synthesis. • The nanocomposite material showed exchange bias effect.

  10. Copper Bioaccumulation and Depuration in Common Carp (Cyprinus carpio) Following Co-exposure to TiO2 and CuO Nanoparticles.

    Science.gov (United States)

    Mansouri, Borhan; Maleki, Afshin; Johari, Seyed Ali; Shahmoradi, Behzad; Mohammadi, Ebrahim; Shahsavari, Siros; Davari, Behroz

    2016-11-01

    Metal oxide nanoparticles (NPs), such as TiO2 and CuO, are widely applied in an increasing number of products and applications, and therefore their release to the aquatic ecosystems is unavoidable. However, little is known about joint toxicity of different NPs on tissues of aquatic organisms, such as fish. This study was conducted to assess the uptake and depuration of Cu following exposure to CuO NPs in the presence of TiO2 NPs in the liver, intestine, muscle, and gill of common carp, Cyprinus carpio. Carps with a mean total length of 23 ± 1.5 cm and mean weight of 13 ± 1.3 g were divided into 6 groups of 15 each (1 control group) and exposed to TiO2 NPs, CuO NPs, and a mixture of TiO2 and CuO NPs for periods of 20 days for uptake and 10 days for depuration. The determination of total Cu concentration was carried out by an ICP-OES. The order of Cu uptake in different tissues of the carps was liver > gill > muscle > intestine in both levels of CuO NPs alone; results showed that the total Cu concentrations in the presence of TiO2 nanoparticles were increased and were in the sequence of liver > gill > intestine > muscle. In depuration period, Cu concentrations were decreased in all treatments in the sequence of gill > intestine > muscle > liver. Uptake of Cu in different tissues of common carp increased with increasing concentration and time and was tissues- and time-dependent. In conclusion, this study suggested that the uptake of Cu in the tissues of common carp increased in the joint presence of TiO2 NPs.

  11. Dynamics of Quasiparticles in CuO2 Planes

    Science.gov (United States)

    Mattis, Daniel C.

    At 5 electrons per cell, planar CuO2 is an antiferromagnetic insulator rather than a Fermi liquid. We consider the effects of adding a few electrons or holes into such an insulator and derive a relation between the insulating energy gap and effective mass m* of the added carriers. We find m{el}{*} to differ from m{hol}{*} , with both being temperature dependent.

  12. Multiphonon hopping of carriers in CuO thin films

    Science.gov (United States)

    Serin, T.; Yildiz, A.; Şahin, Ş. H.; Serin, N.

    2011-10-01

    We have performed a detailed study of the electrical conduction process in CuO thin films deposited by the sol-gel dip coating technique in a temperature range 280-420 K. The electrical conduction is analyzed within the framework of various hopping conduction models. Multiphonon hopping conduction mechanism is found to dominate the electrical transport in the entire temperature region. Our results are consistent with this model of hopping conduction mechanisms with weak carrier-lattice coupling.

  13. Effect of NaOH concentration on structural, surface and antibacterial activity of CuO nanorods synthesized by direct sonochemical method

    Science.gov (United States)

    Sonia, S.; Jayram, Naidu Dhanpal; Suresh Kumar, P.; Mangalaraj, D.; Ponpandian, N.; Viswanathan, C.

    2014-02-01

    Highly efficient Copper oxide (CuO) nanorods were synthesized by using one step sonochemical method under room temperature with change in NaOH concentration. XRD confirms the prepared nanorods are in pure monoclinic phase with lattice constants a = 4.68 Å, b = 3.42 Å, and c = 5.13 Å and FESEM analysis reveals an average diameter of 50-100 nm. Optical absorption spectra exhibits the strong blue shift compared with bulk and the bandgap increases with decreasing the size of the nanorods which is due to the nanosize effect. The composition of CuO nanorods were characterized by Fourier Transform Infra-Red spectroscopy (FTIR) which confirms the formation of monoclinic phase of CuO and the Thermal analysis was done by Thermo Gravimetric Analysis (TGA). The antibacterial properties of copper oxide nanorods were investigated using human pathogens and was compared based on diameter of inhibition zone using agar well diffusion method. The synthesized copper oxide nanostructures show excellent antibacterial activity against Salmonella typhimurium than Staphylococcus aureus strain.

  14. Evaluation of a cloud point extraction approach for the preconcentration and quantification of trace CuO nanoparticles in environmental waters.

    Science.gov (United States)

    Majedi, Seyed Mohammad; Kelly, Barry C; Lee, Hian Kee

    2014-03-01

    The cloud point extraction (CPE) of commercial copper(II) oxide nanoparticles (CuO NPs, mean diameter of 28nm) in water samples was fully investigated. Factors such as Triton X-114 (TX-114) concentration, pH, incubation temperature and time, were optimized. The effects of CuO NP behavior like agglomeration, dissolution, and surface adsorption of natural organic matter, Cu(2+), and coating chemicals, on its recovery were studied. The results indicated that all the CPE factors had significant effects on the extraction efficiency. An enrichment factor of ∼89 was obtained under optimum CPE conditions. The hydrodynamic diameter of CuO NPs increased to 4-5 μm upon agglomeration of NP-micelle assemblies, and decreased at pH >10.0 at which the extraction efficiency was also lowered. The solubility and therefore, the loss of NPs were greatly enhanced at pH 5 mg C L(-1) and Cu(2+) >2 times that of CuO NPs, lowered and enhanced the extraction efficiency, respectively. Pre-treatment of samples with 3% wv(-1) of hydrogen peroxide and 10 mM of ethylenediaminetetraacetic acid minimized the interferences posed by DOC and Cu(2+), respectively. The decrease in CPE efficiency was also evident for ligands like poly(ethylene glycol). The TX-114-rich phase could be determined with either inductively coupled plasma mass spectrometry following microwave digestion, or graphite furnace atomic absorption spectrometry. The detection limits for CuO NPs were 0.02 and 0.06 μg L(-1) using these techniques, respectively. The optimum sample pre-treatment and CPE conditions were successfully applied to the river and wastewater samples. The relative recoveries of CuO NPs spiked at 5-100 μg L(-1) (as Cu) in these samples were in the range of between 59.2 and 108.2%. The approach demonstrates a robust analytical method for detecting trace levels of CuO NPs at their original states and assessing their exposure risks in real aquatic environments.

  15. Transport measurements on individual CuO 2 double layers

    Science.gov (United States)

    Mößle, M.; Kleiner, R.; Gatt, R.; Onellion, M.; Müller, P.

    2000-11-01

    Oxygen loss at the surface of Bi 2Sr 2CaCu 2O 8+ x single crystals provides CuO 2 layers with different critical temperatures. Particularly for overdoped crystals this allows to achieve a T c maximum near the surface. We performed transport measurements of this oxygen depleted layer. Samples were prepared by evaporating four Pb or Ag electrodes on top of freshly cleaved Bi 2Sr 2CaCu 2O 8+ x single crystals. Using overdoped crystals with a bulk T c of 55 to 60 K, the outermost layer was found to be underdoped with T c down to 30 K while the adjacent one was near optimal doping with T c between 80 and 90 K. The T c of the third layer was close to the bulk value. For temperatures above the bulk T c often only one CuO 2 double layer was found to be superconducting. We discuss current transport measurements with current flow along the CuO 2 layers.

  16. CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Liu, Chung Chiun; Ward, Benjamin J.

    2008-01-01

    Nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been found to be useful as an electrical-resistance sensory material for measuring the concentration of carbon dioxide in air. SnO2 is an n-type semiconductor that has been widely used as a sensing material for detecting such reducing gases as carbon monoxide, some of the nitrogen oxides, and hydrocarbons. Without doping, SnO2 usually does not respond to carbon dioxide and other stable gases. The discovery that the electrical resistance of CuO-doped SnO2 varies significantly with the concentration of CO2 creates opportunities for the development of relatively inexpensive CO2 sensors for detecting fires and monitoring atmospheric conditions. This discovery could also lead to research that could alter fundamental knowledge of SnO2 as a sensing material, perhaps leading to the development of SnO2-based sensing materials for measuring concentrations of oxidizing gases. Prototype CO2 sensors based on CuO-doped SnO2 have been fabricated by means of semiconductor-microfabrication and sol-gel nanomaterial-synthesis batch processes that are amendable to inexpensive implementation in mass production.

  17. The influence of fluorine on the structures and properties of Pr sub 2 sub - sub x Sr sub x CuO sub 4 sub - sub y (x = 0.0, 0.4, 1.0)

    CERN Document Server

    Yang Jin Ling; Tang Wei Hua; Rao Guang Hui; Liang Jing Kui; Jin Duo

    1997-01-01

    Introducing F into the lattices of the copper oxides Pr sub 2 CuO sub 4 , Pr sub 1 sub . sub 6 Sr sub 0 sub . sub 4 CuO sub 4 and PrSrCuO sub 4 sub - sub y is accomplished via a low-temperature fluorination reaction using CuF sub 2 as the fluorinating reagent. The oxyfluorides retain the structures of their precursors, but striking lattice expansions are observed. No trace of SrF sub 2 was detected in the fluorinated products. F doping was successfully used to induce superconductivity in the oxyfluoride PrSrCu(O, F) sub 4 sub - subdelta (T sub c = 15 K) with a reduced CuO sub 2 plane and in the presence of apical anions, but failed to optimize the carrier density and induce superconductivity in Pr sub 2 CuO sub 4 sub - sub x F sub x and Pr sub 1 sub . sub 6 Sr sub 0 sub . sub 4 CuO sub 4 sub - sub x F sub x. (author)

  18. Effect of CuO Addition on the Sintering Behavior and Electrical Conductivity of 3Y-TZP

    Institute of Scientific and Technical Information of China (English)

    Ahmed A.Hassan; Omar Abdelal A.; S.M. EL-Hout

    2007-01-01

    Yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) doped with CuO was prepared, to get two compositions, 0.3 and 1 mole fraction CuO, respectively. The dilatometric study of the samples showed sintering to be improved for the samples doped with 0.3 mole fraction CuO, and to be deteriorated for the samples doped with 1 mole fraction CuO. The 1 mole fraction CuO doped 3Y-TZP showed higher tetragonal/monoclinic phase transformation which was accompanied by grain growth. The electrical conductivity decreased with the addition of CuO.

  19. New vision to CuO, ZnO, and TiO{sub 2} nanoparticles: their outcome and effects

    Energy Technology Data Exchange (ETDEWEB)

    Chibber, Sandesh, E-mail: sandeshchibber@gmail.com [Aligarh Muslim University, Department of Biochemistry, F/O Life Sciences (India); Ansari, Shakeel Ahmed [King Abdulaziz University, Centre of Excellence in Genomic and Medicine Research (Saudi Arabia); Satar, Rukhsana [Ibn Sina National College for Medical Sciences, Department of Biochemistry (Saudi Arabia)

    2013-04-15

    Nanomaterials and nanotechnology have attracted more and more attention due to their wide ranges of applications in various fields. With a high level of surface energy, high magnetism, high surface area, and low melting point, engineered nanoparticles (ENPs) has been widely used in industry for various applications. Metal nanoparticles, in particular, have been shown to cause significant biological effects. Review discusses cytotoxic to neurotoxic effects of CuO, ZnO, and TiO{sub 2} nanoparticles based on the scenario drawn from various in vitro and in vivo studies. ENPs such as TiO{sub 2} and ZnO NPs have great practical importance in industrial applications. CuO NPs is also widely used in biomedical applications as catalyst supports, drug carriers, and gene delivery. However, study conducted on TiO{sub 2} NPs have forecast that oxidative DNA damage could be attributed due to reduced glutathione levels with concomitant increase in lipid peroxidation and reactive oxygen species generation. Moreover, there are many evidences showing that ZnO NP and CuO NPs generates ROS production and can cause cell death in different types of cultured cell. Nanoparticle toxicity is assessed by set of tests designed to characterize a given risk and also the mechanism for related outcomes. Conclusively, it becomes more and more important for nanotechnologist to understand the potential health effects of ENPs and what new methodology can be applied to reveal problems like gene silencing and inhibition in antioxidant defense mechanism which can be occurred on severe effects to oxidative stress by ENPs.

  20. Facile Synthesis of Colloidal CuO Nanocrystals for Light-Harvesting Applications

    Directory of Open Access Journals (Sweden)

    Yee-Fun Lim

    2012-01-01

    Full Text Available CuO is an earth-abundant, nontoxic, and low band-gap material; hence it is an attractive candidate for application in solar cells. In this paper, a synthesis of CuO nanocrystals by a facile alcohothermal route is reported. The nanocrystals are dispersible in a solvent mixture of methanol and chloroform, thus enabling the processing of CuO by solution. A bilayer solar cell comprising of CuO nanocrystals and phenyl-C61-butyric acid methyl ester (PCBM achieved a power conversion efficiency of 0.04%, indicating the potential of this material for light-harvesting applications.

  1. Facile Synthesis of Colloidal CuO Nanocrystals for Light-Harvesting Applications

    KAUST Repository

    Lim, Yee-Fun

    2012-01-01

    CuO is an earth-abundant, nontoxic, and low band-gap material; hence it is an attractive candidate for application in solar cells. In this paper, a synthesis of CuO nanocrystals by a facile alcohothermal route is reported. The nanocrystals are dispersible in a solvent mixture of methanol and chloroform, thus enabling the processing of CuO by solution. A bilayer solar cell comprising of CuO nanocrystals and phenyl-C61-butyric acid methyl ester (PCBM) achieved a power conversion efficiency of 0.04%, indicating the potential of this material for light-harvesting applications.

  2. CuO three-dimensional flowerlike nanostructures: Controlled synthesis and characterization

    Science.gov (United States)

    Zhang, Xia; Guo, Yong-Gang; Liu, Wei-Min; Hao, Jing-Cheng

    2008-06-01

    CuO three-dimensional (3D) flowerlike nanostructures were successfully synthesized on copper surface by a simple solution method. CuO nanostructure was systematically studied by scanning electron microscopy, transmission electron microscopy, x-ray powder diffraction, and x-ray photoelectron spectrum. The factors to control the morphology and size of the CuO nanostructures were explored, showing that the reaction time and the concentration of starting regents play important roles in the formation of the CuO 3D nanostructures.

  3. Kinetics of wet oxidation of formic acid and acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. [Univ. of Mumbai (India). Dept. of Chemical Technology

    1997-11-01

    Oxidation of lower molecular weight carboxylic acids such as formic, acetic, glyoxalic, and oxalic acids is often the rate-controlling step during wet oxidation (WO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WO of formic acid was studied in the absence and presence of a cupric sulfate as catalyst in the temperature range 150--240 C and oxygen partial pressure range 0.345--1.380 MPa. Wet oxidation of acetic acid was carried out in the presence of cupric sulfate in the temperature range 215--235 C. Homogeneous copper sulfate was found to be a very good catalyst for oxidation of formic acid and acetic acid.

  4. Enhancement of the electrochemical behavior of CuO nanoleaves on MWCNTs/GC composite film modified electrode for determination of norfloxacin.

    Science.gov (United States)

    Devaraj, Manoj; Deivasigamani, Ranjith Kumar; Jeyadevan, Santhanalakshmi

    2013-02-01

    A novel and facile (single-step) method was developed for the synthesis of CuO nanoleaves in the presence of a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA) at pH 10.5. The mechanism and self-assembly for the formation of CuO nanoleaves are discussed. The structure and morphology of CuO nanoleaves are characterized by means of Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopic (TEM) studies. The CuO/MWCNTs modified glassy carbon (GC) electrode was fabricated via the drop-casting of CuO nanoleaves suspension on MWCNTs/GC surface. In order to investigate the electrochemical behavior of norfloxacin, cyclic voltammetry (CV) and differential pulse voltammetric analysis (DPV) were carried out and compare the oxidation behavior on CuO/MWCNTs/GC, MWCNTs/GC and bare GC. The electrocatalytic oxidation of norfloxacin was studied (pH 7.2) on CuO/MWCNTs/GC electrode and found an irreversible behavior in the range from 0 to +1.1 V with an oxidation peak at 0.91 V in physiological conditions. The quantitative detection of norfloxacin was obtained with a limit of detection of 3.21×10(-7) M within a linear range from 1 μM to 47.7 μM. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Proteomic response of mussels Mytilus galloprovincialis exposed to CuO NPs and Cu{sup 2+}: An exploratory biomarker discovery

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Tânia, E-mail: tania.gomes@niva.no; Chora, Suze; Pereira, Catarina G.; Cardoso, Cátia; Bebianno, Maria João

    2014-10-15

    Highlights: • Different protein expression patterns, tissue and Cu form dependent. • Different cellular mechanisms involved in CuO NPs and Cu{sup 2+} toxicity. • CuO NPs toxicity mediated by cell signalling cascades that result in apoptosis. • Caspase 3/7–1, catL, Zn-finger, precol-D as new molecular targets for both Cu forms in mussels. - Abstract: CuO NPs are one of the most used metal nanomaterials nowadays with several industrial and other commercial applications. Nevertheless, less is known about the mechanisms by which these NPs inflict toxicity in mussels and to what extent it differs from Cu{sup 2+}. The aim of this study was to investigate changes in protein expression profiles in mussels Mytilus galloprovincialis exposed for 15 days to CuO NPs and Cu{sup 2+} (10 μg L{sup −1}) using a proteomic approach. Results demonstrate that CuO NPs and Cu{sup 2+} induced major changes in protein expression in mussels’ showing several tissue and metal-dependent responses. CuO NPs showed a higher tendency to up-regulate proteins in the gills and down-regulate in the digestive gland, while Cu{sup 2+} showed the opposite tendency. Distinctive sets of differentially expressed proteins were found, either common or specific to each Cu form and tissue, reflecting different mechanisms involved in their toxicity. Fifteen of the differentially expressed proteins from both tissues were identified by MALDI-TOF-TOF. Identified proteins indicate common response mechanisms induced by CuO NPs and Cu{sup 2+}, namely in cytoskeleton and cell structure (actin, α-tubulin, paramyosin), stress response (heat shock cognate 71, putative C1q domain containing protein), transcription regulation (zinc-finger BED domain-containing protein 1, nuclear receptor subfamily 1G) and energy metabolism (ATP synthase F0 subunit 6). CuO NPs alone also had a marked effect on other biological processes, namely oxidative stress (GST), proteolysis (cathepsin L) and apoptosis (caspase 3/7-1). On

  6. Investigation of the incommensurate and commensurate magnetic superstructures of LiCuVO4 and CuO on the basis of the isotropic spin exchange and classical spin approximations.

    Science.gov (United States)

    Dai, D; Koo, H-J; Whangbo, M-H

    2004-06-28

    The spin lattices of magnetic oxides LiCuVO(4) and CuO are made up of CuO(2) ribbon chains. The incommensurate and commensurate magnetic superstructures of these oxides were examined by calculating the total spin exchange interaction energies of their long-range order spin arrangements on the basis of the isotropic spin exchange and classical spin approximations. The incommensurate superstructure (0, 0.532, 0) of LiCuVO(4) was analyzed to find that the next-nearest-neighbor spin exchange interaction J(nnn) is more strongly antiferromagnetic than the nearest-neighbor spin exchange interaction J(nn) in the CuO(2) chains. With this finding, we reassessed the relative strengths of the spin exchange interactions of LiCuVO(4) and CuO and then analyzed the relative energies of their long-range order spin arrangements. The incommensurate superstructure (0, 0.532, 0) of LiCuVO(4) is explained when the J(nn)/J(nnn) ratio is -0.40. Both the incommensurate superstructure (0.506, 0, -0.483) and the commensurate superstructure (0.5, 0, -0.5) of CuO, which occur at 231 and 212.5 K, respectively, are well explained in terms of the calculated total spin exchange interaction energies. The incommensurate superstructure of CuO becomes commensurate by a slight change in one interchain spin exchange interaction, which is due probably to a slight structure change brought about by the temperature lowering.

  7. Polymeric Graphitic Carbon Nitride Doped with CuO Dispersed on Dealuminated Clinoptilolite (CuO/HCP: Synthesis and Characterisation

    Directory of Open Access Journals (Sweden)

    Saheed Olalekan Sanni

    2015-01-01

    Full Text Available CuO dispersed on dealuminated clinoptilolite (CuO/HCP and further doped with polymeric graphitic carbon nitride (CuO/HCP-g-C3N4 was synthesized through 2 facile routes: precipitation method for CuO/HCP and impregnation through ultrasonication method for the hybrid composite material. The hybrid composite material crystalline phase, surface morphology, and structural and thermal properties were investigated by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy-dispersive X-ray analysis (EDAX, Fourier transform infrared spectroscopy (FTIR, and thermal analysis. The formation of the hybrid composite material was confirmed by XRD showing crystalline phase of CuO and g-C3N4 present on the surface of dealuminated clinoptilolite (HCP. SEM images analysis depicts no aggregation of the mixed metal oxide semiconductor nanoparticles at the center of HCP. The hybrid composite material, CuO/HCP-g-C3N4, with a good homogeneously dispersed metal oxide conductor having excellent catalytic activities has been synthesized.

  8. SYNTHESIS OF THE SPINEL Al 2 CuO4 THROUGH NITRATES DECOMPOSITION AND SUBSEQUENT THERMAL TREATMENT

    Directory of Open Access Journals (Sweden)

    Rogério Navarro Correia de Siqueira

    2014-06-01

    Full Text Available Composite materials made by a Cu matrix containing ceramic crystals, for example Al2 O3 , could be used for producing non-consumable electrodes with a superior life span in comparison with pure Cu. The operation of the mentioned device in oxidant conditions could lead to the formation of ternary phases of the system Al-Cu-O, the spinel Al2 CuO4 , for example, whose synthesis based on nitrate mixtures thermal decomposition followed by thermal treatment at 1,123 K defines the main goal of the present work. In this context, the effect of some important process variables, such as time and sintering grade of the solid bed, has been studied. The results indicate that the spinel Al2CuO4 is indeed a possible inclusion in electrodes constructed with Cu-Al2O3 composites, with significant formation kinetics for the imposed temperature. Moreover, the compactation of the initial oxide bed can limit the final conversion achieved.

  9. Toxicity of Ag, CuO and ZnO nanoparticles to selected environmentally relevant test organisms and mammalian cells in vitro: a critical review.

    Science.gov (United States)

    Bondarenko, Olesja; Juganson, Katre; Ivask, Angela; Kasemets, Kaja; Mortimer, Monika; Kahru, Anne

    2013-07-01

    Nanoparticles (NPs) of copper oxide (CuO), zinc oxide (ZnO) and especially nanosilver are intentionally used to fight the undesirable growth of bacteria, fungi and algae. Release of these NPs from consumer and household products into waste streams and further into the environment may, however, pose threat to the 'non-target' organisms, such as natural microbes and aquatic organisms. This review summarizes the recent research on (eco)toxicity of silver (Ag), CuO and ZnO NPs. Organism-wise it focuses on key test species used for the analysis of ecotoxicological hazard. For comparison, the toxic effects of studied NPs toward mammalian cells in vitro were addressed. Altogether 317 L(E)C50 or minimal inhibitory concentrations (MIC) values were obtained for algae, crustaceans, fish, bacteria, yeast, nematodes, protozoa and mammalian cell lines. As a rule, crustaceans, algae and fish proved most sensitive to the studied NPs. The median L(E)C50 values of Ag NPs, CuO NPs and ZnO NPs (mg/L) were 0.01, 2.1 and 2.3 for crustaceans; 0.36, 2.8 and 0.08 for algae; and 1.36, 100 and 3.0 for fish, respectively. Surprisingly, the NPs were less toxic to bacteria than to aquatic organisms: the median MIC values for bacteria were 7.1, 200 and 500 mg/L for Ag, CuO and ZnO NPs, respectively. In comparison, the respective median L(E)C50 values for mammalian cells were 11.3, 25 and 43 mg/L. Thus, the toxic range of all the three metal-containing NPs to target- and non-target organisms overlaps, indicating that the leaching of biocidal NPs from consumer products should be addressed.

  10. Comparison and distribution of copper oxide nanoparticles and copper ions in activated sludge reactors.

    Science.gov (United States)

    Zhang, Dongqing; Trzcinski, Antoine P; Oh, Hyun-Suk; Chew, Evelyn; Tan, Soon Keat; Ng, Wun Jern; Liu, Yu

    2017-05-12

    Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO4). It was found that 0.1 mg/L of CuO NPs had negligible effects on Chemical Oxygen Demand (COD) and ammonia removal. However, the presence of 1, 10 and 50 mg/L of CuO NPs decreased COD removal from 78.7% to 77%, 52.1% and 39.2%, respectively (P copper ions were more toxic towards microorganisms compared to CuO NPs. CuO NPs were removed effectively (72-93.2%) from wastewater due to a greater biosorption capacity of CuO NPs onto activated sludge, compared to the copper ions (55.1-83.4%). The SEM images clearly showed the accumulation and adsorption of CuO NPs onto activated sludge. The decrease in Live/dead ratio after 5 h of exposure of CuO NPs and Cu(2+) indicated the loss of cell viability in sludge flocs.

  11. A structure study of copper oxide for monolayer dispersion of anatase supported

    Institute of Scientific and Technical Information of China (English)

    Fen-LanZi; Xiao-haiCai; 等

    2001-01-01

    The monolayer dispersion of copper oxide on the surface of anatase and its effect on the properties have been studied by X-ray photoelectron spectroscopy(XPS) and X-ray extended absorption fine structure(EXAFS).XPS results give an utmost dispersion capacity of 7.2mg/gTiO2.Strong interactions between copper oxide and anatase can be seen from EXAFS results.The structure of the supported CuO species is strongly dependent on the amount of CuO loading.When the content of CuO loading is below the utmost dispersion capacity,the surface of CuO/TiO2 is dominated by the highly dispersed CuO species having no-Cu-O-Cu-chains,The copper ion is located in an octahedral coordination environment,and the Cu-O-coordination distance is much longer than that in pure crystalline CuO,when CuO loading is exceeds the utmost dispersion capacity,crystalline CuO is formed on the surface of CuO/TiO2,From the result of the sturcture study,it is Cu-O octahedral Coordination and coordination distance change in comparation with pure crystalline Cuo on the surface CuO/TiO2 that have catalytic activity.

  12. Synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires obtained by aerosol assisted CVD

    Energy Technology Data Exchange (ETDEWEB)

    Lugo-Ruelas, M. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Universidad Autónoma de Chihuahua, Facultad de Ingeniería, Circuito No. 1, Nuevo Campus Universitario, Apdo. Postal 1552, Chihuahua, Chih. C.P. 31240 (Mexico); Amézaga-Madrid, P. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Esquivel-Pereyra, O. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Universidad Autónoma de Chihuahua, Facultad de Ingeniería, Circuito No. 1, Nuevo Campus Universitario, Apdo. Postal 1552, Chihuahua, Chih. C.P. 31240 (Mexico); Antúnez-Flores, W.; Pizá-Ruiz, P.; Ornelas-Gutiérrez, C. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico)

    2015-09-15

    Highlights: • Nanorods and nanowires of CuO were successfully synthesized by AACVD technique. • The carrier gas velocity was a determinant factor for the growth of nanorods or nanowires. • The increase of deposition time generates the reduction in the evenness and distribution density. • The crystalline phase of nanorods and nanowires was monoclinic tenorite. - Abstract: Copper oxide is a particularly interesting material because it presents photovoltaic, electrochemical and catalytic properties. Its unique properties are very important in the area of nanotechnology and may be an advantage because these nanomaterials can be applied in the design and manufacture of nanosensors, photocatalysis area, nanolasers switches and transistors. Nowadays one-dimensional nanostructures as nanorods, nanowires, etc., have generated a great importance and have received considerable attention and study due to their unique physical and chemical properties. In this work we report the synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires grown by aerosol assisted chemical vapor deposition onto a CuO, ZnO and TiO{sub 2} thin film covered and bare borosilicate glass substrate. Concentration of the precursor solution and carrier gas flux were previously optimized and fixed at 0.1 mol dm{sup −3} and 5 L min{sup −1}, respectively. Other deposition parameters such as substrate temperature, as well the carrier gas velocity and deposition time were varied from 623 to 973 K, 0.88 to 1.77 m s{sup −1} and 11 to 16 min, respectively. Their influence on the morphology, microstructure and optical properties of the nanorods and nanowires were analyzed. The crystalline structure of the materials was characterized by grazing incidence X-ray diffraction; results indicate the presence of the tenorite phase. Surface morphology and microstructure were studied by field emission scanning electron microscopy, and high resolution transmission electron

  13. STRUCTURAL AND ELECTRONIC PROPERTIES OF CuO, CuO2 AND Cu2O NANOCLUSTERS – A DFT APPROACH

    Directory of Open Access Journals (Sweden)

    Chandiramouli RAMANATHAN

    2015-06-01

    Full Text Available The realistic structures of CuO, CuO2 and Cu2O were completely optimized using density functional theory approach. The different structures were optimized to study the structural stability, dipole moment, point symmetry, HOMO-LUMO gap, ionization potential, electron affinity and binding energy of CuO, CuO2 and Cu2O. The electronic properties of clusters were discussed in terms of HOMO-LUMO gap, density of states, ionization potential and electron affinity. This information will provide an insight for the synthesis of nanomaterials with proper geometry which finds its potential importance in engineering applications.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6459

  14. Study of the C-14-contamination potential of C-impurities in CuO and Fe

    NARCIS (Netherlands)

    Vandeputte, K; Moens, L; Dams, R; van der Plicht, Johannes

    1998-01-01

    The carbon concentration in CuO and iron was determined by isolating C. The values were in agreement with results reported in other studies. Contaminating carbon from CuO and Fe was transformed to AMS targets and measured for C-14. C-traces in CuO were shown to be the major contribution to the C-14

  15. Anomalous Raman spectra from La2CuO4

    Science.gov (United States)

    Burns, Gerald; Dacol, F. H.

    1990-03-01

    We show that some published Raman spectra from the superconductors (La2-xSrx)CuO4 and La2NiO4 are incorrect. We believe that these spectra were obtained when the samples were ``burnt'' by the focused laser beam and were actually due to La2O3. Similar anomalous results can be obtained when starting with Nd2CuO4 where the spectra come from Nd2O3. A spectrum distinctly different from those of La2O3 or Nd2O3 is obtained from Y2O3.

  16. Chronic effects of CuO Nanoparticles on Lymnaea stagnalis

    DEFF Research Database (Denmark)

    Falk, Nina; Zwicky, Julie; Rewentlow, Julie

    Due to their small size and high surface-to-volume ratio, the properties and reactivity of NPs are different from those of their bulk forms. However, these properties might cause different behaviour and effects in the environment and investigations of possible nano specific effects are thus highl...... relevant. Investigation of the long-term effects of CuO NPs on growth, mortality and precopulation of Hyalella azteca compared to CuCl2 and to further examine possible delayed effects and ability to recover from Cu exposure....

  17. Influence of the surface morphology and structure on the gas-sorption properties of SiO2CuO x nanocomposite materials: X-ray spectroscopy investigations

    Science.gov (United States)

    Shmatko, V. A.; Yalovega, G. E.; Myasoedova, T. N.; Brzhezinskaya, M. M.; Shtekhin, I. E.; Petrov, V. V.

    2015-02-01

    Thin films of SiO2CuO x nanocomposite materials were synthesized by the sol-gel method upon deposition of solutions containing 1, 3, 5, and 7 wt % Cu. The scanning electron microscopy examination of the surface morphology revealed that a change in the copper concentration in the initial solution has an influence on the size and amount of crater-like pores formed in the amorphous silicon dioxide matrix and on the localization of copper crystallites on the surface of the films. X-ray absorption near-edge structure (XANES) spectroscopy and X-ray photoelectron spectroscopy (XPS) investigations showed that the structure of crystallites is predominantly formed by divalent copper oxide (CuO). However, an increase in the copper concentration in the initial solution leads to a systematic increase in the content of the Cu2O phase. At copper concentrations of 1 and 7 wt %, the surface layers are most likely characterized by the formation of several divalent copper oxides (Cu(OH)2, CuO, CuSiO3), which results in the deterioration of the gas-sensitive characteristics of the material. It was established that the optimum set of parameters (the presence of pores, localization of crystallites, copper phase composition in the crystallites) for the best gas-sensitive characteristics of SiO2CuO x composite films is observed at copper concentrations of 3 and 5 wt % in the initial solution.

  18. Evaluation of a cloud point extraction approach for the preconcentration and quantification of trace CuO nanoparticles in environmental waters

    Energy Technology Data Exchange (ETDEWEB)

    Majedi, Seyed Mohammad [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Kelly, Barry C. [Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore); Lee, Hian Kee, E-mail: chmleehk@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); National University of Singapore Environmental Research Institute, T-Lab Building #02-01, 5A Engineering Drive 1, Singapore 117411 (Singapore)

    2014-03-01

    Highlights: • The robustness of cloud point extraction approach was investigated for the analysis of trace CuO NPs in water. • The behavior and fate, and therefore, the recovery of CuO NPs varied substantially under different extraction conditions. • The effects of environmental factors on the NP behavior and extraction were determined and minimized. • Limits of detection of 0.02 and 0.06 μg L⁻¹ were achieved using ICP-MS and GF-AAS, respectively. • Environmental water samples were successfully pre-treated and analyzed. Abstract: The cloud point extraction (CPE) of commercial copper(II) oxide nanoparticles (CuO NPs, mean diameter of 28 nm) in water samples was fully investigated. Factors such as Triton X-114 (TX-114) concentration, pH, incubation temperature and time, were optimized. The effects of CuO NP behavior like agglomeration, dissolution, and surface adsorption of natural organic matter, Cu²⁺, and coating chemicals, on its recovery were studied. The results indicated that all the CPE factors had significant effects on the extraction efficiency. An enrichment factor of ~89 was obtained under optimum CPE conditions. The hydrodynamic diameter of CuO NPs increased to 4–5 μm upon agglomeration of NP-micelle assemblies, and decreased at pH >10.0 at which the extraction efficiency was also lowered. The solubility and therefore, the loss of NPs were greatly enhanced at pH <8.5 and in the first 60 min of incubation, whereas it declined at elevated incubation temperatures. Our results showed that the dissolved organic carbon (DOC) >5 mg C L⁻¹ and Cu²⁺ >2 times that of CuO NPs, lowered and enhanced the extraction efficiency, respectively. Pre-treatment of samples with 3% w v⁻¹ of hydrogen peroxide and 10 mM of ethylenediaminetetraacetic acid minimized the interferences posed by DOC and Cu²⁺, respectively. The decrease in CPE efficiency was also evident for ligands like poly(ethylene glycol). The TX-114-rich phase could be determined

  19. The behavior and effect of CuO in Ag/SnO{sub 2} materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: Wangjun1983@stu.xjtu.edu.cn [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Liu, Wei, E-mail: 810779396@qq.com [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Li, Dongmei, E-mail: 946346365@qq.con [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Yaping, E-mail: ypwang@mail.xjtu.edu.cn [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China)

    2014-03-05

    Highlights: • The crystallized monoclinic CuO in CuO-doped SnO{sub 2} nanoparticles had formed. • The crystallized monoclinic CuO distributed on the surface of SnO{sub 2} nanoparticles. • Ag/SnO{sub 2} materials adding CuO exhibited denser microstructure and better hardness. • Ag/SnO{sub 2} materials adding CuO exhibited better arc erosion resistance. • The addition of CuO can obviously inhibited the spattering loss of molten droplet. -- Abstract: In this paper, the behavior of CuO in CuO-doped SnO{sub 2} nanoparticles was investigated; the effect of the addition of CuO on physical properties and arc erosion behavior of Ag/SnO{sub 2} materials were examined. The CuO-doped SnO{sub 2} nanoparticles were structurally characterized by X-ray diffraction (XRD) and High-resolution Transmission Electron Microscope (HR-TEM). The surface morphology of arc eroded Ag/SnO{sub 2} materials was characterized by Scanning Electron Microscope (SEM). The results indicated that the crystallized monoclinic CuO in CuO-doped SnO{sub 2} nanoparticles has formed and distributed on the surface of SnO{sub 2} nanoparticles. It was found that Ag/SnO{sub 2} materials adding CuO exhibited denser microstructure and better hardness as well as better arc erosion resistance compared with Ag/SnO{sub 2} materials. The arc erosion results and theoretical analysis indicated that the addition of CuO in Ag/SnO{sub 2} materials can obviously inhibited the spattering loss of molten droplets.

  20. Performance of silica-supported copper oxide sorbents for SOx/NOx-removal from flue gas I. Sulphur dioxide absorption and regeneration kinetics

    NARCIS (Netherlands)

    Kiel, J.H.A.; Prins, W.; Swaaij, van W.P.M.

    1992-01-01

    Sulphur dioxide absorption and regeneration kinetics of several silica-supported copper oxide (CuO) sorbents were studied in a microbalance over a temperature range of 300 to 450°C. The porous silica support was prepared according to a sol-gel technique, and CuO was deposited on this support through

  1. Investigation of the electronic structure of CuO by means of resonant X-ray Raman scattering

    CERN Document Server

    Doering, G

    2001-01-01

    excited state. By means of a perturbation theoretical treatment of the Coulomb interaction between the core-hole and the 3d-electrons an expression for the cross-section of the shakeup-process is derived. Thereby the observed excitation energy dependence of the shakeup-satellite's intensity and its position in the energy loss spectrum can be explained. Furthermore, its intensity shows a strong dependence on the scattering angle in certain scattering geometries. By means of a model calculation this dependence is attributed to a polarisation-effect. In this thesis the electronic structure of CuO is investigated utilizing resonant X-ray Raman Scattering. The special properties of this transition metal oxide are emphasized and the potential of the method is shown. First it is explained how one can draw conclusions about the unoccupied density of states of CuO and its symmetry from measurements of the copper K-alpha fluorescence by using an excitation energy of a few eV below the absorption threshold. By this mean...

  2. Eradication of multi-drug resistant bacteria by a novel Zn-doped CuO nanocomposite.

    Science.gov (United States)

    Malka, Eyal; Perelshtein, Ilana; Lipovsky, Anat; Shalom, Yakov; Naparstek, Livnat; Perkas, Nina; Patick, Tal; Lubart, Rachel; Nitzan, Yeshayahu; Banin, Ehud; Gedanken, Aharon

    2013-12-09

    Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabric using ultrasound irradiation. The optimization of the processing conditions, the specific reagent ratio, and the precursor concentration results in the formation of uniform nanoparticles with an average size of ≈30 nm. The antibacterial activity of the Zn-doped CuO Cu₀.₈₈Zn₀.₁₂O in a colloidal suspension or deposited on the fabric is tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria. A substantial enhancement of 10,000 times in the antimicrobial activity of the Zn-CuO nanocomposite compared to the pure CuO and ZnO nanoparticles (NPs) is observed after 10 min exposure to the bacteria. Similar activities are observed against multidrug-resistant bacteria (MDR), (i.e., Methicillin-resistant S. aureus and MDR E. coli) further emphasizing the efficacy of this composite. Finally, the mechanism for this enhanced antibacterial activity is presented.

  3. Hartee Fock Symmetry Breaking Effects in La2CuO4: Hints for connecting the Mott and Slater Pictures and Pseudogap Prediction

    Directory of Open Access Journals (Sweden)

    Alejandro Cabo Montes de Oca

    2010-03-01

    Full Text Available This work expands the results and derivations presented in a recent letter. It is argued that symmetry breaking Hartree-Fock (HF solutions of a simple model of the Cu-O planes in La2CuO4, are able to describe the insulator and antiferromagnetic characters of this material. Then, this classical primer of a Mott insulator is alternatively obtained here as an exact Slater insulator within the simplest of the first principles schemes. Moreover, pseudogap HF states are also predicted. The maximal energy gap of 100 meV over the Fermi surface of this wavefunction, reasonably well matches the ARPES upper pseudogap measurements for La2CuO4 in the zero doping limit. These surprising results followed after eliminating spin and crystal symmetry constraints usually imposed on the HF orbitals. The discussion helps to clarify the role of the antiferromagnetism and pseudogaps in the physics of the HTSC materials and indicates a promising way to start conciliating the Mott and Slater pictures for the description of the transition metal oxides.

  4. Green synthesis of CuO nanoparticles using aqueous extract of Thymus vulgaris L. leaves and their catalytic performance for N-arylation of indoles and amines.

    Science.gov (United States)

    Nasrollahzadeh, Mahmoud; Sajadi, S Mohammad; Rostami-Vartooni, Akbar; Hussin, Sarbast Mamand

    2016-03-15

    Copper oxide (CuO) nanoparticles (NPs) were synthesized by biological method using aqueous extract of Thymus vulgaris L. leaves as a reducing and capping agent. The progress of the reaction was monitored using UV-visible spectroscopy. The advantages of this procedure are simple operation, use of cheap, natural, nontoxic and benign precursors, absence of toxic reagents and mild and environmentally friendly conditions. The green synthesized CuO NPs was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). More importantly, the green synthesized CuO NPs was found to be an excellent heterogeneous catalyst for ligand-free N-arylation of indoles and amines. The N-arylated products were obtained in good to excellent yield and the catalyst can be recovered and reused for further catalytic reactions with almost no loss in activity.

  5. TiO2 coated CuO nanowire array: Ultrathin p-n heterojunction to modulate cationic/anionic dye photo-degradation in water

    Science.gov (United States)

    Scuderi, Viviana; Amiard, Guillaume; Sanz, Ruy; Boninelli, Simona; Impellizzeri, Giuliana; Privitera, Vittorio

    2017-09-01

    We report the photocatalytic efficiency of CuO nanowires covered with a thin TiO2 film, studied by dyes degradation in water. The CuO nanowires were synthesized on Cu foils by thermal oxidation. A subsequent TiO2 deposition (7, 15, 30, 50 nm thick) was performed by atomic layer deposition, developing an ultrathin p-n heterojunction. A structural characterization was obtained by X-ray diffraction analysis, scanning and transmission electron microscopies equipped with energy dispersive x-ray analysis. The photocatalytic activity of the investigated materials was tested by the degradation of a cationic (methylene blue) or anionic (methyl orange). The relevance of the reported results was discussed in relation with the effects of the ultrathin p-n TiO2/CuO heterojunction. The two semiconductors are in intimate connection increasing the exposed surface and only TiO2 is directly in contact with water. This allowed to study systematically the effect of the electric filed generated by the p-n junction on the interface TiO2/liquid and therefore to modulate cationic/anionic dyes photo-degradation in water.

  6. Influence of CuO catalyst in the nanoscale range on SnO2 surface for H2S gas sensing applications

    Indian Academy of Sciences (India)

    Vinay Gupta; S Mozumdar; Arijit Choudhuri; K Sreenivas

    2005-10-01

    The dispersal of CuO catalyst on the surface of the semiconducting SnO2 film is found to be of vital importance for improving the sensitivity and the response speed of a SnO2 gas sensor for H2S gas detection. Ultra-thin CuO islands (8 nm thin and 0.6 mm diameter) prepared by evaporating Cu through a mesh and subsequent oxidation yield a fast response speed and recovery. Ultimately nanoparticles of Cu (average size = 15 nm) prepared by a chemical technique using a reverse micelle method involving the reduction of Cu(NO3)2 by NaBH4 exhibited significant improvement in the gas sensing characteristics of SnO2 films. A fast response speed of ∼ 14 s and a recovery time of ∼ 60 s for trace level ∼ 20 ppm H2S gas detection have been recorded. The sensor operating temperature (130°C) is low and the sensitivity ( = 2.06 × 103) is high. It is found that the spreading over of CuO catalyst in the nanoscale range on the surface of SnO2 allows effective removal of excess adsorbed oxygen from the uncovered SnO2 surface due to spill over of hydrogen dissociated from the H2S-CuO interaction.

  7. One-pot hydrothermal growth of raspberry-like CeO2 on CuO microsphere as copper-based catalyst for Rochow reaction

    Science.gov (United States)

    Jin, Zheying; Li, Jing; Shi, Laishun; Ji, Yongjun; Zhong, Ziyi; Su, Fabing

    2015-12-01

    In this work, we prepared a novel structure comprising of raspberry-like CeO2 deposited on CuO microspheres (Ce-CuO) for Rochow reaction. The synthesis was carried out via a facile one-pot hydrothermal reaction without using any template, in which, the basic copper carbonate microspheres were first formed via self-assembly of basic copper carbonate nanorods, followed with deposition of cerium hydroxide. After calcination, they were transformed into Ce-CuO but still maintained the hierarchical structure, and meanwhile, mesoporous structure was formed (for simplicity, we will only state them as metal oxide in the following context). The samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and scanning electron microscopy (SEM) techniques. When used as a Cu-based catalyst, Ce-CuO exhibited superior catalytic property to the single CuO, CeO2 and their physically mixture in the Rochow reaction with dimethyldichlorosilane (M2) selectivity increased from ca. 65 to 83.7%. The higher M2 selectivity of Ce-CuO is mainly due to its larger surface area and the synergistic effect between CuO and CeO2. This work demonstrates that catalytic performance of the Cu-based can be improved by adding Ce rare-earth element and by carefully controlling their structures.

  8. Copper oxide nanoparticles inhibit the metabolic activity of Saccharomyces cerevisiae.

    Science.gov (United States)

    Mashock, Michael J; Kappell, Anthony D; Hallaj, Nadia; Hristova, Krassimira R

    2016-01-01

    Copper oxide nanoparticles (CuO NPs) are used increasingly in industrial applications and consumer products and thus may pose risk to human and environmental health. The interaction of CuO NPs with complex media and the impact on cell metabolism when exposed to sublethal concentrations are largely unknown. In the present study, the short-term effects of 2 different sized manufactured CuO NPs on metabolic activity of Saccharomyces cerevisiae were studied. The role of released Cu(2+) during dissolution of NPs in the growth media and the CuO nanostructure were considered. Characterization showed that the 28 nm and 64 nm CuO NPs used in the present study have different primary diameter, similar hydrodynamic diameter, and significantly different concentrations of dissolved Cu(2+) ions in the growth media released from the same initial NP mass. Exposures to CuO NPs or the released Cu(2+) fraction, at doses that do not have impact on cell viability, showed significant inhibition on S. cerevisiae cellular metabolic activity. A greater CuO NP effect on the metabolic activity of S. cerevisiae growth under respiring conditions was observed. Under the tested conditions the observed metabolic inhibition from the NPs was not explained fully by the released Cu ions from the dissolving NPs. © 2015 SETAC.

  9. Comparative toxicity of copper oxide bulk and nano particles in Nile Tilapia; Oreochromis niloticus: Biochemical and oxidative stress

    Directory of Open Access Journals (Sweden)

    Amr A. Abdel-Khalek

    2015-10-01

    Full Text Available Nile Tilapia; Oreochromis niloticus are commonly used in the assessment of aquatic environment quality and also considered as useful bio-indicators during environmental pollution monitoring. The LC50/96 h of copper oxide (bulk & nano particles [CuO (BPs & NPs] were 2205 & 150 mg/l, respectively. Two tested concentrations of CuO (BPs & NPs were selected: the first concentration was equivalent to (1/10 (220.5 & 15 mg/l, and the second was equivalent to (1/20 (110.25 & 7.5 mg/l LC50/96 h·CuO (BPs & NPs, respectively. While serum glucose, liver function tests (AST, ALT and ALP and kidney function tests (creatinine and uric acid showed a significant increase, serum total proteins, albumin, globulin and total lipids showed a significant decrease. Both liver and gill tissues of the studied fish showed a reduction in GSH content and an elevation in MDA and GPx activities. The present study also showed an elevation in liver CAT & SOD activities when exposed to both concentrations of CuO BPs and in the case of gills when exposed to both concentrations of CuO (BPs & NPs, although activity of these enzymes showed an inhibition in the liver when exposed to both concentrations of CuO NPs. The present study investigated whether CuO NPs are more toxic than CuO BPs.

  10. Low-Thermal-Budget Photonic Processing of Highly Conductive Cu Interconnects Based on CuO Nanoinks: Potential for Flexible Printed Electronics.

    Science.gov (United States)

    Rager, Matthew S; Aytug, Tolga; Veith, Gabriel M; Joshi, Pooran

    2016-01-27

    In the developing field of printed electronics, nanoparticle based inks such as CuO show great promise as a low-cost alternative to other metal-based counterparts (e.g., silver). In particular, CuO inks significantly eliminate the issue of particle oxidation before and during the sintering process that is prevalent in Cu-based formulations. We report here the scalable and low-thermal-budget photonic fabrication of Cu interconnects employing a roll-to-roll (R2R)-compatible pulse-thermal-processing (PTP) technique that enables phase reduction and subsequent sintering of ink-jet-printed CuO patterns onto flexible polymer templates. Detailed investigations of curing and sintering conditions were performed to understand the impact of PTP system conditions on the electrical performance of the Cu patterns. Specifically, the impact of energy and power of photonic pulses on print conductivity was systematically studied by varying the following key processing parameters: pulse intensity, duration, and sequence. Through optimization of such parameters, highly conductive prints were obtained in <1 s with resistivity values as low as 10 μΩ cm (corresponding to ∼17% of the International Annealed Copper Standard (IACS) conductivity) was achieved. It was also observed that the introduction of an initial ink-drying step in ambient atmosphere, after the printing and before sintering, leads to significant improvements in mechanical integrity and electrical performance of the printed Cu patterns. Moreover, the viability of CuO reactive inks, coupled with the PTP technology and pre-sintering ink-drying protocols, has also been demonstrated for the additive integration of a low-cost Cu temperature sensor onto a flexible polymer substrate.

  11. Effects of CuO nanoparticles on compressive strength of self-compacting concrete

    Indian Academy of Sciences (India)

    Ali Nazari; Shadi Riahi

    2011-06-01

    In the present study, the compressive strength, thermal properties and microstructure of self-compacting concrete with different amounts of CuO nanoparticles have been investigated. CuO nanoparticles with an average particle size of 15 nm were added to self-compacting concrete and various properties of the specimens were measured. The results indicate that CuO nanoparticles are able to improve the compressive strength of self-compacting concrete and reverse the negative effects of superplasticizer on compressive strength of the specimens. CuO nanoparticles as a partial replacement of cement up to 4 wt.% could accelerate C–S–H gel formation as a result of the increased crystalline Ca(OH)2 amount at the early ages of hydration. Increasing CuO nanoparticle content to more than 4 wt.%, causes reduced compressive strength because of unsuitable dispersion of nanoparticles in the concrete matrix. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results, all indicate that CuO nanoparticles up to 4 wt.% could improve the mechanical and physical properties of the specimens. Finally, CuO nanoparticles improved the pore structure of concrete and caused shifting of the distributed pores from harmless to low harm.

  12. Preparation and photocatalytic activities of 3D flower-like CuO nanostructures

    Science.gov (United States)

    Qingfei, Fan; Qi, Lan; Meili, Zhang; Ximei, Fan; Zuowan, Zhou; Chaoliang, Zhang

    2016-08-01

    Hierarchical 3D flower-like CuO nanostructures on the Cu substrates were synthesized by a wet chemical method and subsequent heat treatment. The synthesis, structure and morphologies of obtained samples under different concentrations of Na2S2O3 were investigated in detail and the possible growth mechanisms of the 3D flower-like CuO nanostructures were discussed. Na2S2O3 plays a key role in the generation of the 3D flower-like CuO nanostructures. When the concentration of Na2S2O3 is more than 0.4 mol/L, the 3D flower-like CuO nanostructures can be prepared on the Cu foils. The photocatalytic performances were studied by analyzing the degradation of methyl orange (MO) in aqueous solution in the presence of hydroxide water (H2O2). The 3D flower-like CuO nanostructures exhibit higher photocatalytic activity (96.2% degradation rate) than commercial CuO particles (36.3% degradation rate). The origin of the higher photocatalytic activity of the 3D flower-like CuO nanostructures was also discussed. Project supported by the High-Tech Research and Development Program of China (No. 2009AA03Z427).

  13. Dimensionality of high temperature superconductivity in oxides

    Science.gov (United States)

    Chu, C. W.

    1989-01-01

    Many models have been proposed to account for the high temperature superconductivity observed in oxide systems. Almost all of these models proposed are based on the uncoupled low dimensional carrier Cu-O layers of the oxides. Results of several experiments are presented and discussed. They suggest that the high temperature superconductivity observed cannot be strictly two- or one-dimensional, and that the environment between the Cu-O layers and the interlayer coupling play an important role in the occurrence of such high temperature superconductivity. A comment on the very short coherence length reported is also made.

  14. Copper Oxide Nanoparticles Induced Mitochondria Mediated Apoptosis in Human Hepatocarcinoma Cells

    Science.gov (United States)

    Siddiqui, Maqsood A.; Alhadlaq, Hisham A.; Ahmad, Javed; Al-Khedhairy, Abdulaziz A.; Musarrat, Javed; Ahamed, Maqusood

    2013-01-01

    Copper oxide nanoparticles (CuO NPs) are heavily utilized in semiconductor devices, gas sensor, batteries, solar energy converter, microelectronics and heat transfer fluids. It has been reported that liver is one of the target organs for nanoparticles after they gain entry into the body through any of the possible routes. Recent studies have shown cytotoxic response of CuO NPs in liver cells. However, the underlying mechanism of apoptosis in liver cells due to CuO NPs exposure is largely lacking. We explored the possible mechanisms of apoptosis induced by CuO NPs in human hepatocellular carcinoma HepG2 cells. Prepared CuO NPs were spherical in shape with a smooth surface and had an average diameter of 22 nm. CuO NPs (concentration range 2–50 µg/ml) were found to induce cytotoxicity in HepG2 cells in dose-dependent manner, which was likely to be mediated through reactive oxygen species generation and oxidative stress. Tumor suppressor gene p53 and apoptotic gene caspase-3 were up-regulated due to CuO NPs exposure. Decrease in mitochondrial membrane potential with a concomitant increase in the gene expression of bax/bcl2 ratio suggested that mitochondria mediated pathway involved in CuO NPs induced apoptosis. This study has provided valuable insights into the possible mechanism of apoptosis caused by CuO NPs at in vitro level. Underlying mechanism(s) of apoptosis due to CuO NPs exposure should be further invested at in vivo level. PMID:23940521

  15. Copper oxide nanoparticles induced mitochondria mediated apoptosis in human hepatocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Maqsood A Siddiqui

    Full Text Available Copper oxide nanoparticles (CuO NPs are heavily utilized in semiconductor devices, gas sensor, batteries, solar energy converter, microelectronics and heat transfer fluids. It has been reported that liver is one of the target organs for nanoparticles after they gain entry into the body through any of the possible routes. Recent studies have shown cytotoxic response of CuO NPs in liver cells. However, the underlying mechanism of apoptosis in liver cells due to CuO NPs exposure is largely lacking. We explored the possible mechanisms of apoptosis induced by CuO NPs in human hepatocellular carcinoma HepG2 cells. Prepared CuO NPs were spherical in shape with a smooth surface and had an average diameter of 22 nm. CuO NPs (concentration range 2-50 µg/ml were found to induce cytotoxicity in HepG2 cells in dose-dependent manner, which was likely to be mediated through reactive oxygen species generation and oxidative stress. Tumor suppressor gene p53 and apoptotic gene caspase-3 were up-regulated due to CuO NPs exposure. Decrease in mitochondrial membrane potential with a concomitant increase in the gene expression of bax/bcl2 ratio suggested that mitochondria mediated pathway involved in CuO NPs induced apoptosis. This study has provided valuable insights into the possible mechanism of apoptosis caused by CuO NPs at in vitro level. Underlying mechanism(s of apoptosis due to CuO NPs exposure should be further invested at in vivo level.

  16. Copper oxide nanoparticles induced mitochondria mediated apoptosis in human hepatocarcinoma cells.

    Science.gov (United States)

    Siddiqui, Maqsood A; Alhadlaq, Hisham A; Ahmad, Javed; Al-Khedhairy, Abdulaziz A; Musarrat, Javed; Ahamed, Maqusood

    2013-01-01

    Copper oxide nanoparticles (CuO NPs) are heavily utilized in semiconductor devices, gas sensor, batteries, solar energy converter, microelectronics and heat transfer fluids. It has been reported that liver is one of the target organs for nanoparticles after they gain entry into the body through any of the possible routes. Recent studies have shown cytotoxic response of CuO NPs in liver cells. However, the underlying mechanism of apoptosis in liver cells due to CuO NPs exposure is largely lacking. We explored the possible mechanisms of apoptosis induced by CuO NPs in human hepatocellular carcinoma HepG2 cells. Prepared CuO NPs were spherical in shape with a smooth surface and had an average diameter of 22 nm. CuO NPs (concentration range 2-50 µg/ml) were found to induce cytotoxicity in HepG2 cells in dose-dependent manner, which was likely to be mediated through reactive oxygen species generation and oxidative stress. Tumor suppressor gene p53 and apoptotic gene caspase-3 were up-regulated due to CuO NPs exposure. Decrease in mitochondrial membrane potential with a concomitant increase in the gene expression of bax/bcl2 ratio suggested that mitochondria mediated pathway involved in CuO NPs induced apoptosis. This study has provided valuable insights into the possible mechanism of apoptosis caused by CuO NPs at in vitro level. Underlying mechanism(s) of apoptosis due to CuO NPs exposure should be further invested at in vivo level.

  17. One-step preparation of magnetic imprinted nanoparticles adopting dopamine-cupric ion as a co-monomer for the specific recognition of bovine hemoglobin.

    Science.gov (United States)

    Gao, Ruixia; Zhang, Lili; Hao, Yi; Cui, Xihui; Liu, Dechun; Zhang, Min; Tang, Yuhai

    2015-10-01

    A novel magnetic core-shell polydopamine-cupric ion complex imprinted polymer was prepared in one-step through surface imprinting technology, which could specifically recognize bovine hemoglobin from the real blood samples. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results showed that the cupric ion played an important role in the recognition of template proteins. The saturating adsorption capacity of this kind of imprinted polymers was 2.23 times greater than those of imprinted polymers without cupric ion. The imprinting factor of the imprinted materials was as high as 4.23 for the template molecule. The selective separation bovine hemoglobin from the real blood sample is successfully applied. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity and satisfactory selectivity for the template protein make this polymer attractive in the separation of high-abundance proteins. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Surfactant-free Synthesis of CuO with Controllable Morphologies and Enhanced Photocatalytic Property

    OpenAIRE

    Wang, Xing; Yang, Jiao; Shi, Liuxue; Gao, Meizhen

    2016-01-01

    A green synthesis for nanoleave, nanosheet, spindle-like, rugby-like, dandelion-like and flower-like CuO nanostructures (from 2D to 3D) is successfully achieved through simply hydrothermal synthetic method without the assistance of surfactant. The morphology of CuO nanostructures can be easily tailored by adjusting the amount of ammonia and the source of copper. By designing a time varying experiment, it is verified that the flower- and dandelion-like CuO structures are synthesized by the sel...

  19. The reactions of CuO at high pressure and high temperature

    CERN Document Server

    Ren, G Z; Wang, X C; Ma, H A; Guo, X B; Liu, J T; Zou Guang Tian

    2002-01-01

    The decomposition behaviour of CuO is studied at high temperature and high pressure. Experimental pressure and temperature determine the result. In the region of higher temperature and pressure (>=5.5 GPa, >=1400 deg. C), the product is just copper. In the region of lower temperature and pressure (< 5.0 GPa, < 1100 deg. C), CuO does not decompose. Between the two regions, the product is a mixture of Cu and Cu sub 2 O or a mixture of Cu sub 2 O and CuO.

  20. Theory of phonon properties in doped and undoped CuO nanoparticles

    Science.gov (United States)

    Bahoosh, S. G.; Apostolov, A. T.; Apostolova, I. N.; Wesselinowa, J. M.

    2012-07-01

    We have studied the phonon properties of CuO nanoparticles and have shown the importance of the anharmonic spin-phonon interaction. The Raman peaks of CuO nanoparticles shift to lower frequency and become broader as the particle size decreases in comparison with those of bulk CuO crystals owing to size effects. By doping with different ions, in dependence of their radius compared to the host ionic radius the phonon energies ω could be reduced or enhanced. The phonon damping is always enhanced through the ion doping effects.

  1. Exchange bias effect in composites of cuo nanoparticles and nanosilica glass

    Science.gov (United States)

    Ranjan Saha, Dhriti; Kumar Nandi, Arun; Chakravorty, Dipankar

    2014-04-01

    Nanodimensional silica based glass containing iron ions was prepared within the compressed pellet of CuO nanoparicles. The nanocomposite material showed exchange bias effect. This effect arose due to ferromagnetic iron doped CuO phase and antiferromagnetic CuO interface formation within the nanocomposite during the synthesis process. Coercive field as a function of temperature was fitted with Arhenius-Neel equation and extracted blocking temperature was 511 K. The value of effective anisotropy constant for the nanocomposite was found to be 3.64x105 erg/cc.

  2. Transforming from paramagnetism to room temperature ferromagnetism in CuO by ball milling

    Directory of Open Access Journals (Sweden)

    Daqiang Gao

    2011-12-01

    Full Text Available In this work, we experimentally demonstrate that it is possible to induce ferromagnetism in CuO by ball milling without any ferromagnetic dopant. The magnetic measurements indicate that paramagnetic CuO is driven to the ferromagnetic state at room temperature by ball milling gradually. The saturation magnetization of the milled powders is found to increase with expanding the milling time and then decrease by annealing under atmosphere. The fitted X-ray photoelectron spectroscopy results indicate that the observed induction and weaken of the ferromagnetism shows close relationship with the valence charged oxygen vacancies (Cu1+-VO in CuO.

  3. Lattice dynamics of La 2CuO 4 and YBa 2Cu 3O 7

    Science.gov (United States)

    Kimura, Shunji; Sota, Takayuki; Suzuki, Katsuo

    1990-08-01

    We report lattice dynamics calculations of La 2CuO 4 and YBa 2Cu 3O 7 where the mode assignment is fully performed. It is found that frequencies of the in-plane bond streching 0 vibration mode phonons are much higher than those of the bond bending 0 vibration mode phonons in La 2CuO 4 while they are close in YBa 2Cu 3O 7. The bond streching mode phonons and the bond bending mode phonons can couple to electrons near E F in YBa 2Cu 3O 7 but the latter can not in La 2CuO 4.

  4. Density of states in La2CuO4+y

    Science.gov (United States)

    Gold, A.; Ghazali, A.

    1991-06-01

    We describe the excess holes in the CuO2 sheets of La2CuO4+y as a two-dimensional hole gas in a quantum well in the presence of negatively charged impurities. We calculate the density of states with a multiple-scattering approach. We discuss the broadening of the impurity band with increasing y, which corresponds to an increasing hole concentration. The spectral density, which describes for vanishing hole concentration the Fourier transform of the squared wave function, is evaluated. We compare our results with recent measurements of La2CuO4+y with y<0.007.

  5. Evaluation of cytotoxicity, morphological alterations and oxidative stress in Chinook salmon cells exposed to copper oxide nanoparticles.

    Science.gov (United States)

    Srikanth, Koigoora; Pereira, Eduarda; Duarte, Armando C; Rao, Janapala Venkateswara

    2016-05-01

    The current study is aimed to study cytotoxicity and oxidative stress mediated changes induced by copper oxide nanoparticles (CuO NPs) in Chinook salmon cells (CHSE-214). To this end, a number of biochemical responses are evaluated in CHSE-214 cells which are as follows [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] MTT, neutral red uptake (NRU), lactate dehydrogenase (LDH), protein carbonyl (PC), lipid peroxidation (LPO), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione sulfo-transferase (GST), superoxide dismutase (SOD), catalase (CAT), 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS), respectively. The 50% inhibition concentration (IC50) of CuO NPs to CHSE-214 cells after 24 h exposure was found to be 19.026 μg ml(-1). Viability of cells was reduced by CuO NPs, and the decrease was dose dependent as revealed by the MTT and NRU assay. CHSE-214 cells exposed to CuO NPs induced morphological changes. Initially, cells started to detach from the surface (12 h), followed by polyhedric, fusiform appearance (19 h) and finally the cells started to shrink. Later, the cells started losing their cellular contents leading to their death only after 24 h. LDH, PC, LPO, GSH, GPx, GST, SOD, CAT, 8-OHdG and ROS responses were seen significantly increased with the increase in the concentration of CuO NPs when compared to their respective controls. However, significant decrease in GSSG was perceptible in CHSE-214 cells exposed to CuO NPs in a dose-dependent manner. Our data demonstrated that CuO NPs induced cytotoxicity in CHSE-214 cells through the mediation of oxidative stress. The current study provides a baseline for the CuO NPs-mediated cytotoxic assessment in CHSE-214 cells for the future studies.

  6. Visible light induced degradation of methylene blue using CeO{sub 2}/V{sub 2}O{sub 5} and CeO{sub 2}/CuO catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, R. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India); Physics Research Centre, Dhanalakshmi College of Engineering, Dr. V.P.R. Nagar, Manimangalam, Chennai 601301 (India); Joicy, S. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India); Gupta, V.K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Vice Chancellor, Dr. R M L Avadh University Faizabad, UP 224001 (India); Narayanan, V. [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Stephen, A., E-mail: stephen_arum@hotmail.com [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2013-12-01

    In the present study, the nanocatalysts CeO{sub 2}, V{sub 2}O{sub 5}, CuO, CeO{sub 2}/V{sub 2}O{sub 5} and CeO{sub 2}/CuO were synthesized by thermal decomposition method. This method is simple, fast and cost effective compared with other preparation methods. The synthesized catalysts were characterized by different techniques. The XRD and XPS results confirmed the structure and the oxidization states of the nanocomposite materials. DRS results suggested that the prepared CeO{sub 2}/V{sub 2}O{sub 5} and CeO{sub 2}/CuO nanocomposites can generate more electrons and holes under visible light irradiation. The photocatalytic activities of prepared catalysts were evaluated using the degradation of aqueous methylene blue solution as a model compound under visible light irradiation. In addition, the nanocomposite (CeO{sub 2}/V{sub 2}O{sub 5} and CeO{sub 2}/CuO) materials were employed to degrade the textile effluent under visible light condition. - Highlights: • The catalysts were synthesized via a facile thermal decomposition method which was simple, fast and feasible method. • Degradation of methylene blue and real effluent were carried out under visible light. • The photocatalytic activity of nanocomposite materials is higher than that of single phase material.

  7. Absence of dipolar ordering in Co doped CuO

    Science.gov (United States)

    Chaudhary, N. Vijay Prakash; Murthy, J. Krishna; Venimadhav, A.

    2016-12-01

    Polycrystalline CuO samples with Co doping were prepared by solid state method with flowing oxygen condition and examined their structural and multiferroic properties. Structural studies have confirmed single phase monoclinic crystal structure of all samples, however, in Co doped samples a decrease in volume with an increase in monoclinic distortion is found. For pristine sample, temperature dependent magnetization has confirmed two antiferromagnetic (AFM) transitions at 213 K and 230 K and frequency independent dielectric peaks at these AFM transitions suggesting the ferroelectric nature. Magnetization of the Co doped samples has showed a marginal increase in ordering temperature of the high-temperature AFM transition and decrease in low temperature AFM ordering temperature. Further, doped samples have shown giant dielectric constant with no signature of ferroelectricity. The X-ray photoelectric spectroscopy study has revealed multiple valance states for both Co and Cu in the doped samples that simultaneously explain the giant dielectric constant and suppression of ferroelectric order.

  8. Prospects of Emerging Engineered oxide nanomaterials and their Applications

    Directory of Open Access Journals (Sweden)

    Jitendra Gangwar

    2016-06-01

    Full Text Available This review article mainly focused on the recent progress on the synthesis and characterization of emerging artificially engineered nanostructures of oxide materials as well as their potential applications. A fundamental understanding about the state-of-the-art of the synthesis for different size, shape and morphology, which can be tuned to the desired properties of oxide nanomaterials have discussed in details in this review. The present review covers the a wide range of artificially engineered oxide nanomaterials such as cadmium-, cupric-, nickel-, magnesium-, zinc-, titanium-, tin-, aluminium-, and vanadium-oxides and their useful applications in sensors, optical displays, nanofluids and defence.

  9. Ultrafast cooling and heating scenarios for the laser-induced phase transition in CuO

    Science.gov (United States)

    Hellsvik, Johan; Mentink, Johan H.; Lorenzana, José

    2016-10-01

    The multiferroic compound CuO exhibits low-temperature magnetic properties similar to antiferromagnetic iron oxides, while the electronic properties have much more in common with the high-Tc cuprate superconductors. This suggests novel possibilities for the ultrafast optical excitation of magnetism. On the basis of atomistic spin dynamics simulations, we study the effect of phonon-assisted multimagnon absorption and photodoping on the spin dynamics in the vicinity of the first-order phase transition from collinear to spin-spiral magnetic order. Similar as in recent experiments, we find that for both excitations the phase transition can proceed on the picosecond timescale. Interestingly, however, these excitation mechanisms display very distinct dynamics. Following photodoping, the spin system first cools down on subpicosecond time scales, which we explain as an ultrafast magnetocaloric effect. Opposed to this, following phonon-assisted multimagnon excitation, the spin systems rapidly heats up and subsequently evolves to the noncollinear phase even under the influence of isotropic exchange interactions alone.

  10. Electrical and optical properties of hybrid polymer solar cells incorporating Au and CuO nanoparticles

    Directory of Open Access Journals (Sweden)

    Aruna P. Wanninayake

    2015-12-01

    Full Text Available In this study, to enhance the power conversion efficiency (PCE of the polymer solar cells (PSCs, Gold (Au and Copper oxide nanoparticles (CuO-NPs are incorporated into the PEDOT:PSS and P3HT/PCBM active layers respectively. PSCs with a constant CuO-NP content were fabricated with varying amounts of Au NPs. Addition of Au NPs increased the power conversion efficiency by up to 18% compared to a reference cell without Au-NPs. The short circuit current(Jsc of the cells containing 0.06 mg of Au NPs was measured at 7.491 mA/cm2 compared to 6.484 mA/cm2 in the reference cells with 0.6 mg of CuO nanoparticles; meanwhile, the external quantum efficiency(EQE increased from 53% to 61%, showing an enhancement of 15.1%. Au-NPs improved the charge collection at the anode, which results in higher short circuit current and fill factor. However, the strong near field surrounding Au-NPs due to localized surface plasmonic resonance (LSPR effect is not distributed into the active layer. Instead, it is spread horizontally through the PEDOT:PSS layer, thus minimizing the light absorption in the active layer.

  11. Dependence of copper species on the nature of the support for dispersed CuO catalysts.

    Science.gov (United States)

    Gervasini, Antonella; Manzoli, Maela; Martra, Gianmario; Ponti, Alessandro; Ravasio, Nicoletta; Sordelli, Laura; Zaccheria, Federica

    2006-04-20

    Copper catalysts prepared by chemisorption-hydrolysis technique over silica (Cu/Si) and silica-alumina (Cu/SiAl) supports were studied to understand the role of the support on the nature and surface properties of the copper species stabilized on their surfaces. The morphological and surface properties of the copper phases have been characterized by complementary techniques, such as HRTEM, EXAFS-XANES, EPR, XPS, and FTIR. For the FTIR investigation, molecular probes (CO and NO) were also adsorbed on the surfaces to test the reactivity of the copper species. Moreover, the catalytic performances of the two catalysts have been compared in the HC-SCR reaction (NO reduction by C(2)H(4)) performed in highly oxidant conditions. The superior activity and selectivity of the supported silica-alumina catalyst with respect to that supported on silica could be related with the different nature of the copper species stabilized on the two supports, as emerged from the results obtained from the spectroscopic investigations. Small and well-dispersed CuO particles were present on silica, whereas isolated copper ions predominated on silica-alumina, likely in regions rich in alumina that made some exchangeable sites available, as indicated by FTIR spectra of adsorbed CO. The less positive global charge of copper species on Cu/SiAl than in Cu/Si has been confirmed by EPR, XPS, and EXAFS-XANES analyses.

  12. Surfactant-free Synthesis of CuO with Controllable Morphologies and Enhanced Photocatalytic Property

    Science.gov (United States)

    Wang, Xing; Yang, Jiao; Shi, Liuxue; Gao, Meizhen

    2016-03-01

    A green synthesis for nanoleave, nanosheet, spindle-like, rugby-like, dandelion-like and flower-like CuO nanostructures (from 2D to 3D) is successfully achieved through simply hydrothermal synthetic method without the assistance of surfactant. The morphology of CuO nanostructures can be easily tailored by adjusting the amount of ammonia and the source of copper. By designing a time varying experiment, it is verified that the flower- and dandelion-like CuO structures are synthesized by the self-assembly and Ostwald ripening mechanism. Structural and morphological evolutions are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectra. Additionally, the CuO nanostructures with different morphologies could serve as a potential photocatalyst on the photodecomposition of rhodamine B (RhB) aqueous solutions in the presence of H2O2 under visible light irradiation.

  13. Solution-processable carboxylate-capped CuO nanoparticles obtained by a simple solventless method

    Science.gov (United States)

    Estruga, Marc; Roig, Anna; Domingo, Concepción; Ayllón, José A.

    2012-08-01

    Carboxylate-capped CuO nanoparticles were obtained via a simple solventless route, based on the thermal decomposition at 120 °C of solid precursors. The reaction mixture consisted of copper acetate monohydrate, acting as the CuO precursor, and different organic carboxylic acids (lauric, phenylvaleric or 3,6,9-trioxadecanoic acid) used as the capping agent. The proposed method, in good agreement with environmentally friendly practices, produced dry nanoparticles, thereby totally eliminating the need of washing, filtration, or other downstream steps. Transmission electron micrographs show crystalline roughly spherical CuO nanoparticles with average diameters between 3.1 and 5.5 nm depending on the capping ligand. The laurate-capped CuO nanoparticles showed a paramagnetic behaviour at room temperature, while a weak ferromagnetic component was detected at low temperature (acid tail enabled the straightforward dispersibility of nanoparticles in common solvents and assisted in the deposition of the material as thin films.

  14. Ultrasonochemical-Assisted Synthesis of CuO Nanorods with High Hydrogen Storage Ability

    Directory of Open Access Journals (Sweden)

    Gang Xiao

    2011-01-01

    Full Text Available Uniform CuO nanorods with different size have been synthesized in a water-alcohol solution through a fast and facile ultrasound irradiation assistant route. Especially, the as-prepared CuO nanorods have shown a strong size-induced enhancement of electrochemical hydrogen storage performance and exhibit a notable hydrogen storage capacity and big BET surface area. These results further implied that the as-prepared CuO nanorods could be a promising candidate for electrochemical hydrogen storage applications. The observation of the comparison experiments with different concentrations of NaOH, ethanol, CTAB, and HTMA while keeping other synthetic parameters unchanged leads to the morphology and size change of CuO products.

  15. Flower-like CuO synthesized by CTAB-assisted hydrothermal method

    Indian Academy of Sciences (India)

    Yunling Zou; Yan Li; Nan Zhang; Xiulin Liu

    2011-07-01

    Flower-like CuO nanostructures have been synthesized by cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. Here, CuCl2.2H2O was used as copper raw material, and sodium hydroxide was used as precipitate. The resulting CuO powders were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). X-ray diffraction (XRD) pattern exhibited the nanocrystalline nature with monoclinic structure for the as-synthesized nanostructures. FESEM images indicated that the flower-like CuO nanostructures are composed of many interconnected nanosheets in size of several micrometres in length and width and 60–80 nm in thickness. The possible formation mechanism of flower-like CuO nanostructures was discussed.

  16. Azide-Alkyne Huisgen [3+2] Cycloaddition Using CuO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hyunjoon Song

    2012-11-01

    Full Text Available Recent developments in the synthesis of CuO nanoparticles (NPs and their application to the [3+2] cycloaddition of azides with terminal alkynes are reviewed. With respect to the importance of click chemistry, CuO hollow NPs, CuO hollow NPs on acetylene black, water-soluble double-hydrophilic block copolymer (DHBC nanoreactors and ZnO–CuO hybrid NPs were synthesized. Non-conventional energy sources such as microwaves and ultrasound were also applied to these click reactions, and good catalytic activity with high regioselectivity was observed. CuO hollow NPs on acetylene black can be recycled nine times without any loss of activity, and water-soluble DHBC nanoreactors have been developed for an environmentally friendly process.

  17. Single versus repeated applications of CuO and Ag nanomaterials and their effect on soil microflora.

    Science.gov (United States)

    Schlich, Karsten; Beule, Lukas; Hund-Rinke, Kerstin

    2016-08-01

    Nanomaterials enter the terrestrial environment via the repeated application of sludge to soils over many years. The goal of this investigation was to compare the effects of CuO and Ag nanomaterials on soil microorganisms after a single application and after repeated applications ultimately resulting in the same test concentrations. The effect on soil microorganisms was determined using the ammonium oxidation (ISO 15685), enzymatic activity patterns (ISO 22939) and MicroResp™ tests on days 28, 56 and 84. The comparability of single and repeated applications of ion-releasing nanomaterials depended on the test endpoint and duration. No significant differences between single and repeated applications were observed when testing nitrifying microorganisms and exoenzymes, but differences were observed in the substrate-induced respiration test. The three test systems used together provide more comprehensive information about the impact of different nanomaterials on the soil microflora and its diversity.

  18. Copper Oxide Nanoparticles Induce Autophagic Cell Death in A549 Cells

    Science.gov (United States)

    Zhao, Yan; Guo, Feng; Jiang, Chengyu

    2012-01-01

    Metal oxide nanoparticles (NPs) are among the most highly produced nanomaterials, and have many diverse functions in catalysis, environmental remediation, as sensors, and in the production of personal care products. In this study, the toxicity of several widely used metal oxide NPs such as copper oxide, silica, titanium oxide and ferric oxide NPs, were evaluated In vitro. We exposed A549, H1650 and CNE-2Z cell lines to metal oxide NPs, and found CuO NPs to be the most toxic, SiO2 mild toxic, while the other metal oxide NPs had little effect on cell viability. Furthermore, the autophagic biomarker LC3-II significantly increased in A549 cells treated with CuO NPs, and the use of the autophagy inhibitors wortmannin and 3-methyladenin significantly improved cell survival. These results indicate that the cytoxicity of CuO NPs may involve the autophagic pathway in A549 cells. PMID:22916263

  19. Oxides Catalysts of Rare Earth and Transient Metal for Catalytic Oxidation of Benzene

    Institute of Scientific and Technical Information of China (English)

    Liang Kun; Li Rong; Chen Jianjun; Ma Jiantai

    2004-01-01

    The catalysts of CeO2 and the mixture of CeO2 and CuO were prepared, and the activities of these catalysts for completely oxidizing benzene were studied.The results show that the optimal proportion of CeO2/CuO is 6: 4.The highest temperature at which benzene was completely oxidized on these catalysts at different airspeed was measured.Compared these catalysts with the noble metal used, our catalysts had superiority in the resources and the industrial cost besides good activities.

  20. Electronic anisotropy in single-crystal La2CuO4

    Science.gov (United States)

    Cheong, S.-W.; Fisk, Z.; Kwok, R. S.; Remeika, J. P.; Thompson, J. D.; Gruner, G.

    1988-04-01

    We have measured resistivity ρ components both parallel and perpendicular to the Cu-O planes in single-crystalline La2CuO4. Substantial anisotropy, reaching values as large as 103, is observed in the resistivity. The temperature dependence of ρ, together with Hall effect and thermoelectric power measurements, suggests hopping conduction between localized states at low temperatures, with diffusive transport at higher temperatures. These results are in contradistinction to previous reports.

  1. Hydrogen gas detection of Nb2O5 nanoparticle-decorated CuO nanorod sensors

    Science.gov (United States)

    Kheel, Hyejoon; Sun, Gun-Joo; Lee, Jae Kyung; Mirzaei, Ali; Choi, Seungbok; Lee, Chongmu

    2017-01-01

    Pristine and Nb2O5 nanoparticles-decorated CuO nanorods were prepared successfully by a two step process: the thermal evaporation of a Cu foil and the spin coating of NbCl5 solution on CuO nanorods followed by thermal annealing. X-ray diffraction was performed to examine the structure and purity of the synthesized nanoatuctures. Scanning electron microscopy was used to examine the morphology and shape of the nanostuctures. The Nb2O5 nanoparticles-decorated CuO nanorod sensor showed responses of 217.05-862.54%, response times of 161-199 s and recovery times of 163-171 s toward H2 gas with concentrations in a range of 0.5 - 5% at the optimal working temperature of 300 °C. The Nb2O5 nanoparticle-decorated CuO nanorod sensor showed superior sensing performance to the pristine CuO nanorod sensor for the same H2 concentration range. The underlying mechanism for the enhanced hydrogen sensing performance of the CuO nanorods decorated with Nb2O5 nanoparticles is discussed.

  2. Synthesis of CuO nanoflower and its application as a H2O2 sensor

    Indian Academy of Sciences (India)

    Aixia Gu; Guangfeng Wang; Xiaojun Zhang; Bin Fang

    2010-02-01

    CuO three-dimensional (3D) flower-like nanostructures were successfully synthesized by a simple method at 100°C with Cu(NO3)2.3H2O and NH3.H2O for 6 h in the absence of any additives. We found that NH3.H2O amount was critical for CuO morphology evolution. The phase analysis was carried out using X-ray diffraction (XRD) and the result confirmed that the CuO nanoflowers were single-phase. The morphological investigations by field emission scanning electron microscope (FESEM) revealed that the CuO nanoflowers were mono-dispersed in a large quantity and consisted of nanosheets. And then, CuO nanoflowers were successfully used to modify a gold electrode to detect H2O2 with cyclic voltammetry (CV) and amperometric (AC). It was found that CuO nanoflowers may be of great potential for H2O2 electrochemical sensing.

  3. RF sputtered CuO thin films: Structural, optical and photo-catalytic behavior

    Science.gov (United States)

    Al-Ghamdi, Attieh A.; Khedr, M. H.; Shahnawaze Ansari, M.; Hasan, P. M. Z.; Abdel-wahab, M. Sh.; Farghali, A. A.

    2016-07-01

    Nanocrystalline CuO thin films were deposited for 600, 1200 and 1800 s on glass substrate using RF magnetron sputtering technique. The films deposited at room temperature were crystalline and showed Tenorite phase of CuO. The increase in average particle size from 6.67 nm to 9.09 nm and the thickness from 160 nm to 490 nm was observed with the increase in deposition time. The optical band gap was decreased from 2.2 eV to 1.73 eV as the film thickness was increased. The intensity of PL peak showed its maximum for the film deposited for 600 s and minimum for 1800 s. Some unusual emission peaks were observed due to the quantization effect and lattice/surface defects. The CuO films with different thicknesses could be used as photo-catalysts for the degradation of Methylene blue (MB) from the wastewater. Under the exposure of 200 W energy of tungsten lamp, CuO thin films showed excellent photo-catalytic activities. CuO thin film of minimum thickness of around 160 nm responded as a best catalyst for MB degradation. The films were very stable and have a speciality to be recycled without much loss of their photo-catalytic activity. These characteristics have proved the high possibility of commercial applications of CuO thin films in environmental remediation.

  4. Synthesis and characterization of CuO nano particles using precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Malviya, Nitin; Oswal, Nidhi [Department of Applied Physics, Shri G.S. Institute of Technology & Science, Indore – 452003 (India); Carpenter, Gopal; Gupta, Nitish, E-mail: nitish.nidhi75@gmail.com [Department of Applied Chemistry, Shri G.S. Institute of Technology & Science, Indore-452003 (India)

    2015-06-24

    A simple and efficient synthesis of CuO nanoparticles was carried out by precipitation method using copper metal chips as precursor and sodium hydroxide as a stabilizing agent at different calcinations temperatures (100°C, 150°C, and 175°C). The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). XRD indicated monoclinic structure of CuO. SEM indicated the variation in nanostructures with the heating temperatures and FTIR inidcated Cu-O stretching frequencies. The CuO nanostructures with the average particle size of about 16.52 nm were prepared at 100°C for 3 hr. When the calcinations temperature was increased to 150°C and 175°C, CuO nanostructures with the particle size of about 17.41 nm, and 18.44 nm were obtained respectively. This aqueous precipitation method can give a large scale production of CuO nanoparticles easily.

  5. Structure and Catalytic Behavior of CuO-ZrO-CeO2 Mixed Oxides

    Institute of Scientific and Technical Information of China (English)

    王恩过; 陈诵英

    2002-01-01

    The effect of doping CuO on the structure and properties of zirconia-ceria mixed oxide was studied. The results show that addition of CuO decreases the reduction temperature of ceria, and stabilizes the cubic structure of mixed oxides, and enhances catalytic activity of CuO-ZrO-CeO2 mixed oxides for CO oxidation. Increasing ceria content in the mixed oxides can enhance the catalytic activity, but some impurities such as sulfate make catalytic activity falling. There is little effect of calcination temperature on catalytic activities, implying that these catalysts are effective with good thermal stability.

  6. Preparation and Characterization of CuO Nanowires on Carbon Fibers%CuO纳米线在碳纤维上的制备与表征

    Institute of Scientific and Technical Information of China (English)

    张中泉; 刘颖; 肖松涛; 田亮亮; 强成文; 徐金城

    2011-01-01

    通过热氧化镀铜碳纤维,在碳纤维上制备了CuO纳米线.利用热重分析研究了镀铜碳纤维的热氧化过程.通过扫描电子显微镜、X射线衍射以及透射电子显微镜研究了退火温度、时间以及碳纤维对CuO纳米线生长的影响.结果表明,所制备的CuO纳米线为单斜型单晶结构,在碳纤维上制备CuO纳米线的最佳条件为400℃退火2h.并讨论了CuO纳米线在碳纤维上的生长机理.%CuO nanowires were prepared on carbon fibers by thermal oxidizing copper coated carbon fibers.Thermogravimetry analysis was applied to study the oxidation details of copper coated carbon fibers in air. The influence of annealing temperature, time and carbon fibers on the growth of CuO nanowires was investigated by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. CuO nanowires obtained on the carbon fibers were characterized to be monoclinic-type monocrystalline structure. The optimum preparation condition of CuO nanowires on carbon fibers is annealed at 400 ℃ for 2h. The possible mechanism responsible for the growth of nanowires on carbon fibers was also discussed.

  7. Phase and structural transformations in annealed copper coatings in relation to oxide whisker growth

    Energy Technology Data Exchange (ETDEWEB)

    Dorogov, M.V.; Priezzheva, A.N. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Vlassov, S., E-mail: vlassovs@ut.ee [Institute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga (Latvia); Kink, I.; Shulga, E. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Dorogin, L.M. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); ITMO University, Kronverkskiy 49, 197101 Saint Petersburg (Russian Federation); Lõhmus, R. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Tyurkov, M.N.; Vikarchuk, A.A. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Romanov, A.E. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); ITMO University, Kronverkskiy 49, 197101 Saint Petersburg (Russian Federation); Ioffe Physical Technical Institute, RAS, Polytechnicheskaya 26, 194021 Saint Petersburg (Russian Federation)

    2015-08-15

    Highlights: • Coatings prepared by Cu microparticle electrodeposition. • Structural and phase transformation in Cu coatings annealed at 400 °C. • Annealing is accompanied by intensive growth of CuO whiskers. • Layered oxide phases (Cu{sub 2}O and CuO) in the coating are characterized. • Formation of volumetric defects in the coating is demonstrated. - Abstract: We describe structural and phase transformation in copper coatings made of microparticles during heating and annealing in air in the temperature range up to 400 °C. Such thermal treatment is accompanied by intensive CuO nanowhisker growth on the coating surface and the formation of the layered oxide phases (Cu{sub 2}O and CuO) in the coating interior. X-ray diffraction and focused ion beam (FIB) are employed to characterize the multilayer structure of annealed copper coatings. Formation of volumetric defects such as voids and cracks in the coating is demonstrated.

  8. Facile synthesis of magnetic metal (Mn, Fe, Co, and Ni) oxides nanocrystals via a cation-exchange reaction.

    Science.gov (United States)

    Ning, Jiajia; Xiao, Guanjun; Wang, Li; Zou, Bo; Liu, Bingbing; Zou, Guangtian

    2011-02-01

    Magnetic metal (Mn, Fe, Co, and Ni) oxides nanocrystals with small size and uniform size distribution are synthesized via a cation-exchange reaction. Two experimental stages are included in the synthesis of metal oxides nanocrystals. Firstly, Cu(OH)2 decomposes to CuO nanocrystals, induced by free metal cations. Compared to CuO nanocrystals produced without any free metal cation, the free metal cation has an important influence on the shape and size of CuO. Secondly, free metal cations exchange with the Cu2+ cation in the CuO nanocrystals to get Mn3O4, Fe2O3, CoO and NiO nanocrystals by cation-exchange reactions. The magnetic properties of these metal oxides nanocrystals have been investigated, all the nanocrystals are superparamagnetic at room temperature.

  9. A facile approach for cupric ion detection in aqueous media using polyethyleneimine/PMMA core-shell fluorescent nanoparticles

    Science.gov (United States)

    Chen, Jian; Zeng, Fang; Wu, Shuizhu; Su, Junhua; Zhao, Jianqing; Tong, Zhen

    2009-09-01

    A facile approach was developed to produce a dye-doped core-shell nanoparticle chemosensor for detecting Cu2+ in aqueous media. The core-shell nanoparticle sensor was prepared by a one-step emulsifier-free polymerization, followed by the doping of the fluorescent dye Nile red (9-diethylamino- 5H-benzo[alpha] phenoxazine-5-one, NR) into the particles. For the nanoparticles, the hydrophilic polyethyleneimine (PEI) chain segments serve as the shell and the hydrophobic polymethyl methacrylate (PMMA) constitutes the core of the nanoparticles. The non-toxic and biocompatible PEI chain segments on the nanoparticle surface exhibit a high affinity for Cu2+ ions in aqueous media, and the quenching of the NR fluorescence is observed upon binding of Cu2+ ions. This makes the core-shell nanoparticle system a water-dispersible chemosensor for Cu2+ ion detection. The quenching of fluorescence arises through intraparticle energy transfer (FRET) from the dye in the hydrophobic PMMA core to the Cu2+/PEI complexes on the nanoparticle surface. The energy transfer efficiency for PEI/PMMA particles with different diameters was determined, and it is found that the smaller nanoparticle sample exhibits higher quenching efficiency, and the limit for Cu2+ detection is 1 µM for a nanoparticle sample with a diameter of ~30 nm. The response of the fluorescent nanoparticle towards different metal ions was investigated and the nanoparticle chemosensor displays high selectivity and antidisturbance for the Cu2+ ion among the metal ions examined (Na+, K+, Mg2+, Ca2+, Zn2+, Hg2+, Mn2+, Fe2+, Ni2+, Co2+ and Pb2+). This emulsifier-free, biocompatible and sensitive fluorescent nanoparticle sensor may find applications in cupric ion detection in the biological and environmental areas.

  10. Transparent magnetic state in single crystal Nd(1.85)Ce(0.15)CuO(4-y) superconductors

    Science.gov (United States)

    Zuo, F.

    1995-01-01

    Several experimental studies have been reported as evidence of Josephson coupling between the superconducting layers in the highly anisotropic oxide such as the Bi2Sr2CaCu2O8 and Tl2Ba2CuO6 systems. These include the large penetration depth of 100 mu m measured, ac and dc Josephson effects. Recently two critical temperatures corresponding to Josephson coupling in between the layers and the Berezinskii-Kosterlitz-Thouless transition in the ab-plane have been directly observed in the transport measurements. If the field is applied parallel to the superconducting layers, the magnetic excitation is not the conventional Abrikosov vortices, but the Josephson vortices which extend lambda(sub ab) in the c-axis direction and lambda(sub J) = gamma s in the plane (s is the interlayer distance, gamma is the anisotropy constant). Because of the weak screening effect associated with the Josephson vortices, there have been predictions of magnetic transparent states at magnetic field above a characteristic field H(sub J), a behavior distinctively different from that of the type-II superconductors. In this paper, we report an experimental result which illustrates a transition from the Meissner state to the magnetic transparent state in single crystal of Nd(1.85)Ce(0.15)CuO(4-y). Magnetization has been measured as a function of temperature and field in the magnetic field parallel or close to ab-plane geometry. For a fixed magnetic field, the magnetization shows a two-step transition in M(T); for a fixed temperature, the magnetization shows an abrupt change to almost zero value above a characteristic field H(sub J), an indication of magnetic transparent state. The data of magnetization as a function of field clearly deviates from the behavior predicted by the Abrikosov theory for type-II superconductors. Instead, the data fit well into the picture of Josephson decoupling between the CuO2 layers.

  11. Chemical Looping with Copper Oxide as Carrier and Coal as Fuel Boucle chimique pour la combustion du charbon avec un transporteur d’oxygène à base d’oxyde de cuivre

    Directory of Open Access Journals (Sweden)

    Eyring E.M.

    2011-04-01

    Full Text Available A preliminary analysis has been conducted of the performance of a Chemical Looping system with Oxygen Uncoupling (CLOU with copper oxide as the oxygen carrier and coal approximated by carbon as the fuel. The advantages of oxygen uncoupling are demonstrated by providing the energy balances, the circulation rate of oxygen carrier, the oxygen carrier mass loadings, the carbon burnout and oxygen partial pressure in the fuel reactor. Experimental data on the cycling of cuprous oxide to cupric oxide and kinetics for the oxidation and decomposition reactions of the oxides were obtained for use in the analysis. For this preliminary study unsupported oxides were utilized. The decomposition temperatures were rapid at the high temperature of 950°C selected for the fuel reactor. The oxidation kinetics peaked at about 800°C with the decrease in rate at higher temperatures, a decrease which is attributed in the literature to the temperature dependence of the diffusional resistance of the CuO layer surrounding the Cu2O; the diffusion occurs through grain boundaries in the CuO layers and the rate of diffusion decreases as a consequence of growth of CuO grains with increasing temperature. The analysis shows the advantages of CLOU in providing rapid combustion of the carbon with carbon burnout times lower than the decomposition times of the oxygen carrier. For the full potential of CLOU to be established additional data are needed on the kinetics of supported oxides at the high temperatures (>850°C at which oxygen is released by the CuO in the fuel reactor. Une analyse préliminaire a été conduite pour estimer les performances d’un procédé en boucle chimique découplé (CLOU, chemical looping uncoupling pour la combustion du charbon avec un transporteur d’oxygène à base d’oxyde de cuivre. Les avantages de ce système sont démontrés en établissant le bilan énergétique, l’inventaire et le débit de circulation du matériau transportant l

  12. Synthesis and electrochemical properties of SnO2-CuO nanocomposite powders

    Institute of Scientific and Technical Information of China (English)

    MA Ming-you; HE Ze-qiang; XIAO Zhuo-bing; HUANG Ke-long; XIONG Li-zhi; WU Xian-ming

    2006-01-01

    SnO2-CuO nanocomposite powders were prepared by chemical coprecipitation method using SnCl4·5H2O, NH3·H2O and Cu(NO3)2·3H2O as raw materials. The powders were characterized by thermogravimertric(TG) analysis and differential thermal analysis(DTA), X-ray diffraction(XRD), and scanning electron microscope(SEM). The electrochemical properties of SnO2-CuO and undoped SnO2 powders as anode materials of lithium ion batteries were investigated comparatively by galvanostatic charge-discharge experiments and AC impedance. The results show that SnO2-CuO nanocomposite powders with the average particle size of 87 nm can be obtained by this method. The structure of SnO2 does not change with the introduction of CuO, but the average particle size of nano-SnO2 decreases. SnO2-CuO nanocomposite powders show a reversible capacity of 752 mA·h/g and better cycleability compared with nano-SnO2. The capacity retention rates after 60 cycles of nano-SnO2-CuO and SnO2 are 93.6% and 92.0% at the chargedischarge rate of 0.1 C, respectively, which suggests that the introduction of CuO into SnO2 can improve the cycleability of nanoSnO2.

  13. On the low-lying states of CuO

    Science.gov (United States)

    Bagus, P. S.; Nelin, C. J.; Bauschlicher, C. W., Jr.

    1984-01-01

    Self consistent field and correlated wave functions have been computed for the ground and for several low-lying states of CuO. The ground state is X(2)PI and the lowest excited state, at approximately 8,000/cm above X(2)PI, is a previously unidentified 2-sigma(+) state. The separation of these states is compared to that for the similar states of KO and is analysed in terms of integrals between orbitals of the separated free ions. A classification of the states of the molecule based on states of Cu(+) and O(-) which leads to a division into manifolds of states arising from Cu(+) 3d(10) and Cu(+) 3d(9) 4s(1) is considered. It is predicted that the state of the 3d(9) 4s(1) manifold are 10,000 to 30,000/cm above the ground state and assign the observed A2-sigma(+) state at 16,500/cm to this manifold.

  14. CuO and ZnO Nanoparticles Modify Interkingdom Cell Signaling Processes Relevant to Crop Production.

    Science.gov (United States)

    Anderson, Anne J; McLean, Joan E; Jacobson, Astrid R; Britt, David W

    2017-05-12

    As the world population increases, strategies for sustainable agriculture are needed to fulfill the global need for plants for food and other commercial products. Nanoparticle formulations are likely to be part of the developing strategies. CuO and ZnO nanoparticles (NPs) offer potential as fertilizers, as they provide bioavailable essential metals, and as pesticides, because of dose-dependent toxicity. Effects of these metal oxide NPs on rhizosphere functions are the focus of this review. These NPs at doses of ≥10 mg metal/kg change the production of key metabolites involved in plant protection in a root-associated microbe, Pseudomonas chlororaphis O6. Altered synthesis occurs in the microbe for phenazines, which function in plant resistance to pathogens, the pyoverdine-like siderophore that enhances Fe bioavailability in the rhizosphere and indole-3-acetic acid affecting plant growth. In wheat seedlings, reprogramming of root morphology involves increases in root hair proliferation (CuO NPs) and lateral root formation (ZnO NPs). Systemic changes in wheat shoot gene expression point to altered regulation for metal stress resilience as well as the potential for enhanced survival under stress commonly encountered in the field. These responses to the NPs cross kingdoms involving the bacteria, fungi, and plants in the rhizosphere. Our challenge is to learn how to understand the value of these potential changes and successfully formulate the NPs for optimal activity in the rhizosphere of crop plants. These formulations may be integrated into developing practices to ensure the sustainability of crop production.

  15. Safe-by-Design CuO Nanoparticles via Fe-Doping, Cu-O Bond Length Variation, and Biological Assessment in Cells and Zebrafish Embryos.

    Science.gov (United States)

    Naatz, Hendrik; Lin, Sijie; Li, Ruibin; Jiang, Wen; Ji, Zhaoxia; Chang, Chong Hyun; Köser, Jan; Thöming, Jorg; Xia, Tian; Nel, Andre E; Mädler, Lutz; Pokhrel, Suman

    2017-01-24

    The safe implementation of nanotechnology requires nanomaterial hazard assessment in accordance with the material physicochemical properties that trigger the injury response at the nano/bio interface. Since CuO nanoparticles (NPs) are widely used industrially and their dissolution properties play a major role in hazard potential, we hypothesized that tighter bonding of Cu to Fe by particle doping could constitute a safer-by-design approach through decreased dissolution. Accordingly, we designed a combinatorial library in which CuO was doped with 1-10% Fe in a flame spray pyrolysis reactor. The morphology and structural properties were determined by XRD, BET, Raman spectroscopy, HRTEM, EFTEM, and EELS, which demonstrated a significant reduction in the apical Cu-O bond length while simultaneously increasing the planar bond length (Jahn-Teller distortion). Hazard screening was performed in tissue culture cell lines and zebrafish embryos to discern the change in the hazardous effects of doped vs nondoped particles. This demonstrated that with increased levels of doping there was a progressive decrease in cytotoxicity in BEAS-2B and THP-1 cells, as well as an incremental decrease in the rate of hatching interference in zebrafish embryos. The dissolution profiles were determined and the surface reactions taking place in Holtfreter's solution were validated using cyclic voltammetry measurements to demonstrate that the Cu(+)/Cu(2+) and Fe(2+)/Fe(3+) redox species play a major role in the dissolution process of pure and Fe-doped CuO. Altogether, a safe-by-design strategy was implemented for the toxic CuO particles via Fe doping and has been demonstrated for their safe use in the environment.

  16. GC-MS metabolomics analysis of mesenchymal stem cells treated with copper oxide nanoparticles.

    Science.gov (United States)

    Murgia, Antonio; Mancuso, Luisa; Manis, Cristina; Caboni, Pierluigi; Cao, Giacomo

    2016-10-01

    Human exposure to copper oxide (CuO) nanoparticles (NPs) is rapidly increasing and for this reason reliable toxicity test systems are urgently needed. Recently, the acute cytotoxicity of CuO NPs using the new toxicity test based on human bone marrow mesenchymal stem cells (hBMMSCs) has been evaluated. It was shown that CuO NPs are much more toxic when compared to CuO microparticles (MPs). Several studies associate CuO toxicity to a possible alteration of reactive oxygen species (ROS) system. Unluckily, the mechanism that causes the toxicity is still not clear. In this work, the polar metabolite pool of treated cells, at the corresponding IC50 value, for CuO micro and NPs has been studied by gas chromatography coupled to mass spectrometry (GC-MS) and multivariate statistical data analysis. By the same means, differences due to different treatments, on samples, were investigated. Results of discriminant analysis were considered with the aim of finding the relevant metabolites unique for each class. Serine, glyceric acid, and succinic acid were upregulated on samples treated with CuO microparticles, while glutamine was the only discriminant metabolite for the class of samples treated with nanoparticles.

  17. Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

    Directory of Open Access Journals (Sweden)

    François Perreault

    2010-01-01

    Full Text Available Copper oxide nanoparticles (CuO NPs, used in antifouling paints of boats, are released in the environment and can induce toxicity to aquatic organisms. In this report, we used chlorophyll a fluorescence imaging to evaluate CuO NPs toxicity in Lemna gibba. This approach allowed to evaluate the differential effect of CuO NPs on photosynthesis of whole L. gibba plants. Exposure to 0.1 to 0.4 g/L CuO NPs during 48h induced strong inhibition of photosynthetic processes resulting in a decrease of plant growth. By using fluorescence imaging, different photosynthetic parameters were evaluated simultaneously in microplate conditions. Imaging of FO fluorescence yield showed the decrease of leaf photosynthetic active surface for whole plants exposed to CuO NPs. This method showed that CuO NPs inhibited photosystem II maximal, photosystem II operational quantum yields, and photochemical quenching of fluorescence associated with electron transport. Nonphotochemical fluorescence quenching as an indicator of energy dissipation not used in photosynthesis was shown to be increased by the effect of CuO NPs. Such approach in microplate conditions provides synchronous high repetition measurements for numerous plants. This study may give a reliable methodological approach to evaluate toxicity risk of NPs in aquatic ecosystems.

  18. Optical and structural properties of CuO nanofilm: Its diode application

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, Ibrahim Y. [Bingoel University, Faculty of Sciences and Arts, Department of Chemistry, 12000 Bingoel (Turkey); Guellue, O., E-mail: omergullu@gmail.co [Batman University, Faculty of Sciences and Arts, Department of Physics, 72060 Batman (Turkey)

    2010-03-04

    The high crystalline CuO nanofilms have been prepared by spin coating and annealing combined with a simple chemical method. The obtained films have been characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-vis (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy. Structural analysis results demonstrate that the single phase CuO on Si (1 0 0) substrate is of high a crystalline structure with a dominant in monoclinic (1 1 1) orientation. FT-IR results confirm the formation of pure CuO phase. UV-vis absorption measurements indicate that the band gap of the CuO films is 2.64 eV. The PL spectrum of the CuO films shows a broad emission band centered at 467 nm, which is consistent with absorption measurement. Also, Au/CuO/p-Si metal/interlayer/semiconductor (MIS) diodes have been fabricated. Electronic properties (current-voltage) of these structures were investigated. In addition, the interfacial state properties of the MIS diode were obtained. The interface-state density of the MIS diode was found to vary from 6.21 x 10{sup 12} to 1.62 x 10{sup 12} eV{sup -1} cm{sup -2}.

  19. Preparation and characterization of CuO catalyst for the thermolysis treatment of distillery wastewater.

    Science.gov (United States)

    Sharma, Deepak; Prajapati, Abhinesh Kumar; Choudhary, Rumi; Kaushal, Rajesh Kumar; Pal, Dharm; Sawarkar, Ashish N

    2017-08-16

    CuO catalyst was prepared from copper sulfate by alkali precipitation method followed by drying and calcination. Characterization of CuO catalyst using X-ray diffraction, Brunauer-Emmett-Teller, and Barrett-Joyner-Halenda surface area analysis envisaged the effectiveness of CuO as a catalyst for the treatment of biodigester effluent (BDE) emanated from distilleries. The catalytic thermolysis is an efficient advance treatment method for distillery biodigester effluent (BDE). CT treatment of BDE was carried out in a 0.5 dm(3) thermolytic batch reactor using CuO as a catalyst at different pH (1-9), temperatures (80-110°C), and catalyst loadings (1-4 kg/m(3)). With CuO catalyst, a temperature of 110°C, catalyst loading of 4 kg/m(3), and pH of 2 was found to be optimal, providing a maximum reduction in chemical oxygen demand of 65%. The settling characteristics at different temperatures of CT-treated sludge were also presented.

  20. Structural, optical and room-temperature ferromagnetic properties of Fe-doped CuO nanostructures

    Science.gov (United States)

    Mohamed Basith, N.; Judith Vijaya, J.; John Kennedy, L.; Bououdina, M.

    2013-09-01

    Pure CuO and Fe-doped CuO nanostructures with different weight ratios (0.5, 1.0, 1.5, and 2.0 at wt% of Fe) were synthesized via the microwave combustion method. The synthesized samples were characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). XRD patterns refined by the Rietveld method indicated the formation of single-phase monoclinic structure and also confirmed that Fe ions successfully incorporated into CuO crystal lattice by occupying Cu ionic sites. Interestingly, the morphology was found to change considerably from nanoflowers to nano-rod and disk-shaped then to nanoparticles with the variation of Fe content. The optical band gap calculated using DRS was found to be 2.8 eV for pure CuO and increases up to 3.4 eV with increasing ‘Fe’ content. Photoluminescence measurements also confirm these results. The magnetic measurements indicated that the obtained nanostructures are found to be room temperature ferromagnetism (RTF) with an optimum value of saturation magnetization at 2.0 wt% of Fe-doped CuO, i.e. 1.2960×10-3 emu/g.

  1. Toxicity of CuO Nanoparticles to Structure and Metabolic Activity of Allium cepa Root Tips.

    Science.gov (United States)

    Deng, Fei; Wang, Shuling; Xin, Hua

    2016-11-01

    Roots of Allium cepa were exposed to six CuO NPs suspensions (0, 5, 10, 20, 40, 80 mg L(-1)) in this study. Results revealed that with the increase of CuO NPs concentration, the Cu content in roots increased significantly. Compared to control, onion roots treated with CuO NPs (except 5 mg L(-1) suspension) grew slowly after 24 h. The surface of the root cap and meristematic zone were obviously damaged. The apical meristem of roots treated by 10 mg L(-1) and above concentrations stopped division. The nucleus of meristematic cells deformed, and nucleoli number increased. The plasmolysis occurred, and the cell membrane and nuclear membrane fractured. With the increase of CuO NPs concentration, the MDA content increased, and the root activity decreased. When dealt with 80 mg L(-1) CuO NPs for 72 h, onion roots appeared to be corroded.

  2. Chemical Quenching of Positronium in CUO/Al2O3 Catalysts

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-Jun; LIU Zhe-Wen; CHEN Zhi-Quan; WANG Shao-Jie

    2011-01-01

    CuO/Al2O3 catalysts were prepared by mixing CuO and γ-Al2O3 nanopowders. Microstructure and chemical environment of the catalysts are characterized by positron annihilation spectroscopy. The positron annihilation lifetime measurements reveal two long lifetime components τ3 and τ4, which correspond to ortho-positronium (o-Ps) annihilating in microvoids and large pores, respectively. With increasing CuO content from 0 to 40 wt%, both τ4 and its intensity I4 show significant decrease, which indicates quenching effect of o-Ps. The para-positronium (p-Ps) intensities derived from multi-Gaussian fitting of the coincidence Doppler broadening spectra also decreases gradually with increasing CuO content. This excludes the possibility of spin-conversion of positronium. Therefore, the chemical quenching by CuO is probably responsible for the decrease of o-Ps lifetime. Variation in the o-Ps annihilation rate λ4 (1/τ4) as a function of CuO content can be well fitted by a straight line, and the slope of the fitting Jine is (1.83 ± 0.05) × 107 s-1.

  3. 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.

  4. X-ray transmission through nanostructured and microstructured CuO materials

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, M.Z. [Area de Ciencias Tecnologicas, Centro Universitario Franciscano, Rua dos Andradas, 1614, CEP 97010-032 Santa Maria, RS (Brazil); Kuenzel, R., E-mail: roselikunzel@gmail.co [Universidade de Sao Paulo, Instituto de Fisica, Departamento de Fisica Nuclear, Cidade Universitaria, CEP 05508-090 Sao Paulo, SP (Brazil); Okuno, E. [Universidade de Sao Paulo, Instituto de Fisica, Departamento de Fisica Nuclear, Cidade Universitaria, CEP 05508-090 Sao Paulo, SP (Brazil); Levenhagen, R.S. [Universidade Federal de Sao Paulo, Departamento de Ciencias Exatas e da Terra, Rua Arthur Ridel, 275, Jardim Eldorado, CEP 09941-510 Diadema, SP (Brazil); Basegio, T.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Materiais, Avenida Osvaldo Aranha, 99, CEP 90035-190 Porto Alegre, RS (Brazil)

    2011-02-15

    This study presents a comparison of the X-ray transmission through microsized and nanosized materials. For this purpose CuO nanoparticles, with 13.4 nm average grain size, and CuO microparticles, with a mean particle size of 56{mu}m, were incorporated separately to beeswax in a concentration of 5%. Results show that the transmission through the above material plates with microsized and nanosized CuO was almost the same for X-ray beams generated at 60 and 102 kV tube voltages. However, for the radiation beams generated at 26 and 30 kV tube voltages the X-rays are more attenuated by the nanostructured CuO plates by a factor of at least 14%. Results suggest that the difference in the low energy range may be due to the higher number of particles/gram in the plates designed with CuO nanoparticles and due to the grain size effect on the X-ray transmission.

  5. Fine CuO anisotropic nanoparticles supported on mesoporous SBA-15 for selective hydrogenation of nitroaromatics.

    Science.gov (United States)

    Sareen, Shweta; Mutreja, Vishal; Singh, Satnam; Pal, Bonamali

    2016-01-01

    SBA-15 modified with APTMS (3-aminopropyl trimethoxysilane) having pore diameter (∼8 nm) has been synthesized and impregnated with 1-10 wt.% Cu using Cu(NO3)2 as a metal source followed by calcination at 350 °C. As-prepared CuO/ap-SBA-15 powder showed changes in the color from white for bare SBA-15 to light green due to formation of anisotropic CuO nanoparticles that exhibited a characteristic plasmon absorption band at 359 and 747 nm. TEM studies showed a change in the morphology of CuO NPs as a function of increased Cu loading. Moreover, well dispersed CuO nanospheres (∼5-6 nm) and nanorods (aspect ratio ∼11-20 nm) having monoclinic crystal phase were observed within the mesoporous channels of SBA-15. Elemental mapping studies confirmed uniform distribution of CuO nanoparticles on the surface of SBA-15. An increase in surface area was also observed from 694 m(2) g(-1) for SBA-15 to 762 m(2) g(-1) for 10 wt.% Cu loading probably due to the deposition of excess of CuO nanoparticles on the outer siliceous surface. The catalytic activity also increased with Cu loading and 10 wt.% CuO/ap-SBA-15 catalyst displayed the highest catalytic activity for the reduction of m-chloronitrobenzene and m-nitrotoluene with 83% and 100% selectivity for m-chloroaniline and m-aminotoluene respectively.

  6. Highly efficient photocatalytic activity of CuO quantum dot decorated rGO nanocomposites

    Science.gov (United States)

    Dutta, Shibsankar; Das, Kajari; Chakrabarti, Kaushik; Jana, D.; De, S. K.; De, Sukanta

    2016-08-01

    CuO quantum dots (QD) of size 4.5 nm decorated on a rGO sheet to form nanocomposites with different weight percentages via a simple soft chemical route was reported here. Tuning of CuO QD absorption towards the visible region from the UV region in the presence of rGO was also observed. The luminescence of rGO was found to be quenched in rGO-CuO nanocomposites due to charge transfer from the lowest unoccupied molecular orbital of the rGO layer to the conduction band of CuO. Systematic and concise studies of photocatalytic performance towards degradation of methylene blue (MB) dye by CuO QD along with rGO-CuO nanocomposites were presented in this work. A nanocomposite with an equal weight percentage of rGO and CuO degrades almost 99% of MB under irradiation of visible light for 50 min, showing maximum degradation efficiency.

  7. Translocation and biotransformation of CuO nanoparticles in rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Peng, Cheng; Duan, Dechao; Xu, Chen; Chen, Yongsheng; Sun, Lijuan; Zhang, Hai; Yuan, Xiaofeng; Zheng, Lirong; Yang, Yuanqiang; Yang, Jianjun; Zhen, Xiangjun; Chen, Yingxu; Shi, Jiyan

    2015-02-01

    Metal-based nanoparticles (MNPs) may be translocated and biochemically modified in vivo, which may influence the fate of MNPs in the environment. Here, synchrotron-based techniques were used to investigate the behavior of CuO NPs in rice plants exposed to 100 mg/L CuO NPs for 14 days. Micro X-ray fluorescence (μ-XRF) and micro X-ray absorption near edge structure (μ-XANES) analysis revealed that CuO NPs moved into the root epidermis, exodermis, and cortex, and they ultimately reached the endodermis but could not easily pass the Casparian strip; however, the formation of lateral roots provided a potential pathway for MNPs to enter the stele. Moreover, bulk-XANES data showed that CuO NPs were transported from the roots to the leaves, and that Cu (II) combined with cysteine, citrate, and phosphate ligands and was even reduced to Cu (I). CuO NPs and Cu-citrate were observed in the root cells using soft X-ray scanning transmission microscopy (STXM).

  8. The novel transparent sputtered p-type CuO thin films and Ag/p-CuO/n-Si Schottky diode applications

    Directory of Open Access Journals (Sweden)

    A. Tombak

    2015-01-01

    Full Text Available In the current paper, the physical properties and microelectronic parameters of direct current (DC sputtered p-type CuO film and diode have been investigated. The film of CuO as oxide and p-type semiconductor is grown onto glass and n-Si substrates by reactive DC sputtering at 250 °C. After deposition, a post-annealing procedure is applied at various temperatures in ambient. Through this research, several parameters are determined such structural, optical and electrical magnitudes. The thickness of CuO thin films goes from 122 to 254 nm. A (111-oriented cubic crystal structure is revealed by X-ray analysis. The grain size is roughly depending on the post-annealing temperature, it increases with temperature within the 144–285 nm range. The transmittance reaches 80% simultaneously in visible and infrared bands. The optical band gap is varied between 1.99 and 2.52 eV as a result of annealing temperature while the resistivity and the charge carrier mobility decrease with an increase in temperature from 135 to 14 Ω cm and 0.92 to 0.06 cm2/Vs, respectively. The surface of samples is homogenous, bright dots are visible when temperature reaches the highest value. As a diode, Ag/CuO/n-Si exhibits a non-ideal behavior and the ideality factor is about 3.5. By Norde method, the barrier height and the series resistance are extracted and found to be 0.96 V and 86.6 Ω respectively.

  9. Effects of copper oxide nanoparticles on developing zebrafish embryos and larvae

    Directory of Open Access Journals (Sweden)

    Sun Y

    2016-03-01

    Full Text Available Yan Sun, Gong Zhang, Zizi He, Yajie Wang, Jianlin Cui, Yuhao Li Department of Pathology, Key Laboratory of Tumor Microenvironment and Neurovascular Regulation, Nankai University School of Medicine, Tianjin, People’s Republic of China Abstract: Copper oxide nanoparticles (CuO NPs are used for a variety of purposes in a wide range of commercially available products. Some CuO NPs probably end up in the aquatic systems, thus raising concerns about aqueous exposure toxicity, and the impact of CuO NPs on liver development and neuronal differentiation remains unclear. In this study, particles were characterized using Fourier transform infrared spectra, scanning electron microscopy, and transmission electron microscopy. Zebrafish embryos were continuously exposed to CuO NPs from 4 hours postfertilization at concentrations of 50, 25, 12.5, 6.25, or 1 mg/L. The expression of gstp1 and cyp1a was examined by quantitative reverse transcription polymerase chain reaction. The expression of tumor necrosis factor alpha and superoxide dismutase 1 was examined by quantitative reverse transcription polymerase chain reaction and Western blotting. Liver development and retinal neurodifferentiation were analyzed by whole-mount in situ hybridization, hematoxylin–eosin staining, and immunohistochemistry, and a behavioral test was performed to track the movement of larvae. We show that exposure of CuO NPs at low doses has little effect on embryonic development. However, exposure to CuO NPs at concentrations of 12.5 mg/L or higher leads to abnormal phenotypes and induces an inflammatory response in a dose-dependent pattern. Moreover, exposure to CuO NPs at high doses results in an underdeveloped liver and a delay in retinal neurodifferentiation accompanied by reduced locomotor ability. Our data demonstrate that short-term exposure to CuO NPs at high doses shows hepatotoxicity and neurotoxicity in zebrafish embryos and larvae. Keywords: copper oxide nanoparticles

  10. Improved electrochemical performances of CuO nanotube array prepared via electrodeposition as anode for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-10-15

    Graphical abstract: CuO nanotube array electrodes prepared by electrodeposition method exhibit an excellent lithium ion storage ability as anode of Li-ion battery. - Highlights: • CuO nanotube arrays are synthesized by an electrodeposition method. • CuO nanotube shows a high-rate performance. • CuO nanotube shows an excellent cycling performance. - Abstract: We report a facile strategy to prepared CuO nanotube arrays directly grown on Cu plate through the electrodeposition method. The as-prepared CuO nanotubes show a quasi-cylinder nanostructure with internal diameters of ca. ∼100 nm, external diameters of ca. ∼120 nm, and average length of ∼3 μm. As an anode for lithium ion batteries, the electrochemical properties of the CuO nanotube arrays are investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. Due to the unique nanotube nanostructure, the as-prepared CuO electrodes exhibit good rate performance (550 mAh g{sup −1} at 0.1 C and 464 mAh g{sup −1} at 1 C) and cycling performance (581 mAh g{sup −1} at 0.1 C and 538 mAh g{sup −1} at 0.5 C)

  11. Inhibition of anaerobic wastewater treatment after long-term exposure to low levels of CuO nanoparticles.

    Science.gov (United States)

    Otero-González, Lila; Field, Jim A; Sierra-Alvarez, Reyes

    2014-07-01

    CuO nanoparticles (NPs) are released into wastewater due to the widespread use and generation as by-product in various applications (e.g. semiconductor manufacturing). However, information on the behavior and impact of CuO NPs on wastewater treatment processes is very limited. The objective of this study was to evaluate the fate and long-term effect of CuO NPs (average size = 37 nm) on high-rate anaerobic bioreactors. A laboratory-scale upflow anaerobic sludge blanket reactor was operated with a synthetic wastewater containing low concentrations of CuO NPs (1.4 mg Cu L(-1)) and a mixture of volatile fatty acids for 107 days. CuO NPs were largely removed during anaerobic treatment and on the average only 20-32% of the NPs fed to the reactor escaped with the effluent. Scanning electron microscopy and chemical analysis confirmed that CuO NPs were partitioned into the anaerobic sludge. While short-term exposure to CuO NPs (1.4 mg Cu L(-1)) only caused minor inhibition to methanogenesis, extended exposure caused severe toxicity and reduced the acetoclastic methanogenic activity by more than 85%. Moreover, the reactor performance was completely disrupted and the methane production decreased by more than 50%. The study is the first to demonstrate a significant long-term effect of low levels of CuO NPs on methanogenesis.

  12. Insight into the adsorption and dissociation of water over different CuO(111) surfaces: The effect of surface structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jin; Zhang, Riguang, E-mail: zhangriguang@tyut.edu.cn; Wang, Baojun; Ling, Lixia

    2016-02-28

    dissociation compared to the initial dissociation step of H{sub 2}O, OH species is considered as the dominant product on those surfaces. Oxygen-rich surface is the most favorable for the initial dissociation of H{sub 2}O both thermodynamically and kinetically than other two surfaces. The calculated vibrational frequencies for the adsorbed H{sub 2}O and OH species on CuO(111) surfaces can be applied to guide the experimental research of surface vibrational spectroscopy. In addition, our results may provide a basis for the study of H{sub 2}O interaction with other metal oxide surfaces.

  13. Effect of CuO on the Formation Mechanism of Calcium Sulphoaluminate

    Institute of Scientific and Technical Information of China (English)

    MA Suhua; SHEN Xiaohong; HUANG Yeping; ZHONG Baiqian

    2008-01-01

    Calcium sulphoaluminate was prepared with chemical reagents in this paper.The formation mechanism of calcium sulphoaluminate and effect of CuO on the formation mechanism of calcium sulphoaluminate were investigated by the chemical analysis,X-ray diffraction(XRD),and differential scanning calorimetry(DSC).The results show that there are three ways in the formation of calcium sulphoaluminate.CuO can promote the decomposition of calcium carbonate and decrease the formation temperature of calcium sulphoaluminate(C4A3S).When the burning temperature is below 1000℃,the addition of CuO can promote the formation of calcium sulphoaluminate,while CuO can not favor the formation of calcium sulphoaluminate above 1000℃.

  14. Magnetodielectric effect in composites of nanodimensional glass and CuO nanoparticles

    Science.gov (United States)

    Ranjan Saha, Dhriti; Mukherjee, Manabendra; Chakravorty, Dipankar

    2012-11-01

    Nanocomposites comprising CuO particles of average diameter 21 nm coated with 5 nm silica glass containing iron ions were synthesized by a chemical route. An ion exchange reaction at the nanoglass/CuO interface produced iron-doped CuO with copper ion vacancies within the nanoparticles. Room temperature ferromagnetic-like behavior was observed in the nanocomposites. This was ascribed to uncompensated spins contributed by Fe ions with associated copper ion vacancies. A rather high value of magnetodielectric parameter in the range 16-26% depending on the measuring frequency was exhibited by these nanocomposites at a magnetic field of 10 KOe. This was caused by a magnetoresistance of 33% in the iron doped CuO nanoparticles. The experimental results were fitted to the Maxwell-Wagner Capacitor model developed by Catalan. These materials will be suited for magnetic sensor applications.

  15. Synthesis and Structural Study of Sr2CuO3+δ Superconductor under High Pressure

    Institute of Scientific and Technical Information of China (English)

    LIU Qing-Qing; WANG Fu-Ren; LI Feng-Ying; CHEN Liang-Chen; YU Ri-Cheng; JIN Chang-Qing; LI Yan-Chun; LIU Jing

    2008-01-01

    A single-phase Sr2CuO3+δ superconductor is synthesized under high temperature and high pressure, in which oxygen atoms only partially occupy the apical sites next to the CuO2 planes and act as hole-dopants. The superconducting transition temperature with Tcmax = 75 K is achieved in the material. Structure analysis from x-ray powder diffraction data show that this material crystallizes into a K2NiF4 structure with tetragonal unit cell of α = 3.795(3) (A) and c = 12.507(1) (A). Energy-dispersive synchrotron x-ray-diffraction studies at ambient are performed on powder samples of St2CuO3+δ in a diamond-anvil cell at pressure up to 35 GPa. Anisotropic compressibility is found. Pressure-induced isostructural phase transition might exist as revealed by the discontinuous change of crystal cell volume V with pressure.

  16. Electronic structure of CuO2 planes: From insulator to superconductor

    Science.gov (United States)

    Larosa, S.; Vobornik, I.; Zwick, F.; Berger, H.; Grioni, M.; Margaritondo, G.; Kelley, R. J.; Onellion, M.; Chubukov, A.

    1997-07-01

    Using angle-resolved photoemission and linearly polarized synchrotron radiation, we measured the electronic band structure of electronic states of CuO2 plane materials ranging from insulators (Sr2CuO2Cl2) to overdoped superconductors (Bi2Sr2CaCu2O8+x). We report three results: (i) The CuO2 containing insulator possesses a spin-density-wave (SDW) ground state; (ii) there are precursors of the SDW state for underdoped Bi2Sr2CaCu2O8+x; (iii) an extended saddle-point-type van Hove singularity is neither a necessary nor a sufficient condition for a high superconducting transition temperature, Tc.

  17. High performance HTPB-based energetic nanomaterial with CuO nanoparticles.

    Science.gov (United States)

    de la Fuente, José Luis; Mosquera, Gonzalo; París, Rodrigo

    2009-12-01

    This work describes the first example to demonstrate the enhancement of performances of composite highly energetic materials by mean of employing standard CuO nano-powder as burning rate catalyst in comparison to micro-fillers. The solid composite propellants with CuO microparticles are less stable due to oversensitivity to pressure variations, but the nano-structured composite propellant yields high stable burning rates over a broad pressure range. In addition, the incorporation of CuO nanoparticles in the formulations of these energetic materials also improves their combustion and thermal properties, according to the characterization obtained by differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). These results indicate the excellent benefits found in using these nanoparticles as additive for solid rocket propulsion applications.

  18. Structure and magnetic properties of Mn-doped CuO solids

    Institute of Scientific and Technical Information of China (English)

    FAN Chong-fei; PAN Li-qing; ZHU Hao; QIU Hong-mei; WANG Feng-ping; WU Ping; QIU Hong; ZHANG Yue; J. Q. XIAO

    2005-01-01

    The CuO doped with 5%-20% Mn(molar fraction) solids were sintered from CuO and MnO2 powder at high temperature (1 273 K) for 8 h. X-ray diffraction was used to determine the solid crystallinity and to address the formation of secondary phases. It is found that it is difficult to achieve pure Cu1-xMnxO phase using standard solid phase reaction. However, sintering under a pressure of 27.7 MPa significantly reduces the undesirable second phase CuMn2O4, providing a route to achieve pure Cu1-xMnx O phase. SQUID magnetometry was employed to characterize the magnetic properties. Mn-doped CuO presents ferromagnetic characteristics below 70 K. Electrical transport properties were measured in a current-perpendicular-to-plane(CPP) geometry using the PPMS, which suggests variable-range hopping mechanism.

  19. Nonlinear optical properties of laser deposited CuO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen Aiping [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Guang, E-mail: gyang@mail.hust.edu.c [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Long Hua; Li Fang; Li Yuhua [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu Peixiang, E-mail: lupeixiang@mail.hust.edu.c [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2009-06-01

    In this work we investigate the third-order optical nonlinearities in CuO films by Z-scan method using a femtosecond laser (800 nm, 50 fs, 200 Hz). Single-phase CuO thin films have been obtained using pulsed laser deposition technique. The structure properties, surface image, optical transmittance and reflectance of the films were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and UV-vis spectroscopy. The Z-scan results show that laser-deposited CuO films exhibit large nonlinear refractive coefficient, n{sub 2} = - 3.96 x 10{sup -17} m{sup 2}/W, and nonlinear absorption coefficient, {beta} = - 1.69 x 10{sup -10} m/W, respectively.

  20. Growth and humidity sensing properties of plate-like CuO nanostructures

    Science.gov (United States)

    Bayansal, F.; Çetinkara, H. A.; Çankaya, G.

    2014-03-01

    This paper describes a simple, low-temperature and cost-effective liquid-phase method to synthesize homogenous plate-like CuO nanostructures and their sensitivity to humidity. Scanning electron microscopy illustrated that the synthesized CuO nanoplates have thicknesses of ~100 nm. X-ray diffraction measurements showed that the CuO nanostructures have high crystallinity with monoclinic crystal structure preferentially in ? and ? directions. From the temperature-dependant dark electrical resistivity measurements, the ionization energies of the impurity levels and thermal band gap energies of the films are found as 0.30, 0.32 and 1.37, 1.39 for as-synthesized and annealed films, respectively. Gas sensing characteristics of the films were investigated for different concentrations of humidity, isopropyl alcohol, methanol, ethanol, chloroform and acetone vapours. It was found that the sensor is sensitive to humidity but not to the other volatile organic compounds.

  1. Organometallic Synthesis of CuO Nanoparticles: Application in Low-Temperature CO Detection.

    Science.gov (United States)

    Jońca, Justyna; Ryzhikov, Andrey; Palussière, Ségolène; Esvan, Jérome; Fajerwerg, Katia; Menini, Philippe; Kahn, Myrtil L; Fau, Pierre

    2017-08-24

    A metal-organic approach has been employed for the preparation of anisotropic CuO nanoparticles. These nanostructures have been characterized by transmission and high resolution transmission electron microscopy, field-emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The CuO nanoparticles have been deposited as gas-sensitive layers on miniaturized silicon devices. At an operating temperature of 210 °C, the sensors present an optimum response toward carbon monoxide correlated with a fast response (Rn) and short recovery time. A high sensitivity to CO (Rn≈150 %, 100 ppm CO, RH 50 %) is achieved. These CuO nanoparticles serve as a very promising sensing layer for the fabrication of selective CO gas sensors working at a low temperature. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Morphology- and facet-controlled synthesis of CuO micro/nanomaterials and analysis of their lithium ion storage properties

    Science.gov (United States)

    Liu, Xiaodi; Liu, Guangyin; Wang, Lijuan; Li, Yinping; Ma, Yupei; Ma, Jianmin

    2016-04-01

    Hierarchical CuO architectures and monodisperse CuO nanoplates are synthesized via a hydrothermal method with the assistance of ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). The products are characterized by XRD, SEM, TEM, HRTEM, BET, and XPS, and the results indicate that the CuO architectures are composed of nanosheets with exposed (001) facets and the CuO nanoplates are single crystals enclosed by (200) facets. More specially, it is found that [Bmim]Cl serves as an effective template for the synthesis of CuO nanoplates by adsorbing on the (200) planes of monoclinic CuO. When evaluated as anode materials for lithium-ion batteries, CuO architectures possess higher discharge capacity, better cycling stability, and better rate capability than CuO nanoplates. The initial discharge capacity of CuO architectures is 1096 mAh g-1 at a rate of 0.5 C, whereas CuO nanoplates exhibit a lower capacity of 878.4 mAh g-1. Moreover, after 50 cycles, CuO architectures and CuO nanoplates can deliver discharge capacities of 465.6 and 281.6 mAh g-1, respectively.

  3. Low temperature synthesis of seed mediated CuO bundle of nanowires, their structural characterisation and cholesterol detection

    Energy Technology Data Exchange (ETDEWEB)

    Ibupoto, Z.H., E-mail: zafar.hussin.ibupoto@liu.se [Department of Science and Technology, Linköping University, Campus Norrköping, SE-60174 Norrköping (Sweden); Khun, K. [Department of Science and Technology, Linköping University, Campus Norrköping, SE-60174 Norrköping (Sweden); Liu, X. [Department of Physics, Chemistry, and Biology (IFM), Linköping University, 58183 Linköping Sweden (Sweden); Willander, M. [Department of Science and Technology, Linköping University, Campus Norrköping, SE-60174 Norrköping (Sweden)

    2013-10-15

    In this study, we have successfully synthesised CuO bundle of nanowires using simple, cheap and low temperature hydrothermal growth method. The growth parameters such as precursor concentration and time for duration of growth were optimised. The field emission scanning electron microscopy (FESEM) has demonstrated that the CuO bundles of nanowires are highly dense, uniform and perpendicularly oriented to the substrate. The high resolution transmission electron microscopy (HRTEM) has demonstrated that the CuO nanostructures consist of bundle of nanowires and their growth pattern is along the [010] direction. The X-ray diffraction (XRD) technique described that CuO bundle of nanowires possess the monoclinic crystal phase. The surface and chemical composition analyses were carried out with X-ray photoelectron spectroscopy (XPS) technique and the obtained results suggested the pure crystal state of CuO nanostructures. In addition, the CuO nanowires were used for the cholesterol sensing application by immobilising the cholesterol oxidase through electrostatic attraction. The infrared reflection absorption spectroscopy study has also revealed that CuO nanostructures are consisting of only Cu-O bonding and has also shown the possible interaction of cholesterol oxidase with the sharp edge surface of CuO bundle of nanowires. The proposed cholesterol sensor has demonstrated the wide range of detection of cholesterol with good sensitivity of 33.88 ± 0.96 mV/decade. Moreover, the CuO bundle of nanowires based sensor electrode has revealed good repeatability, reproducibility, stability, selectivity and a fast response time of less than 10 s. The cholesterol sensor based on the immobilised cholesterol oxidase has good potential applicability for the determination of cholesterol from the human serum and other biological samples. - Highlights: • This study describes the synthesis of bundle of CuO nanowires by hydrothermal method. • CuO nanostructures exhibit good alignment and

  4. pH-Dependent Antimicrobial Properties of Copper Oxide Nanoparticles in Staphylococcus aureus.

    Science.gov (United States)

    Hsueh, Yi-Huang; Tsai, Ping-Han; Lin, Kuen-Song

    2017-04-08

    The antimicrobial properties of CuO nanoparticles have been investigated, but the underlying mechanisms of toxicity remain the subject of debate. Here, we show that CuO nanoparticles exhibit significant toxicity at pH 5 against four different Staphylococcus aureus (S. aureus) strains, including Newman, SA113, USA300, and ATCC6538. At this pH, but not at pH 6 and 7, 5 mM CuO nanoparticles effectively caused reduction of SA113 and Newman cells and caused at least 2 log reduction, whereas 20 mM killed most strains but not USA300. At 5 mM, the nanoparticles were also found to dramatically decrease reductase activity in SA113, Newman, and ATCC6538 cells, but not USA300 cells. In addition, analysis of X-ray absorption near-edge structure and extended X-ray absorption fine structure confirmed that S. aureus cells exposed to CuO nanoparticles contain CuO, indicating that Cu(2+) ions released from nanoparticles penetrate bacterial cells and are subsequently oxidized intracellularly to CuO at mildly acidic pH. The CuO nanoparticles were more soluble at pH 5 than at pH 6 and 7. Taken together, the data conclusively show that the toxicity of CuO nanoparticles in mildly acidic pH is caused by Cu(2+) release, and that USA300 is more resistant to CuO nanoparticles (NPs) than the other three strains.

  5. Enhanced stability and dissolution of CuO nanoparticles by extracellular polymeric substances in aqueous environment

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Lingzhan; Wang, Chao; Hou, Jun, E-mail: hhuhjyhj@126.com; Wang, Peifang; Ao, Yanhui; Li, Yi; Lv, Bowen; Yang, Yangyang; You, Guoxiang; Xu, Yi [Hohai University, Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education (China)

    2015-10-15

    Stability of engineered nanoparticles in aquatic environment is an essential parameter to evaluate their fate, bioavailability, and potential toxic effects toward living organisms. As CuO NPs enter the wastewater systems, they will encounter extracellular polymeric substances (EPS) from microbial community before directly interacting with bacterial cells. EPS may play an important role in affecting the stability and the toxicity of CuO NPs in aquatic environment. In this study, the influences of flocculent sludge-derived EPS, as well as model protein (BSA) and natural polysaccharides (alginate) on the dissolution kinetics and colloidal stability of CuO NPs were investigated. Results showed that the presence of NOMs strongly suppressed CuO NPs aggregation, confirmed by DLS, zeta potentials, and TEM analysis. The enhanced stability of CuO NPs in the presence of EPS and alginate were attributed to the electrostatic combined with steric repulsion, while the steric-hindrance effect may be the predominant mechanism retarding nano-CuO aggregation for BSA. Higher degrees of copper release were achieved with the increasing concentrations of NOMs. EPS are more effective than alginate and BSA in releasing copper, probably due to the abundant functional groups and the excellent metal-binding capacity. The ratio of free-Cu{sup 2+}/total dissolved Cu significantly decreased in the presence of EPS, indicating that EPS may affect the speciation and Cu bioavailability in aqueous environment. These results may be important for assessing the fate and transport behaviors of CuO NPs in the environment as well as for setting up usage regulation and treatment strategy.

  6. Local and CMOS-compatible synthesis of CuO nanowires on a suspended microheater on a silicon substrate.

    Science.gov (United States)

    Zhang, Kaili; Yang, Yang; Pun, E Y B; Shen, Ruiqi

    2010-06-11

    This paper presents the synthesis of CuO nanowires using a localized thermal heating method in ambient air. It employs local heat sources defined in micro-resistive heaters fabricated by a standard polysilicon-based surface micromachining process instead of a global furnace heating. Since the synthesis is performed globally at room temperature, the presented process is compatible with standard CMOS. The synthesized CuO nanowires are characterized by scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy. It is found that this approach provides a simple method to locally synthesize suspended CuO nanowires on polysilicon microbridges on silicon substrates, thus allowing for integration of CuO nanowires into silicon-based devices. It provides a significant step towards the process integration of CuO nanowires with MEMS to realize functional devices.

  7. Effect of precipitating agent NaOH on the preparation of copper oxide nanostructures for electrochemical applications

    OpenAIRE

    Balasubramaniam, M.; S Balakumar

    2016-01-01

    Copper oxide (CuO) nanostructures with different concentrations of sodium hydroxide for electrochemical applications such as supercapacitors have been synthesized using a simple and low-cost precipitation method. X-ray diffraction pattern confirmed the formation of CuO nanostructures without any impurities and further confirmed its highly crystalline, single phase, monoclinic nature. UV-diffuse reflectance spectral (UVDRS) studies provided the absorption edge of the material and the estimated...

  8. Application of Sonication and Microwave Irradiation to Boost Continuous Fabrication of the Copper(II Oxide Sub-Micron Particles

    Directory of Open Access Journals (Sweden)

    Grzegorz Dzido

    2015-03-01

    Full Text Available Viability of the continuous-flow synthesis of rhomboidal copper(II oxide (CuO micro- and nanonoparticles was demonstrated. It has been shown that ultrasonic mixing of reactants, in the stage of Cu(OH2 synthesis, followed by microwave irradiation of the resulting suspension, gives very fine particles of CuO at high yield and within minutes. Near optimal parameters for the synthesis of fine particles in the continuous reactor were determined.

  9. Physical and electrical properties of copper oxide doped bismuth borate glasses

    Science.gov (United States)

    Dhiman, R. L.; Kundu, Virender Singh; Arora, Susheel; Maan, A. S.

    2013-06-01

    The role of CuO on the physical and electrical properties in x CuO.(25-x)Bi2O3.75B2O3;(5≤x≤20) glass system has been investigated. The glasses were prepared by normal melt quench technique. The density and molar volume of the glasses decreases with increase in CuO (mol %). The dc conductivity was measured in the temperature range 413-513 K. The conduction mechanism in these glasses was discussed in terms of small polaron hopping (SPH) theory proposed by Mott. The activation energy is found to decrease with increasing copper oxide content. The dc conductivity increases with increase in CuO content and ranging from 6.02×10-12 (Ωm)-1 to 1.096×10-10 (Ωm)-1 at 450K.

  10. SILAC-based quantitative proteomic analysis of human lung cell response to copper oxide nanoparticles.

    Science.gov (United States)

    Edelmann, Mariola J; Shack, Leslie A; Naske, Caitlin D; Walters, Keisha B; Nanduri, Bindu

    2014-01-01

    Copper (II) oxide (CuO) nanoparticles (NP) are widely used in industry and medicine. In our study we evaluated the response of BEAS-2B human lung cells to CuO NP, using Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics and phosphoproteomics. Pathway modeling of the protein differential expression showed that CuO NP affect proteins relevant in cellular function and maintenance, protein synthesis, cell death and survival, cell cycle and cell morphology. Some of the signaling pathways represented by BEAS-2B proteins responsive to the NP included mTOR signaling, protein ubiquitination pathway, actin cytoskeleton signaling and epithelial adherens junction signaling. Follow-up experiments showed that CuO NP altered actin cytoskeleton, protein phosphorylation and protein ubiquitination level.

  11. SILAC-based quantitative proteomic analysis of human lung cell response to copper oxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Mariola J Edelmann

    Full Text Available Copper (II oxide (CuO nanoparticles (NP are widely used in industry and medicine. In our study we evaluated the response of BEAS-2B human lung cells to CuO NP, using Stable isotope labeling by amino acids in cell culture (SILAC-based proteomics and phosphoproteomics. Pathway modeling of the protein differential expression showed that CuO NP affect proteins relevant in cellular function and maintenance, protein synthesis, cell death and survival, cell cycle and cell morphology. Some of the signaling pathways represented by BEAS-2B proteins responsive to the NP included mTOR signaling, protein ubiquitination pathway, actin cytoskeleton signaling and epithelial adherens junction signaling. Follow-up experiments showed that CuO NP altered actin cytoskeleton, protein phosphorylation and protein ubiquitination level.

  12. Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application

    Directory of Open Access Journals (Sweden)

    Thekkae Padil VV

    2013-02-01

    Full Text Available Vinod Vellora Thekkae Padil, Miroslav ČerníkLaboratory of Chemical Remediation Processes, Institute for Nanomaterials, Advanced Technology and Innovation, Technical University of Liberec, Studentská 1402/2, Liberec, Czech RepublicBackground: Copper oxide (CuO nanoparticles have attracted huge attention due to catalytic, electric, optical, photonic, textile, nanofluid, and antibacterial activity depending on the size, shape, and neighboring medium. In the present paper, we synthesized CuO nanoparticles using gum karaya, a natural nontoxic hydrocolloid, by green technology and explored its potential antibacterial application.Methods: The CuO nanoparticles were synthesized by a colloid-thermal synthesis process. The mixture contained various concentrations of CuCl2 · 2H2O (1 mM, 2 mM, and 3 mM and gum karaya (10 mg/mL and was kept at 75°C at 250 rpm for 1 hour in an orbital shaker. The synthesized CuO was purified and dried to obtain different sizes of the CuO nanoparticles. The well diffusion method was used to study the antibacterial activity of the synthesized CuO nanoparticles. The zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration were determined by the broth microdilution method recommended by the Clinical and Laboratory Standards Institute.Results: Scanning electron microscopy analysis showed CuO nanoparticles evenly distributed on the surface of the gum matrix. X-ray diffraction of the synthesized nanoparticles indicates the formation of single-phase CuO with a monoclinic structure. The Fourier transform infrared spectroscopy peak at 525 cm−1 should be a stretching of CuO, which matches up to the B2u mode. The peaks at 525 cm−1 and 580 cm−1 indicated the formation of CuO nanostructure. Transmission electron microscope analyses revealed CuO nanoparticles of 4.8 ± 1.6 nm, 5.5 ± 2.5 nm, and 7.8 ± 2.3 nm sizes were synthesized with various concentrations of CuCl2 · 2H2O (1 mM, 2 mM, and

  13. Controlled Growth of Copper Oxide Nano-Wires through Direct Oxidation

    Science.gov (United States)

    Hilman, Joann; Neupane, Ravi; Yost, Andrew J.; Chien, Teyu

    Copper oxides, both Cu2O and CuO, have many applications in solar cells, sensors, and nano-electronics. The properties of the copper oxides are further influenced by the dimension of the materials, especially when made in nanoscale. In particular, the properties of the copper oxide nanowires could be tuned by their structures, lengths, and widths. While several methods have been reported to grow nanowires, direct oxidation is arguably the most economical one. This research examines the effects of oxidization duration and temperature in dry air environment on the development of copper oxide nanowires in order to achieve cost effective controllable growth. Using the direct oxidation method in dry air we have demonstrated growth of CuO nano-wires at temperatures as low as 300 °C and as short as 1hr. Furthermore we have observed that the lengths and diameters of the CuO NWs can be controlled by the duration and temperature of the oxidation process. WY NASA Space Grant Consortium.

  14. Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes

    Directory of Open Access Journals (Sweden)

    Seo Seung-Deok

    2011-01-01

    Full Text Available Abstract In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO nanodiscs through dehydrogenation of 1-dimensional Cu(OH2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

  15. Comparison of stripe modulations in La1.875Ba0.125CuO4 and La1.48Nd0.4Sr0.12CuO4

    Science.gov (United States)

    Wilkins, S. B.; Dean, M. P. M.; Fink, Jörg; Hücker, Markus; Geck, J.; Soltwisch, V.; Schierle, E.; Weschke, E.; Gu, G.; Uchida, S.; Ichikawa, N.; Tranquada, J. M.; Hill, J. P.

    2011-11-01

    We report combined soft and hard x-ray scattering studies of the electronic and lattice modulations associated with stripe order in La1.875Ba0.125CuO4 and La1.48Nd0.4Sr0.12CuO4. We find that the amplitude of both the electronic modulation of the hole density and the strain modulation of the lattice is significantly larger in La1.875Ba0.125CuO4 than in La1.48Nd0.4Sr0.12CuO4 and is also better correlated. The in-plane correlation lengths are isotropic in each case; for La1.875Ba0.125CuO4, ξhole=255±5 Å, whereas for La1.48Nd0.4Sr0.12CuO4, ξhole=111±7 Å. We find that the modulations are temperature independent in La1.875Ba0.125CuO4 in the low temperature tetragonal phase. In contrast, in La1.48Nd0.4Sr0.12CuO4, the amplitude grows smoothly from zero, beginning 13 K below the LTT phase transition. We speculate that the reduced average tilt angle in La1.875Ba0.125CuO4 results in reduced charge localization and incoherent pinning, leading to the longer correlation length and enhanced periodic modulation amplitude.

  16. Synthesis of High-Density Poinsettia-Like Microstructure of CuO by the Hydrothermal Method and Its Ethanol Sensing Properties

    Science.gov (United States)

    Hien, Vu Xuan; Minh, Vu Duy; Phuoc, Luong Huu; Vuong, Dang Duc; Heo, Young-Woo; Chien, Nguyen Duc

    2017-06-01

    Highly uniform and dense poinsettia-like microstructures of CuO were synthesized by a facile hydrothermal method. The effect of the treatment time on the growth of the CuO microstructures was investigated. The CuO microflowers with diameters in the range 3-5 μm were composed of many interconnected nanoleaves (1-2 μm in diameter and 20-30 nm in thickness). A plausible growth mechanism for the formation of the CuO microstructures has been proposed and discussed. In addition, the ethanol sensing properties of the CuO microflowers were characterized at 150-350°C. The poinsettia-like microstructures of CuO exhibited better response to ethanol when compared to the sensing properties of the CuO nanoleaves. The sensing mechanism based on the models of carrier transport and leaf-to-leaf contact has been proposed and discussed.

  17. In-plane optical response of $Bi_{2}Sr_{2}CuO_{6}$

    NARCIS (Netherlands)

    Tsvetkov, A. A.; Schützmann, J.; Marel, D. van der

    1997-01-01

    Published in: Phys. Rev. B 55 (1997) 14152 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We report on infrared reflectivity measurements of the $ab$-plane response of superconducting Bi$_2$Sr$_2$CuO$_6$ single crystals. The frequency dependent conductivity has a

  18. Solution-processable carboxylate-capped CuO nanoparticles obtained by a simple solventless method

    Energy Technology Data Exchange (ETDEWEB)

    Estruga, Marc [Universitat Autonoma de Barcelona, Department of Chemistry (Spain); Roig, Anna; Domingo, Concepcion [CSIC, Institut de Ciencia de Materials de Barcelona (Spain); Ayllon, Jose A., E-mail: joseantonio.ayllon@uab.es [Universitat Autonoma de Barcelona, Department of Chemistry (Spain)

    2012-08-15

    Carboxylate-capped CuO nanoparticles were obtained via a simple solventless route, based on the thermal decomposition at 120 Degree-Sign C of solid precursors. The reaction mixture consisted of copper acetate monohydrate, acting as the CuO precursor, and different organic carboxylic acids (lauric, phenylvaleric or 3,6,9-trioxadecanoic acid) used as the capping agent. The proposed method, in good agreement with environmentally friendly practices, produced dry nanoparticles, thereby totally eliminating the need of washing, filtration, or other downstream steps. Transmission electron micrographs show crystalline roughly spherical CuO nanoparticles with average diameters between 3.1 and 5.5 nm depending on the capping ligand. The laurate-capped CuO nanoparticles showed a paramagnetic behaviour at room temperature, while a weak ferromagnetic component was detected at low temperature (<40 K). It was also proved that the chemical structure of the carboxylic acid tail enabled the straightforward dispersibility of nanoparticles in common solvents and assisted in the deposition of the material as thin films.

  19. Spin Dynamics of $La_{2}CuO_{4}$ and the Two-Dimensional Heisenberg Model

    CERN Document Server

    Sandvik, A W; Barbara, U C S; Barbara, UC Santa

    1994-01-01

    The spin-lattice relaxation rate $1/T_1$ and the spin echo decay rate $1/T_{2G}$ for the 2D Heisenberg model are calculated using quantum Monte Carlo and maximum entropy analytic continuation. The results are compared to recent experiments on La$_2$CuO$_4$, as well as predictions based on the non-linear $\\sigma$-model.

  20. Room temperature ferromagnetism in Fe-doped CuO nanoparticles.

    Science.gov (United States)

    Layek, Samar; Verma, H C

    2013-03-01

    The pure and Fe-doped CuO nanoparticles of the series Cu(1-x)Fe(x)O (x = 0.00, 0.02, 0.04, 0.06 and 0.08) were successfully prepared by a simple low temperature sol-gel method using metal nitrates and citric acid. Rietveld refinement of the X-ray diffraction data showed that all the samples were single phase crystallized in monoclinic structure of space group C2/c with average crystallite size of about 25 nm and unit cell volume decreases with increasing iron doping concentration. TEM micrograph showed nearly spherical shaped agglomerated particles of 4% Fe-doped CuO with average diameter 26 nm. Pure CuO showed weak ferromagnetic behavior at room temperature with coercive field of 67 Oe. The ferromagnetic properties were greatly enhanced with Fe-doping in the CuO matrix. All the doped samples showed ferromagnetism at room temperature with a noticeable coercive field. Saturation magnetization increases with increasing Fe-doping, becomes highest for 4% doping then decreases for further doping which confirms that the ferromagnetism in these nanoparticles are intrinsic and are not resulting from any impurity phases. The ZFC and FC branches of the temperature dependent magnetization (measured in the range of 10-350 K by SQUID magnetometer) look like typical ferromagnetic nanoparticles and indicates that the ferromagnetic Curie temperature is above 350 K.

  1. Magnetodielectric effect in composites of nanodimensional glass and CuO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan Saha, Dhriti [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Kolkata- 700032 (India); Mukherjee, Manabendra [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF BidhanNagar, Kolkata- 700064, India. (India); Chakravorty, Dipankar, E-mail: mlsdc@iacs.res.in [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Kolkata- 700032 (India)

    2012-11-15

    Nanocomposites comprising CuO particles of average diameter 21 nm coated with 5 nm silica glass containing iron ions were synthesized by a chemical route. An ion exchange reaction at the nanoglass/CuO interface produced iron-doped CuO with copper ion vacancies within the nanoparticles. Room temperature ferromagnetic-like behavior was observed in the nanocomposites. This was ascribed to uncompensated spins contributed by Fe ions with associated copper ion vacancies. A rather high value of magnetodielectric parameter in the range 16-26% depending on the measuring frequency was exhibited by these nanocomposites at a magnetic field of 10 KOe. This was caused by a magnetoresistance of 33% in the iron doped CuO nanoparticles. The experimental results were fitted to the Maxwell-Wagner Capacitor model developed by Catalan. These materials will be suited for magnetic sensor applications. - Highlights: Black-Right-Pointing-Pointer Synthesis of nanocomposites comprising CuO nanoparticles and interfacial nanodimensional silica glass. Black-Right-Pointing-Pointer These exhibited ferromagnetic-like behavior at room temperature. Black-Right-Pointing-Pointer High value of magnetodielectric parameter was obtained in the range 16-26% depending on the measuring frequency. Black-Right-Pointing-Pointer The Maxwell-Wagner Capacitor model of Catalan was used satisfactorily to explain the results.

  2. Theory of phonon properties in doped and undoped CuO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bahoosh, S.G. [Institute of Physics, Martin-Luther-University, D-06099 Halle (Germany); Apostolov, A.T. [University of Architecture, Civil Engineering and Geodesy Faculty of Hydrotechnics, Department of Physics, 1, Hristo Smirnenski Blvd., 1046 Sofia (Bulgaria); Apostolova, I.N. [University of Forestry, Faculty of Forest Industry, 10, Kl. Ohridsky Blvd., 1756 Sofia (Bulgaria); Wesselinowa, J.M., E-mail: julia@phys.uni-sofia.bg [University of Sofia, Department of Physics, 5 J. Bouchier Blvd., 1164 Sofia (Bulgaria)

    2012-07-02

    We have studied the phonon properties of CuO nanoparticles and have shown the importance of the anharmonic spin–phonon interaction. The Raman peaks of CuO nanoparticles shift to lower frequency and become broader as the particle size decreases in comparison with those of bulk CuO crystals owing to size effects. By doping with different ions, in dependence of their radius compared to the host ionic radius the phonon energies ω could be reduced or enhanced. The phonon damping is always enhanced through the ion doping effects. -- Highlights: ► The phonon properties of CuO nanoparticles are studied using a miscroscopic model. ► The phonon energy decreases whereas the damping increases with decreasing of particle size. ► It is shown the importance of the anharmonic spin–phonon interaction. ► By doping with RE-ions the phonon energy is reduced, whereas with TM-ions it is enhanced. ► The phonon damping is always enhanced through the ion doping effects.

  3. Green synthesis of CuO nanoparticles using Cassia auriculata leaf ...

    African Journals Online (AJOL)

    Methods: CuO NPs were prepared by heating a mixture of 10 mL of 0.01 M CuSO4 ... Results: The gradual change in color of the reaction solution from brownish yellow to ... variety of applications, including in catalysts, gas .... that the surface charge and size distribution play .... in providing the funds and lab facilities for this.

  4. CuO nanorods/graphene nanocomposites for high-performance lithium-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi; Zhao, Jun; Shan, Wanfei; Xia, Xinbei; Xing, Lili; Xue, Xinyu, E-mail: xuexinyu@mail.neu.edu.cn

    2014-03-25

    Highlights: • CuO/GNS nanocomposites are synthesized by a hydrothermal method. • CuO/GNSs as LIB anodes exhibit much higher cyclability and capacity than CuO nanostructures. • Such excellent performances can be attributed to the synergistic effect between CuO and GNSs. -- Abstract: CuO/graphene nanocomposites are synthesized by a hydrothermal method, and their application as anodes of lithium-ion batteries has been investigated. CuO nanorods are uniformly coating on the surface of graphene nanosheets. CuO/graphene nanocomposites exhibit high cyclability and capacity. After 50 cycles, the capacity can maintain at 692.5 mA h g{sup −1} at 0.1 C rate (10 h per half cycle). Such a high performance can be attributed to the synergistic effect between graphene nanosheets and CuO nanorods. The present results indicate that CuO/graphene nanocomposites have potential applications in the anodes of lithium-ion battery.

  5. In-plane optical response of $Bi_{2}Sr_{2}CuO_{6}$

    NARCIS (Netherlands)

    Tsvetkov, A. A.; Schützmann, J.; Marel, D. van der

    1997-01-01

    Published in: Phys. Rev. B 55 (1997) 14152 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We report on infrared reflectivity measurements of the $ab$-plane response of superconducting Bi$_2$Sr$_2$CuO$_6$ single crystals. The frequency dependent conductivity has a

  6. Oxygen Isotope Effect and Structural Phase Transitions in La2CuO4-Based Superconductors.

    Science.gov (United States)

    Crawford, M K; Farneth, W E; McCarronn, E M; Harlow, R L; Moudden, A H

    1990-12-07

    The oxygen isotope effect on the superconducting transition temperature (alpha(o)) varies as a function of x in La2-xSrxCuO(4) and La2-xBaxCuO(4), with the maximum alpha(o) values (alpha(o) >/= 0.5) found for x near 0.12. This unusual x dependence implies that the isotope effect is influenced by proximity to the Abma --> P4(2)/ncm structural phase transition in these systems. Synchrotron x-ray difaction measurements reveal little change in lattice parameters or orthorhombicity due to isotope exchange in strontium-doped materials where alpha(o) > 0.5, eliminating static structural distortion as a cause of the large isotope effects. The anomalous behavior of alpha(o) in both strontium- and barium-doped materials, in combination with the previously discovered Abma --> P4(2)/ncm structural phase-transition in La(1.88)B(0.12)CuO(4), suggests that an electronic contribution to the lattice instability is present and maximizes at approximately 1/8 hole per copper atom. These observations indicate a dose connection between hole doping of the Cu-O sheets, tilting instabilities of the CuO(6) octahedra, and superconductivity in La(2)CuO(4)-based superconductors.

  7. Slave Boson Description of CuO2 Planes of the High-Temperature Superconductors

    Science.gov (United States)

    Mrkonjic, Ivana; Barisic, Slaven

    Slave-boson mean-field calculation is carried out analytically for doped CuO2 conduction planes, described by the extended Emery model which is parameterized by Cu-O charge transfer energy Δpd, Cu-O hopping t0, O-O hopping t' and Coulomb repulsion U localized on Cu site, taken as infinite. At zero doping δ, finite small t' expands the range of stability of the covalent, conducting state, characterized by renormalized band parameters Δpf and t, on the expense of insulating t=0 state, which, however, remains stable at larger Δpd. For sufficiently large Δpd, Δpf saturates at 4|t'|. Finite doping suppresses the insulating state nearly symmetrically with respect to its sign. The regime with Δpf close to 4|t'| fits remarkably well ARPES spectra of Y123, Bi2212 and LSCO, and, in the latter case, explains the observed strong doping-dependence of the effective Cu-O hopping.

  8. Magnetic fluctuations in La1.95Ba0.05CuO4

    DEFF Research Database (Denmark)

    Hayden, S.M.; Aeppli, G.; Mook, H.;

    1991-01-01

    Neutron-scattering and resistivity experiments on single crystals of La1.95Ba0.05CuO4 are described. On warming to as high as 250 K, the correlation length does not change, and the temperature dependence of the generalized susceptibility chi(Q, omega) is due solely to the temperature dependence o...

  9. Legionella pneumophila transcriptional response following exposure to CuO nanoparticles

    Science.gov (United States)

    Copper ions are an effective antimicrobial agent used to control Legionnaires’ disease and Pontiac fever arising from institutional drinking water systems. Here we present data on an alternative bactericidal agent, CuO nanoparticles (CuO-NPs), and test its efficacy at three conce...

  10. Polymer-Controlled Growth of CuO Nanodiscs in the Mild Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    PENG Yin; LIU Zhengyin; YANG Zihui

    2009-01-01

    CuO nanodiscs have been synthesized on a large scale by a facile solution-based method using polymers as crystal growth modifiers. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and high resolu-tion transmission electron microscopy (HRTEM) were carded out to characterize the structures and morphologies of the obtained products. The effects of reaction temperature, concentrations of polyacrylamide (PAM) and reac-tants on the morphology and size of the product were studied. The results revealed that the CuO nanodisc had sin-gle-crystal monoclinic structures, and grew along (002) and (110) planes. Experimental conditions had all influence on the shape and size of the final products, but polymer PAM played the key role in formation of the CuO nanodisc.A possible growth mechanism of the CuO nanostructures based on typical polymer-crystal interactions in a mild aqueous solution was given. Polymer-directed crystal growth may provide promising routes to rational synthesis of various ordered inorganic and inorganic-organic hybrid materials with complex forms and structural specialization.

  11. Use of Vegetable Waste Extracts for Controlling Microstructure of CuO Nanoparticles: Green Synthesis, Characterization, and Photocatalytic Applications

    Directory of Open Access Journals (Sweden)

    Hameed Ullah

    2017-01-01

    Full Text Available Chemical syntheses involve either hazardous reactants or byproducts which adversely affect the environment. It is, therefore, desirable to develop synthesis processes which either do not involve hazardous reactants or consume all the reactants giving no byproducts. We have synthesized CuO nanoparticles (NPs adhering to some of the principles of green chemistry. The CuO NPs have been synthesized exploiting extracts of vegetable wastes, that is, Cauliflower waste and Potatoes and Peas peels. The extracts were aimed to work as capping agents to get control over the microstructure and morphology of the resulting CuO NPs. The green synthesized CuO NPs were characterized to explore the microstructure, morphology, optical bandgaps, and photocatalytic performances. XRD revealed that the CuO NPs of all the samples crystallized in a single crystal system, that is, monoclinic. However, the morphologies and the optical bandgaps energies varied as a function of the extract of vegetable waste. Similarly, the CuO NPs obtained through different extracts have shown different photocatalytic activities. The CuO NPs produced with extract of Cauliflower have shown high degradation of MB (96.28% compared to obtained with Potatoes peels (87.37% and Peas peels (79.11%.

  12. Effects of CuO Nanoparticles on Microstructure, Physical, Mechanical and Thermal Properties of Self-Compacting Cementitious Composites

    Institute of Scientific and Technical Information of China (English)

    Ali Nazari; Shadi Riahi

    2011-01-01

    In the present study, split tensile strength of self-compacting concrete with different amount of CuO nanoparticles has been investigated. CuO nanoparticles with the average particle size of 15 nm were added partially to self compacting concrete and split tensile strength of the specimens has been measured. The results indicate that CuO nanoparticles are able to improve the split tensile strength of self compacting concrete and recover the negative effects of polycarboxylate superplasticizer on split tensile strength. CuO nanoparticle as a partial replacement of cement up to 4 wt% could accelerate C-S-H gel formation as a result of increased crystalline Ca(OH)2 amount at the early ages of hydration. The increase of the CuO nanoparticles more than 4 wt% causes the decrease of the split tensile strength because of unsuitable dispersion of nanoparticles in the concrete matrix. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of related peaks to hydrated products in X-ray diffraction (XRD) results all also indicate that CuO nanoparticles up to 4 wt% could improve the mechanical and physical properties of the specimens. Finally, CuO nanoparticles could improve the pore structure of concrete and shift the distributed pores to harmless and few-harm pores.

  13. Novel β-C3N4/CuO nanoflakes: facile synthesis and unique photocatalytic performance

    Science.gov (United States)

    Zou, Lan-Rong; Huang, Gui-Fang; Li, Dong-Feng; Tian, Qing-Nan; Yang, Ke; Si, Yuan; Chang, Shengli; Zhang, Xue-Ao; Huang, Wei-Qing

    2017-09-01

    For the first time, novel β-C3N4/CuO composites with superior photocatalytic activity are successfully fabricated via a facile reflux method followed by a thermal process. The morphologies, particle size and microstructure of the synthesized β-C3N4/CuO composites largely depended upon copper chloride and the volume ratio of V water:V ethanol in the mixed precursors. The fabricated β-C3N4/CuO nanoflakes exhibited obviously enhanced visible light photocatalytic activity for the degradation of methylene blue (MB) with an  ∼3.4 and 1.9 fold increase in efficiency over that of pure g-C3N4 and commercial P25, respectively. The β-C3N4/CuO composite photocatalyst also showed photocatalytic activity for the degradation of methyl orange (MO). Moreover, the β-C3N4/CuO nanoflakes showed almost no loss of photocatalytic activity after three recycles of the degradation of the MB. A multiple synergetic mechanism in β-C3N4/CuO nanoflakes, which is featured by the highly reactive {0 0 2} facets, exposed many active sites of nanoflakes and the efficient charge separation are proposed to account for the distinguished photocatalytic activity. This work provides a facile and cost-effective strategy for designing novel β-C3N4/CuO photocatalysts for application in environmental purification.

  14. Effect of metal oxide nanoparticles on microbial community structure and function in two different soil types.

    Science.gov (United States)

    Frenk, Sammy; Ben-Moshe, Tal; Dror, Ishai; Berkowitz, Brian; Minz, Dror

    2013-01-01

    Increased availability of nanoparticle-based products will, inevitably, expose the environment to these materials. Engineered nanoparticles (ENPs) may thus find their way into the soil environment via wastewater, dumpsters and other anthropogenic sources; metallic oxide nanoparticles comprise one group of ENPs that could potentially be hazardous for the environment. Because the soil bacterial community is a major service provider for the ecosystem and humankind, it is critical to study the effects of ENP exposure on soil bacteria. These effects were evaluated by measuring bacterial community activity, composition and size following exposure to copper oxide (CuO) and magnetite (Fe3O4) nanosized (soil types were examined: a sandy loam (Bet-Dagan) and a sandy clay loam (Yatir), under two ENP concentrations (1%, 0.1%). Results indicate that the bacterial community in Bet-Dagan soil was more susceptible to change due to exposure to these ENPs, relative to Yatir soil. More specifically, CuO had a strong effect on bacterial hydrolytic activity, oxidative potential, community composition and size in Bet-Dagan soil. Few effects were noted in the Yatir soil, although 1% CuO exposure did cause a significant decreased oxidative potential and changes to community composition. Fe3O4 changed the hydrolytic activity and bacterial community composition in Bet-Dagan soil but did not affect the Yatir soil bacterial community. Furthermore, in Bet-Dagan soil, abundance of bacteria annotated to OTUs from the Bacilli class decreased after addition of 0.1% CuO but increased with 1% CuO, while in Yatir soil their abundance was reduced with 1% CuO. Other important soil bacterial groups, including Rhizobiales and Sphingobacteriaceae, were negatively affected by CuO addition to soil. These results indicate that both ENPs are potentially harmful to soil environments. Furthermore, it is suggested that the clay fraction and organic matter in different soils interact with the ENPs and reduce

  15. Contribution of physicochemical characteristics of nano-oxides to cytotoxicity.

    Science.gov (United States)

    Xu, Mingsheng; Fujita, Daisuke; Kajiwara, Shoko; Minowa, Takashi; Li, Xianglan; Takemura, Taro; Iwai, Hideo; Hanagata, Nobutaka

    2010-11-01

    To identify the key physicochemical properties of nano-oxides governing cytotoxicity, we investigate the contribution of the size, shape, morphology, and electronic properties of ten types of insulator (SiO(2), CeO(2) and Al(2)O(3)) and semiconductor (ZnO and CuO) nano-oxides to cytotoxicity using the NIH3T3 and A549 cell lines as models. We find that the shape of the Al(2)O(3) (nanoparticle versus nanowhisker) and the morphology of the SiO(2) (porous versus non-porous nanoparticles) did not have obvious effect on the observed cytotoxicity, and the size of the nano-oxides cannot be regarded as an indicator of cytotoxicity. By contrast, we find that the cell viability exposed to the semiconductor nano-oxides was much lower than that exposed to the insulator nano-oxides. Moreover, the Al-doped ZnO nanoparticle (NP) was more toxic than the non-doped ZnO NP, whereas the Al-doped CuO NP was less toxic than the non-doped CuO NP but more toxic than the Al(2)O(3) NP. Correspondingly, the valence band X-ray photoelectron spectra of the nano-oxides show the density of states of the Al-doped ZnO NP (the Al-doped CuO NP) is higher (lower) than that of the non-doped ZnO NP (the non-doped CuO NP). These results suggest that the electronic properties of nano-oxides may play an important role in the observed cytotoxicity. The results have implications for selectively tailoring the toxic effect and establishing predictive models for the design of various types of nanomaterials with unique properties and for the understanding of interactions between nanomaterials with biological system.

  16. Electrochemical properties of CuO hollow nanopowders prepared from formless Cu–C composite via nanoscale Kirkendall diffusion process

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong Min [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kim, Jong Hwa [Daegu Center, Korea Basic Science Institute, 80 Daehakro Bukgu, Daegu 702-701 (Korea, Republic of); Choi, Yun Ju [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Cho, Jung Sang [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of)

    2016-06-25

    Hollow CuO nanopowders are prepared using a simple spray drying process that relied on nanoscale Kirkendall diffusion; these nanopowders have potential applications in lithium-ion batteries. Citric acid is used as both the carbon source material and chelating agent and plays a key role in the preparation of the hollow nanopowders. The formless Cu–C composite that formed as an intermediate product transforms into slightly aggregated CuO hollow nanopowders after post-treatment at 300 and 400 °C under an air atmosphere. The CuO hollow nanopowders exhibit higher initial discharge capacities and better cycling performances than those of the filled-structured CuO nanopowders, which are prepared at a post-treatment temperature of 500 °C under an air atmosphere. The discharge capacities of the CuO nanopowders post-treated at 300, 400, and 500 °C for the 150{sup th} cycle at a current density of 1 A g{sup −1} are 793, 632, and 464 mA h g{sup −1}, respectively, and their capacity retentions calculated from the maximum discharge capacities are 88, 80, and 73%, respectively. The CuO nanopowders with hollow structures exhibit better structural stability for repeated lithium insertion and desertion processes than those with filled structures. - Highlights: • Hollow CuO nanopowders are prepared using a simple spray drying process. • Cu–C composite transforms into CuO hollow nanopowders by Kirkendall diffusion. • Hollow CuO nanopowders show good electrochemical properties for lithium-ion storage.

  17. Low-Power Laser Ignition of Aluminum/Metal Oxide Nanothermites

    Science.gov (United States)

    2014-01-01

    low-energy laser irradiation. Traditional primers contain lead compounds such as lead azide and lead styphnate which are toxic to both user and the...consistent with the specifications of the supplier. Among the different types of metal oxide nanopowders available, copper oxide (CuO), molybdenum oxide (MoO3...nanothermites to friction. Depending on the thermite to-be-synthesized, first the copper oxide (250 mg), the molybdenum oxide (200 mg), or the

  18. Emergency Treatment and Nursing for Batches of Patients with Cupric Chloride Toxicosis%氯化铜中毒患者的急救护理

    Institute of Scientific and Technical Information of China (English)

    王艳梅; 王科

    2011-01-01

    Objective To probe the emergency treatment and nursing for batches of patients with cupric chloride toxicosis. Methods The poisoning patients underwent a series of treating procedures concerning transferring patients promptly,cleaning skin,blocking the absorption of poison,take special antidote such as sodium dimercaptopropane sulphonate scientificly and reasonablely,as well as observing the changes of athogenetic condition closely, preventing complications and giving psychological counseling. Results Nine patients with cupric chloride toxicosis were discharged after recovery. Conclusion The using of antidote of sodium dimercaptopropane sulphonate in time with meticulous nursing plays the key role in improving the success ratio of the rescue.%目的 探讨急性氯化铜中毒患者的抢救与护理方法.方法 及时将患者脱离中毒现场、清洗皮肤、阻断毒物吸收,科学、合理地使用特效解毒剂二巯基丙磺酸钠注射液,密切观察病情变化并精心护理,预防并发症以及给予心理疏导.结果 9例急性氯化铜中毒全部痊愈出院.结论 及时使用特效解毒剂二巯基丙磺酸钠注射液,辅以全身心的护理,是提高氯化铜中毒患者抢救成功率的关键.

  19. Study on Catalytic Wet Oxidation of H2S into Sulfur on Fe/Cu Catalyst

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process,and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.

  20. Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application.

    Science.gov (United States)

    Thekkae Padil, Vinod Vellora; Černík, Miroslav

    2013-01-01

    Copper oxide (CuO) nanoparticles have attracted huge attention due to catalytic, electric, optical, photonic, textile, nanofluid, and antibacterial activity depending on the size, shape, and neighboring medium. In the present paper, we synthesized CuO nanoparticles using gum karaya, a natural nontoxic hydrocolloid, by green technology and explored its potential antibacterial application. The CuO nanoparticles were synthesized by a colloid-thermal synthesis process. The mixture contained various concentrations of CuCl2 • 2H2O (1 mM, 2 mM, and 3 mM) and gum karaya (10 mg/mL) and was kept at 75°C at 250 rpm for 1 hour in an orbital shaker. The synthesized CuO was purified and dried to obtain different sizes of the CuO nanoparticles. The well diffusion method was used to study the antibacterial activity of the synthesized CuO nanoparticles. The zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration were determined by the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. Scanning electron microscopy analysis showed CuO nanoparticles evenly distributed on the surface of the gum matrix. X-ray diffraction of the synthesized nanoparticles indicates the formation of single-phase CuO with a monoclinic structure. The Fourier transform infrared spectroscopy peak at 525 cm(-1) should be a stretching of CuO, which matches up to the B2u mode. The peaks at 525 cm(-1) and 580 cm(-1) indicated the formation of CuO nanostructure. Transmission electron microscope analyses revealed CuO nanoparticles of 4.8 ± 1.6 nm, 5.5 ± 2.5 nm, and 7.8 ± 2.3 nm sizes were synthesized with various concentrations of CuCl2 • 2H2O (1 mM, 2 mM, and 3 mM). X-ray photoelectron spectroscopy profiles indicated that the O 1s and Cu 2p peak corresponding to the CuO nanoparticles were observed. The antibacterial activity of the synthesized nanoparticles was tested against Gram-negative and positive cultures. The formed CuO

  1. Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application

    Science.gov (United States)

    Padil, Vinod Vellora Thekkae; Černík, Miroslav

    2013-01-01

    Background Copper oxide (CuO) nanoparticles have attracted huge attention due to catalytic, electric, optical, photonic, textile, nanofluid, and antibacterial activity depending on the size, shape, and neighboring medium. In the present paper, we synthesized CuO nanoparticles using gum karaya, a natural nontoxic hydrocolloid, by green technology and explored its potential antibacterial application. Methods The CuO nanoparticles were synthesized by a colloid-thermal synthesis process. The mixture contained various concentrations of CuCl2 • 2H2O (1 mM, 2 mM, and 3 mM) and gum karaya (10 mg/mL) and was kept at 75°C at 250 rpm for 1 hour in an orbital shaker. The synthesized CuO was purified and dried to obtain different sizes of the CuO nanoparticles. The well diffusion method was used to study the antibacterial activity of the synthesized CuO nanoparticles. The zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration were determined by the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. Results Scanning electron microscopy analysis showed CuO nanoparticles evenly distributed on the surface of the gum matrix. X-ray diffraction of the synthesized nanoparticles indicates the formation of single-phase CuO with a monoclinic structure. The Fourier transform infrared spectroscopy peak at 525 cm−1 should be a stretching of CuO, which matches up to the B2u mode. The peaks at 525 cm−1 and 580 cm−1 indicated the formation of CuO nanostructure. Transmission electron microscope analyses revealed CuO nanoparticles of 4.8 ± 1.6 nm, 5.5 ± 2.5 nm, and 7.8 ± 2.3 nm sizes were synthesized with various concentrations of CuCl2 • 2H2O (1 mM, 2 mM, and 3 mM). X-ray photoelectron spectroscopy profiles indicated that the O 1s and Cu 2p peak corresponding to the CuO nanoparticles were observed. The antibacterial activity of the synthesized nanoparticles was tested against Gram-negative and positive

  2. Kinetics of wet air oxidation of glyoxalic acid and oxalic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. (Univ. of Bombay (India). Dept. of Chemical Technology)

    1994-12-01

    Oxidation of lower molecular weight monobasic and dibasic acids such as formic acid, acetic acid, glyoxalic acid, and oxalic acid is often the rate-controlling step during wet air oxidation (WAO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WAO of glyoxalic acid and oxalic acid was studied in absence and presence of a cupric sulfate catalyst in the temperature range of 120--245 C and oxygen partial pressure of 0.345--1.380 MPa. The wet oxidation of oxalic acid was found to require more severe conditions as compared to glyoxalic acid. The reaction mechanism and kinetic model have been discussed.

  3. The Reduction of Aqueous Metal Species on the Surfaces of Fe(II)-Containing Oxides: The Role of Surface Passivation

    Science.gov (United States)

    White, A.F.; Peterson, M.L.

    1998-01-01

    The reduction of aqueous transition metal species at the surfaces of Fe(II)- containing oxides has important ramifications in predicting the transport behavior in ground water aquifers. Experimental studies using mineral suspensions and electrodes demonstrate that structural Fe(II) heterogeneously reduces aqueous ferric, cupric, vanadate and chromate ions on magnetite and ilmenite surfaces. The rates of metal reduction on natural oxides is strongly dependent on the extent of surface passivation and redox conditions in the weathering environment. Synchrotron studies show that surface oxidation of Fe(II)-containing oxide minerals decreases their capacity for Cr(VI) reduction at hazardous waste disposal sites.

  4. Catalytic activity of CuO-Gd0.1Ti0.1Zr0.1Ce0.7O2 in CO oxidation

    Indian Academy of Sciences (India)

    IGOR V ZAGAYNOV; ELENA YU LIBERMAN

    2016-06-01

    (1-10wt.%) CuO-Gd0.1Ti0.1Zr0.1Ce0.7O2 mesoporous catalysts were prepared by simple coprecipitationmethod with sonication and tested for CO oxidation. The catalysts show the highest activity dueto better dispersion of CuO species as well as enhanced interaction between CuO and the developed support. Itwas shown that these systems have full conversion at temperature of 60–65◦C.

  5. Intrinsic kinetics of the oxidation of methane over an industrial copper II oxide catalyst on a gamma-alumina support

    NARCIS (Netherlands)

    Veldsink, J.W.; Veldsink, J.W.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1995-01-01

    The kinetic rate of the heterogeneously catalysed methane oxidation reaction was studied at temperatures ranging from 723 to 923 K and atmospheric pressure. A commercially available CuO catalyst supported by thermally stable γ-Al2O3 was used as the catalyst. This kinetic study was carried out in ord

  6. Two Dimensional Incommensurate Spin Excitations and Lattice Fluctuations in La2 - x Bax CuO4

    Science.gov (United States)

    Wagman, J. J.; Carlo, J. P.; van Gastel, G.; Zhao, Y.; Kallin, A. B.; Mazurek, E.; Dabkowska, H. A.; Savicii, A.; Granroth, G. E.; Yamani, Z.; Tun, Z.; Gaulin, B. D.

    2013-03-01

    'Hour-glass' shaped dispersions of antiferromagnetic (AF) spin fluctuations are a robust feature common to many high temperature superconductors. In 214 cuprates, these phenomena are well known to display a strong dependence on the concentration of holes that are introduced into the copper oxide planes by doping. The incommensurability (IC) of the two dimensional magnetic order in this system is sensitive to hole concentration. Here, we present a series of neutron scattering measurements on single crystals of La2 - x Bax CuO4 (LBCO), with 0 . 035 <= x <= 0 . 095 , a doping range that spans the transition from diagonal to parallel IC ordering wavevectors, and from non-superconducting to superconducting ground states. Our measurements map out the evolution of the spin excitations for energies below ~ 50 meV, and focus on an enhancement in the scattered intensity centered in the 17-20 meV at the AF IC positions. This regime corresponds to the approximate crossing of very dispersive spin excitations and weakly dispersive low lying optic phonons in LBCO. NSERC, Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy

  7. The Effect of Green Synthesized CuO Nanoparticles on Callogenesis and Regeneration of Oryza sativa L.

    Science.gov (United States)

    Anwaar, Sadaf; Maqbool, Qaisar; Jabeen, Nyla; Nazar, Mudassar; Abbas, Fazal; Nawaz, Bushra; Hussain, Talib; Hussain, Syed Z.

    2016-01-01

    In this study, we have investigated the effect of copper oxide nanoparticles (CuO-NPs) on callogenesis and regeneration of Oryza sativa L (Super Basmati, Basmati 2000, Basmati 370, and Basmati 385). In this regard, CuO-NPs have been bio-synthesized via Azadirachta indica leaf extract. Scanning electron microscope (SEM) analysis depicts average particle size of 40 ± 5 nm with highly homogenous and spherical morphology. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been employed to confirm the phase purity of the synthesized NPs. It is found that CuO-NPs exhibit very promising results against callus induction. It is attributed to the fact that green synthesized CuO-NPs at optimum dosage possess very supportive effects on plant growth parameters. In contrast to callogenesis, differential regeneration pattern has been observed against all of the examined O. sativa L. indigenous verities. Overall observation concludes that CuO, being one of the essential plant nutrients, has greatly tailored the nutritive properties at nano-scale. PMID:27630655

  8. [Analysis of alkaline CuO degradation products of acid detergent fiber from tobacco leaves by using liquid chromatography].

    Science.gov (United States)

    Hao, Weiqiang; Wang, Leijun; Wu, Shun; Yue, Bangyi; Chen, Qiang; Zhang, Peipei

    2015-07-01

    The acid detergent fiber (ADF) from tobacco leaves was obtained by treating the sample with petroleum ether-ethanol (6:4, v/v), 30 g/L sodium dodecylsulfate and 0.5 mol/L sulphuric acid containing 20 g/L hexadecyl trimethyl ammonium bromide successively. The ADF was degraded by the alkaline CuO oxidation procedure. In this work, six samples of ADF degradation products from tobacco leaves were prepared. The samples were analyzed by using gradient liquid chromatography (LC) where an Ultimate XB C18 column was used as stationary phase, with a mixture of methanol and water as mobile phase, at a column temperature of 35 °C and a flow rate of 0.8 mL/min. Dual wavelengths of 280 nm and 320 nm were chosen for the detection. It was found that there were four characteristic peaks for the ADF degradation products. By taking these peaks as research object, the optimum time for the degradation was found to be 5 h and the sample solution could be kept stable within 7 days. The established method may provide a new approach for the studies of the differences between lignin composition in different tobacco leaves and the relationship between lignin content and the smoking quality of tobacco leaves.

  9. Catalytic wet oxidation of the pretreated synthetic pulp and paper mill effluent under moderate conditions.

    Science.gov (United States)

    Garg, Anurag; Mishra, I M; Chand, Shri

    2007-01-01

    In the present study, catalytic wet oxidation (CWO) was investigated for the destruction of organic pollutants in the thermally pretreated effluent from a pulp and paper mill under moderate temperature and pressure conditions. The thermal pretreatment studies were conducted at atmospheric pressure and 368K using copper sulfate as a catalyst. The thermal pretreatment reduced COD by about 61%. The filtrate of the thermal pretreatment step was used at pH 8.0 for CWO at 383-443K temperature and a total pressure of 0.85MPa for 4h. Catalysts used for the reaction include copper sulfate, 5% CuO/95% activated carbon, 60% CuO/40% MnO(2), and 60% CuO/40% CeO(2). Maximum COD reduction was found to be 89% during CWO step using 5% CuO/95% activated carbon with a catalyst loading of 8gl(-1) at 443K and 0.85MPa total pressure. Overall COD reduction for the pretreatment and the CWO was found to be 96%. Besides this, 60% CuO/40% CeO(2) catalyst also exhibited the similar activity as that of obtained with 5% CuO/95% activated carbon catalyst at 423K temperature and 0.85MPa total pressure. The pH of the solution during the experimental runs decreases initially due to the formation of carboxylic acid and then increases due to the decomposition of acids.

  10. Toxicity of CuO nanoparticles and Cu ions to tight epithelial cells from Xenopus laevis (A6)

    DEFF Research Database (Denmark)

    Thit, Amalie; Selck, Henriette; Bjerregaard, Henning F.

    2013-01-01

    ) was used to investigate toxicity of copper (Cu) in 3 different forms; Cu ions (Cu2+), CuO NPs (6 nm) and poly-dispersed CuO NPs (100 nm, poly-CuO). Continuous exposures at concentrations of 143–200 μM demonstrated that cytotoxicity differed among the 3 Cu forms tested and that the effects depend on cell...... state (dividing or differentiated). Dividing cells treated with poly-CuO, CuO NPs (6 nm) or Cu2+ showed cell cycle arrest and caused significant increase in cell death via apoptosis after 48 h, 6 and 7 days of treatment, respectively. Treatment with either CuO NPs (6 nm) or Cu2+ caused significant...... decrease in cell proliferation. Treatments of differentiated cells, revealed the same patterns of toxicity for Cu forms tested, but after shorter exposure periods....

  11. CuFe2 O4 -CuO Nanocomposites as Promising Materials for Solar Hydrogen Generation

    Science.gov (United States)

    Razavi, Mehdi; Amrollahi, Pouya; Yazdimamaghani, Mostafa; Tayebi, Lobat; Vashaee, Daryoosh

    2014-03-01

    Currently, hydrogen is produced, almost exclusively, by waterelectrolysis. This method can take advantage of economies of scale and most established techniques of producing hydrogen. We developed a nanocomposite material system composed of CuFe2O4 and CuO semiconductor particles to produce hydrogen by electrolysis of water. The nanocomposite powder was prepared using the sol-gel method. Techniques of X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, transmission electron microscopy and UV diffuse reflectance analysis were employed to characterize the synthesized products.The results confirmed the formation of CuFe2O4-CuO nanocomposite powder. The hydrogen evolution was successfully observed over the new hetero-system of CuFe2O4-CuO. The electrolysis activity depended on the concentration of CuO in the system. In order to enhance the hydrogen production, we further optimized the composite material versus the concentration of the compounds.

  12. Characterization and DC Conductivity of Novel CuO doped Polyvinyl Alcohol (PVA Nano-composite Films

    Directory of Open Access Journals (Sweden)

    Chivukula Srikanth

    2014-10-01

    Full Text Available DC conductivity of PVA-CuO nano-composite films have been studied in the present work. The composites were prepared by solution-casting technique. The prepared PVA-CuO composites have been characterized by X-ray diffraction (XRD analysis, Fourier Transform Infrared Spectroscopy (FT-IR, Scanning Electron Microscopy (SEM and Energy Dispersive X-ray Spectroscopy (EDXS; which confirmed the presence of CuO in polyvinyl alcohol and the formation of the composite. DC conductivity studies show thermally activated behavior of all the composites. The conductivity was found to increase with the increase in temperature indicating the semiconducting behavior of all the compositions. The activation energy increases as the content of CuO nanoparticles increases from 1 to 4 in wt% in the PVA- CuO nano-composites. Maximum conductivity was observed in 4 wt% of CuO in polyvinyl alcohol.

  13. Formation of Hierarchical CuO Nanostructures on Copper Foil by Chemical Bath Deposition for Applications in Superhydrophobic Surfaces

    Directory of Open Access Journals (Sweden)

    Felizco Jenichi Clairvaux

    2016-01-01

    Full Text Available Hierarchical CuO nanostructures (urchin-like and grassy island structure were successfully synthesized by a simple chemical bath deposition method at low temperature of 70°C in a short reaction time of 1h. XRD analysis revealed the presence of pure crystalline monoclinic CuO. Morphological analysis revealed the formation of spherical structures composed of numerous hair-like structures. The pH of the solution was also investigated to have a great effect on the morphology of the CuO nanostructures. At lower pH, the structures tend to form urchin-like structures; while at higher pH, the structures tend to form grass-like islands. A growth mechanism was also proposed in this paper. Lastly, wettability test proved the stable superhydrophobic property of the CuO nanostructured thin film surface.

  14. Speciation of ZnO and CuO nanoparticles exposed to culture medium and lymphocyte cells

    Data.gov (United States)

    U.S. Environmental Protection Agency — Spectral fits and linear combination data for ZnO and CuO nanoparticles exposure during toxicity testing. This dataset is associated with the following publication:...

  15. Synthesis of chrysalis-like CuO nanocrystals and their catalytic activity in the thermal decomposition of ammonium perchlorate

    Indian Academy of Sciences (India)

    Jun Wang; Shanshan He; Zhanshuang Li; Xiaoyan Jing; Milin Zhang; Zhaohua Jiang

    2009-11-01

    Chrysalis-like morphologies of CuO have been synthesized in large-quantity via a simple chemical deposition method without the use of any complex instruments and reagents. CuO nanocrystals showed a different morphology at three different temperatures, 25, 60 and 100°C. The particle size, morphology and crystal structure of the samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectra. The catalytic effect of CuO nanoparticles on the decomposition of ammonium perchlorate (AP) was investigated by STA 409 PC thermal analyzer at a heating rate of 10°C min-1 from 35 to 500°C. Compared with the thermal decomposition of pure AP, the addition of CuO nanoparticles decreased the decomposition temperature of AP by about 85°C.

  16. Preparation and sonocatalytic activity of monodisperse porous bread-like CuO via thermal decomposition of copper oxalate precursors

    Science.gov (United States)

    Zhang, Lihui; Liu, Rong; Yang, Heqing

    2012-04-01

    Porous bread-like CuO have been obtained via the thermal decomposition of copper oxalate precursor synthesized by the room temperature reaction of Cu(NO3)2 with Na2C2O4 in water. These bread-like CuO with the monoclinic structure are well dispersed with good monodispersity, their diameters are about 1.5 μm. The sonocatalytic activity of porous CuO for the degradation of acid scarlet dye was studied. It was found that the as-prepared porous CuO nanostructures exhibit efficient sonocatalytic ability for the degradation of acid scarlet dye in the presence of H2O2, which are expected to be useful in the treatment of non- or low-transparent wastewaters.

  17. Unravelling the quantum-entanglement effect of noble gas coordination on the spin ground state of CUO

    CERN Document Server

    Tecmer, Pawel; Legeza, Ors; Reiher, Markus

    2013-01-01

    The accurate description of the complexation of the CUO molecule by Ne and Ar noble gas matrices represents a challenging task for present-day quantum chemistry. Especially, the accurate prediction of the spin ground state of different CUO--noble-gas complexes remains elusive. In this work, the interaction of the CUO unit with the surrounding noble gas matrices is investigated in terms of complexation energies and dissected into its molecular orbital quantum entanglement patterns. Our analysis elucidates the anticipated singlet--triplet ground-state reversal of the CUO molecule diluted in different noble gas matrices and demonstrates that the strongest uranium-noble gas interaction is found for CUOAr4 in its triplet configuration.

  18. Effects of copper oxide nanoparticles on developing zebrafish embryos and larvae.

    Science.gov (United States)

    Sun, Yan; Zhang, Gong; He, Zizi; Wang, Yajie; Cui, Jianlin; Li, Yuhao

    2016-01-01

    Copper oxide nanoparticles (CuO NPs) are used for a variety of purposes in a wide range of commercially available products. Some CuO NPs probably end up in the aquatic systems, thus raising concerns about aqueous exposure toxicity, and the impact of CuO NPs on liver development and neuronal differentiation remains unclear. In this study, particles were characterized using Fourier transform infrared spectra, scanning electron microscopy, and transmission electron microscopy. Zebrafish embryos were continuously exposed to CuO NPs from 4 hours postfertilization at concentrations of 50, 25, 12.5, 6.25, or 1 mg/L. The expression of gstp1 and cyp1a was examined by quantitative reverse transcription polymerase chain reaction. The expression of tumor necrosis factor alpha and superoxide dismutase 1 was examined by quantitative reverse transcription polymerase chain reaction and Western blotting. Liver development and retinal neurodifferentiation were analyzed by whole-mount in situ hybridization, hematoxylin-eosin staining, and immunohistochemistry, and a behavioral test was performed to track the movement of larvae. We show that exposure of CuO NPs at low doses has little effect on embryonic development. However, exposure to CuO NPs at concentrations of 12.5 mg/L or higher leads to abnormal phenotypes and induces an inflammatory response in a dose-dependent pattern. Moreover, exposure to CuO NPs at high doses results in an underdeveloped liver and a delay in retinal neurodifferentiation accompanied by reduced locomotor ability. Our data demonstrate that short-term exposure to CuO NPs at high doses shows hepatotoxicity and neurotoxicity in zebrafish embryos and larvae.

  19. Extended Drude model analysis of n-doped cuprate, Pr0.85LaCe0.15CuO4

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seok Bae; Jung, Eil Ho; Roh, Seul Ki; Hwang, Jung Seek [Dept. of Physics, Sungkyunkwan University, Suwon (Korea, Republic of); Song, Dong Joon; Kim, Chang Young [Dept. of Physics, Yonsei University, Seoul (Korea, Republic of)

    2015-12-15

    We investigated optical properties of an electron-doped copper oxide high temperature superconductor, Pr0.85LaCe0.15CuO4 (PLCCO) single crystal. We obtained the optical conductivity from measured reflectance at various temperatures. We found our data contained c-axis longitudinal optical (LO) phonon modes due to miscut and intrinsic lattice distortion. We applied an extended Drude model to study the correlations between charge carriers in the system. The LO phonons appear as strong sharp peaks in the optical scattering rate. We tried to remove the LO phonon modes by using the energy loss function, which also shows the LO phonons as peaks, and could not remove them completely. We extracted the electron-boson spectral density function using a generalized Allen's formula. We observed that the resulting electron-boson density show similar temperature dependence as hole-doped cuprates.

  20. Facile Synthesis of Copper Oxide Nanoparticles via Electrospinning

    Directory of Open Access Journals (Sweden)

    Abdullah Khalil

    2014-01-01

    Full Text Available A novel approach for synthesizing copper oxide (CuO nanoparticles (NPs through electrospinning is reported. The approach is based on producing rough and discontinuous electrospun nanofibers from a precursor based on copper acetate salt and polyvinyl alcohol (PVA polymer. Selectively removing the polymeric phase from the fibers produced highly rough CuO nanofibers, which were composed of NPs that are weakly held together in a one-dimensional (1D manner. Sonication in a suitable liquid under controlled conditions completely disintegrated the nanofibers into NPs, resulting in the formation of uniform CuO NPs suspension. Aberration corrected high resolution transmission electron microscope (HRTEM showed that the obtained NPs are highly crystalline and nearly sphere-like with a diameter of 30 to 70 nm. Thus, electrospinning, which is a low cost and industrially scalable technique, can also be employed for economic and large scale synthesis of NPs.

  1. Nitrogen-monoxide gas-sensing properties of transparent p-type copper-oxide nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soojeong; Kim, Hyojin; Kim, Dojin [Chungnam National University, Daejeon (Korea, Republic of)

    2015-01-15

    We report the nitrogen-monoxide (NO) gas-sensing properties of transparent p-type copper-oxide (CuO) nanorod arrays synthesized by using the hydrothermal method with a CuO nanoparticle seed layer deposited on a glass substrate via sputtering process. We synthesized polycrystalline CuO nanorods measuring 200 to 300 nm in length and 20 to 30 nm in diameter for three controlled molarity ratios of 1:1, 1:2 and 1:4 between copper nitrate trihydrate [Cu(NO{sub 2}){sub 2}·3H{sub 2}O] and hexamethylenetetramine (C{sub 6}H{sub 12}N{sub 4}). The crystal structures and morphologies of the synthesized CuO nanorod arrays were examined using grazing incidence X-ray diffraction and scanning electron microscopy. The gas-sensing measurements for NO gas in dry air indicated that the CuO nanorodarray-based gas sensors synthesized under hydrothermal condition at a molarity ratio of 1:2 showed the best gas sensing response to NO gas. These CuO nanorod-array gas sensors exhibited a highly sensitive response to NO gas, with a maximum sensitivity of about 650% for 10 ppm NO in dry air at an operating temperature of 100 .deg. C. These transparent p-type CuO nanorod-array gas sensors have shown a reversible and reliable response to NO gas over a range of operating temperatures. These results indicate certain potential use of p-type oxide semiconductor CuO nanorods as sensing materials for several types of gas sensors, including p - n junction gas sensors.

  2. CdS quantum dots modified CuO inverse opal electrodes for ultrasensitive electrochemical and photoelectrochemical biosensor

    OpenAIRE

    2015-01-01

    The CuO inverse opal photonic crystals (IOPCs) were synthesized by the sol-gel method and modified with CdS quantum dots by successive ionic layer adsorption and reaction (SILAR). CdS QDs modified CuO IOPCs FTO electrodes of different SILAR cycles were fabricated and their electrochemical properties were studied by cyclic voltammetry (CV) and chronoamperometry (I–t). Structure and morphology of the samples were characterized by transmission electron microscopy (TEM), scanning electron microsc...

  3. The effect of CuO NPs on reactive oxygen species and cell cycle gene expression in roots of rice.

    Science.gov (United States)

    Wang, Shuling; Liu, Hanzhu; Zhang, Yuxi; Xin, Hua

    2015-03-01

    To evaluate the effect of CuO nanoparticles (NPs) on root growth, root reactive oxygen species (ROS) production, and the expression of 2 genes (OsCDC2 and OsCYCD) associated with root growth of Oryza sativa (rice), rice roots were treated with 5 mg/L CuO NP suspension, 5 mg/L CuO bulk particle suspension, and 0.27 mg/L CuSO4  · 5H2 O solution, with distilled water as control. The results indicated that CuO NPs and Cu(2+) severely inhibited the elongation and biomass of rice roots after 72-h exposure. Dyeing with 7'-dichlorodihydrofluorescein-diacetate (DCFH-DA) showed that in all 3 treatment groups, the fluorescence was primarily located in the meristem zone, demonstrating that the meristem zone was where ROS were primarily generated. In addition, a significant increase in ROS was detected in the meristem zone of roots treated with the CuO NP suspension and the CuSO4  · 5H2 O solution, both of which greatly influenced the expression level of OsCDC2 and OsCYCD. The impact of Cu(2+) on these 2 genes was smaller than that of CuO NPs. The Cu content in roots of rice after treatment with CuO NPs was much higher than that found after the other treatments, which indicated that CuO NPs may have been absorbed into root tissue. Collectively, these data suggest that growth inhibition, higher ROS production, and gene expression inhibition may be caused not only by the ions themselves, but also the NPs. © 2014 SETAC.

  4. Magnetic properties of doped and undoped CuO nanoparticles taking into account spin-phonon interactions

    Science.gov (United States)

    Wesselinowa, J. M.

    2011-03-01

    We have studied the influence of doping effects on magnetization M and Neel temperature T of CuO nanoparticles based on the Heisenberg model including spin-phonon interactions. The experimentally obtained room temperature magnetization M is due to surface or/and doping effects in CuO nanoparticles. We have shown the importance of the effect of the spin-phonon interaction on different properties.

  5. Magnetic properties of doped and undoped CuO nanoparticles taking into account spin-phonon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Wesselinowa, J.M., E-mail: julia@phys.uni-sofia.b [University of Sofia, Department of Physics, 5 J. Bouchier Blvd., 1164 Sofia (Bulgaria)

    2011-03-14

    We have studied the influence of doping effects on magnetization M and Neel temperature T{sub N} of CuO nanoparticles based on the Heisenberg model including spin-phonon interactions. The experimentally obtained room temperature magnetization M is due to surface or/and doping effects in CuO nanoparticles. We have shown the importance of the effect of the spin-phonon interaction on different properties.

  6. One-dimensional variable range hopping conduction in a single crystal of La 2CuO 4+y

    Science.gov (United States)

    Corraze, B.; Ribault, M.

    1993-02-01

    We have measured the resistivity perpendicular to the CuO 2 planes, in the magnetically ordered phases of a single crystal of La 2CuO 4+y as a function of temperature. Within a limited temperature range a one-dimensional variable range hopping conduction mechanism is identified, in zero magnetic field. The analysis of both the temperature range and the magnetic field variation shows that this mechanism is strongly dependent on the intraplane and on the interplane couplings.

  7. NTP technical report on the toxicity studies of Cupric Sulfate (CAS No. 7758-99-8) Administered in Drinking Water and Feed to F344/N Rats and B6C3F1 Mice.

    Science.gov (United States)

    Hebert, Charles

    1993-07-01

    Cupric sulfate is an inorganic salt which is widely used in industry, agriculture, and veterinary medicine. Its applications include use as an algicide in potable waters and as a feed additive and therapeutic agent in swine, sheep, and cattle. Because copper salts are found in human water supplies, toxicity studies of cupric sulfate pentahydrate were conducted in male and female F344/N rats and B6C3F1 mice by the drinking water (2-week studies only) and dosed feed routes (2-week and 13-week studies). Animals were evaluated for hematology, clinical chemistry, urinalysis, reproductive toxicity, tissue metal accumulation, and histopathology. In the 2-week drinking water studies, groups of five rats and five mice per sex received cupric sulfate at concentrations of 300 to 30,000 ppm for 15 days. One female rat, one male mouse, and three female mice in the 3000 ppm groups and all rats and mice in the 10,000 and 30,000 ppm groups died before the end of the studies. The remaining mice and rats in the 3000 ppm groups gained little or lost weight. Water consumption in the three highest dose groups of both species was reduced by more than 65%. Clinical signs observed in these groups were typical of those seen in moribund animals and were attributed to dehydration. The only gross or microscopic change specifically related to cupric sulfate toxicity was an increase in the size and number of cytoplasmic protein droplets in the epithelium of the renal proximal convoluted tubule in male rats from the 300 and 1000-ppm groups. In the 2-week feed studies, groups of five rats and five mice per sex were fed diets containing 1000 to 16,000 ppm cupric sulfate. No chemical-related deaths occurred in any dose group. Compared to the controls, rats and mice in the two highest dose groups had reduced body weight gains which were attributed to decreased feed consumption. Hyperplasia with hyperkeratosis of the squamous epithelium on the limiting ridge of the forestomach was seen in rats and

  8. Novel CuCr2O4 embedded CuO nanocomposites for efficient photodegradation of organic dyes

    Science.gov (United States)

    Mageshwari, K.; Sathyamoorthy, R.; Lee, Jeong Yong; Park, Jinsub

    2015-10-01

    Novel photocatalyst based on CuO-CuCr2O4 nanocomposites was synthesized for different Cr3+ concentration by reflux condensation method, and their photocatalytic activity was evaluated by monitoring the photodegradation of methyl orange (MO) and methylene blue dyes (MB) under UV light irradiation. Phase evolution by X-ray diffraction showed monoclinic CuO and tetragonal CuCr2O4 as the components of the prepared nanocomposites. Morphological analysis by scanning electron microscope and transmission electron microscope revealed that the incorporation of Cr3+ in CuO lattice alters the morphology of CuO from microsphere to cluster shape. Photoluminescence spectra of CuO-CuCr2O4 nanocomposites exhibited reduced PL emissions compared to pure CuO, indicating the low recombination rate of photogenerated electrons and holes. As expected, the CuCr2O4 loaded CuO showed enhanced photocatalytic activity for MO and MB dyes, and the kinetic studies suggest that the degradation follows pseudo-first-order kinetics. The enhanced photocatalytic activity of CuO-CuCr2O4 nanocomposites can be attributed to the presence of CuCr2O4 as an electron acceptor, which improves the effective charge separation in CuO.

  9. A chemical reaction controlled mechanochemical route to construction of CuO nanoribbons for high performance lithium-ion batteries.

    Science.gov (United States)

    Chen, Kunfeng; Xue, Dongfeng

    2013-12-07

    We reported a chemical reaction controlled mechanochemical route to synthesize mass CuO nanosheets by manual grinding in a mortar and pestle, which does not require any solvent, complex apparatus and techniques. The activation of chemical reactions by milling reactants was thus proved, and the energy from mechanical grinding promotes the fast formation of CuO nanoribbons. The resultant materials have preferential nanoscale ribbon-like morphology that can show large capacity and high cycle performance as lithium-ion battery anodes. After 50 cycles, the discharge capacity of CuO nanoribbon electrodes is 614.0 mA h g(-1), with 93% retention of the reversible capacity. The thermodynamic reactions of the CuO battery showed size-dependent characterization. The microstructures of CuO nanosheets and reaction routes can be controlled by the ratio of NaOH/CuAc2 according to the chemical reactions involved. The intact nanoribbon structure, thin-layer, and hierarchical structures endow present CuO materials with high reversible capacity and excellent cycling performances. The simple, economical, and environmentally friendly mechanochemical route is of great interest in modern synthetic chemistry.

  10. Vibronic dispersion in the copper oxide superconductors

    Science.gov (United States)

    Goodenough, J. B.; Zhou, J.-S.

    1994-02-01

    Attempts to describe the normal-state electronic behavior of the copper oxide superconductors have been unable to reconcile the following observations: (i) a well-defined Fermi surface with a locus predicted by band theory, but having charge carriers of a sign predicted for a Mott-Hubbard splitting of the band; (ii) a change in sign of the carriers to that predicted by band theory, but without a significant change in the locus of the Fermi surface, on overdoping beyond the narrow superconductive compositional range; (iii) a remarkable stability of the narrow range of superconductive charge-carrier concentrations in the CuO2 sheets even in the presence of charge transfer from nonsuperconductive intergrowth layers; (iv) a dramatic sensitivity of the Néel temperature of the parent compound to oxidation of the CuO2 sheets, but the persistence of antiferromagnetic spin fluctuations into the superconductive compositions; and (v) unusual transport properties that cannot be treated within the Migdal approximation and are insensitive to high magnetic fields. To address this impasse, we propose a phenomenological polaron model based on the observation that the system must accommodate to the coexistence of ``ionic'' and ``covalent'' Cu-O bonding having different equilibrium Cu-O bond lengths. We designate this entity a correlation polaron. Covalent Cu-O bonding with molecular-orbital formation occurs within the polaron, which moves in a background of ionic Cu-O bonding. Vibronic coupling at the ``avoided crossover'' from ionic to covalent bonding allows diffusional motion of uncoupled polarons without any motional enthalpy in the mobility. At temperatures T>Tl>~300 K the polarons are uncoupled and move randomly; in the narrow superconductive compositional range they condense below Tl to form a distinguishable thermodynamic phase consisting of extended vibronic states. In this ``polaron liquid,'' a distinction between bonding and antibonding states within the polarons opens a

  11. Gas-Phase Synthesis of Bimetallic Oxide Nanoparticles with Designed Elemental Compositions for Controlling the Explosive Reactivity of Nanoenergetic Materials

    Directory of Open Access Journals (Sweden)

    Ji Young Ahn

    2011-01-01

    Full Text Available We demonstrate a simple and viable method for controlling the energy release rate and pressurization rate of nanoenergetic materials by controlling the relative elemental compositions of oxidizers. First, bimetallic oxide nanoparticles (NPs with a homogeneous distribution of two different oxidizer components (CuO and Fe2O3 were generated by a conventional spray pyrolysis method. Next, the Al NPs employed as a fuel were mixed with CuO-Fe2O3 bimetallic oxide NPs by an ultrasonication process in ethanol solution. Finally, after the removal of ethanol by a drying process, the NPs were converted into energetic materials (EMs. The effects of the mass fraction of CuO in the CuO-Fe2O3 bimetallic oxide NPs on the explosive reactivity of the resulting EMs were examined by using a differential scanning calorimeter and pressure cell tester (PCT systems. The results clearly indicate that the energy release rate and pressurization rate of EMs increased linearly as the mass fraction of CuO in the CuO-Fe2O3 bimetallic oxide NPs increased. This suggests that the precise control of the stoichiometric proportions of the strong oxidizer (CuO and mild oxidizer (Fe2O3 components in the bimetallic oxide NPs is a key factor in tuning the explosive reactivity of EMs.

  12. Photocurrent enhancement of d.c. sputtered copper oxide thin films

    Indian Academy of Sciences (India)

    P Samarasekara; M A K Mallika Arachchi; A S Abeydeera; C A N Fernando; A S Disanayake; R M G Rajapakse

    2005-08-01

    Copper oxide (CuO) thin films with photocurrent as high as 25 Α/cm2 were deposited on conductive glass substrates using d.c. reactive sputtering. This was the highest reported photocurrent for sputtered -type copper oxide measured in the electrolyte KI. The photocurrent drastically increased up to 25 Α/cm2 as the sputtering pressure and the substrate temperature were increased up to 8.5 mbar and 192°C, respectively. All the synthesized films contained single phase of CuO in this range of pressure and substrate temperature. Variation of the photocurrent, photovoltage, structure and absorbance with deposition conditions were studied in detail.

  13. Controlled fabrication of photoactive copper oxide-cobalt oxide nanowire heterostructures for efficient phenol photodegradation.

    Science.gov (United States)

    Shi, Wenwu; Chopra, Nitin

    2012-10-24

    Fabrication of oxide nanowire heterostructures with controlled morphology, interface, and phase purity is critical for high-efficiency and low-cost photocatalysis. Here, we have studied the formation of copper oxide-cobalt nanowire heterostructures by sputtering and subsequent air annealing to result in cobalt oxide (Co(3)O(4))-coated CuO nanowires. This approach allowed fabrication of standing nanowire heterostructures with tunable compositions and morphologies. The vertically standing CuO nanowires were synthesized in a thermal growth method. The shell growth kinetics of Co and Co(3)O(4) on CuO nanowires, morphological evolution of the shell, and nanowire self-shadowing effects were found to be strongly dependent on sputtering duration, air-annealing conditions, and alignment of CuO nanowires. Finite element method (FEM) analysis indicated that alignment and stiffness of CuO-Co nanowire heterostructures greatly influenced the nanomechanical aspects such as von Mises equivalent stress distribution and bending of nanowire heterostructures during the Co deposition process. This fundamental knowledge was critical for the morphological control of Co and Co(3)O(4) on CuO nanowires with desired interfaces and a uniform coating. Band gap energies and phenol photodegradation capability of CuO-Co(3)O(4) nanowire heterostructures were studied as a function of Co(3)O(4) morphology. Multiple absorption edges and band gap tailings were observed for these heterostructures, indicating photoactivity from visible to UV range. A polycrystalline Co(3)O(4) shell on CuO nanowires showed the best photodegradation performance (efficiency ~50-90%) in a low-powered UV or visible light illumination with a sacrificial agent (H(2)O(2)). An anomalously high efficiency (~67.5%) observed under visible light without sacrificial agent for CuO nanowires coated with thin (∼5.6 nm) Co(3)O(4) shell and nanoparticles was especially interesting. Such photoactive heterostructures demonstrate unique

  14. Effect of Cobalt Doping on Nanostructured CuO Thin Films

    Science.gov (United States)

    Bayansal, Fatih; Taşköprü, Turan; Şahin, Bünyamin; Çetinkara, Hacı Ali

    2014-07-01

    The growth of cobalt-doped nanostructured CuO thin films using the successive ionic layer adsorption and reaction (SILAR) method is presented. It is found that Co doping considerably influences the structural (X-ray diffraction (XRD)), morphological (finite-element-scanning electron microscopy (FESEM)), and optical (ultraviolet/visible (UV/vis.) and Raman) properties of the films. XRD experiments evidence that the crystallite size of the films decreased with increasing Co doping. FESEM images reveal that the grain size of the nanostructures decreased with increasing doping concentration. By UV/vis. analysis, it is found that Co doping has a decreasing effect on band gap energy. The broadening and downshift of the Raman peaks are mainly attributed to the quantum confinement effect of CuO nanostructures.

  15. Realistic electronic structure calculations for magnetic insulators like La2CuO4

    Science.gov (United States)

    Grant, J. B.; McMahan, A. K.

    1991-01-01

    We suggest that Hartree-Fock theory is a good starting point for the solution of ab initio-derived extended Hubbard Hamiltonians for magnetic insulators like La2CuO4, as indicated by surprisingly accurate results for the superchange frequencies and insulating gaps for this material and isostructural La2NiO4, K2CuF4, and K2NiF4. Limited configuration interaction beyond Hartree-Fock theory is then used to demonstrate that admixtures of a1- (d23z-r2 -) symmetry states at energies somewhat away from the gap edge are essential to the dispersion of the first quasiparticle branch in La2CuO4 for doped-in holes.

  16. Controlled synthesis of CuO nanostructures on Cu foil, rod and grid

    Energy Technology Data Exchange (ETDEWEB)

    Vanithakumari, S.C.; Shinde, S.L. [Materials Research Centre, Indian Institute of Science, C.V. Raman Avenue, Malleswaram, Bangalore 560012, Karnataka (India); Nanda, K.K., E-mail: nanda@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, C.V. Raman Avenue, Malleswaram, Bangalore 560012, Karnataka (India)

    2011-05-15

    CuO nanowires are synthesized by heating Cu foil, rod and grid in ambient without employing a catalyst or gas flow at temperatures ranging from 400 to 800 deg. C for a duration of 1-12 h. Scanning electron microscopy (SEM) investigation reveals the formation of nanowires. The structure, morphology and phase of the as-synthesized nanowires are analyzed by various techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). It is found that these nanowires are composed of CuO phase and the underlying film is of Cu{sub 2}O. A systematic study is carried out to find the possibilities for the transformation of one phase to another completely. A possible growth mechanism for the nanowires is also discussed.

  17. Comparison of the Oxidation Rates of Some New Copper Alloys

    Science.gov (United States)

    Ogbuji, Linus U. J. Thomas; Humphrey, Donald L.

    2002-01-01

    Copper alloys were studied for oxidation resistance and mechanisms between 550 and 700 C, in reduced-oxygen environments expected in rocket engines, and their oxidation behaviors compared to that of pure copper. They included two dispersion-strengthened alloys (precipitation-strengthened and oxide-dispersion strengthened, respectively) and one solution-strengthened alloy. In all cases the main reaction was oxidation of Cu into Cu2O and CuO. The dispersion-strengthened alloys were superior to both Cu and the solution-strengthened alloy in oxidation resistance. However, factors retarding oxidation rates seemed to be different for the two dispersion-strengthened alloys.

  18. Growth and characterisation of bulk Sr2CuO2Cl2 single crystals

    NARCIS (Netherlands)

    Hien, NT; Franse, JJM; Pothuizen, JJM; Li, TW; Menovsky, AA

    1997-01-01

    Large bulk single crystals of the Sr2CuO2Cl2 compound with dimensions of 15 x 6 x 4 mm(3) have been grown directly from the melt by the floating-zone method using a light-image furnace. The optimal growth conditions are found in a mixed atmosphere of 0.2 bar oxygen and 1.2 bar argon. Results of the

  19. Spontaneous ferromagnetic spin ordering at the surface of La$_2$CuO$_4$

    OpenAIRE

    2007-01-01

    Magnetic properties of high purity stoichiometric La$_2$CuO$_4$ nanoparticles are systematically investigated as a function of particle size. Ferromagnetic single-domain spin clusters are shown to spontaneously form at the surface of fine grains as well as paramagnetic defects. Hysteresis loops and thermomagnetic irreversibility are observed in a wide temperature range $5 - 350$ K with the remnant moment and coercivity gradually decreasing with increasing temperature. Possible origins of the ...

  20. Solid-State Thermal Decoposition Method for the Preparation of CuO Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Dehno Khalaji

    2012-12-01

    Full Text Available In this paper, CuO nanoparticles  have been synthesized via solid- state thermal decomposition using copper(II Schiff base complexes as new precursors at 600ºC under air atmosphere for 3 h. Surface morphology of the products were characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray diffraction (XRD and scanning electron microscopy (SEM.

  1. The structure and energies of peroxy bipolarons in La sub 2 CuO sub 4

    CERN Document Server

    Catlow, C R A; Zhang, X

    1998-01-01

    We present calculations of the binding energies of peroxy (O sub 2 sup 2 sup -) bipolarons in La sub 2 CuO sub 4. Our results strongly suggest that these species are weakly bound with respect to isolated hole species. Estimates of the effective mass of the bipolaronic species based on our calculated relaxed geometries are consistent with experimental observation for the superconducting state of the material. (author). Letter-to-the-editor

  2. Fluctuating in the hopping rate of CuO thin films with respect to substrate temperature

    Science.gov (United States)

    Serin, N.; Yildiz, A.; Çam, E.; Uzun, Ş.; Serin, T.

    2012-10-01

    Electrical transport properties in CuO thin films processed using d.c. magnetron sputtering technique is investigated to understand the correlation between the processing conditions and electrical properties. It is identified that the temperature dependent conductivity of the investigated films is controlled by the multi-phonon hopping conduction mechanism. A detailed analysis in terms of carrier hopping parameters is used to correlate electrical transport properties with the d.c. magnetron sputtering conditions.

  3. Proximity-induced superconductivity in monolayer CuO2 on cuprate substrates

    Science.gov (United States)

    Zhu, Guo-Yi; Zhang, Fu-Chun; Zhang, Guang-Ming

    2016-11-01

    To understand the recently observed high temperature superconductivity in the monolayer CuO2 grown on the Bi2Sr2CaCu2O8 + δ substrates, we propose a two-band model of the hybridized oxygen px and py orbitals with the proximity effect of the substrate. We demonstrate that both the nodal and nodeless superconducting states can be induced by the proximity effect, depending on the strengths of the pairing parameters.

  4. Microwave absorption and resistively shunted Josephson junctions in high temperature CuO superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, J.S.; Huang, M.X.; Bhagat, S.M. (Dept. of Physics, Univ. of Maryland, College Park, MD (United States)); Kish, K.; Tyagi, S. (Dept. of Physics and Atmospheric Science, Drexel Univ., Philadelphia, PA (United States))

    1992-11-01

    We report that the field dependence of the magnetoabsorption (virgin curve) in all pristine granular CuO type (HTSC) superconductors follows a one-parameter expression. This ''universal'' result is combined with previous measurements on field and temperature dependences of microwave absorption in HTSC to demonstrate that a simple model based on resistively shunted Josehpson junctions is adequate to qualitatively account for almost all the observations on powders, pellets, thin films and single crystals. (orig.).

  5. Enargite oxidation: A review

    Science.gov (United States)

    Lattanzi, Pierfranco; Da Pelo, Stefania; Musu, Elodia; Atzei, Davide; Elsener, Bernhard; Fantauzzi, Marzia; Rossi, Antonella

    2008-01-01

    . At alkaline pH, the reactivity of enargite is apparently slightly greater. XPS spectra of surfaces conditioned at pH 11 have been interpreted as evidence of formation of a number of surface species, including cupric oxide and arsenic oxide. Treatment with hypochlorite solutions at pH 12.5 quickly produces a coating of cupric oxide. Electrochemical oxidation of enargite typically involves low current densities, confirming that the oxidation process is slow. Important surface changes occur only at high applied potentials, e.g. + 0.74 V vs. SHE. It is confirmed that, at acidic pH, the dominant process is Cu dissolution, accompanied (at + 0.56 V vs. SHE, pH = 1) by formation of native sulphur. At alkaline pH, a number of surface products have been suggested, including copper and arsenic oxides, and copper arsenates. XPS studies of the reacted surfaces demonstrate the evolution of Cu from the monovalent to the divalent state, the formation of As-O bonds, and the oxidation of sulphur to polysulphide, sulphite and eventually sulphate. In most natural and quasi-natural (mining) situations, it is expected that enargite reactivity will be slow. Moreover, it is likely that the release of arsenic will be further slowed down by at least temporary trapping in secondary phases. Therefore, an adequate management of exposed surfaces and wastes should minimize the environmental impact of enargite-bearing deposits. In spite of an increasing body of data, there are several gaps in our knowledge of enargite oxidation. The exact nature of most mechanisms and products remains poorly constrained, and there is a lack of quantitative data on the dependence on parameters such as pH and dissolved oxygen.

  6. Support-dependent active species formation for CuO catalysts: Leading to efficient pollutant degradation in alkaline conditions.

    Science.gov (United States)

    Li, Yibing; Guo, Lianshuang; Huang, Dekang; Jawad, Ali; Chen, Zhuqi; Yang, Jiakuan; Liu, Weidong; Shen, Yan; Wang, Mingkui; Yin, Guochuan

    2017-04-15

    Redox metal ions play the crucial role in versatile advanced oxidation technologies, in which controlling the active species formation through catalyst design is one of the key challenges in oxidant utilization. This work describes an example of different active species formations in CuO-mediated degradation just because of supporting material differences. Although three CuO catalysts were prepared by similar procedures, it was found that CuO-MgO catalyst demonstrated high efficiency in phenol degradation with bicarbonate activated H2O2, in which the superoxide radical is crucial, while hydroxyl radical and singlet oxygen are ignorable. For the CuO-MgO-Al2O3 and CuO-Al2O3 catalysts, the degradation proceeds by popular hydroxyl radical based process, however, the efficiency was poor. The EPR experiments also confirmed the absence of hydroxyl radical in CuO-MgO system but its presence in CuO-MgO-Al2O3 and CuO-Al2O3 system. The high catalytic efficiency with ignorable hydroxyl radical in the CuO-MgO system leads us to propose that an alternative Cu(III) species dominates the degradation. The basic MgO support may facilitate the formation of the Cu(III) species, whereas the neutral MgO-Al2O3 and acidic Al2O3 supports are unable to stabilize the high valent Cu(III) species, leading to the common hydroxyl radical mechanism with low efficiency of H2O2 in alkaline conditions. Copyright © 2016. Published by Elsevier B.V.

  7. Synthesis and characterization of tenorite (CuO nanoparticles from smelting furnace dust(SFD

    Directory of Open Access Journals (Sweden)

    Darezereshki E.

    2013-01-01

    Full Text Available Tenorite (CuO nanoparticles were prepared from a dilute CuSO4 solution. The solution was obtained by leaching (pH=1.5 of smelting furnace dust of Sarcheshmeh Copper Complex, Iran. The recovery of copper from the acidic sulphate solution was carried out by solvent extraction using Lix 984-N. Tenorite nanoparticles were synthesized by direct thermal decomposition of Langite [Cu4(OH6SO4(H2O2] as a precursor which was calcinated in air for 2 h at 750°C. The Samples were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The average diameter of the spherical pure CuO nanoparticles and their crystallite size were estimated to be 92 nm and 40nm, respectively. The simplicity of the present method suggests its potential application at industrial scale as a cheap and convenient way to produce pure CuO nanoparticles from dilute CuSO4 solutions obtained from leaching of smelting furnace dust.

  8. Heterojunction characteristics of ZnO and CuO substrates formed by direct bonding

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hiroshi; Fujishima, Masahide; Komiyama, Takao; Chonan, Yasunori; Yamaguchi, Hiroyuki; Aoyama, Takashi [Department of Electronics and Information Systems, Akita Prefectural University, Yuri-honjo, Akita 015-0055 (Japan)

    2012-06-15

    The n-ZnO/p-CuO heterojunction characteristics have been investigated by direct bonding of ZnO and CuO substrates at room temperatures, and by post-annealing at 800 C. The ZnO substrate was fabricated by mixing of ZnO and Al{sub 2}O{sub 3} (2%) powders, pressing at 50 MPa, and sintering at 1400 C while the CuO substrate was fabricated by mixing of CuO and Li{sub 2}CO{sub 3} (1%) powders, pressing at 300 MPa, and sintering at 700 C. Rectifying behaviour with an ideality factor of 126 was observed after bonding of these substrates. Post-annealing of the heterojunction, however, significantly increased both the forward and the reverse currents, and the rectifying behaviour was lost. Symmetrical I-V curves with threshold voltages of about {+-} 1 V were observed and this degradation could be explained by impurity (Al and Li) segregation at the junction interface. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Effect of Extracellular Polymeric Substances on CuO Nanoparticle Dissolution and Colloidal Stability

    Science.gov (United States)

    Adeleye, A. S.; Keller, A. A.

    2013-12-01

    Extracellular polymeric substances (EPS) are high molecular weight polymers produced by microorganisms growing in natural as well as artificial environments. EPS may interact with engineered nanomaterials (ENMs) in aquatic systems via electrostatic and/or hydrophobic associations, therefore, influencing the fate and transport of ENMs. In this study the effect of soluble EPS isolated from Isochrysis galbana, a marine phytoplankton, on the dissolution kinetics and colloidal stability of CuO nanoparticles was investigated. EPS was characterized by measuring hydrodynamic diameter, total organic carbon, carbohydrate, and protein concentrations. CuO nanoparticles were more stable in the presence of EPS in aqueous media as indicated by hydrodynamic size and average count rate measurements. The effect of pH and ionic strength on dissolution was also studied. [Cu2+] and [Cu]total detected after a week were 5.70 mg L-1 and 7.08 mg L-1 respectively when 10 mg L-1 CuO nanoparticles was kept in 10 mM NaCl at pH 4. In the presence of 5 mg-C EPS L-1, [Cu2+] and [Cu]total were slightly lower at 5.0 mg L-1 and 5.53 mg L-1 respectively. Although observed [Cu2+] and [Cu]total were significantly lower at neutral and alkaline pH conditions, a similar pattern was observed.

  10. Study on HNS-Ⅳ Initiated by Flyer Driven by Cupric Azide%叠氮化铜驱动飞片起爆HNS-Ⅳ的研究

    Institute of Scientific and Technical Information of China (English)

    郭俊峰; 曾庆轩; 李明愉; 李兵

    2015-01-01

    针对以叠氮化铜微装药为基础的MEMS起爆传爆序列,利用数值模拟的方法研究起爆序列结构对起爆性能的影响.研究结果表明:飞片的剪切形状与文献结果相符.在装药直径一定的情况下,随着装药厚度的增加,飞片速度增加;当装药厚度为0.5mm、装药直径大于0.7mm时,增加装药直径不能进一步增加飞片速度;当叠氮化铜的尺寸为Φ0.7mm×0.5mm、加速膛长度为0.56mm时,系统能够起爆HNS-IV炸药.利用文献数据拟合得到了HNS-IV炸药的冲击起爆判据,模拟结果符合HNS-Ⅳ的冲击起爆判据.%Aimed at MEMS booster train based on micro charge involving cupric azide, numerical simulation method was utilized to study the effect of the structure of booster train on shock-initiation performance. Simulation results indicate that the shear of flyer shape is consistent with literature results. To a certain charge diameter, the flyer velocity is increased as the charge thickness increasing. While the flyer velocity cannot continue to increase with the diameter increasing, when the charge thickness is 0.5 mm and the charge diameter exceeds 0.7mm. When the charge size of cupric azide is Φ 0.7mm×0.5 mm and the length of barrel is 0.56 mm, HNS-IV explosive can be initiated by this system. The shock-initiation criterion of HNS-Ⅳ explosive fitted by literature results is determined, which is consistent with the simulation results.

  11. 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...

  12. X-ray diffraction and high-resolution TEM observations of biopolymer nanoskin-covered metallic copper fine particles: preparative conditions and surface oxidation states.

    Science.gov (United States)

    Yonezawa, Tetsu; Uchida, Yoshiki; Tsukamoto, Hiroki

    2015-12-28

    Metallic copper fine particles used for electro conductive pastes were prepared by the chemical reduction of cupric oxide microparticles in the presence of gelatin. After reduction, the fine particles were collected by decantation with pH control and washing, followed by drying at a moderate temperature. The surface oxidation state of the obtained copper fine particles could be considerably varied by altering the pH of the particle dispersion, as shown by X-ray diffraction and high-resolution transmission electron microscopy. Our results strongly indicate that decantation under a nitrogen atmosphere can prevent the oxidation of copper fine particles but a slight oxidation was found.

  13. Enhancements of thermal conductivities with Cu, CuO, and carbon nanotube nanofluids and application of MWNT/water nanofluid on a water chiller system.

    Science.gov (United States)

    Liu, Minsheng; Lin, Mark Chingcheng; Wang, Chichuan

    2011-04-05

    In this study, enhancements of thermal conductivities of ethylene glycol, water, and synthetic engine oil in the presence of copper (Cu), copper oxide (CuO), and multi-walled carbon nanotube (MWNT) are investigated using both physical mixing method (two-step method) and chemical reduction method (one-step method). The chemical reduction method is, however, used only for nanofluid containing Cu nanoparticle in water. The thermal conductivities of the nanofluids are measured by a modified transient hot wire method. Experimental results show that nanofluids with low concentration of Cu, CuO, or carbon nanotube (CNT) have considerably higher thermal conductivity than identical base liquids. For CuO-ethylene glycol suspensions at 5 vol.%, MWNT-ethylene glycol at 1 vol.%, MWNT-water at 1.5 vol.%, and MWNT-synthetic engine oil at 2 vol.%, thermal conductivity is enhanced by 22.4, 12.4, 17, and 30%, respectively. For Cu-water at 0.1 vol.%, thermal conductivity is increased by 23.8%. The thermal conductivity improvement for CuO and CNT nanofluids is approximately linear with the volume fraction. On the other hand, a strong dependence of thermal conductivity on the measured time is observed for Cu-water nanofluid. The system performance of a 10-RT water chiller (air conditioner) subject to MWNT/water nanofluid is experimentally investigated. The system is tested at the standard water chiller rating condition in the range of the flow rate from 60 to 140 L/min. In spite of the static measurement of thermal conductivity of nanofluid shows only 1.3% increase at room temperature relative to the base fluid at volume fraction of 0.001 (0.1 vol.%), it is observed that a 4.2% increase of cooling capacity and a small decrease of power consumption about 0.8% occur for the nanofluid system at a flow rate of 100 L/min. This result clearly indicates that the enhancement of cooling capacity is not just related to thermal conductivity alone. Dynamic effect, such as nanoparticle dispersion

  14. Enhancements of thermal conductivities with Cu, CuO, and carbon nanotube nanofluids and application of MWNT/water nanofluid on a water chiller system

    Science.gov (United States)

    Liu, Minsheng; Lin, Mark Chingcheng; Wang, Chichuan

    2011-12-01

    In this study, enhancements of thermal conductivities of ethylene glycol, water, and synthetic engine oil in the presence of copper (Cu), copper oxide (CuO), and multi-walled carbon nanotube (MWNT) are investigated using both physical mixing method (two-step method) and chemical reduction method (one-step method). The chemical reduction method is, however, used only for nanofluid containing Cu nanoparticle in water. The thermal conductivities of the nanofluids are measured by a modified transient hot wire method. Experimental results show that nanofluids with low concentration of Cu, CuO, or carbon nanotube (CNT) have considerably higher thermal conductivity than identical base liquids. For CuO-ethylene glycol suspensions at 5 vol.%, MWNT-ethylene glycol at 1 vol.%, MWNT-water at 1.5 vol.%, and MWNT-synthetic engine oil at 2 vol.%, thermal conductivity is enhanced by 22.4, 12.4, 17, and 30%, respectively. For Cu-water at 0.1 vol.%, thermal conductivity is increased by 23.8%. The thermal conductivity improvement for CuO and CNT nanofluids is approximately linear with the volume fraction. On the other hand, a strong dependence of thermal conductivity on the measured time is observed for Cu-water nanofluid. The system performance of a 10-RT water chiller (air conditioner) subject to MWNT/water nanofluid is experimentally investigated. The system is tested at the standard water chiller rating condition in the range of the flow rate from 60 to 140 L/min. In spite of the static measurement of thermal conductivity of nanofluid shows only 1.3% increase at room temperature relative to the base fluid at volume fraction of 0.001 (0.1 vol.%), it is observed that a 4.2% increase of cooling capacity and a small decrease of power consumption about 0.8% occur for the nanofluid system at a flow rate of 100 L/min. This result clearly indicates that the enhancement of cooling capacity is not just related to thermal conductivity alone. Dynamic effect, such as nanoparticle dispersion

  15. Enhancements of thermal conductivities with Cu, CuO, and carbon nanotube nanofluids and application of MWNT/water nanofluid on a water chiller system

    Directory of Open Access Journals (Sweden)

    Lin Mark

    2011-01-01

    Full Text Available Abstract In this study, enhancements of thermal conductivities of ethylene glycol, water, and synthetic engine oil in the presence of copper (Cu, copper oxide (CuO, and multi-walled carbon nanotube (MWNT are investigated using both physical mixing method (two-step method and chemical reduction method (one-step method. The chemical reduction method is, however, used only for nanofluid containing Cu nanoparticle in water. The thermal conductivities of the nanofluids are measured by a modified transient hot wire method. Experimental results show that nanofluids with low concentration of Cu, CuO, or carbon nanotube (CNT have considerably higher thermal conductivity than identical base liquids. For CuO-ethylene glycol suspensions at 5 vol.%, MWNT-ethylene glycol at 1 vol.%, MWNT-water at 1.5 vol.%, and MWNT-synthetic engine oil at 2 vol.%, thermal conductivity is enhanced by 22.4, 12.4, 17, and 30%, respectively. For Cu-water at 0.1 vol.%, thermal conductivity is increased by 23.8%. The thermal conductivity improvement for CuO and CNT nanofluids is approximately linear with the volume fraction. On the other hand, a strong dependence of thermal conductivity on the measured time is observed for Cu-water nanofluid. The system performance of a 10-RT water chiller (air conditioner subject to MWNT/water nanofluid is experimentally investigated. The system is tested at the standard water chiller rating condition in the range of the flow rate from 60 to 140 L/min. In spite of the static measurement of thermal conductivity of nanofluid shows only 1.3% increase at room temperature relative to the base fluid at volume fraction of 0.001 (0.1 vol.%, it is observed that a 4.2% increase of cooling capacity and a small decrease of power consumption about 0.8% occur for the nanofluid system at a flow rate of 100 L/min. This result clearly indicates that the enhancement of cooling capacity is not just related to thermal conductivity alone. Dynamic effect, such as

  16. Effects of CuO Nanoparticles on Physiological and Biochemical Behaviors of Wheat (Triticum aestivum L.) Root%纳米氧化铜对小麦根系生理生化行为的影响

    Institute of Scientific and Technical Information of China (English)

    金盛杨; 王玉军; 汪鹏; 翁南燕; 周东美

    2011-01-01

    To explore the effects of metal nanoparticles on plant growth, agar culture simulating soil was used to characterize the root elongation and relative physiological and biochemical behavior of wheat (Trilicum aesttvum L.) under stress of copper oxide nanoparticles (CuO NPs). The results showed that the inhibition of root elongation in agar was exponentially correlated with the concentration of CuO NPs, which was increased slightly at a lower concentration (10 mg/L) of CuO NPs but decreased greatly at a higher concentration (100 mg/L). It should be noted that the variation of superoxide dismutase (SOD) activity shared the same trend as the inhibition of root elongation under CuO NPs exposure. Furthermore, with increasing of CuO NPs from 1 to 100 mg/L, the content of malonaldehyde (MDA) continuously increased while the protein content sharply decreased in roots. These results demonstrated that the inhibition of root elongation could be mainly attributed to the peroxide injury of plant cell membrane under CuO NPs exposure. Interestingly, wheat root may exhibit the adaptive response through enhancing the root vitality to alleviate the phytotoxicity induced by CuO NPs.%为阐明纳米金属材料暴露对植物生长的影响及其作用机制,采用模拟土壤的琼脂培养方法研究了纳米氧化铜(CuONPs)对小麦(Triticum aestivum L.)根伸长及相关生理生化行为的影响.结果表明:小麦根伸长与CuO NPs暴露浓度之间存在指数相关关系,在低浓度CuO NPs (10 mg/L)暴露下得到一定程度促进,而在高浓度(100 mg/L)下受到强烈抑制.小麦根内超氧化物歧化酶(SOD)活性随CuO NPs暴露浓度的变化趋势与小麦根伸长具有一致性.另外,在1~100mg/L范围内,随着CuO NPs暴露浓度的升高,小麦根内丙二醛(MDA)含量不断增加,但植物蛋白含量急剧降低.以上结果说明CuO NPs对根伸长抑制主要是由于纳米材料暴露造成植物细胞膜氧化损伤,小麦能通

  17. Dual Role of Selected Antioxidants Found in Dietary Supplements: Crossover between Anti- and Pro-oxidant Activities in the Presence of Copper

    Science.gov (United States)

    Yin, Jun-Jie; Fu, Peter P.; Lutterodt, Herman; Zhou, Yu-Ting; Antholine, William E.; Wamer, Wayne

    2014-01-01

    Overproduction of reactive oxygen species (ROS) in vivo can result in damage associated with many aging-associated diseases. Defenses against ROS that have evolved include antioxidant enzymes, such as superoxide dismutases, peroxidases, and catalases, which can scavenge ROS. In addition, endogenous and dietary antioxidants play an important role in moderating damage associated with ROS. In this study, we use four common dietary antioxidants to demonstrate that, in the presence of copper (cupric sulfate and cupric gluconate) and physiologically relevant levels of hydrogen peroxide, these antioxidants can also act as pro-oxidants by producing hydroxyl radicals. Using electron spin resonance (ESR) spin trapping techniques, we demonstrate that the level of hydroxyl radical formation is a function of the pH of the medium and the relative amounts of antioxidant and copper. Based on the level of hydroxyl radical formation, the relative pro-oxidant potential of these antioxidants is: cysteine > ascorbate >EGCG > GSH. It has been reported that copper sequestered by protein ligands, as happens in vivo, loses its redox activity (diminishing/abolishing the formation of free radicals). However, in the presence of hydrogen peroxide, cysteine and GSH efficiently react with cupric sulfate sequestered with bovine serum albumin to generate hydroxyl radicals. Overall, the results demonstrate that, in the presence of copper endogenous and dietary antioxidants can also exhibit pro-oxidative activity. PMID:22339379

  18. Sonicated and stirred copper oxide nanoparticles induce similar toxicity and pro-inflammatory response in N-hTERT keratinocytes and SZ95 sebocytes

    Science.gov (United States)

    Piret, Jean-Pascal; Mejia, Jorge; Lucas, Stéphane; Zouboulis, Christos C.; Saout, Christelle; Toussaint, Olivier

    2014-04-01

    The potential toxic and pro-inflammatory effects of rod-shaped copper oxide (CuO) nanoparticles (NPs; 10 ± 3 nm in thickness and 74 ± 17 nm in length) were studied on N-hTERT keratinocytes and SZ95 sebocytes and on reconstructed human epidermis. Non-sonicated and sonicated CuO NPs induced similar cellular toxicity. The toxic effect of CuO NPs (non-sonicated and sonicated) was more pronounced in keratinocytes than in sebocytes. Pro-oxidant effects of CuO NPs were demonstrated by showing increase in the production of reactive oxygen species and decrease of cellular glutathione. In addition, DNA-binding activities suggested that redox-sensitive transcription factors Nrf2 and NF-κB were implicated in the response of keratinocytes to CuO NPs. Transcriptomic analysis showed an increase in the abundance of transcript species coding for pro-inflammatory interleukins (e.g. IL-8 and IL-1α) and chemokines. In reconstituted human epidermis exposed topically to raw CuO NPs, no effect on the integrity, viability and inflammatory response was noticed.

  19. Degradation and cupric corrosion caused by corrosive sulfur in insulating oil; Zetsuen`yu no rekka to ryuka fushoku

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchie, M.; Miyamoto, T. [Mitsubishi Electric Corp., Tokyo (Japan)

    1995-03-20

    As the voltages and capacities of transformers have been increased, a higher reliability of insulating oil has been demanded. Since the 1970s, sulfurization and streaming electrification of a copper product have attracted attention. In the 1970s, an insulating oil refining method was changed from sulfuric acid refining to hydrogenation refining. In the 1980s, an insulating oil to which benzotriazole (BTA) effective for suppression of streaming electrification is added came to be used. Although the degradation of an insulating oil and the sulfurization in the oil are different phenomena, it has been found out that copper takes part in both of these phenomena. This paper describes the examination of the effect of BTA on the oxidation degradation and sulfurization of insulating oil. The examination was made by using an oxidation degradation evaluation apparatus developed from the above-mentioned viewpoint. The results of the examination show that BTA is very effective in suppressing the oxidation degradation and sulfurization of insulating oil. 11 refs., 13 figs., 2 tabs.

  20. 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.

  1. Designed synthesis of MOx (M = Zn, Fe, Sn, Ni, Mn, Co, Ce, Mg, Ag), Pt, and Au nanoparticles supported on hierarchical CuO hollow structures.

    Science.gov (United States)

    Zhang, Zailei; Jung, Ji Chul; Yan, Ning

    2016-12-01

    Despite intensive research into support substrates for the dispersal of nanoparticles and their applications, there has been a lack of general methods to produce metal oxide hollow substrates supporting a wide range of metal and metal oxides. Herein, a synthetic protocol for the preparation of CuO hollow structure-supported MOx (M = Zn, Fe, Ni, Sn, Mn, Co, Ce, Mg, and Ag) and noble metals (Pt and Au) with the desired properties and shell structure, such as CuO/Fe2O3, CuO/ZnO, CuO/SnO2, CuO/MgO, CuO/NiO, CuO/Mn2O3, CuO/CoO, CuO/CeO2, CuO/Ag2O, CuO/Pt, CuO/Au hollow cubes, CuO/ZnO double-shell hollow cubes, CuO/SnO2 double-shell hollow octahedra, CuO/SnO2/Fe2O3 and CuO/Mn2O3/NiO double-shell hollow cubes, was developed based on controlled calcination and etching. These hybrid hollow structures were employed not only as support substrates but also as active constituents for catalytic reactions. As an example, we demonstrated that CuO/ZnO hollow cubes are remarkably efficient in converting solid chitin biomass to liquid chemicals in methanol. In addition, CuO/ZnO double-shell hollow cubes were highly effective in the oxidation of benzyl alcohol in the presence of H2O2, whereas CuO/Pt and CuO/Au hollow cubes promoted the oxidation of benzyl alcohol in pure O2. The strategy developed in this work extends the controllable fabrication of high-quality CuO hollow structure-supported nanoparticles using various compositions and shell structures, paving the way to the exploration and systematic comparison of these materials in a wider range of applications.

  2. Solid state green synthesis and catalytic activity of CuO nanorods in thermal decomposition of potassium periodate

    Science.gov (United States)

    Patel, Vinay Kumar; Bhattacharya, Shantanu

    2017-09-01

    The present study reports a facile solid state green synthesis process using the leaf extracts of Hibiscus rosa-sinensis to synthesize CuO nanorods with average diameters of 15–20 nm and lengths up to 100 nm. The as-synthesized CuO nanorods were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and selected area electron diffraction. The formation mechanism of CuO nanorods has been explained by involving the individual role of amide I (amino groups) and carboxylate groups under excess hydroxyl ions released from NaOH. The catalytic activity of CuO nanorods in thermal decomposition of potassium periodate microparticles (µ-KIO4) microparticles was studied by thermo gravimetric analysis measurement. The original size (~100 µm) of commercially procured potassium periodate was reduced to microscale length scale to about one-tenth by PEG200 assisted emulsion process. The CuO nanorods prepared by solid state green route were found to catalyze the thermal decomposition of µ-KIO4 with a reduction of 18 °C in the final thermal decomposition temperature of potassium periodate.

  3. Effect of CuO addition on structure and electrical properties of low temperature sintered quaternary piezoelectric ceramics

    Indian Academy of Sciences (India)

    Jianhua Li

    2013-10-01

    The ceramics were prepared successfully by CuO additions to Pb[(Mn1/3Sb2/3)0.06(Ni1/2W1/2)0.02-(Zr0.49Ti0.51)0.92]O3. Effect of the addition on sintering temperature, structure and electrical properties of ceramics was investigated. The piezoelectric ceramics was prepared by solid-state reaction. Sintering experiments were accomplished at temperature between 950 and 1100 °C added 0.3–1.0 wt% CuO. The sintering temperature was reduced from 1250 °C (without CuO additions) to 970 °C when CuO-doped. The ceramics sintered at 970 °C for 2 h with 0.7 wt% CuO exhibited r = 1845, tan = 0.15%, 33 = 395 pC/N, p = 0.58 and m = 1830, which were the highest values. With increasing CuO doping, c becomes lower. Jahn–Teller effect was used to explain the contraction of -axis and simultaneous extension of -axis in the lattice.

  4. Structural studies of Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$ $+$ Ag superconducting system

    Indian Academy of Sciences (India)

    N RADHIKESH RAVEENDRAN; A K SINHA; R RAJARAMAN; M PREMILA; E P AMALADASS; K VINOD; J JANAKI; S KALAVATHI; AWADHESH MANI

    2016-06-01

    We have studied for the first time the effect of Ag addition (0–15 wt%) to the superconducting system, Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$, on its crystal structure and local structural features, using synchrotron X-ray diffraction(SXRD) and Raman spectroscopy, respectively. SXRD and subsequent Rietveld refinement studies on powders of Nd$_{1.85}$Ce$_{0.15}$CuO$_4$ $+$ Ag system indicate a small but significant change in lattice parameter upon Ag addition, showing evidence for possible incorporation of Ag to the extent of $\\sim$1 wt%. Raman spectroscopic studies indicate that the parent structure of Nd$_{1.85}$Ce$_{0.15}CuO$_{4}$ remains unaffected with no major local structural changes on doping with silver. However, all Raman modes show minor phonon hardening upon Ag addition, which is consistent with the unit cell volume reduction as is observed in XRD. A systematic bleaching out of the apical oxygen defect mode was also observed with increased Ag addition. Polarized Raman measurements helped to identify the asymmetric nature of the B1g Raman mode. X-ray diffraction studies on pellets of Nd$_{1.85}$Ce$_{0.15}CuO$_4$ $+$ Ag system further indicate a randomization of preferred orientation upon Ag addition. The superconductivity of the Nd$_{1.85}$Ce$_{0.15}$CuO$_4$ $+$ Ag system has been well characterized for all the compositions studied.

  5. Onion-like carbon coated CuO nanocapsules: A highly reversible anode material for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguo, E-mail: liuxianguohugh@gmail.com [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Bi, Nannan; Feng, Chao [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Or, Siu Wing [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Sun, Yuping [Center for Engineering practice and Innovation Education, Anhui University of Technology, Maanshan 243002 (China); Jin, Chuangui; Li, Weihuo; Xiao, Feng [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2014-02-25

    Highlights: • Onion-like carbon–coated CuO nanocapsules have been synthesized. • Onion-like carbon leads to the improved stability and electric conductivity. • CuO/C nanocapsules maintain a reversible capacity of 628.7 mA h g{sup −1} after 50 cycles. -- Abstract: The synthesis and characterization of CuO/C nanocapsules for application as anode material in lithium ion batteries are reported. Introduction of onion-like carbon shell on the CuO nanoparticles leads to the improved stability, electric conductivity and electrochemical performance. When evaluated as potential anode materials for lithium-ion batteries, the novel CuO/C nanocapsules deliver an initial discharge capacity of 1043.9 mA h g{sup −1} at 100 mA g{sup −1} and maintain a high reversible capacity of 628.7 mA h g{sup −1} after 50 charge–discharge cycles, much higher than those of the CuO nanoparticles. A postmortem analysis of the CuO and CuO/C anodes subjected to prolonged cycling reveals the existence of a lower degree of surface cracking and particle breakage in the CuO/C anode than the CuO anode.

  6. Morphology-controllable synthesis of CuO nanostructures and their catalytic activity for the reduction of 4-nitrophenol

    Science.gov (United States)

    Che, Wei; Ni, Yonghong; Zhang, Yuxing; Ma, Yue

    2015-02-01

    The investigation on the correlation between properties and shapes of nanomaterials always draws increased interest. However, the correlation between properties and shapes of CuO nanostructures was rarely reported in the previous works. The shape-controlled preparation of CuO nanostructures was successfully realized in the present work via a simple oil-bath route in air at 170 °;C for 30 min, employing CuCl2•2H2O and NaOH as the reactants. It was found that CuO nanocrystals with leaf-like, dumbbell-like and flowerlike structures were obtained through introducing various additives. At the same time, the correlation between properties and shapes was investigated. It was found that the catalytic performances of the as-prepared CuO nanostructures for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in NaBH4 aqueous solution were dependent on its morphologies. Experiments showed that the first-order rate constants for CuO nanostructures with various shapes were in turn 35.5‧ 10-3 s-1 (leaf-like nanosheets), 4.77‧ 10-3 s-1 (dumbbell-like architectures), 10.6‧ 10-3 s-1 (flowerlike nanostructures). The present research provides a new catalyst selection for the reduction of 4-NP to 4-AP in excess NaBH4 aqueous solution, which has potential application in industrial production.

  7. Magnetic-Field-Induced Soft-Mode Quantum Phase Transition in the High-Temperature Superconductor La1.855Sr0.145CuO4

    DEFF Research Database (Denmark)

    Chang, J.; Christensen, Niels Bech; Niedermayer, C.

    2009-01-01

    Inelastic neutron-scattering experiments on the high-temperature superconductor La1.855Sr0.145CuO4 reveal a magnetic excitation gap Delta that decreases continuously upon application of a magnetic field perpendicular to the CuO2 planes. The gap vanishes at the critical field required to induce long...

  8. Field-induced interplanar magnetic correlations in the high-temperature superconductor La1.88Sr0.12CuO4

    DEFF Research Database (Denmark)

    Rømer, A. T.; Jensen, P.; Jacobsen, H.

    2015-01-01

    We present neutron-scattering studies of the interplanar magnetic correlations in the high-temperature superconductor La1.88Sr0.12CuO4 (Tc=27 K). The correlations are studied both in a magnetic field applied perpendicular to the CuO2 planes, and in zero field under different cooling conditions. We...

  9. Evolution of CuO poly-crystalline layers to coherent single-crystalline dots on ZnO nanorods upon annealing

    Science.gov (United States)

    Wang, Ruey-Chi; Hou, Yuan-Ru; Chen, Yi-Wen

    2017-02-01

    ZnO/CuO p-n heterojunctions have attracted much attention for device applications, but coherent junctions, which are crucial for controlling electrical properties, still remain a challenge due to different crystal structure. In this work, CuO single-crystalline dots are coherently synthesized on ZnO nanorods by using a proposed two-step process. Transmission electron microscopy images confirm the formation of CuO coherent dots on single-crystalline ZnO nanorods upon annealing the nanorods covered with a poly-crystalline CuxO layer. The coherent dots exhibit two types of epitaxial orientations: CuO [002] ǀǀ ZnO [ 10 1 bar 1 ], CuO [111] ǀǀ ZnO [0002], and CuO [002] ǀǀ ZnO [ 10 1 bar 1 bar ], CuO [111] ǀǀ ZnO [ 000 2 bar]. As the thickness of the as-deposited CuxO layer increases from 10 to 30 nm, the aspect ratio of the resulting CuO dots decreases from 0.43 to 0.21, approaching a film-like morphology. This work provides a route to prepare CuO coherent single-crystalline structures on ZnO, which is one step further toward fabricating excellent CuO/ZnO nanodevices.

  10. Microwave-assisted template-free synthesis of butterfly-like CuO through Cu2Cl(OH)3 precursor and the electrochemical sensing property

    Science.gov (United States)

    Xie, Hanjie; Zhu, Lianjie; Zheng, Wenjun; Zhang, Jing; Gao, Fubo; Wang, Yan

    2016-11-01

    An energy-efficient and environmentally friendly microwave-assisted method was adopted for synthesis of butterfly-like CuO assembled by nanosheets through a Cu2Cl(OH)3 precursor, using no template. Formation mechanism of the butterfly-like CuO was explored and discussed systematically for the first time on the basis of both experimental results and crystal structure transformations in atomic level. The electrochemical sensing properties of the butterfly-like CuO modified electrode to ascorbic acid (AA) were studied for the first time. The results reveal that Cu(OH)2 nanowires were formed once the Cu2+ ions, located in between two CuO4 parallelogram chains of a Cu2Cl(OH)3 precursor, dissolve into the solution as Cu(OH)42- complex ions after ion exchange reactions and simultaneous assemble along a axis. Upon microwave irradiation, the adjacent CuO4 parallelogram chains of the Cu(OH)2 nanowires dehydrate and assemble along c axis, forming CuO nanosheets with (002) as the main exposed facet, which were further assembled to butterfly-like CuO under the action of microwave field, suggesting that microwave field functions like a 'directing agent'. The butterfly-like CuO modified electrode shows good electrochemical sensing properties to AA with a low detecting limit, short response time and wide linear response range.

  11. Synthesis and microwave modification of CuO nanoparticles: crystallinity and morphological variations, catalysis, and gas sensing.

    Science.gov (United States)

    Yang, Chao; Xiao, Feng; Wang, Jide; Su, Xintai

    2014-12-01

    CuO nanoparticles with different morphologies were synthesized by chemical precipitation and subsequently modified by microwave hydrothermal processing. The nanoparticles were precipitated by the introduction of a strong base to an aqueous solution of copper cations in the presence/absence of the polyethylene glycol and urea additives. The modification of the nanoparticles was subsequently carried out by a microwave hydrothermal treatment of suspensions of the precipitates, precipitated with and without the additives. X-ray powder diffraction analysis indicated that the crystallinity and crystallite size of the CuO nanoparticles increased after the microwave hydrothermal modification. Microscopy observations revealed the morphology changes induced by microwave hydrothermal processing. The thermal decomposition of ammonium perchlorate and the detection of volatile gases were performed to evaluate the catalytic and gas sensing properties of the synthesized CuO nanoparticles.

  12. Building energetic material from novel salix leaf-like CuO and nano-Al through electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yan Jun; Li, Xueming [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

    2016-11-15

    In this study, an energetic material was prepared by depositing nano-Al on CuO arrays via electrophoretic deposition (EPD), which offers a feasible route for nano-Al integration. The morphology and structure of the CuO arrays and Al/CuO composites were characterized by scanning electron microscopy and X-ray diffraction. The CuO arrays were homogenously salix leaf-like structure with a width of ⁓150 to 200 nm. The energy density of Al/CuO composites was approximate to 1454.5 J/g by integrating the differential scanning calorimetry (DSC) plot and the combustion performance was recorded by a high-speed camera. Moreover, the combustion flames were violent and the whole reaction process only lasted 72.2 ms, indicating that the energy of the Al/CuO nanothermite can be released effectively.

  13. Temperature dependence of the electronic structure of La2CuO4 in the multielectron LDA+GTB approach

    Science.gov (United States)

    Makarov, I. A.; Ovchinnikov, S. G.

    2015-09-01

    The band structure of La2CuO4 in antiferromagnetic and paramagnetic phases is calculated at finite temperatures by the multielectron LDA+GTB method. The temperature dependence of the band spectrum and the spectral weight of Hubbard fermions is caused by a change in the occupation numbers of local multielectron spin-split terms in the antiferromagnetic phase. A decrease in the magnetization of the sublattice with temperature gives rise to new bands near the bottom of the conduction band and the top of the valence band. It is shown that the band gap decreases with increasing temperature, but La2CuO4 remains an insulator in the paramagnetic phase as well. These results are consistent with measurements of the red shift of the absorption edge in La2CuO4 with increasing temperature.

  14. Effect of nano CuO on the ionic conductivity of PVC-PEG blend polymer electrolytes

    Science.gov (United States)

    Ravindran, Dhandapani; Vickraman, Palanichamy

    2013-06-01

    Nano CuO was prepared by co-precipitation method and it was incorporated as filler in PVC-PEG blend based solid polymer electrolytes with lithium perchlorate (LiClO4) as salt. The PVC: CuO ratio was systematically varied in order to study its effect on the ionic conductivity behavior of electrolyte membranes. The membranes were subjected to XRD and impedance analysis. The analysis shows that the conductivity profile was strongly influenced by the PVC: CuO ratio. The membrane with PVC/CuO: PEG: PC: LiClO4=23/2:15:50:10 exhibits higher conductivity of 4.0×10-6 S/cm at room temperature.

  15. Characterization of CuO Species and Thermal Solid-Solid Interaction in CuO/CeO2-Al2O3 Catalyst by In-Situ XRD, Raman Spectroscopy and TPR

    Institute of Scientific and Technical Information of China (English)

    He Mai; Luo Mengfei; Fang Ping

    2006-01-01

    Transference of CuO species and thermal solid-solid interaction in CuO/CeO2-Al2O3 catalyst prepared by an impregnation method were characterized by in-situ XRD, Raman spectroscopy and H2-TPR techniques.For the catalyst calcined at 300 ℃, two kinds of CuO species coexist on the surface, that is, highly dispersed and bulk CuO crystalline phase.Four kinds of CuO species are present for the catalyst calcined at 600 ℃: (1) highly dispersed CuO, (2) bulk CuO on the surface, (3) bulk CuO in the internal layer of CeO2, and (4) CuAl2O4 formed from CuO-Al2O3 interaction.For the catalyst calcined at 800 ℃, besides very little highly dispersed and bulk CuO on the surface, most of the CuO has transferred into the internal layer of CeO2 and the mass of CuAl2O4 are increased.At 900 ℃, all of CuO has diffused into the internal layer of CeO2 and formed CuAl2O4.The results show that the distribution of CuO species in the catalysts depends on the calcination temperature;the different CuO species can be effectively confirmed by in-situ XRD, Raman spectroscopy and H2-TPR techniques.

  16. Spontaneous ferromagnetic spin ordering at the surface of La2CuO4

    Science.gov (United States)

    Yusupov, R. V.; Kabanov, V. V.; Mihailovic, D.; Conder, K.; Müller, K. A.; Keller, H.

    2007-07-01

    Magnetic properties of high purity stoichiometric La2CuO4 nanoparticles are systematically investigated as a function of particle size. Ferromagnetic single-domain spin clusters are shown to spontaneously form at the surface of fine grains as well as paramagnetic defects. Hysteresis loops and thermomagnetic irreversibility are observed in a wide temperature range 5-350K with the remnant moment and coercivity gradually decreasing with increasing temperature. Possible origins of the spontaneous surface ferromagnetic clusters and the relation of our data to the appearance of unusual magnetic phenomena and phase separation of doped cuprates are discussed.

  17. Dielectric constant of multiferroic pure and doped CuO nanoparticles

    Science.gov (United States)

    Apostolov, A. T.; Apostolova, I. N.; Wesselinowa, J. M.

    2014-08-01

    Within a microscopic model and a Green's function technique we have calculated the temperature and magnetic field dependence of the dielectric function ɛ(T,H) in CuO nanoparticles (NPs) taking into account frustration, single-ion anisotropy, s-d coupling, spin-phonon interaction and linear magnetoelectric coupling. ɛ(T) shows weak and broad anomalies at the two magnetic phase transition temperatures TN 2 and TN 1 due to the magnetoelectric coupling. ɛ(H) decreases with increasing of H and the kinks disappear. The changes of ɛ with ion doping are discussed. Comparisons to experimental data are made.

  18. Hall effect studies of Bi 2Sr 2CuO x crystals

    Science.gov (United States)

    Hou, X. H.; Li, J. W.; Zhang, J. L.; Guo, S. Q.; Yin, B.; Xiong, J. W.; Dong, C.; Zhao, Z. X.

    1994-12-01

    We have investigated the temperature dependencies of the in-plane resistivity and the Hall coefficient in Bi 2Sr 2CuO x crystals across the metal-insulator (MI) transition. In the insulator crystal at low temperature (32Kconduction is governed by a two-dimensional variable-range-hopping mechanism. In the superconducting crystal the Hall coefficient Rh exhibit a characteristic maximum at about 90 K, and after MI transition the maximum disappeared. We believe that the maximum in Rh-T curve represents the common feature of all the high Tc superconductors.

  19. Hopping conduction in In-doped CuO thin films

    Science.gov (United States)

    Yildiz, A.; Horzum, Ş.; Serin, N.; Serin, T.

    2014-11-01

    Electrical transport properties of undoped and In-doped CuO thin films (1, 5 and 10 at. %) are investigated by mean of resistivity in the temperature range of 115-300 K. Electrical transport mechanism of films is explained on the basis of the variable-range hopping (VRH) conduction. Upon doping, appreciable changes are found in resistivity. Temperature dependent resistivity shows a complex correlation with increasing In concentration. This situation is well explained by fluctuations in the hopping distance and the density of states at the Fermi level.

  20. Synthesis of Cu3N from CuO and NaNH2

    Directory of Open Access Journals (Sweden)

    Akira Miura

    2014-12-01

    Full Text Available We report on the low-temperature synthesis of submicron-sized Cu3N powder produced from CuO and NaNH2 powder mixture by heating at 150–190 °C in a Teflon-sealed autoclave. The structure was the anti-RuO3 type with a lattice parameter of 0.3814(1 nm, and strong optical absorption was observed below ∼1.9 eV. This synthesis method has the potential of facile control of the reaction with less use of ammonia sources.

  1. A Class of Effective of Decarboxylative Perfluoroalkylating Reagents: [(phen)2Cu](O2CRF)

    KAUST Repository

    Huang, Yangjie

    2016-04-13

    This article describes the invention of a class of effective reagents [(phen)2Cu](O2CRF) (1) for the decarboxylative perfluoroalkylation of aryl and heteroaryl halides. Treatment of the copper tert-butyloxide with phenanthroline ligands, with subsequent addition of perfluorocarboxylic acids afforded the air-stable copper(I) perfluorocarboxylato complexes 1. These complexes reacted with a variety of aryl and heteroaryl halides to form perfluoroalkyl(hetero)arenes in moderate to high yields. Computational studies suggested that the coordination of the second phen ligand may reduce the energy barrier for the decarboxylation of perfluorocarboxylate to facilitate the perfluoroalkylation.

  2. Effect of CuO Doping on the Electrical Behavior of ZrO2

    Institute of Scientific and Technical Information of China (English)

    SABA,Beg; SARITA; POOJA,Varshney

    2007-01-01

    Electrical conductivity has been measured at different temperatures for ZrO2 doped with various molar ratios of CuO. The conductivity increases due to migration of vacancies, created by doping. The conductivity was found to increase with increase in temperature till 220 ℃ and thereafter decrease due to collapse of the fluorite framework.A second rise in conductivity around 500 ℃ was observed due to phase transition of ZrO2. X-ray powder diffraction, DTA and IR studies were carried out for confirming doping effect and phase transition in ZrO2.

  3. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent. Part 2. The regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    ter Maat, Hendrik; ter Maat, H.; Hogendoorn, Kees; Versteeg, Geert

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

  4. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to 75

  5. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

  6. Embalagem a vácuo: efeito no escurecimento e endurecimento do feijão durante o armazenamento

    Directory of Open Access Journals (Sweden)

    Rafaella Araújo Zambaldi Lima

    2014-09-01

    Full Text Available A influência do uso de embalagem a vácuo no controle do escurecimento e endurecimento do tegumento foi avaliada em feijões da cv. 'Pérola'. Os feijões após secos foram submetidos a diferentes embalagens: polietileno seladas a vácuo (espessura de 80µm, polietileno seladas sem vácuo (espessura de 80µm e embalagem comercial (espessura de 20µm, armazenados por oito meses em condições ambiente. Foram realizadas análises de umidade, tempo de cozimento, cor, atividade enzimática e compostos fenólicos, logo após a secagem e em intervalos de dois meses até o oitavo mês. O tempo de cozimento foi maior para os grãos acondicionados em embalagem comercial do que nas outras embalagens, ao final do armazenamento. Os grãos embalados em sacos de polietileno selados a vácuo apresentaram menor queda nos valores de L*. As amostras da embalagem selada a vácuo apresentaram atividade da Peroxidase e Polifenoloxidase inferior aos grãos da embalagem comercial. O teor de fenólicos totais não apresentou diferença significativa. O uso da embalagem selada a vácuo foi eficiente em retardar o aumento no tempo de cozimento, o escurecimento do tegumento, a atividade das enzimas Polifenoloxidase e Peroxidase da cultivar 'Pérola', durante o armazenamento por oito meses em condição ambiente.

  7. Synthesis, Characterization, and Sunlight Mediated Photocatalytic Activity of CuO Coated ZnO for the Removal of Nitrophenols.

    Science.gov (United States)

    Qamar, M Tariq; Aslam, M; Ismail, Iqbal M I; Salah, Numan; Hameed, A

    2015-04-29

    CuO@ZnO core-shell catalysts, coated by varying the CuO layer density ranging from 0.5% to 10%, were synthesized with the aim to enhance the photocatalytic activity of ZnO in sunlight and control its photocorrosion. Initially, the Cu(2+) ions were impregnated on presynthesized ZnO by wet impregnation and finally converted to CuO layers by calcination. The optical and structural characterization of the synthesized powders was performed by DRS, PL, Raman spectroscopy, and XRD analysis, respectively. The homogeneity of the coated layers was explored by FESEM. The photocatalytic activity of CuO coated ZnO was investigated for the degradation of mononitrophenols (2-, 3-, and 4-nitrophenol) and dinitrophenols (2,4-, 2,5-, and 2,6-dinitrophenol) in the exposure of the complete spectrum and visible region (420-800 nm) of sunlight. The effect of the increasing density coated layers of CuO on photocatalytic activity was evaluated for the degradation of 4-NP. Compared to pristine ZnO, a substantial increase in the degradation/mineralization ability was observable for the catalysts coated with 0.5% and 1% CuO, whereas a detrimental effect was noticed for higher coating density. Prior to photocatalytic studies, as evaluated by cyclic voltammetry (CV), compared to pure ZnO, a significant suppression of photocorrosion was noticed, under illumination, for catalysts coated with lower CuO coating. The progress of the photocatalytic degradation process was monitored by HPLC while the mineralization ability of the synthesized catalysts was estimated by TOC. The estimation of the released ions and their further interaction with the excited states and the reactive oxygen was monitored by ion chromatography (IC).

  8. Chemical bond properties and Mossbauer spectroscopy in (La1-xMx)2CuO4 (M=Ba, Sr)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By using the average band-gap model, the chemical bond properties of (La1-x Mx)2CuO4(M=Ba, Sr) were calculated . The calculated covalencies for Cu(O and La(O bond in the compounds are 0.3 and 0.03 respectively. M?ssbauer isomer shifts of 57Fe doped in La2CuO4 and 119Sn doped in La2CuO4 were calculated by using the chemical surrounding factor defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identified in 57Fe and 119Sn doped La2CuO4.

  9. Microscopic annealing process and its impact on superconductivity in T'-structure electron-doped copper oxides.

    Science.gov (United States)

    Kang, Hye Jung; Dai, Pengcheng; Campbell, Branton J; Chupas, Peter J; Rosenkranz, Stephan; Lee, Peter L; Huang, Qingzhen; Li, Shiliang; Komiya, Seiki; Ando, Yoichi

    2007-03-01

    High-transition-temperature superconductivity arises in copper oxides when holes or electrons are doped into the CuO(2) planes of their insulating parent compounds. Whereas hole doping quickly induces metallic behaviour and superconductivity in many cuprates, electron doping alone is insufficient in materials such as R(2)CuO(4) (R is Nd, Pr, La, Ce and so on), where it is necessary to anneal an as-grown sample in a low-oxygen environment to remove a tiny amount of oxygen in order to induce superconductivity. Here we show that the microscopic process of oxygen reduction repairs Cu deficiencies in the as-grown materials and creates oxygen vacancies in the stoichiometric CuO(2) planes, effectively reducing disorder and providing itinerant carriers for superconductivity. The resolution of this long-standing materials issue suggests that the fundamental mechanism for superconductivity is the same for electron- and hole-doped copper oxides.

  10. Sub-50 nm patterning of functional oxides by soft lithographic edge printing

    NARCIS (Netherlands)

    George, A.; ten Elshof, Johan E.

    2012-01-01

    We report a fast, versatile and reproducible method to make arbitrary nanoscale patterns of functional metal oxides by edge transfer printing of aqueous metal-loaded water-soluble polyacrylic acid (PAA) solutions on silicon. Patterns of ZnO, CuO, NiO and Fe2O3 with lateral dimensions below 50 nm

  11. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete, Part I

    DEFF Research Database (Denmark)

    Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noelle

    2015-01-01

    Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely...

  12. Genotoxicity of copper oxide nanoparticles with different surface chemistry on rat bone marrow mesenchymal stem cells

    DEFF Research Database (Denmark)

    Zhang, Wenjing; Jiang, Pengfei; Chen, Wei

    2016-01-01

    The surface chemistry of nanoparticles (NPs) is one of the critical factors determining their cellular responses. In this study, the cytotoxicity and genotoxicity of copper oxide (CuO) NPs with a similar size but different surface chemistry to rat bone marrow mesenchymal stem cells (MSCs) were...

  13. Jahn-Teller assisted polaronic hole hopping as a charge transport mechanism in CuO nanograins

    Science.gov (United States)

    Younas, M.; Nadeem, M.; Idrees, M.; Akhtar, M. J.

    2012-04-01

    Impedance spectroscopy has been employed to investigate the dielectric and electric transport phenomena in sol-gel synthesized CuO nanograins. Semiconducting features of the grains and grain boundaries have been endorsed to the thermal activation of the localized charge carriers. On cooling below 303 K, a transition from Jahn-Teller polaron hopping mechanism to the Mott's variable range hopping mechanism has been observed owing to random potential fluctuations among localized sites. Activation energies for conduction and relaxation processes at grain boundaries provide strong signatures for the involvement of Jahn-Teller adiabatic small polarons as a charge transport mechanism in CuO nanograins.

  14. Double-exchange driven ferromagnetic metal-paramagnetic insulator transition in Mn-doped CuO

    Science.gov (United States)

    Filippetti, Alessio; Fiorentini, Vincenzo

    2006-12-01

    Employing ab initio self-interaction-corrected local-spin-density calculations, we explain the nature of the ferromagnetic, metallic phase of Mn-doped CuO (an antiferromagnetic insulator when undoped), and of its concurrent transitions to a paramagnetic, insulating phase. Mn-induced donor levels enable conduction through ferromagnetically aligned Mn centers and ferromagnetic CuO planes via double exchange. In the paramagnetic insulating phase, a polaron hopping mechanism consistent with the experiments is envisaged. Our results suggest the intriguing possibility of designing double-exchange driven ferromagnetic cuprates.

  15. Comparative effects of dissolved copper and copper oxide nanoparticle exposure to the sea anemone, Exaiptasia pallida

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Samreen; Goddard, Russell H.; Bielmyer-Fraser, Gretchen K., E-mail: gkbielmyer@valdosta.edu

    2015-03-15

    Highlights: • Differences between CuO NP and CuCl{sub 2} exposure were characterized. • Copper accumulation in E. pallida was concentration-dependent. • E. pallida exposed to CuCl{sub 2} accumulated higher copper tissue burdens. • The oxidative stress response was greater in E. pallida exposed to CuO NP. • Both forms of copper inhibited CA activity in E. pallida. - Abstract: Increasing use of metal oxide nanoparticles (NP) by various industries has resulted in substantial output of these NP into aquatic systems. At elevated concentrations, NP may interact with and potentially affect aquatic organisms. Environmental implications of increased NP use are largely unknown, particularly in marine systems. This research investigated and compared the effects of copper oxide (CuO) NP and dissolved copper, as copper chloride (CuCl{sub 2}), on the sea anemone, Exaiptasia pallida. Sea anemones were collected over 21 days and tissue copper accumulation and activities of the enzymes: catalase, glutathione peroxidase, glutathione reductase, and carbonic anhydrase were quantified. The size and shape of CuO NP were observed using a ecanning electron microscope (SEM) and the presence of copper was confirmed by using Oxford energy dispersive spectroscopy systems (EDS/EDX). E. pallida accumulated copper in their tissues in a concentration- and time-dependent manner, with the animals exposed to CuCl{sub 2} accumulating higher tissue copper burdens than those exposed to CuO NP. As a consequence of increased copper exposure, as CuO NP or CuCl{sub 2}, anemones increased activities of all of the antioxidant enzymes measured to some degree, and decreased the activity of carbonic anhydrase. Anemones exposed to CuO NP generally had higher anti-oxidant enzyme activities than those exposed to the same concentrations of CuCl{sub 2}. This study is useful in discerning differences between CuO NP and dissolved copper exposure and the findings have implications for exposure of aquatic

  16. Facile synthesis of novel tunable highly porous CuO nanorods for high rate lithium battery anodes with realized long cycle life and high reversible capacity.

    Science.gov (United States)

    Wang, Linlin; Gong, Huaxu; Wang, Caihua; Wang, Dake; Tang, Kaibin; Qian, Yitai

    2012-11-07

    Various CuO nanostructures have been well studied as anode materials for lithium ion batteries (LIBs); however, there are few reports on the synthesis of porous CuO nanostructures used for anode materials, especially one-dimensional (1D) porous CuO. In this work, novel 1D highly porous CuO nanorods with tunable porous size were synthesized in large-quantities by a new, friendly, but very simple approach. We found that the pore size could be controlled by adjusting the sintering temperature in the calcination process. With the rising of calcination temperature, the pore size of CuO has been tuned in the range of ∼0.4 nm to 22 nm. The porous CuO materials have been applied as anode materials in LIBs and the effects of porous size on the electrochemical properties were observed. The highly porous CuO nanorods with porous size in the range of ∼6 nm to 22 nm yielded excellent high specific capacity, good cycling stability, and high rate performance, superior to that of most reported CuO nanocomposites. The CuO material delivers a high reversible capacity of 654 mA h g(-1) and 93% capacity retention over 200 cycles at a rate of 0.5 C. It also exhibits excellent high rate capacity of 410 mA h g(-1) even at 6 C. These results suggest that the facile synthetic method of producing a tunable highly porous CuO nanostructure can realize a long cycle life with high reversible capacity, which is suitable for next-generation high-performance LIBs.

  17. Characterisation and Optical Studies of Copper Oxide Nanostructures Doped with Lanthanum Ions

    Directory of Open Access Journals (Sweden)

    Varughese G.

    2014-12-01

    Full Text Available Copper Oxide is an extensively studied group II-VI semiconductor with optical properties. It exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the CuO crystal. CuO nano materials with an average particle size of 15-27 nm are synthesized by chemical route. XRD, SEM, FTIR UV-Vis and EDS characterize the samples. The percentage of doping material is confirmed from the EDS spectra. The average crystal size of the prepared CuO: La nanopowder is determined by XRD. The UV absorption spectra revealed the absorption edge at wavelength 389 nm indicating the smaller size of CuO:La nano particle. The optical direct band gap energy of doped CuO nanoparticle is found to be in the range 3.149 eV. The increasing red shift with decreasing particle size suggests that the defects responsible for the intra gap states are primarily surface defect. The La doped CuO is highly effective and can significantly enhance the photo catalytic degradation.

  18. Optical and electrical properties of Cu-based all oxide semi-transparent photodetector

    Science.gov (United States)

    Kim, Hong-Sik; Patel, Malkeshkumar; Yadav, Pankaj; Kim, Joondong; Sohn, Ahrum; Kim, Dong-Wook

    2016-09-01

    Zero-bias operating Cu oxide-based photodetector was achieved by using large-scale available sputtering method. Cu oxide (Cu2O or CuO) was used as p-type transparent layer to form a heterojunction by contacting n-type ZnO layer. All metal-oxide materials were employed to realize transparent device at room temperature and showed a high transparency (>75% at 600 nm) with excellent photoresponses. The structural, morphological, optical, and electrical properties of Cu oxides of CuO and Cu2O are evaluated in depth by UV-visible spectrometer, X-ray diffraction, scanning electron microscopy, atomic force microscopy, Kelvin probe force microscopy, and Hall measurements. We may suggest a route of high-functional Cu oxide-based photoelectric devices for the applications in flexible and transparent electronics.

  19. Cupric citrate as growth promoter for broiler chickens in different rearing stages Citrato cúprico como promotor de crescimento de frangos de corte diferentes em fases de criação

    Directory of Open Access Journals (Sweden)

    Mônica Maria de Almeida Brainer

    2003-01-01

    Full Text Available Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200 were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1 during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d. A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05 on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P Citrato cúprico foi apontado como alternativa ao sulfato cúprico como promotor de crescimento na dieta de frangos. Este trabalho avaliou a eficácia do citrato cúprico em diferentes fases da criação de frangos de corte. Foram utilizados 1200 pintos machos, em um experimento em blocos casualizados, com cinco tratamentos, seis repetições e 40 aves por parcela. Os tratamentos consistiram de uma dieta não suplementada ou suplementada com citrato cúprico anidro (75 mg Cu kg-1 de 1 a 21 dias, de 22 a 42 dias ou de 1 a 42 dias, ou com sulfato cúprico pentahidratado (200 mg Cu kg-1 de 1 a 42 dias. Foram avaliados o desempenho das aves e o resíduo de cobre na cama. Dietas, à base de milho e farelo de soja, e água foram fornecidas à vontade durante todo o período experimental. Não houve efeito da suplementação de cobre (P > 0,05 sobre o peso vivo, ganho de peso, consumo de ração, conversão alimentar e mortalidade mais refugagem. Os frangos que receberam citrato cúprico na ração a partir dos 22 dias tiveram, no período 22-42 dias

  20. Direct Growth of Copper Oxide Films on Ti Substrate for Nonenzymatic Glucose Sensors

    Directory of Open Access Journals (Sweden)

    Xiaoxu Ji

    2014-01-01

    Full Text Available Copper oxide (CuO films directly grown on Ti substrate have been successfully prepared via a hydrothermal method and used to construct an amperometric nonenzymatic glucose sensor. XRD and SEM were used to characterize the samples. The electrochemical performances of the electrode for detection of glucose were investigated by cyclic voltammetry and chronoamperometry. The CuO films based glucose sensors exhibit enhanced electrocatalytic properties which show very high sensitivity (726.9 μA mM−1 cm−2, low detection limit (2 μM, and fast response (2 s. In addition, reproducibility and long-term stability have been observed. Low cost, convenience, and biocompatibility make the CuO films directly grown on Ti substrate electrodes a promising platform for amperometric nonenzymatic glucose sensor.