- Infrared spectra and structures of the coinage metal dihydroxide molecules
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Laser-ablated Cu, Ag, and Au atoms react with H2O2 and with H2 + O2 molecules during condensation in excess argon to give four new IR absorptions in each system (O-H stretch, M-O-H bend, O-M-O stretch, and M-O-H
- Wang, Xuefeng,Andrews, Lester
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- In situ X-ray photoelectron spectroscopy study of the oxidation of CuGaSe2
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The thermal and native oxidation of CuGaSe2 thin films was studied by in situ X-ray photoelectron spectroscopy (XPS). The special design of the XPS chamber allowed to measure XP-spectra under oxidizing gas atmospheres at pressures of up to 5 mb
- Würz,Rusu,Schedel-Niedrig,Lux-Steiner,Bluhm,H?vecker,Kleimenov,Knop-Gericke,Schl?gl
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- One-step bulk synthesis of stable, near unit-cell sized oxide nanoparticles and nanoparticle blends using KO2
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Presented here is a novel one-step synthesis of oxide or hydroxide nanoparticles using, for the first time, potassium superoxide (KO2). This work demonstrates that the reaction of KO2 with different salt solutions produces grams of stable, near unit-cell sized nanoparticles. This new synthetic technique is applied to representative elements from across the periodic table to rapidly produce nanometer sized oxides or hydroxides of Mg, Al, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Sn, Tl, Pb, and Ce. This technique is also used to produce blends of nanoparticles, demonstrating the ability to prepare complex materials such as nanoparticulate blends of a lithium cathode material (LiCoO2), the multiferroic compound (BiMnO3+δ), and the superconducting YBa2Cu3O7-γ. This article not subject to U.S. Copyright. Published 2014 by the American Chemical Society.
- Sutto, Thomas E.
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- A surfactant free synthesis and formation mechanism of hollow Cu2O nanocubes using Cl- ions as the morphology regulator
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Hollow nanomaterials have attracted intense attention due to their special structures and potential applications in many fields. In this paper, we report a surfactant free synthesis of hollow Cu2O nanocubes by reducing Cu2+ precursors using Cl- ions as the morphology regulator at room temperature. It is found that in the presence of Cl- ions, hollow Cu2O nanocubes can be easily synthesized by directly reducing Cu2+ precursors with ascorbic acid. Through well-designed experiments, we propose that, in this surfactant free synthetic route, the formation of hollow Cu2O nanocubes results from a reaction activated Kirkendall diffusion process of cubic CuCl intermediates, which are formed in the reaction process and act as self-sacrificial templates. The amounts of Cl- ions and NaOH are two key factors to determine whether hollow Cu2O nanocubes are formed or not.
- Wang, Qiuxiang,Kuang, Qin,Wang, Kunshui,Wang, Xue,Xie, Zhaoxiong
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- Non-enzymatic electrochemical glucose sensing by Cu2O octahedrons: elucidating the protein adsorption signature
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A facile solution based chemical route has been developed for the synthesis of cuprous oxide (Cu2O) octahedrons employing polyvinylpyrrolidone (PVP ~ 10k) at a relatively low temperature (50 °C) in aqueous medium and their response towards electrochemical non-enzymatic glucose sensing has been precisely investigated. The amperometric analysis reveals two calibration ranges (0.1 μM-1 mM and 1-7 mM) for the modified electrodes, with an excellent glucose specific selectivity over other interfering materials like sucrose, fructose, ascorbic acid (AA) and dopamine (DA). Careful analysis of the amperometric outcomes unveils a low limit of detection (LOD) of 0.96 μM (S/N = 3) along with exceptionally good stability and repeatability. Furthermore, the octahedral Cu2O modified electrodes exhibit a fast response time (~1.5 s) with acceptable sensitivity and are found to be exceedingly reliable for the real time analysis of human serum samples (relative error 3.2%) compared to commercial glucose biosensors. Detailed survey of the adsorption of four most common blood proteins onto the negatively charged surface of Cu2O octahedrons using steady state fluorescence, dynamic light scattering (DLS), zeta potential (ζ) and circular dichroism (CD) in aqueous dispersions delineates the electrostatic interaction driven low protein adsorption that strongly indicates their further potential applicability in medical devices for targeted monitoring of glucose. This journal is
- Rakshit, Soumyadipta,Ghosh, Srabanti,Roy, Rimi,Bhattacharya, Subhash Chandra
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- CuO nanomaterials for p-type dye-sensitized solar cells
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In p-type dye-sensitized solar cells (p-DSSCs), NiO is the most commonly used p-type semiconductor. Nevertheless, because of the drawbacks of NiO, much effort has been made to search for suitable substitutes. Herein, three different morphologies of CuO nanomaterials were used to prepare photocathodes for p-DSSCs, which have a deeper valence band and a higher dielectric constant compared to that of NiO. We observe that CuO is unstable in the presence of iodide/triiodide electrolyte, while cobalt complexes with bipyridine ligands are more suitable redox shuttles. We also note that the average transport time in CuO is shorter than that in NiO. Finally, the deep absorbance of CuO in the visible range indicates that suitable sensitizers for the CuO p-DSSC must exhibit high extinction coefficient and absorption bands located in the lower energy part of the solar spectrum (>600 nm) to be exploitable. In this case such CuO based photocathodes represent valuable systems to exploit the near-infrared (NIR) region.
- Jiang, Tengfei,Bujoli-Doeuff, Martine,Farré, Yoann,Pellegrin, Yann,Gautron, Eric,Boujtita, Mohammed,Cario, Laurent,Jobic, Stéphane,Odobel, Fabrice
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p. 112765 - 112770
(2016)
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- Nonenzymatic hydrogen peroxide biosensor based on four different morphologies of cuprous oxide nanocrystals
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In this work, we synthesized four different morphologies of cuprous oxide (Cu2O) nanocrystals (cube, rhombic dodecahedra, octahedra, and extended hexapod) by a hydrothermal method. Then, the four different morphologies of Cu2O were immobilized separately on a glassy carbon electrode (GCE) to construct a non-enzymatic hydrogen peroxide (H2O2) biosensor. We systematically explored the electrocatalytic activities of the four different Cu2O nanocrystals towards H2O2, which are strongly dependent on the shape of the Cu2O nanocrystals. It is shown that the modified electrodes exhibited excellent electrocatalysis for H2O2reduction by electrochemical experiments. Moreover, the {111}-bounded extended hexapod Cu2O, {111}-bounded octahedral Cu2O and the {110}-bounded rhombic dodecahedral Cu2O nanocrystals are significantly more active than the {100}-bounded cubic Cu2O nanocrystals, as the {111} and {110} face contain copper atoms on the surface with dangling bonds, and are expected to interact more strongly with negatively charged ions or molecules. This journal is
- Zhong, Yanmei,Li, Yancai,Li, Shunxing,Feng, Shuqing,Zhang, Yayun
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- Sebacato-bridged Cu(II) phen complexes: Syntheses and crystal structures of 2∞[Cu2(phen)2L4/2] (H2O)6 and [(phen)2Cu(μ-L)Cu(phen)2](HL)2 (H2L)(H2O)4 (H2L = sebacic acid; phen = 1,10-phenanthroline)
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Reactions of freshly-prepared Cu(OH)2 with sebacic acid (H2L) and 1,10-phenanthroline (phen) in EtOH/H2O (1:1 v/v) and CH3OH/H2O (1:1 v/v) and at pH 6.4 afforded two novel sebacato-bridged Cu(II) phen complexes 2∞[Cu2(phen)2L4/2] (H2O)6 (1) and [(phen)2Cu(μ-L)Cu(phen)2](HL)2 (H2L)(H2O)4 (2), respectively, Complex 1 consists of 2D 2∞[Cu2(phen)2L4/2] layers and lattice H2O molecules. The Cu atoms are each square-pyramidally coordinated by two N atoms of one phen ligand and three O atoms of different sebacato ligands. Two adjacent square pyramids are edge-shared to form [Cu2N4O4] dimers, which are interlinked by sebacato ligands to 2D 2∞[Cu2(phen)2L4/2] layers with rhombus-like 52-membered rings. The resulting layers are assembled by interlayer π-π stacking interactions and hydrogen bonding interactions. Complex 2 comprises divalent [(phen)2Cu(μ-L)Cu(phen)2] complex cations, hydrogensebacate anions, sebacic acid molecules and lattice H2O molecules. In the divalent complex cations, the Cu atoms are each octahedrally coordinated by four N atoms of two phen ligands and two O atoms of one bis-chelating sebacato ligand. The complex cations are assembled via π-π stacking interactions into positively charged 2D network. The hydrogensebacate anions, sebacic acid molecules and H2O molecules build negatively charged 2D hydrogen-bonded networks. Both positively and negatively charged 2D networks are interwoven with each other to generate a novel supramolecular architecture.
- Wei, Dan-Yi,Kong, Zu-Ping,Zheng, Yue-Qing
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- Copper-Catalysed Oxidation of Cyanide by Peroxide in Alkaline Aqueous Solution
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The oxidation of cyanide by peroxide in alkaline aqueous solution is catalysed by copper complexes.In the presence of excess cyanide, copper(II) is reduced to form the tricyanocuprate(I) complex.The cyanogen oxidation product is hydrolysed with disproportionation to cyanate and cyanide: 2CuII + 2CN(-) --> 2CuI + (CN)2; (CN)2 + 2OH(-) --> OCN(-) + CN(-) + H2O; CuI + 3CN(-) Cu(CN)3(2-).The stoichiometry and kinetics of the catalysed oxidation have been investigated.Hydrogen peroxide oxidizes coordinated cyanide with a rate that is first order in peroxide and first order in copper but independent of cyanide concentration in the presence of excess cyanide.Cu(CN)3(2-) + H2O2 --> Cu(CN)2(-) + OCN(-) + H2O; Cu(CN)2(-) + CN(-) Cu(CN)3(2-).When the excess cyanide is consumed and Cu(CN)2(-) becomes the dominant species, the reaction becomes more complex and less efficient.Under certain conditions the stoichiometry revealed a peroxide-to-Cu(CN)2(-) ratio of about 6:1, instead of the minimum of 2.5:1 required for the oxidation of the coordinated cyanide to cyanate and the CuI to Cu(OH)2.This suggests that peroxide is consumed by a copper-catalysed disproportionation, in competition with oxidation of the coordinated cyanide.An intermediate yellow complex forms while peroxide is present, before Cu(OH)2 finally precipitates.The consequence of this mechanism is that the most efficient process for the destructive oxidation of cyanide has a high cyanide-to-copper ratio, to minimize the final concentration of Cu(CN)2(-) which consumes peroxide inefficiently.The rate of the reaction depends on the concentration of copper, however, which must be large enough for a satisfactory turnover.
- Beattie, James K.,Polyblank, Gregory A.
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- One-step template-free solution route for Cu(OH)2 nanowires
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Cu(OH)2 nanowires with a diameter of 8-10 nm and lengths of tens of micrometers were fabricated in the basic solution by dropping simply NaOH solution into CuCl2 solution at ambient temperature. The formation mechanism of nanowires was discussed. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize the samples.
- Sun, Jinhe,Jia, Yongzhong,Jing, Yan,Yao, Ying,Li, Wu
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- Sub-3 nm Ultrafine Cu2O for Visible Light Driven Nitrogen Fixation
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Cu2O, a low-cost, visible light responsive semiconductor photocatalyst represents an ideal candidate for visible light driven photocatalytic reduction of N2 to NH3 from the viewpoint of thermodynamics, but it remains unexplored. Reported here is the successful synthesis of uniformly sized and ultrafine Cu2O platelets, with a lateral size of a CuII-containing layered double hydroxide with ascorbic acid. The supported ultrafine Cu2O offered excellent performance and stability for the visible light driven photocatalytic reduction of N2 to NH3 (the Cu2O-mass-normalized rate as high as 4.10 mmol g (Formula presented.) ?1 h?1 at λ>400 nm), with the origin of the high activity being long-lived photoexcited electrons in trap states, an abundance of exposed active sites, and the underlying support structure. This work guides the future design of ultrafine catalysts for NH3 synthesis and other applications.
- Zhang, Shuai,Zhao, Yunxuan,Shi, Run,Zhou, Chao,Waterhouse, Geoffrey I. N.,Wang, Zhuan,Weng, Yuxiang,Zhang, Tierui
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- Design and understanding of a high-performance gas sensing material based on copper oxide nanowires exfoliated from a copper mesh substrate
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We report a novel and facile route to synthesize a 1D needlelike CuO gas sensor utilizing simple solution-treatment, heat-treatment and sonication processes based on copper meshes (CMs) for the first time. We have demonstrated that the architectural 1D CuO sensor displays a substantial improvement of response magnitude toward a series of toxic organic molecules. We expect that our work may provide a new inspiration for synthesizing 1D semiconductor nanowires for gas sensing application.
- Yang, Fuchao,Guo, Jie,Liu, Mingming,Yu, Shen,Yan, Ningbo,Li, Jing,Guo, Zhiguang
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- Copper hydroxide nanoneedle and nanotube arrays fabricated by anodization of copper
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Cu(OH)2 nanoneedle and nanotube arrays were electrochemically synthesized by anodization of a copper foil in an aqueous solution of KOH. The nanoneedles and nanotubes were constructed from nanosheets of Cu(OH) 2. Controlling the electrochemical conditions can qualitatively modulate the lengths, amounts, and shapes of Cu(OH)2 nanostructures. The composition of as-prepared Cu(OH)2 nanostructures has been confirmed by X-ray diffraction and select-area electron diffraction. The influences of the KOH concentration of the aqueous electrolyte, the reaction temperature, and current density on the morphology of Cu(OH)2 nanostructures were investigated, and the formation mechanism of the nanostructures is discussed. Furthermore, Cu(OH)2 nanoneedles can be successfully transformed to CuO nanoneedles with little morphology change by heating. This work developed a simple, clean, and effective route for fabrication of large area Cu(OH)2 or CuO nanostructured films.
- Wu, Xufeng,Bai, Hua,Zhang, Jiaxin,Chen, Feng'en,Shi, Gaoquan
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- Low-temperature template synthesis of [4,6,6-trimethyl-2,6-dithioxo-3,7-diazanon-4-enebis(imidothioato)]copper(II) in gelatin-immobilized Cu2[Fe(CN)6] matrix materials
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Complexation in gelatin-immobilized copper(II) hexacyanoferrate(II) matrices on contact with alkaline (pH l O) aqueous solutions containing dithiooxamide and acetone was studied. Under these conditions, template synthesis occurs to give the chelate CuL [L
- Mikhailov
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- Adsorption removal of Congo red from aqueous solution by polyhedral Cu2O nanoparticles: Kinetics, isotherms, thermodynamics and mechanism analysis
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Polyhedral cuprous oxide nanoparticles (Cu2O NPs) with rough surfaces were prepared by a one-pot sonochemical precipitation method. The products were characterized by SEM, XRD, EDS, XPS, and UV-Vis DRS, respectively. The adsorption behavior of Congo red (CR) from aqueous solution onto the as-prepared Cu2O NPs was systematically investigated. The equilibrium and kinetic studies suggested that the adsorption process followed Freundlich isotherm and pseudo-second order model, respectively. The as-prepared Cu2O NPs exhibited remarkable adsorption properties toward CR. The maximum adsorption capacity at 20 °C was 3904 mg g-1, which was the highest reported value so far in adsorption removal of CR. Together with the evaluation of the thermodynamic parameters such as Gibbs free energy, enthalpy and entropy change, our results show that the adsorption of CR onto Cu2O is a spontaneous, endothermic and chemisorption process. A putative interaction model between CR and Cu2O NPs was proposed. Moreover, the Cu2O adsorbent could be photocatalytically regenerated and reused without significant loss of its adsorption capability.
- Shu, Jinxia,Wang, Zhonghua,Huang, Yijiang,Huang, Ni,Ren, Chunguang,Zhang, Wei
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- Novel electrochemical sensors based on cuprous oxide-electrochemically reduced graphene oxide nanocomposites modified electrode toward sensitive detection of sunset yellow
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Control and detection of sunset yellow is an utmost demanding issue, due to the presence of potential risks for human health if excessively consumed or added. Herein, cuprous oxide-electrochemically reduced graphene nanocomposite modified glassy carbon electrode (Cu2O-ErGO/GCE) was developed for the determination of sunset yellow. The Cu2O-ErGO/GCE was fabricated by drop-casting Cu2O-GO dispersion on the GCE surface following a potentiostatic reduction of graphene oxide (GO). Scanning electron microscope and X-ray powder diffractometer was used to characterize the morphology and microstructure of the modification materials, such as Cu2O nanoparticles and Cu2O-ErGO nanocomposites. The electrochemical behavior of sunset yellow on the bare GCE, ErGO/GCE, and Cu2O-ErGO/GCE were investigated by cyclic voltammetry and second-derivative linear sweep voltammetry, respectively. The analytical parameters (including pH value, sweep rate, and accumulation parameters) were explored systematically. The results show that the anodic peak currents of Cu2O-ErGO /GCE are 25-fold higher than that of the bare GCE, due to the synergistic enhancement effect between Cu2O nanoparticles and ErGO sheets. Under the optimum detection conditions, the anodic peak currents are well linear to the concentrations of sunset yellow, ranging from 2.0 × 10?8 mol/L to 2.0 × 10?5 mol/L and from 2.0 × 10?5 mol/L to 1.0 × 10?4 mol/L with a low limit of detection (S/N = 3, 6.0 × 10?9 mol/L). Moreover, Cu2O-ErGO/GCE was successfully used for the determination of sunset yellow in beverages and food with good recovery. This proposed Cu2O-ErGO/GCE has an attractive prospect applications on the determination of sunset yellow in diverse real samples.
- He, Quanguo,Liu, Jun,Liu, Xiaopeng,Xia, Yonghui,Li, Guangli,Deng, Peihong,Chen, Dongchu
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- A simple wet chemical route for large-scale synthesis of Cu(OH)2 nanowires
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Polycrystalline Cu(OH)2 nanowires with a ~ 8 nm avg dia and lengths of up to hundreds of micrometers were synthesized using a simple chemical route at ambient temperature. Several comparative experiments were performed to study the effects on the Cu(OH)2 particle size and shape of PH, NH3, and SO4/2- at different concentration. NH3 and NaOH were required to obtain the Cu(OH)2 nanowires. Cu2+ ion formed complex with anions and ligands present in the precipitating solutions, the bond strength of which follows the order OH- > NH3 > SO4/2-. The most stable species was the square-planar amino complex [Cu(NH3)4/2+. At pH > 8, a large number of nuclei was formed instantaneously that grow to reasonably uniform, but when the concentration of NaOH was above 4 M, only large particle formed because the formation of cuprate ions at high pH led to lower supersaturation and a smaller number of nuclei that grow to large Cu(OH)2 particles.
- Wang, Wenzhong,Lan, Chun,Li, Yuanzhi,Hong, Kunquan,Wang, Guanghou
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- Caffeine-mediated synthesis of CuO nanoparticles: characterization, morphology changes, and bactericidal activity
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This study aims the synthesis of CuO nanoparticles using caffeine as stabilizing agent by precipitation method. The effect of caffeine on the morphology of CuO NPs was studied by varying the concentrations of caffeine. The synthesized CuO NPs were charact
- Mary, A. P. Angeline,Ansari, A. Thaminum,Subramanian
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- Competition of hydrolysis and complex formation in the Cu(NO 3)2, (H+)-NH3·H 2O-H2O system
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The concentration regions of prevalence of various chemical interactions in the Cu(NO3)2, (H+)-NH 3·H9O-H2O system were determined by dilatometry, pH-metry, and electronic spectroscopy of s
- Burkov,Sidorov,Sal'nikov,Kryuchkova
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- Mild template synthesis of (2,8-dithio-3,7-diaza-4,6-dimethyl-5- oxanonanedithioamido-1,9)copper(II) in Cu2[Fe(CN)6] gelatin-immobilized matrices
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Complexation process in Cu2[(Fe(CN)6] gelatin-immobilized matrices in contact with aqueous solutions of dithiooxamide H2N-C(S)-C(S)-NH2 and ethanal H3C-CHO at pH > 10 were studied. The template synthesis was shown to occur under these specific conditions to yield the Cu(II) chelate with tetradentate (N,N,S,S)-ligand (2,8-dithio-3,7-diaza-4,6-dimethyl-5-oxanonanedithioamide-1,9) with a metal:ligand ratio of 1:1. Dithiooxamide and ethanal therein act as ligand syntones. The reaction scheme was suggested. It was established that this tetradentate ligand is not formed in the absence of Cu(II) in a solution in contact with the matrix. Moreover, the attempts made to obtain the title compound through the reactions of known copper(II) dithiooxamide complexes with ethanal failed.
- Mikhailov
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- Catechol Oxidation with Dinuclear Copper Complexes of Aliphatic Tripodal Amino Alcohols
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A set of unsymmetrical tripodal (aminoalkyl)bis(hydoxyalkyl)-amine ligands H4-2 to H4-6 with either ethyl or propyl ligand arms has been prepared and characterized. These ligands react with copper hydroxide and ammonium hexafluorophosphate, copper(II) bromide or tris(triphenylphosphane) copper(I) bromide to give di- and polynuclear complexes. The dinuclear copper complexes 9a-f catalyze the oxidation of 3,5-di-tert-butylcatechol (DTBC). The coordination geometry at the copper center is influenced by the length of the side arms resulting in a different reactivity of complexes 9a-f in the DTBC oxidation. Alternative preparation procedures lead in selected cases to the formation of coordination polymers 10a and 10b. The reversible formation of the poly(dinuclear) cations in 10a illustrates that the apical alcohol groups are labile. The solid-state structures are neither necessarily identical with solution structure nor do they represent the catalytically active species. Electronic spectra, however, agree with a dinuclear structures in solution as indicated by the characteristics of the oxygen-copper-CT. The observation of comparable catalytic activities for complexes 9a-9d renders the bridging coordination of the catechol by both copper ions of a dinuclear complex moiety unlikely. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Jocher, Christoph,Pape, Tania,Seidel, Wolfram W.,Gamez, Patrick,Reedijk, Jan,Hahn, F. Ekkehardt
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- Mechanisms of the polyol reduction of copper(ii) salts depending on the anion type and diol chain length
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The mechanisms of the polyol reduction of copper(ii) compounds were investigated by various systematic experiments. The course of the reduction in ethylene glycol strongly depends on the anion present in solution. Elemental copper can only be obtained in high yields starting from Cu(NO3)2, Cu(OAc)2, or Cu(OH)2; but not from CuCl2 or CuSO4. Intermediate compounds were observed, namely Cu2O, and the alkoxide compounds Cu(C2H4O2) and Cu3(OAc)2(C2H4O2)2. Cu3(OAc)2(C2H4O2)2 was characterised by single-crystal X-ray diffraction. It is a 2D coordination polymer with bridging bidentate acetate and bidentate deprotonated EG ligands leading to vertex- and edge-linked CuO5 polyhedra. Alkoxide compounds were also detected for higher glycol ethers. With growing glycol ether chain length the stability of alkoxide intermediates decreases, enhancing the stability range of Cu2O. Because the majority of copper species is precipitated as copper(ii) alkoxide compounds or Cu2O before the reduction to elemental copper occurs, only few nuclei are formed in solution leading to microparticles instead of nanoparticles. Much smaller but strongly agglomerated particles were observed under alkaline reaction conditions.
- Teichert, Johannes,Doert, Thomas,Ruck, Michael
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- Production and characterization of stable superhydrophobic surfaces based on copper hydroxide nanoneedles mimicking the legs of water striders
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The present work reports a simple and economic route for production and characterization of stable superhydrophobic surfaces from thin copper layers coated on arbitrary solid substrates. The thin copper layer was anodized in a 2 M aqueous solution of potassium hydroxide to form a thin film of copper hydroxide nanoneedles; then the film was reacted with n-dodecanethiol to form a thermally stable Cu(SC12H25)2 superhydrophobic coating. The contact angle of the modified nanoneedle surface was higher than 150°, and its tilt angle was smaller than 2°. Furthermore, the surface fabricated on copper foil kept its superhydrophobic property after heating at 160 °C in air for over 42 h. This technique has also been applied for fabrication of copper wire with superhydrophobic submicrofiber coating to mimic water strider legs. The maximal supporting force of the superhydrophobic copper column has also been investigated in comparison to real water striders.
- Wu, Xufeng,Shi, Gaoquan
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- Antioxidant resveratrol protects against copper oxide nanoparticle toxicity in vivo
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The upsurge in copper oxide nanoparticle (CuONP) applications in various fields triggers hazardous effects on health. Resveratrol, a polyphenol found in plants of stilbene class, has been reported to decrease oxidative stress. The current study investigated the protective effect of resveratrol (RVT) against CuONP-induced hepatotoxicity and nephrotoxicity in male Wistar rats. CuONPs were prepared by precipitation method and characterized by X-ray diffraction (XRD) technique and scanning electron microscopy (SEM). Average crystallite size, lattice parameters (a, b, and c), volume of unit cell, and X-ray density were found to be 33?nm, (a = 4.691??, b = 3.409??, and c = 5.034??), 79.4??3, and 6.506?g/cm3, respectively, from XRD pattern. SEM showed uniform morphology of synthesized nanoparticles. Severe hepatic and renal injury was found in CuONP (300?mg/kg/day intragastrically (i.g.)) group after 7?days as shown by significantly increased serum levels of ALT, AST, creatinine, urea, and total oxidant status along with histopathological alterations. Resveratrol (60?mg/kg) treatment prevented the toxic effects induced by CuONPs. In conclusion, our data showed protective activity of resveratrol against toxic effects of copper oxide nanoparticles presumably through its antioxidant properties. [Figure not available: see fulltext.].
- Khalid, Sana,Afzal, Nabeel,Khan, Junaid Ali,Hussain, Zulfia,Qureshi, Anas Sarwar,Anwar, Hafeez,Jamil, Yasir
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- Real-time in-situ monitoring of the topotactic transformation of TlCu3Se2 into TlCu2Se2
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The solid state transformation of monoclinic TlCu3Se2 into tetragonal TlCu2Se2 by oxidative copper leaching in concentrated ammonia solution has been studied in situ by the use of synchrotron radiation. The diffraction patterns of parent and daughter phase are both sharp, indicating a strong topotactic relationship between them that effectuates a rapid change by chimie douce performed at +19 °C. The transformation rate is strongly connected to the access of oxygen from the surrounding air. The transformation was followed in a real-time mode, being almost complete after 2.5 h with 1 h incubation due to low oxygen content, as shown from refining the diffraction patterns by Rietveld profile technique.
- ?ngstr?m,Sahlberg,Berger
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- Phase transformation-controlled synthesis of CuO nanostructures and their application as an improved material in a carbon-based modified electrode
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Column-shaped CuO nanorods have been synthesized by a two-step "precursor formation-crystallization" process using a hydrothermal method with advantages of being template- and surfactant-free. The regular particle morphology of the as-prepared material was explored to be produced through a good transformation process coupled with a series of phase changes from CuCl, to Cu2(OH)3Cl, to Cu(OH)2, which rely on heat by using NaOH and n-butylamine solution in a sealed vessel, and finally to CuO. Scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), and Raman spectroscopy were employed to characterize the morphology and structures of our samples. The as-prepared CuO nanostructures have been employed to modify a glassy carbon electrode for nonenzymatic glucose oxidation. Compared with the bare glassy carbon electrode, the CuO modified electrode exhibits satisfactory performance with an apparent rate constant of κ as high as 231.0 M-1 s-1 due to its high specific surface area and especially good electron delivery capability of the CuO nanorods.
- Xue, Zhonghua,Li, Mengqian,Rao, Honghong,Yin, Bo,Zhou, Xibin,Liu, Xiuhui,Lu, Xiaoquan
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- Shape-controlled synthesis of copper telluride micro/nanostructures via a simple electrochemical deposition route
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Shape-controllable synthesis of copper telluride micro/nanostructures has been successfully realized in air at room temperature by a simple galvanostatic electrodeposition route. By tuning experimental parameters such as the original Cu and Te sources, additives, deposition currents and media, copper telluride micro/nanostructures with various morphologies, including nanorod arrays, nanosphere-strewn copper telluride dendrites, copper telluride nanowires and star-like hexagonal copper telluride dendrites, were rapidly deposited in air at room temperature for 5 min. The final products were characterized by various means including X-ray diffraction, scanning electron microscopy, (high-resolution) transmission electron microscopy, and energy-dispersive spectrometry. The mechanisms of copper telluride production in various media are discussed. This journal is the Partner Organisations 2014.
- Ni, Yonghong,Zhang, Huying,Xi, Junjun,Wang, Xuemei,Zhang, Yongmei,Xiao, Yanling,Ma, Xiang,Hong, Jianming
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- Kinetic and mechanistic investigations on oxidation of L-tryptophan by diperiodatocuprate(III) in aqueous alkaline medium
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The oxidation of L-tryptophan (L-TRP) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.20 mol dm-3 was studied spectrophotometrically at 298 K. The reaction between DPC and L-tryptophan in alkaline m
- Shetti, Nagaraj P.,Nandibewoor, Sharanappa T.
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- Light-induced copper(II) coordination by a bicyclic tetraaza chelator through a ligand-to-metal charge-transfer reaction
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To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values and high temperatures are applied. We have investigated the effects of the variation in the pH, different anions, and UV irradiation on the chelation rate. UV spectra of mixtures of Cu2+ and [24.31]adz in water show the existence of a longlived two-coordinated copper(II) intermediate (only counting coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu2+ and [24.3 1]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation of the four-coordinated copper(II) complex at a rate up to 7800 fold higher at 25 °C than in the dark. Anions in the solution were found to have three major effects: competitive inhibition due to CuII binding anions, inhibition of the photoinduced transchelation from UV-absorbing anions, and photoredox inhibition from acido ligands capable of acting as electron donors in LMCT reactions. Dissolved O2 was also found to result in photoredox inhibition 2011 American Chemical Society.
- Holm-Jorgensen, Jacob R.,Jensen, Mikael,Bjerrum, Morten J.
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- Structure and magnetic properties of polynuclear chloro- and hydroxo-bridged copper(II) complexes formed by a tetramacrocyclic derivative of 1,4,7-triazacyclononane
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Two new copper(II) complexes of the ligand 1,2,4,5-tetrakis(1,4,7- triazacyclononan-1-ylmethyl)benzene (Ldur) have been synthesized and characterized by single crystal X-ray studies. The first, [Cu4L dur(μ2-OH)4]Cl2(PF 6)2·8H2O (1), was isolated from a solution of Ldur and Cu2+ at pH 9. Under acidic conditions (pH 3), a polymeric complex, {[Cu4Ldur(μ2- Cl)6](PF6)2·10H2O} n (2), crystallized from solution. In both complexes, each of the four triazacyclononane (tacn) rings of the Ldur ligand facially coordinate to separate metal centres. Pairs of Cu(II) centres are then doubly-bridged by hydroxo groups in 1, leading to tetranuclear complex cation units featuring pairs of isolated copper(II) dimers with Cu2(μ 2-OH)2 cores folded at the O·O lines. Two forms of the tetranuclear units, featuring slightly different Cu2(μ 2-OH)2 core geometries, are present in equal amounts within the crystal lattice. In complex 2, chloro bridging ligands link pairs of Cu(II) centres from neighbouring tetranuclear units, forming a 1D helical polymeric structure. Variable-temperature magnetic susceptibility measurements suggest that the hydroxo-bridged copper(II) centres within one of the tetranuclear units in 1 are weakly antiferromagnetically coupled (J = -27 cm-1), whilst those in the other interact ferromagnetically (J = +19 cm-1). Similar measurements indicate weak ferromagnetic coupling (J = +16 cm-1) for the chloro-bridged copper(II) centres in 2.
- Battle, Andrew R.,Graham, Bim,Spiccia, Leone,Moubaraki, Boujemaa,Murray, Keith S.,Skelton, Brian W.,White, Allan H.
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- Enhancing Photocatalytic Activity of Cu2O in Degradation of Sulphonic Acid-Based Dye
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In the present investigation, we synthesized copper (I) oxide nanoparticles (NPs) by the coprecipitation method. The obtained materials were characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDXA), field emission scanning electron microscopy (FESEM), Transmission Electron Microscopy (TEM), and the Brunauer-Emmett-Teller (BET)/Barrett-Joyner-Halenda (BJH) Method. Surface areas and the average particle size were evaluated to be around 4.20 ± 0.04 m2 g?1 and 28 nm, respectively. Then, Ag/Cu2O NPs were synthesized by the same process, examined by X-ray diffraction, and the average particle size obtained was around 118 nm. The photocatalytic degradation of [1,3-Amino phenyl [4-Sulphonic acid][2,6-Dis azo phenyl] 4,4′sulphato ethyl [6′sulpho] ester of Sulphonic acid] (COG-423) was investigated with Cu2O and TiO2 NPs, Cu2O Microparticles (Micro-Ps) and Ag/Cu2O NPs under UV-C irradiation in the presence of hydrogen peroxide as auxiliary oxidant with three parameters including dopant concentration, intensity, and time, as the obtained experimental results showed a good agreement with theoretical values and succeeded to calculate the optimal conditions. Degradation efficiency with Cu2O Micro/NPs under UV-C irradiation (32 W), for 30 min. were determined to be 20.0% and 91.4% respectively, while for the synthesized TiO2 and Ag/Cu2O, NPs were 99.9%. The photocatalytic activity order was of the following nature: Ag/Cu2O ~ TiO2 NPs > Cu2O NPs > Cu2O Micro-Ps.
- Sepahvand,Fazaeli,Jameh-Bozorghi,Niazi
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- New method for the synthesis of cage and polymeric metallosiloxanes
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Cage organometallosiloxanes were synthesized according to a new procedure using monomeric organoalkoxysilanes as the starting compounds. The latter were subjected to hydrolysis immediately before the exchange reaction of sodium silanolate with metal halides. Difficultly accessible metallovinylsiloxanes, metallomethylsiloxanes, and metallosiloxanes containing a functional group in the organic radical at the silicon atom can be readily prepared according to the method proposed.
- Zhdanov,Sergienko,Trankina
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- One-step synthesis of copper compounds on copper foil and their supercapacitive performance
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Nanowire-like Cu(OH)2 arrays, microflower-like CuO standing on Cu(OH)2 nanowires and hierarchical CuO microflowers are directly synthesized via a simple and cost-effective liquid-solid reaction. The specific capacitance of Cu(OH)2, CuO/Cu(OH)2 and CuO are 511.5, 78.44 and 30.36 F g-1, respectively, at a current density of 5 mA cm-2. Therefore, the Cu(OH)2/Cu-foil electrode displays the best supercapacitive performance. The capacitance retention reaches up to 83% after 5000 charge/discharge cycles with the columbic efficiency of ~98%. More importantly, the nanowire Cu(OH)2 transformed into stable nanosheet CuO after about 600 constant current charge-discharge cycles. Additionally, we fabricate an asymmetric supercapacitor with nanowire Cu(OH)2/Cu-foil as a positive electrode, activated carbon (AC) as a negative electrode and 6 mol dm-3 KOH as electrolyte, which exhibits an energy density of 18.3 W h kg-1 at a power density of 326 W kg-1.
- Xu, Panpan,Ye, Ke,Du, Mengmeng,Liu, Jijun,Cheng, Kui,Yin, Jinling,Wang, Guiling,Cao, Dianxue
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- CuO{001} as the Most Active Exposed Facet for Allylic Oxidation of Cyclohexene via a Greener Route
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Allylic oxidation of olefins to α,β-unsaturated carbonyl compounds, especially2-cyclohexen-1-one, by the oxidation of cyclohexene is a prime chemical transformation in the organic industry due to its immense application as an intermediate in the synthesis of fine chemicals, pharmaceutical products, and perfumery products. Herein, we demonstrate microstructured copper oxide (CuO) as an efficient catalyst to oxidize cyclohexene to 2-cyclohexen-1-oneand other value-added intermediates in the presence of aerobic molecular oxygen as oxidant at 80 °C with outstanding conversion of cyclohexene and high selectivity towards 2-cyclohexen-1-one. CuO with diverse shapes was synthesized by a one-step hydrothermal method. CuO plates (PLs) and flowers (FLs) were obtained by varying the ammonia and sodium hydroxide concentration, and CuO spheres (SPs) and hollow spheres (HSs) were prepared by varying the urea concentration. Under optimized conditions, the CuO FL2 catalyst shows the highest conversion of cyclohexene (97.6 %) due to its smaller size, higher surface charge, and high-energy {001} exposed facets. Reaction parameters such as reaction temperature, reaction duration, and catalyst concentration were varied to obtain the optimal reaction conditions for cyclohexene oxidation. Moreover, the CuO FL2 catalyst was recycled several times without any significant loss of catalytic activity, which ascertains recyclability and high stability of the catalyst for industrial use.
- Mal, Diptangshu Datta,Kundu, Joyjit,Pradhan, Debabrata
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- Controlled synthesis of uniform ultrafine CuO nanowires as anode material for lithium-ion batteries
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A simple solution route is used to synthesize ultrafine Cu(OH)2 nanowires by restraining the morphology transformation of early formed 1D nanostructure. The obtained ultrafine nanowires can be well preserved at a low temperature structure transformation in solid state. As anode material for lithium-ion batteries, the ultrafine CuO nanowires exhibit high reversible capacity, superior cycling performance and improved rate capability. The improved electrochemical properties of CuO nanowires are ascribed to their ultrafine size which lead to the reduced over-potential, extra reversible reactions at low potentials and improved interface performance between the electrode and electrolyte.
- Wang, Fei,Tao, Weizhe,Zhao, Mingshu,Xu, Minwei,Yang, Shengchun,Sun, Zhanbo,Wang, Liqun,Song, Xiaoping
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- Structural characterization, ROS-inductive and proteasome inhibitory properties of ternary and binary copper(II) complexes of N2- and N2O2-ligands
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The four copper(II) complexes involving ethylenediamine-N,N-diacetic acid (H2edda) and ethylenediamine (en), viz. [Cu(edda)(en)]H2O 1, [Cu(en)Cl2] 2, [Cu(edda)] 3 and [Cu2(Hedda)2Cl2] 4, were synthesized and characterized by various physical means. The crystal structures of 1 and 4 established them as mononuclear and dichlorido-bridged dicopper(II) complexes respectively. Complexes 1 and 4 showed weak and strong antiferromagnetic Cu...Cu interaction. Dynamic light scattering data of 3 suggested it to be a 3-dimensional coordination polymer in aqueous solution, gel and solid forms. The copper(II) species of 1-4 in aqueous solution were analysed by UV-visible and molar conductivity data. The weak hydroxyl radical-inducing property of free copper(II) ions in solution was enhanced by the chelation of both types of ligands. However, chelation of each or both of these ligands reduce the strong proteasome inhibitory property of the copper(II). All complexes inhibited the three proteolytic sites of the 20S proteasome, with the Trypsin-like site been mostly selectively inhibited.
- Chan, Cheang Wei,Lai, Jing Wei,Ooi, Ing Hong,Er, Hui Meng,Chye, Soi Moi,Tan, Kong Wai,Ng, Seik Weng,Maah, Mohd Jamil,Ng, Chew Hee
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- Simple synthesis of surface-modified hierarchical copper oxide spheres with needle-like morphology as anode for lithium ion batteries
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Hierarchical, nanostructured copper oxide spheres were synthesized in a stirred solution of cupric acetate and ammonium hydroxide. Cetyltrimethylammonium bromide (CTAB) was used as a surfactant to modify the surface morphology of CuO spheres. Ordered nano-needle arrays can be formed on the surface of the CuO spheres (instead of disordered nano-leaves) in the presence of CTAB. Each CuO sphere is about 2 μm in diameter and possesses a large number of nano-needles that are about 20-40 nm in width and more than 300 nm in length. The needle-like hierarchical structure can greatly increase the contact area between CuO and electrolyte, which provides more sites for Li+ accommodation, shortens the diffusion length of Li+ and enhances the reactivity of electrode reaction, especially at high rates. After 50 cycles, the reversible capacity of the prepared needle-like CuO can sustain 62.4% and 56.4% of the 2nd cycle at a rate of 0.1C and 1C, respectively.
- Xiang,Tu,Zhang,Zhou,Wang,Shi
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- In situ structure evolution from Cu(OH)2 nanobelts to copper nanowires
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In situ structural evolution from Cu(OH)2 nanobelts to copper nanowires has been studied by transmission electron microscopy in a vacuum of 3 × 10-8 Torr. The decomposition follows the sequence of Cu(OH)2 → CuO → Cu2O → Cu. The decomposition from Cu(OH)2 to CuO is attributed to electron beam radiation damage. The reduction from CuO to Cu2O is attributed to heat-induced decomposition between 50 and 200°C. For the Cu(OH)2 nanobelts synthesized using the copper grid with and without a carbon coating, the decomposition from Cu2O to Cu takes place between 200 and 300°C and 300 and 600°C, and the final Cu takes the forms of polycrystalline nanowires sheathed with graphitic carbon and nanoparticles, respectively. Therefore, because of the nanostructured nature of the nanowires and large surface area, introducing carbon into the sample synthesis can reduce the decomposition temperature by almost half. This study demonstrates a possible approach for creating metallic copper nanowires by heat-induced decomposition under vacuum at 300°C or even lower.
- Wang, Zhong Lin,Kong, Xiang Yang,Wen, Xiaogang,Yang, Shihe
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- The interaction of Cu2 + ions and NaDC micelles.
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By mixing an aqueous solution of CuCl2 with an NaDC aqueous solution of various concentration and initial molar ratio, seven coordinated samples with distinct appearances and characters were obtained. Their structures and components were investigated by FT-IR spectroscopy, EXAFS (the extended X-ray absorption fine structure), thermal analysis, X-ray diffraction, laser light scattering, TEM (transmission electron micrograph), element analysis and ICP (inductively coupled plasma) analysis. The following conclusions were given: (1) The complexes of Cu2+-NaDC with distinct appearances and properties were synthesized. (2) After Cu(DC)2 dissolved in NaDC aqueous solution, larger micelles (30-90 nm diameter) formed in the supernate, it is a mixed micelle with Cu(DC)2 and NaDC. So these micelles are a new kind of micelle containing two kinds of metal ions. This is a new result using metal ions as bridges to form micelle. (3) According to the different concentration of Cu2+ to NaDC, the complexes formed as gel or poly-crystals. Both the composition of gel complexes and the coordination structure of carboxyl groups with metal ions varied with the initial molar ratio of Cu2+ to Na+. The gel complexes exhibits the non-stoichiometric character. (4) These results are in agreement with physiological condition. All the different states such as gel, precipitate, micelles of various structures are present in bile of gallbladder. We can suggest an ideal model of the interaction between Cu2+ and bile salts in vivo.
- Sun,Yang,Zhang,Hu,Soloway,Weng,Wu
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- Preparation and characterization of Cu(OH)2 and CuO nanowires by the coupling route of microemulsion with homogenous precipitation
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Using CuSO4 and NH3{dot operator}H2O as raw materials, one-dimensional (1D) Cu(OH)2 nanowires were prepared by the coupling route of microemulsion with homogenous precipitation. The morphology and structure of products were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicate that the as-prepared Cu(OH)2 nanowires are of high purity and are single crystalline with orthorhombic structure. The diameter of Cu(OH)2 nanowires ranges from 33?nm to 46?nm and the length ranges from 400?nm to 2000?nm. The effects of different conditions such as the molar ratio of water to surfactant (ω), reactant concentration and the aging time on the morphology and the size of the products were studied. 1D CuO nanowires could be simply obtained by the dehydration of Cu(OH)2, while maintaining the wire-shaped architecture. The catalytic performances of CuO nanocrystals on the thermal decomposition of ammonium perchlorate (AP) were also studied.
- Li, Chengfa,Yin, Yidong,Hou, Haige,Fan, Naiying,Yuan, Fulong,Shi, Yanmei,Meng, Qingling
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- Coordination compounds of 3d-metal 5-sulfosalicylates with thiosemicarbazide
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Copper(II), nickel(II), and cobalt(III) 5-sulfosalicylate complexes with thiosemicarbazide were synthesized and characterized by elemental analyses, IR spectra, diffuse reflectance spectra, and thermo-gravimetric data.
- Koksharova,Kurando,Stoyanova
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- α-Keggin tungstogermanate-supported transition metal complexes: Hydrothermal synthesis, characterization, and magnetism of Cu 2(phen)4(GeW12O40) and [Ni 2(bpy)4(H2O)2(GeW12O 40)]s2H2O
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Two new α-Keggin polyoxometalates, [Cu2(phen) 4(GeW12O40)] (1) and [Ni2(bpy) 4(H2O)2(GeW12O40)] ·2H2O (2) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, single-crystal X-ray diffraction, and magnetic properties. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, and 1 is assembled into two-dimensional (2-D) layers parallel to (1 0 1) based on the adjacent phen π···π stacking interactions (3.788(8) A). Variable temperature magnetic measurements show ferromagnetic behavior from 300 to 2 K. Compound 2 crystallizes in the triclinic system, space group P-1, and 2 is assembled into 2-D layers parallel to (1 0 1) based on the adjacent bpy π···π stacking interactions (3.07 A). Variable temperature magnetic measurements show a weak ferromagnetic behavior from 300 to 26 K followed by antiferromagnetic behavior below 26 K.
- Zhang, Bi-Song,Wu, Chang-Sheng,Qiu, Jian-Ping,Li, Yun-Xia,Liu, Zhen-Xiang
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- Cu(II) and Zn(II) complexes incorporated with active analogue fragments molecule of the aristolochic acid: Crystal structure and biological activity
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Two complexes, [Cu(MDPAc)2(Phen)(H2O)·H2O] (MDPAc = 3,4-(methylenedioxy)phenylacetic-carboxylate, Phen = 1,10-Phenanthroline) and [Zn(MDPAc)2(2,2′-bipy)] (2,2′-bipy = 2,2′-bipyridine), were synthesized and succe
- Feng, Jing,Lei, Yi-Zhu,Wang, Ren-Shu,Wang, Yuan-Lan
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- Investigation of kinetic parameters for ammonium perchlorate thermal decomposition in presence of gCN/CuO by TG-MS analysis and kinetic compensation correction
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The desire to develop a benign burn rate modifier for propellants has accentuated polymeric carbon nitride (gCN) as a potential candidate for the thermal decomposition of ammonium perchlorate (AP). Here, we have synthesized composites of leaf-shaped CuO and gCN via a facile sonochemical approach. From DSC analysis, the addition of gCNCuO1 reduced the decomposition temperature of AP by 59°C and increased the heat release by ~ 1.4 times that of pure AP. The kinetics of AP decomposition was well investigated via in-situ TG-MS technique. From evolved gas analysis evolution of NO, Cl, HCl, N2O/CO2, NO2 and Cl2 fragments were detected. The quantitative interpretation of kinetic parameters for AP decomposition was done using Coats-Redfern method and the normalization of E values were carried out by applying Kinetic Compensation Correction (KCC). After normalization, E values were decreased by 17 ?kJ/mol and 18 ?kJ/mol for the first and second stages respectively.
- Jos, Jisna,Mani, Gladiya,Mathew, Suresh,Radhakrishnan Nair, P.
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- A comparative Study Between Fluka and Microshield Modeling Calculations to study the Radiation-Shielding of Nanoparticles and Plastic Waste composites
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A comparative study has been conducted by using Monte Carlo FLUKA code and Microshieldsoftware programs to study the radiation shielding properties of plastic waste mixed with nano copper oxide (CuO) and phosphotungstic acid (PTA). The variousdiverse percentages of new nanocomposite have been prepared using the compression moulding technique, then they are characterized using Fourier transfer infrared spectrophotometer (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD). The new nanocomposite has been established as a effective shielding material towards gamma radiation due to the presence of dense materials, like nano copper oxide and phosphotungstic acid. The gamma radiation attenuation has been established by using the previously mentioned methods. The results have proved that the mass attenuation coefficients (μm) and effective atomic (Zeff), and electron densities (Nel) of the samples increased with increasing the phosphotungstic acid (PTA) content while the half-value layer (HVL), the tenth value layer (TVL), and the mean free path (MFP) decreased as PTA increased.
- El-Taher, Atef,Zakaly, Hesham M. H.,Pyshkina, Mariia,Allam, Elhassan A.,El-Sharkawy, Rehab M.,Mahmoud, Mohamed E.,Abdel-Rahman, Mohamed A. E.
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p. 1083 - 1090
(2021/04/09)
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- Thiamethoxam Insecticide Degradation with a Leaf-Like Cupric Oxide Monoclinic Structure Synthesized via the Microwave Method
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Abstract: Leaf-like cupric oxide (CuO) with a high purity phase monoclinic structure was synthesized via a microwave method for use as a photocatalyst in the degradation of thiamethoxam insecticide. The synthesis process used copper nitrate and ammonia solution as precursors. The suspensions were treated via microwave irradiation at 600–800 W for 30 min, followed by a constant-temperature calcination process. The phase transitions, thermal stabilities, morphologies, chemical compositions, functional groups, and optical properties of the resulting leaf-like CuO powders were characterized via X-ray powder diffraction, TGA/DSC, SEM, particle size distribution analysis, EDS, FT-IR, UV-DRS, and PL. The experimental findings showed that increasing the microwave power resulted in favorable chemical and physical properties for the powders’ photocatalytic reactions, such as high purity phases, high crystallinity, high uniformity of the leaf-like shapes, smaller particle sizes, narrower size distributions, lower energy bandgaps, and lower rates of electron-hole pair recombination. The photocatalytic degradation of thiamethoxam insecticide using these leaf-like CuO powders under visible light illumination was studied. The concentration of thiamethoxam was analyzed using UV-Vis spectrophotometry. The highest thiamethoxam degradation efficiency was achieved by the CuO powder synthesized via microwave irradiation at 800 watts. Its efficiency was 48.65% in 60 min at a kinetic rate constant of 10.9 × 10?3 min?1.
- Jansanthea,Saovakon,Chomkitichai,Ketwaraporn,Maneepong,Chaiwong,Jaisee,Wansao,Wanaek,Pookmanee
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p. 667 - 678
(2021/06/02)
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- An improved non-enzymatic electrochemical sensor amplified with CuO nanostructures for sensitive determination of uric acid
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This study displays the facile and fluent electrochemical determination of uric acid (UA) through exceptional copper oxide nanostructures (CuO), as an effective sensing probe. The copper oxide nanostructures were fabricated via an aqueous chemical growth method using sodium hydroxide as a reducing agent, which massively hold hydroxide source. Copper oxide nanostructures showed astonishing electrocatalytic behavior in the detection of UA. Different characterization techniques such as XRD, FESEM, and EDS were exploited to determine crystalline nature, morphologies, and elemental composition of synthesized nanostructures. The cyclic voltammetry (CV) was subjected to investigate the electrochemical performance of UA using copper oxide nanostructures modified glassy carbon electrode CuO/GCE. The CV parameters were optimized at a scan rate of 50 mV/s with -0.7 to 0.9 potential range, and the UA response was investigated at 0.4 mV. PBS buffer of pH 7.4 was exploited as a supporting electrolyte. The linear dynamic range for UA was 0.001-351 mM with a very low limit of detection observed as 0.6 μM. The proposed sensor was successfully applied in urine samples for the detection of UA with improved sensitivity and selectivity.
- Agarwal, Shilpi,Ameen, Sidra,Buledi, Jamil A.,Fatima, Almas,Gupta, Vinod Kumar,Karimi, Fatemeh,Malakmohammadi, Salima,Mallah, Arfana,Memon, Saba A.,Solangi, Amber R.
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p. 481 - 491
(2021/05/26)
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- A copper nitride catalyst for the efficient hydroxylation of aryl halides under ligand-free conditions
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Copper nitride (Cu3N) was used as a heterogeneous catalyst for the hydroxylation of aryl halides under ligand-free conditions. The cubic Cu3N nanoparticles showed high catalytic activity, comparable to those of conventional Cu catalysts with nitrogen ligands, demonstrating that the nitrogen atoms in Cu3N act as functional ligands that promote hydroxylation.
- Mitsudome, Takato,Mizugaki, Tomoo,Xu, Hang,Yamaguchi, Sho
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supporting information
p. 6593 - 6597
(2021/08/10)
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- Synthesis, structural, vibrational and DFT investigation of new binuclear molecular Pd–Cu and Cu–Cu complexes formed by Schiff base and hexafluoroacetylacetonate building blocks
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In this work, the first binuclear molecular noble metal-contained complex from the Schiff base (SB) and β-diketonate building blocks, viz. [Pd(acacen)Cu(hfac)2], has been synthesized and investigated in comparison with the homometallic binuclear analog [Cu(acacen)Cu(hfac)2]. The detailed comparative characterization of the structure of these new compounds as well as their molecular SB components [M(acacen)] was performed using crystallography, vibrational spectroscopy and DFT calculations. Experimental IR bands have been assigned based on DFT calculations. The Hirshfeld surface analysis was used as a tool for the better insight into intermolecular contacts. It was shown that despite both bimetallic complexes had similar molecular structure and packing style, the nature of the closest intermolecular contacts in [M(acacen)Cu(hfac)2] differed considerably. A topological analysis of the electron density distribution in [M(acacen)] and [M(acacen)Cu(hfac)2] complexes was carried out and the most probable paths of bond cleavage during decomposition of the compounds were revealed. The binding energies of the molecular components in binuclear complexes were also calculated.
- Basova, Tamara V.,Kovaleva, Evgenia A.,Krasnov, Pavel O.,Morozova, Natalya B.,Nikolaeva, Nataliya S.,Smolentsev, Anton I.,Sukhikh, Alexander A.,Vikulova, Evgeniia S.
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- Preparation of different-sized copper nanoparticles by reducing copper hydroxide and application in lithium-based grease
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Copper nanoparticles with different average particle sizes of 61–139 nm were facilely prepared by the wet chemical reduction of copper hydroxide without or with the use of organic modifier. Sodium dodecyl benzene sulfonate as an organic modifier effective
- Li, Jitai,Wang, Aili,Yin, Hengbo,Zhang, Jin
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p. 2372 - 2381
(2020/01/21)
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- Use of synergistic effects of the co-catalyst, p-n heterojunction, and porous structure for improvement of visible-light photocatalytic H2 evolution in porous Ni2O3/Mn0.2Cd0.8S/Cu3P@Cu2S
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The efficient separation and transfer of photogenerated charge carriers play indispensable roles in improving the photocatalytic H2 evolution activity. Herein, we designed a Ni2O3-modified Mn0.2Cd0.8S/Cu3P@Cu2S (MCS/CPS) p-n heterojunction structure with a porous morphology for efficient and stable photocatalytic H2 evolution under visible-light irradiation. Novel porous Cu3P@Cu2S was obtained using a vulcanization method and Cu2S nanoparticles were grown uniformly in situ on the surface of Cu3P. Ni2O3 was adopted as a co-catalyst on the MCS/CPS p-n heterojunction surfaces to promote electrons transfer. Due to the synergistic effects of the co-catalyst, p-n heterojunction, and porous morphology, the as-synthesized Ni2O3/MCS/CPS composite with 9 wt% Ni2O3 and 2.5 wt% CPS exhibits an optimal photocatalytic H2 evolution rate of 9.2 mmol g?1 h?1, which is 14.4 and 2.4 times higher than those of pure MCS and 9%Ni2O3/MCS, respectively. Meanwhile, the optimal sample exhibits an apparent quantum efficiency of 33.5% at 420 nm and an excellent stability under 20 h of irradiation. Moreover, a possible mechanism for the improved photoactivity of the as-synthesized Ni2O3/MCS/CPS composite has been discussed in this paper.
- Zhang, Dafeng,Tang, Yunxiang,Qiu, Xiaoxue,Yin, Jie,Su, Changhua,Pu, Xipeng
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- Optimal d-band-induced Cu3N as a cocatalyst on metal sulfides for boosting photocatalytic hydrogen evolution
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The development of highly active and non-noble cocatalysts is crucial for sustainable hydrogen (H2) generation through photocatalytic water splitting. Herein, Cu3N nanocrystals (~15 nm) have been first used as a cocatalyst coupled with CdS for efficient photocatalytic H2 evolution with a rate of ~4512 μmol g-1 h-1, achieving a dramatic improvement of 851-fold compared to bare CdS. Mechanistic studies revealed that the appropriate d-band center of Cu3N (-1.875 eV) with promoted photogenerated charge carrier kinetics induced its intrinsic activity, as a result of the balance between the adsorption and desorption of H species.
- Guo, Qing,Huang, Limin,Li, Xu-Bing,Liang, Fei,Sun, Zongzhao,Wang, Yang,Wu, Li-Zhu,Xia, Shu-Guang,Zhang, Z. Conrad
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supporting information
p. 22601 - 22606
(2020/11/21)
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- A strategy to control the grain boundary density and Cu+/Cu0 ratio of Cu-based catalysts for efficient electroreduction of CO2 to C2 products
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Cu(OH)2/CuO nanocomposite-derived Cu2O/Cu was highly efficient for CO2 electroreduction to C2 products. The highest faradaic efficiency and current density could reach 64.5% and 26.2 mA cm-2, respectively. By changing the calcination time, moderate grain boundary density and the Cu+/Cu0 ratio in catalysts can be controlled, leading to a large number of active sites and low interfacial charge transfer resistance.
- Chen, Chunjun,Sun, Xiaofu,Yan, Xupeng,Wu, Yahui,Liu, Mingyang,Liu, Shuaishuai,Zhao, Zhijuan,Han, Buxing
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supporting information
p. 1572 - 1576
(2020/03/23)
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- EXAFS Study on the Coordination Chemistry of the Solvated Copper(II) Ion in a Series of Oxygen Donor Solvents
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The structures of the solvated copper(II) ion in water and nine organic oxygen donor solvents with similar electron-pair donor ability, but with different space-demanding properties at coordination, have been studied by EXAFS. N,N′-Dimethylpropyleneurea and N,N,N′,N′-tetramethylurea are sufficiently space demanding at coordination to make the axial positions not accessible, resulting in square-planar copper(II) solvate complexes with an intense green color. The mean Cu-O bond distances in these two solvate complexes are 1.939(3) and 1.935(3) ?, respectively. The best fits of the remaining solvates, which are light blue in different hues, are obtained with a Jahn-Teller distorted-octahedral model consisting of four strongly bound solvent molecules in the equatorial positions at 1.96(2) ? and two in the axial positions but with different Cu-Oax bond distances: ca. 2.15 and 2.32 ?. This is in agreement with observations in solid-state structures of compounds containing hexaaquacopper(II) complexes crystallizing in noncentrosymmetric space groups and all reported crystal structures containing a [Cu(H2O)5(O-ligand)] complex with Jahn-Teller distortion. Such a structure is in agreement with previous EPR and EXAFS studies proving the hydrated copper(II) ion to be a noncentrosymmetric complex in aqueous solution. The refinements of the EXAFS data of the solids [Cu(H2O)6](ClO4)2, [Cu(H2O)6](BrO3)2, [Cu(H2O)6]SiF6, Cu(NO3)2·2.5H2O, and CuSO4·5H2O gave Cu-O bond distances significantly different from those reported in the crystallographic studies but similar to the configuration and bond distances in the hydrated copper(II) ion in aqueous solution. This may depend on whether the orientation of the axial positions is random in one or three dimensions, giving a mean structure of the solid with symmetry higher than that of the individual complexes. This study presents the very first experimental data from the new X-ray absorption spectroscopy beamline Balder at the MAX IV synchrotron radiation facility in Lund, Sweden, as well as the utilized properties of the beamline.
- Bajnóczi, éva G.,Just, Justus,Klementiev, Konstantin,Lundberg, Daniel,Persson, Ingmar,Sigfridsson Clauss, Kajsa G. V.
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- Green synthesis of CuO nanostructures with bactericidal activities using Simarouba glauca leaf extract
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For the first time, copper oxide (CuO) nanostructures were synthesized through a new green route using the leaf extract of S. glauca and characterized. The XRD pattern of CuO disclosed diffraction peaks correspond to monoclinic crystal structured CuO. The SEM and HR-TEM images demonstrated the presence of CuO nanostructures. The detected Cu and O elements through the EDAX analysis reveal the pristine nature of the hierarchical CuO nanostructures. Hence, this work complete that the potential bactericidal activity exhibited by CuO nanostructures against Gram negative E. coli (MTCC 1698) bacterial strain with zone of inhibition of 28 mm.
- Kalaiyan,Prabu,Suresh,Suresh
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- Simple vapor-solid-reaction route for porous Cu2O nanorods with good HER catalytic activity
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In this work, a simple vapor-solid reaction route was designed for the preparation of porous Cu2O nanorods with good HER catalytic performance, employing Cu(OH)2 nanorods as the precursor and ethylene glycol as the reductant. The reaction was carried out under an Ar atmosphere in the temperature range of 200-280 °C for 2 h. The final product was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), (high-resolution) transmission electron microscopy (TEM/HRTEM), X-ray photoelectron spectroscopy (XPS), HAADF-STEM-EDS mapping and nitrogen adsorption-desorption isotherms. It was found that pure Cu2O was always obtained in the temperature range of 200-280 °C and well retained the outline of the precursor. Nevertheless, electrochemical experiments showed that porous Cu2O nanorods prepared at 200 °C (labeled as Cu2O-200) exhibited much stronger HER catalytic activity than those obtained at higher temperatures, which were labeled as Cu2O-220, Cu2O-240, Cu2O-260 and Cu2O-280, respectively. In an alkaline solution of 1.0 M KOH, Cu2O-200 presented a low overpotential of ~184 mV, a small Tafel slope of 106 mV dec?1, and a high durability over 20 h at a current density of 10 mA cm?2. The above good performances were attributed to the high surface area and high-speed electronic transmission networks of Cu2O-200, which provided fast transportation and short diffusion path for the electrolyte and evolved H2 bubbles.
- Wang, Meifang,Cheng, Xiaomei,Ni, Yonghong
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p. 823 - 832
(2019/01/21)
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- 2D Metal–Organic Framework Derived CuCo Alloy Nanoparticles Encapsulated by Nitrogen-Doped Carbonaceous Nanoleaves for Efficient Bifunctional Oxygen Electrocatalyst and Zinc–Air Batteries
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The development of efficient bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) still remains a challenge in a wide range of renewable energy technologies. Herein, CuCo alloy nanoparticles encapsulated by nitrogen-doped carbonaceous nanoleaves (CuCo-NC) have been synthesized from a Cu(OH)2/2D leaf-like zeolitic imidazolate framework (ZIF-L)-pyrolysis approach. Leaf-like Cu(OH)2 is first prepared by the ultrasound-induced self-assembly of Cu(OH)2 nanowires. The efficient encapsulation of Cu(OH)2 in ZIF-L is obtained owing to the morphology fitting between the leaf-like Cu(OH)2 and ZIF-L. CuCo-NC catalysts present superior electrocatalytic activity and stability toward ORR and OER over the commercial Pt/C and IrO2, respectively, which are further used as bifunctional oxygen electrocatalysts in Zn–air batteries and exhibit impressive performance, with a high peak power density of 303.7 mW cm?2, large specific capacity of up to 751.4 mAh g?1 at 20 mA cm?2, and a superior recharge stability.
- Huo, Meiling,Wang, Bin,Zhang, Chaochao,Ding, Shuping,Yuan, Haitao,Liang, Zuozhong,Qi, Jing,Chen, Mingxing,Xu, Yang,Zhang, Wei,Zheng, Haoquan,Cao, Rui
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p. 12780 - 12788
(2019/09/09)
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- Structural Transformations of [CuEn 3]WO4 Complex Salt in the Range 100–390 K and Its Degradation to [CuEn 2](WO4)·2H2O
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The crystal structure of [CuEn3]WO4 (En is ethylenediamine) is studied in the temperature range 100–390 K. Crystallographic data at 100 K are: a = 27.6903(8) ?, c = 9.9405(3) ?, space group P3?, V = 6600.8(4) ?3, Z = 18. Copper atomic coordination is a distorted square bipyramid. Four short Cu–N distances are within 2.038(5)–2.110(6) ?; two long distances are within 2.374(8)–2.514(7) ?. The lengths of N–H…O interionic contacts lie within 1.96–2.17 ?. A temperature elevation makes the Cu–N distances equal: at 298 K they are within 2.066(2)–2.256(3) ?(a = 16.0391(8) ?, c = 9.9608(6) ?, space group P3?c1, V = 2219.1(3) ?3, Z = 6), and at 390 K they are 2.151(6) ?(a = 9.2986(10) ?, c = 10.0520(14) ?, P3?1c, V = 752.7(2) ?3, Z = 2). In the range from 100 K to 390 K the average W–O distances decrease from 1.776 ? to 1.734 ?. Hirshfeld surfaces of complex cations are analyzed. It is shown that with increasing temperature the number of interionic N–H…O contacts decreases. The [CuEn3]WO4 phase is found to be unstable and on storing in air it transforms into [CuEn2](WO4)·2H2O.
- Khranenko,Sukhikh,Komarov, V. Yu.,Gromilov
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p. 1790 - 1798
(2019/12/24)
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- Silica-Protection-Assisted Encapsulation of Cu2O Nanocubes into a Metal–Organic Framework (ZIF-8) To Provide a Composite Catalyst
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The integration of metal/metal oxide nanoparticles (NPs) into metal–organic frameworks (MOFs) to form composite materials has attracted great interest due to the broad range of applications. However, to date, it has not been possible to encapsulate metastable NPs with high catalytic activity into MOFs, due to their instability during the preparation process. For the first time, we have successfully developed a template protection–sacrifice (TPS) method to encapsulate metastable NPs such as Cu2O into MOFs. SiO2 was used as both a protective shell for Cu2O nanocubes and a sacrificial template for forming a yolk–shell structure. The obtained Cu2O@ZIF-8 composite exhibits excellent cycle stability in the catalytic hydrogenation of 4-nitrophenol with high activity. This is the first report of a Cu2O@MOF-type composite material. The TPS method provides an efficient strategy for encapsulating unstable active metal/metal oxide NPs into MOFs or maybe other porous materials.
- Li, Bo,Ma, Jian-Gong,Cheng, Peng
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supporting information
p. 6834 - 6837
(2018/03/28)
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- Jahn–Teller Effect in the [CuEn3]CrO4 Structure
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A change in the coordination of the copper atom in the crystal structure of [CuEn3]CrO4 (En is ethylenediamine) in studied in the range 150–300 K. According to the single crystal X-ray diffraction (XRD) data at 150 K, the single crystal has a complicated twining character based on the triclinic cell (a = 9.027(2) ?, b = 13.335(3) ?, c = 13.339(3) ?, α = 71.77(3)°, β = 70.53(3)°, γ = 70.42(3)°) composed of two crystallographically independent [CuEn3]2+ complex cations. The coordination of copper atoms is a distorted square bipyramid; four short Cu–N distances lie in the range 2.049-2.082 ?; two long ones are 2.415 ? and 2.470 ?. According to the differential scanning calorimetry (DSC) data, near 218 K there is a phase transition. The single crystal XRD experiment performed at 250 K (a = 15.6992(19) ?, c = 9.7573(13) ?, V = 2082.6(6) ?3, space group P3 ˉ c1 (No. 165), Z = 6) shows that chromate anions are disordered over three positions about the с axis, and Cu–N distances are 2.120-2.177 ?. According to the DSC data, on further heating the structure undergoes yet another two alterations (260 K and 270 K) due to the disordering of oxygen atoms of chromate anions and the subsequent equalization of Cu–N distances. At 300 K in the structure (a = 9.0778(6) ?, c = 9.7715(5) ?, V = 697.4 ?3, space group P3 ˉ c (No. 163), Z = 2) all Cu–N distances are 2.155 ?, and chromate anions are disordered over six positions about the с axis. A comparative crystal chemical analysis of the packing of the studied structures is carried out.
- Sukhikh,Khranenko,Pishchur,Gromilov
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p. 657 - 663
(2018/07/15)
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- A novel glucosamine-linked fluorescent chemosensor for the detection of pyrophosphate in an aqueous medium and live cells
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There is growing interest in monitoring the level of pyrophosphate (PPi) in biological processes due to its significant roles in live organisms. In this paper, we described a Cu2+ ensemble based chemosensor (GN-Cu2+) for highly selective detection of PPi in an aqueous medium and live cells. The fluorescence silent ensemble, GN-Cu2+, was facilely prepared by complexing of the glucosamine-1,8-naphthalimide fluorescent ligand (GN) with paramagnetic Cu2+. The structure of GN was confirmed using 1H NMR, 13C NMR and high-resolution mass spectroscopy (HRMS) assays. The spectroscopic characteristics of GN-Cu2+ were verified in detail through fluorescence emission and UV-vis spectra titration. The decomplexation of GN-Cu2+ by PPi led to the liberation of the fluorescent ligand, GN, and thus the fluorescence was switched on. Spectroscopic studies revealed that GN-Cu2+ possesses excellent tolerance to various anions and even other phosphate series, such as AMP, ADP, ATP, and inorganic phosphate (Pi). The detection limit for PPi was calculated to be 1.0 μM. GN-Cu2+ features several advantages, such as high selectivity, reliability at physiological pH and low cytotoxicity. Intracellular fluorescence imaging measurements indicated that GN-Cu2+ is cell membrane permeable and has been successfully used for the detection of PPi in live MD-AMB-231 cells.
- Meng, Qingtao,Wang, Yue,Feng, Huan,Zhou, Fang,Zhou, Bo,Wang, Cuiping,Zhang, Run,Zhang, Zhiqiang
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p. 2675 - 2681
(2018/02/19)
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- The in situ transformation of the co-product formaldehyde in the reversible hydrolysis of 1,3-dixoane to obtain 1,3-propanediol efficiently
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Herein, a strategy is developed for efficient production of l,3-propanediol via the hydrolysis of 1,3-dioxane by the in situ transformation of the co-product formaldehyde (HCHO) in the presence of Eu(OH)3. The reversible hydrolysis reaction is promoted to yield 98% conversion and 99% 1,3-propanediol selectivity. Furthermore, HCHO is converted to formic acid (HCOOH) which could act as an acidic catalyst in the hydrolysis of 1,3-dioxane. The combination of FT-IR and control experiments demonstrates that HCOOH is generated via the hydrolysis of formate species which formed on the surface of Eu(OH)3.
- Wang, Yehong,Zhang, Jian,Zhang, Zhixin,Hou, Tingting,Zhang, Chaofeng,An, Jinghua,Wang, Feng
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supporting information
p. 1455 - 1458
(2018/04/12)
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- Conversion of glycerol to lactic acid catalyzed by different-sized Cu2O nanoparticles in NaOH aqueous solution
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Different-sized Cu2O nanoparticles with the average particle sizes ranging from 115 to 423 nm were prepared starting from CuSO4 using ascorbic acid as the reductant at room temperature. When Cu2O nanoparticles were used as the catalysts for hydrothermal conversion of glycerol at 230°C in a NaOH aqueous solution, Cu2O nanoparticles effectively catalyzed the hydrothermal conversion of glycerol to lactic acid as compared to the conventional hydrothermal conversion of glycerol in a pure NaOH aqueous solution. Small-sized Cu2O nanoparticles showed higher catalytic activity than the large-sized ones. In a wide glycerol concentration range of 1-2.5 mol/L and a low mole ratio of Cu2O nanoparticle to glycerol of 2.5:100, the glycerol conversion and lactic acid selectivity were more than 86.2% and 87.2%, respectively, after reacting at 230°C for 2 h.
- Shen, Lingqin,Yin, Haixu,Yin, Hengbo,Liu, Si,Wang, Aili
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p. 780 - 787
(2017/01/06)
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- Synthesis of Copper-Chelates Derived from Amino Acids and Evaluation of Their Efficacy as Copper Source and Growth Stimulator for Lactuca sativa in Nutrient Solution Culture
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Five tetradentate ligands were synthesized from l-amino acids and utilized for the synthesis of Cu(II)-chelates 1-5. The efficacy of Cu(II)-chelates as copper (Cu) source and growth stimulator in hydroponic cultivation was evaluated with Lactuca sativa. T
- Kaewchangwat, Narongpol,Dueansawang, Sattawat,Tumcharern, Gamolwan,Suttisintong, Khomson
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p. 9828 - 9837
(2017/11/22)
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- Dual role of Cu2O nanocubes as templates and networking catalysts for hollow and microporous Fe-porphyrin networks
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Cu2O nanocubes were used for the synthesis of hollow and microporous Fe porphyrin networks (H-MFePN). In this synthesis, Cu2O nanocubes performed not only as networking catalysts but also as shape controlling templates. MFePN were formed on the surface of the Cu2O nanocubes through azide-alkyne cycloaddition of tetrakis(4-ethynylphenyl) Fe-porphyrin with 1,4-diazidobenzene. H-MFePN showed excellent catalytic activities in carbene insertion into N-H bonds, maintaining their activities during five recycle tests.
- Kang, Daye,Ko, Ju Hong,Choi, Jaewon,Cho, Kyoungil,Lee, Sang Moon,Kim, Hae Jin,Ko, Yoon-Joo,Park, Kang Hyun,Son, Seung Uk
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supporting information
p. 2598 - 2601
(2017/03/09)
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- Energy-level variations of Cu-doped ZnO fabricated through sol-gel processing
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We evaluated the properties and energy levels of Cu-doped ZnO (CZO) crystals synthesized in different Cu ion additions through sol-gel processing. Different CZO crystals were synthesized with Zn-OH and Cu-OH as precursors under sol-gel reactions in base s
- Liau, Leo Chau-Kuang,Huang, Ji-Siou
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p. 153 - 160
(2017/02/10)
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- Structure of Cu(II) and Pd(II) complexes with 2-(2,2-dimethylhydrazone)pentanone-4
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Palladium(II) and copper(II) complexes with 2-(2,2-dimethylhydrazone) pentanone-4 are synthesized for the first time. The compounds are characterized by IR and NMR spectroscopy, elemental and single crystal X-ray diffraction analyses. The palladium complex crystallizes in the space group I41/a; the copper complex crystallizes in the space group P1?. Both compounds are molecular; the palladium chelate core has a distorted square geometry and that of copper has a distorted tetrahedral geometry. The average M–O and M–N bond lengths are respectively 1.9808(15) ? and 2.0427(17) ? for M = Pd, 1.915(8) ? and 1.97(1) ? for M = Cu. The chelate O–M–N angles are 88.32(7)-91.67(7)° for M = Pd, 93.37(4)-99.02(5)° for M = Cu.
- Kuratieva,Vikulova,Shushanyan,Nikolaeva,Dorovskikh,Mikhaleva,Morozova
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p. 1004 - 1008
(2017/10/31)
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- On verdigris, part I: Synthesis, crystal structure solution and characterisation of the 1-2-0 phase (Cu3(CH3COO)2(OH)4)
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Known synthesis approaches for basic copper(ii) acetates, the main components of historic verdrigis pigments were reinvestigated and revealed to be partially irreproducible. A modification of the reaction conditions led to the successful and reproducible synthesis of the 1-2-0 phase (Cu3(CH3COO)2(OH)4 = 1Cu(CH3COO)2·2Cu(OH)2·0H2O). The phase composition was derived from elemental and thermal analysis and confirmed by the crystal structure solution using synchrotron X-ray powder diffraction (XRPD) data. The 1-2-0 phase crystallises in space group Pbca with lattice parameters of a = 20.9742(1) ?, b = 7.2076(1) ?, and c = 13.1220(1) ?. The crystal structure consists of Cu2(CH3-COO)2(OH)4/3(OH)2/21/3- dimers, which are interconnected by corner sharing Cu(OH)2/3(OH)2/21/3+ squares forming layers perpendicular to the a-axis. The deep blue color of the solid originates from a reflectance maximum at 472 nm and from an absorbance maximum at 676 nm that is comparable with other historic blue pigments like azurite or Egyptian blue. IR- and Raman-spectroscopic properties of the solid were investigated as well, which demonstrated that the obtained product is identical with a previously synthesised verdigris phase that was obtained by applying historical procedures. Therefore, our reference data for the title compound will help to improve the understanding of the multiphase mixtures occurring in historic verdigris samples. The magnetic properties of the 1-2-0 phase were also investigated. At low temperatures the magnetic susceptibility is well described by a spin-1/2 Heisenberg chain with uniform antiferromagnetic nearest-neighbour spin exchange coupling of only one of three Cu magnetic moments. Due to the very strong antiferromagnetic coupling of the Cu2(CH3-COO)2(OH)4/3(OH)2/21/3- dimers their contribution to magnetism becomes relevant above ~140 K, which results in the presence of two distinct temperature regions where Curie-Weiss behaviour of the magnetic susceptibility with different Curie constants and Weiss temperatures is found.
- Bette, Sebastian,Kremer, Reinhard K.,Eggert, Gerhard,Tang, Chiu C.,Dinnebier, Robert E.
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p. 14847 - 14858
(2017/11/14)
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- Cubic nano-copper(I) oxides as reusable catalyst in consecutive decarboxylative C[sbnd]H arylation and carbonylation: rapid synthesis of carbonyl dibenzofurans
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Consecutive chemo- and regio-selective decarboxylative C[sbnd]H arylation, followed by carbonylative C[sbnd]C coupling of aryl halide with isocyanide/alcohol was applied for the first time in one-step synthesis of carbonyl dibenzofurans with nanodomain cuprous oxide under aerobic condition. As a proof of concept, several novel dibenzofurans were synthesized from 2-(3-iodophenoxy)benzoic acid in good yield. The tandem protocol eliminates the use of excess catalysts, hazardous organic solvents, heavy metals like palladium or rhodium, ligands, oxidants, or external additives. More importantly, the cubic Cu(I) nanocatalyst can be recovered and recycled for three consecutive reactions without any significant loss of catalytic activity or any change in its morphology. Use of water as solvent and reusable catalyst makes the reaction environment friendly.
- Pal, Rammyani,Chatterjee, Nivedita,Roy, Manas,Sarkar, Sabyasachi,Sarkar, Swarbhanu,Sen, Asish Kumar
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supporting information
p. 4956 - 4960
(2016/10/21)
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- A new fluorescence chemosensor for selective detection of copper ion in aqueous solution
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A new fluorescent chemosensor based upon 2,5-diphenylfuran and di(2-picolyl)amine (DPA) was designed and synthesized. Its structure was confirmed by single crystal X-ray diffraction and its photophysical properties were studied by absorption and fluorescence spectra. This compound can be used to determine Cu2+ ion with high selectivity among a series of cations in aqueous DMSO. This sensor forms a 1:1 complex with Cu2+ and displays fluorescent quenching.
- Hu, Yang,Ke, Qian,Yan, Chang,Xu, Cai-Hua,Huang, Xiao-Huan,Hu, Sheng-Li
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p. 2239 - 2243
(2016/05/10)
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- In situ generated highly active copper oxide catalysts for the oxygen evolution reaction at low overpotential in alkaline solutions
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Developing efficient water oxidation catalysts made up of earth-abundant elements has attracted much attention as a step toward for future clean energy production. Herein we report a simple one-step method to generate a low cost copper oxide catalyst film in situ from a copper(ii) ethylenediamine complex. The resulting catalyst has excellent activity toward the oxygen evolution reaction in alkaline solutions. A catalytic current density of 1.0 mA cm-2 and 10 mA cm-2 for the catalyst film requires the overpotentials of only ~370 mV and ~475 mV in 1.0 M KOH, respectively. This catalytic performance shows that the new catalyst is one of the best Cu-based heterogeneous OER catalysts to date.
- Liu, Xiang,Cui, Shengsheng,Qian, Manman,Sun, Zijun,Du, Pingwu
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p. 5546 - 5549
(2016/05/09)
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- Hierarchical Self-Assembly of Flower-Shaped CuO With High Photocatalysis Efficiency for Degrading Rhodamine B
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Flower-shaped CuO with hierarchical microstructures was successfully synthesized through an ultrasound-assisted aqueous chemical method. The comparative experiment results show that the phase and morphology of as-obtained products are greatly affected by the volume of ammonia and the time for keeping ultrasonic irradiation, respectively. The prepared CuO microflowers assembled by nanosheets with needle-like tips exhibit a much higher activity than the commercial CuO for degrading Rhodamine B. Additionally, the photocatalytic performance of as-prepared hierarchical CuO microflowers was also evaluated through the degradation of Methylene blue and Methyl orange under the same conditions.
- Ge, Xinqing,Hu, Hanmei,Zheng, Qiang,Sun, Mei
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p. 1519 - 1525
(2016/06/09)
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- The Species of Fehling's Solution
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A species model for the copper(II)/L-(+)-tartaric acid (LH2, tartH2) aqueous system between pH 1.9 and 12.3 has been established by potentiometric, UV/Vis spectroscopic, solubility and crystallographic studies. Eight species were detected, including the oligonuclear major species Cu8L6H-10 in the neutral region and the mononuclear major species CuL2H-4 in the alkaline region, the latter being associated with Fehling's solution. The octanuclear complex was isolated as its lithium salt Li7[Cu8(L-tartH-2)4(L-tartH-1)2(H2O)6]NO3·19H2O (1). The "Fehling species" CuL2H-4 was crystallized as its sodium, potassium and caesium salts, namely K2Na4[Cu(L-tartH-2)2]·12H2O (2), Na6[Cu(L-tartH-2)2]·9H2O (3), Na6[Cu(L-tartH-2)2]·14H2O (4), and Cs6[Cu(L-tartH-2)2]·8H2O (5). Each of them shows a distorted square-planar environment of copper(II), similar to the related non-chiral cuprate [Cu(rac-tartH-2-κ2O2,O3)2]6- (S. Albrecht, P. Klüfers, Z. Anorg. Allg. Chem. 2013, 639, 280-284). By comparing the components of the UV/Vis spectra of Fehling's solution and the solids, we confirmed the identity of the major solution species.
- H?rner, Thomas G.,Klüfers, Peter
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p. 1798 - 1807
(2016/05/02)
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- CuO nanostructures of variable shapes as an efficient catalyst for [3 + 2] cycloaddition of azides with terminal alkyne
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CuO nanostructures of variable shapes: CuO nanospheres (5-10 nm), CuO nanorods (W × L = 24-27 nm × 124-140 nm) and CuO nanowires (W × L = 8-10 nm × 230-270 nm) have been synthesised to study the effect of shape of the catalyst on the Cu(i)-catalysed "click" azide-alkyne cycloaddition. Cu(i) species were generated in situ by the reduction of CuO nanostructures in the presence of sodium ascorbate. CuO nanowires exhibited highest catalytic efficiency for the cycloaddition reaction between azide and terminal alkyne, featuring short reaction time, soft reaction conditions and complete regioselectivity. We have further extended the study by using azides with varying functional groups (-OCH3 and -NO2) and studied the effect of shape of the nanostructures on the rate of the reaction and yield of the triazole products. The activity trend observed was: CuO-NW > CuO-NR > CuO-NS, irrespective of the presence of electron withdrawing or donating groups on the azide.
- Kaur, Anupamjeet,Mann, Sukhmani,Goyal, Bhupesh,Pal, Bhupender,Goyal, Deepti
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p. 102733 - 102743
(2016/11/09)
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- Antibiofilm and membrane-damaging potential of cuprous oxide Nanoparticles against Staphylococcus aureus with reduced susceptibility to vancomycin
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The antimicrobial effects of copper ions and salts are well known, but the effects of cuprous oxide nanoparticles (Cu2O-NPs) on staphylococcal biofilms have not yet been clearly revealed. The present study evaluated Cu2O-NPs for their antibacterial and antibiofilm activities against heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA). Nanoscaled Cu2O, generated by solution phase technology, contained Cu2O octahedral nanoparticles. Field emission electron microscopy demonstrated particles with sizes ranging from 100 to 150 nm. Cu2O-NPs inhibited the growth of S. aureus and showed antibiofilm activity. The MICs and minimum biofilm inhibitory concentrations ranged from 625 μg/ml to 5,000 μg/ml and from 2,500 μg/ml to 10,000 μg/ml, respectively. Exposure of S. aureus to Cu2O-NPs caused leakage of the cellular constituents and increased uptake of ethidium bromide and propidium iodide. Exposure also caused a significant reduction in the overall vancomycin-BODIPY (dipyrromethene boron difluoride [4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene] fluorescent dye) binding and a decrease in the viable cell count in the presence of 7.5% sodium chloride. Cu2O-NP toxicity assessment by hemolysis assay showed no cytotoxicity at 625 to 10,000 μg/ml concentrations. The results suggest that Cu2O-NPs exert their action by disruption of the bacterial cell membrane and can be used as effective antistaphylococcal and antibiofilm agents in diverse medical devices.
- Singh, Avinash,Ahmed, Asar,Prasad, Kashi N.,Khanduja, Sonali,Singh, Satyendra K.,Srivastava, Janmejai K.,Gajbhiye, Namdeo S.
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p. 6882 - 6890
(2015/11/16)
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- Nanodomain cubic copper (I) oxide as reusable catalyst for the synthesis of amides by amidation of aryl halides with isocyanides
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An environmentally benign chemical process for the C-C coupling of aryl halides with isocyanides in aqueous medium has been developed using cubic copper (I) oxide nanoparticles as reusable catalyst. The use of nano-catalyst eliminates the use of any stabi
- Sarkar, Swarbhanu,Pal, Rammyani,Roy, Manas,Chatterjee, Nivedita,Sarkar, Sabyasachi,Sen, Asish Kumar
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supporting information
p. 623 - 626
(2015/02/19)
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- Catalytic properties of Pd nanoparticles supported on Cu2O microspheres for hydrogen peroxide electroreduction
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Cuprous oxide (Cu2O) were synthesized by a wet-chemical approach in aqueous solution and Pd electrocatalysts supported on cuporus oxide (Pd/Cu2O) and Vulcan XC-72 (Pd/C) were synthesized both via modified sodium borohydride reduction method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) methods were used to characterize the surface morphology and composition of the Cu2O nanoparticles and the catalysts. Linear sweep voltammetry (LSV) and chronoamperometry (CA) were employed to evaluate the activity and stability of the catalysts. The results showed that the Cu2O nanoparticles were spherical with a smooth surface and the average diameter was about 600 nm. Pd nanoparticles decorated the surface of the Cu2O nanospheres and agglomerated slightly and the average size of the Pd nanoparticles was about 10 nm. A certain amount of copper oxide and metallic Cu were formed during the preparation of the Pd/Cu2O catalyst. The Pd catalyst supported on cuporus oxide (Pd/Cu2O) showed a superior performance to the catalyst supported on Vulcan XC-72, which was attributed to two reasons. One was that the Pd/Cu2O catalyst had a larger surface area and the other was that all of the support material components, Cu2O itself, copper oxide and the metallic Cu formed in the process of catalyst preparation, had activity for the H2O2 electroreduction reaction to a certain extent.
- Sun, Limei,Zhang, Shuaishuai,Bao, Wuyunga,He, Wurigamula
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p. 53320 - 53325
(2015/06/30)
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- Formation of short three dimensional porous assemblies of super hydrophobic acetylene black intertwined by copper oxide nanorods for a robust counter electrode of DSSCs
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In this study, we synthesized monolithic copper-oxide nanorods (CuO-NRs) and doped into active super hydrophobic acetylene black (AB) nanocrystals via a fast solvation method. The developed short-dimension assemblies are utilized as counter electrode (CE) materials for energy harvesting in dye sensitized solar cells (DSSCs). Cyclic voltammetry and electrochemical impedance spectroscopy analyses reveal that the hybrid (CuO-NRs/AB) CE displays a fast reduction rate of I3- and boosts hole-cascading as compared to those of individual AB CEs, due to the superior catalytic characteristics of CuO-NRs and the good electrical conductivity of AB. The CuO-NRs/AB based DSSCs exhibit an enhanced power conversion efficiency (PCE) of 8.05%, in contrast to AB (6.51%) and pristine Pt (6.96%) CE based DSSCs under the same experimental conditions. The CuO-NRs/AB CE, along with impressive results, has prospective applications in robust DSSCs.
- Ahmad, Waqar,Chu, Liang,Al-Bahrani, Majid Raissan,Yang, Zhichun,Wang, Siliang,Li, Luying,Gao, Yihua
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p. 35635 - 35642
(2015/05/05)
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- Spectacular photocatalytic hydrogen evolution using metal-phosphide/CdS hybrid catalysts under sunlight irradiation
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A highly efficient and robust heterogeneous photocatalytic hydrogen evolution system was established for the first time by using the CoP/CdS hybrid catalyst in water under solar irradiation. The H2-production rate can reach up to 254000 μmol h-1 g-1 during 4.5 h of sunlight irradiation, which is one of the highest values ever reported on CdS photocatalytic systems in the literature.
- Cao, Shuang,Chen, Yong,Wang, Chuan-Jun,Lv, Xiao-Jun,Fu, Wen-Fu
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supporting information
p. 8708 - 8711
(2015/05/20)
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