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ZHANG Meng TU Xianneng WANG Jingyang FANG Tuo WANG Yanli XU Xiaodong ZHANG Milin CHEN Yitung 《高等学校化学研究》2016,32(4):530-533
In this paper, CuO, CuO/Cu2O, Cu2O, Cu2O/Cu and Cu microcrystals were synthesized via a hydrothermal method by mixing Cu(NO3)2·3H2O and NaOH together in the presence of an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate([BMIM]BF4) or 1-butyl-3-methylimidazolium chloride([BMIM]Cl). The structures and the morphologies of the obtained products were characterized by means of X-ray diffractometer(XRD), field-emission scanning electron microscopy/energy-dispersive spectroscopy(FESEM/EDS), transmission electron microscopy/selected area electron diffraction(TEM/SAED) and Raman spectroscopy. The result of XRD indicates that Cu2O and Cu microcrystals are cubic phase and the Raman spectra confirm the presence of carbon. The results of FESEM and TEM images show Cu2O microcrystals as rule cubes of 2 μm in length and Cu particles of 5 μm in diameter. According to the difference between crystal structures, bi-component and single component products were synthesized by adjusting the reaction conditions. A possible formation mechanism of Cu2O and Cu was proposed in[BMIM]BF4. 相似文献
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A system involving two polymer-supported reagents for the selective and organocatalytic oxidation of alcohols to aldehydes or ketones has been developed in which both polymeric reagents can be recovered and reused. 相似文献
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A highly sensitive and fast-response biosensor based on cupric hydroxide/oxide (Cu(OH)2/CuO) nanotube arrays (CNA) was successfully fabricated in this work. CNAs were prepared on copper electrode surface by simply immersing copper electrode in an aqueous solution of NaOH and (NH4)2S2O8. The morphology and the composition of the CNAs were characterized by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD), respectively. The electrocatalytic activity of the CNA modified copper electrodes (CNA/Cu) towards glucose oxidation was investigated by cyclic voltammetry and amperometry. The CNA/Cu showed good non-enzymatic electrocatalytic responses to glucose in alkaline media and can be used for the development of enzyme-free glucose sensors. 相似文献
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Mehdi Roohani Youssef Habibi Ghanbar Ebrahim Alain Dufresne 《European Polymer Journal》2008,44(8):2489-2498
Nanocomposite materials were prepared from copolymers of polyvinyl alcohol and polyvinyl acetate and a colloidal aqueous suspension of cellulose whiskers prepared from cotton linter. The degree of hydrolysis of the matrix was varied in order to vary the hydrophilic character of the polymer matrix and then the degree of interaction between the filler and the matrix. Nanocomposite films were conditioned at various moisture contents, and the dynamic mechanical and thermal properties were characterized using dynamic mechanical analysis and differential scanning calorimetry, respectively. Tensile tests were performed at room temperature to estimate mechanical properties of the films in the non linear range. All the results show that stronger filler/matrix interactions occur for fully hydrolyzed PVA compared to partially hydrolyzed samples. For moist samples, a water accumulation at the interface was evidenced. The reinforcing effect was found to be all the higher as the degree of hydrolysis of the matrix was high. 相似文献
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The composites of graphene nanosheets decorated by Pt nano clusters have been prepared via reduction of graphite oxide and H2PtCl6 in one pot. Electrochemical experiments show that the composites have superior catalytic performance toward methanol oxidation indicating the graphene may have a splendid future as catalysts carrier in electrocatalysis and fuel cell. 相似文献
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Xiuying Wang Feng Zhang Baiying Xia Xingfu Zhu Jiesheng Chen Shilun Qiu Ping Zhang Jixue Li 《Solid State Sciences》2009,11(3):655-659
Multi-walled carbon nanotubes (MWNTs) have been successfully modified with CuO, Cu2O and Cu nanoparticles via a simple method, and the calcination temperature, the amount of NH3·H2O and soaking time play critical roles in controlling the final products. The modified MWNTs have been characterized by X-ray diffraction, infrared spectrum, scanning electron and transmission electron microscopies. Optical absorption of the obtained products has also been investigated, and the quantum confinement effect was illustrated in the absorption spectra. 相似文献
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Cao M Hu C Wang Y Guo Y Guo C Wang E 《Chemical communications (Cambridge, England)》2003,(15):1884-1885
Reducing Cu(OH)4(2-) with hydrazine hydrate and glucose in the presence of a structure-directing surfactant at room temperature gave Cu and Cu2O nanotubes/nanorods, respectively, whereas facile hydrothermal treatment of Cu(OH)4(2-) precursor resulted in CuO nanotubes/nanorods. 相似文献
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Metallic Cu is considered as the promising functional material owing to its high conductivity and harmlessness. Here, metallic Cu which presents a unique interconnected and continuous structure (Cu superstructure) is prepared using Magnolia grandiflora leaves as the biomass reductant, a green process which avoided the release of harmful gases and massive energy consumption. What's more, Cu/CuO, Cu/Cu2O, and CuS nanosheets with different sizes were fabricated using Cu superstructure as the substrate via facile methods, and the morphology is regulated by controlling the relevant factors. The electrochemical sensors based on the three derivations were fabricated to study the sensing performance of glucose. The unique structure of nanosheets encapsulating Cu superstructure guarantees the excellent conductivity of Cu/CuO and Cu/Cu2O composites. Moreover, the electrochemical stability is improved owing to the nanosheet protective layer. Although no metallic Cu was maintained in CuS, the integrated multilayer nanosheets endow CuS with short channels for fast interlayer electronic transmission and with structural stability. 相似文献
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A copper-catalyzed oxidative esterification of 2-carbonyl substituted phenols from the alcohol oxidation level is described. This protocol represents direct access to a range of 2-carbonylated aryl benzoate derivatives, which are important building blocks in the synthesis of natural and pharmacological compounds. 相似文献
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We report a hot-injection method to fabricate monodispersed Cu3PdN nanoparticles (NPs). The crystal structure, morphology, and chemical composition of the as-synthesized Cu3PdN have been characterized by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The as-developed Cu3PdN NPs electrocatalysts show improved activity and enhanced stability for formic acid oxidation compared with the corresponding Pd and Cu3Pd NPs. 相似文献
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Gancitano P Ciriminna R Testa ML Fidalgo A Ilharco LM Pagliaro M 《Organic & biomolecular chemistry》2005,3(13):2389-2392
Valuable organic compounds such as alpha-hydroxy acids are easily synthesised with relevant selectivity enhancement using a sol-gel hydrophobized nanostructured silica matrix doped with the organocatalyst TEMPO: A materials science based synthetic route which cannot be achieved via classical homogeneous synthesis. 相似文献
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New Results on the Chemical Transport of CuO and Cu2O The preparation of CuO crystals by chemical transport reactions with HCl is already well known, a comparison with other transport agents based on the principal of thermodynamic equilibrium and also the rate of transport was missing up to now. We report about experiments with the transport agents HgCl2, Cl2, I2, Nh4Cl, or CuCl; the quantitative evaluation was made by means of the cooperative transport model on the basis of the free energy function. By this way it is possible to find favourable experimental conditions for the suitable transport agents at the outset. It turned out that HgCl2 is an appropriate transport agent which can easily be weighed. Also I2 is useful, whereas the effect fo transport with Cl2 (1 atm/298 K), CuCl, or NH4Cl is very small. We investigated the chemical transport of Cu2o and the conditions for the change of its direction of transport. 相似文献
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Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150 nm-sized Ag(2)O/CuO (92%) or simply CuO (86.6%). When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions and regeneration of catalysts were investigated. Under optimal conditions, a series of aromatic and aliphatic aldehydes were oxidized to the corresponding acids in good yields. 相似文献
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《Radiation Physics and Chemistry》2006,75(11):1926-1929
By extended X-ray absorption fine structural (EXAFS) spectroscopy, copper oxide clusters with a square-plane structure are found in the channels of mesoporous molecular sieve MCM-41. Bond distances of Cu–O and Cu–Cu are 1.90 and 2.80 Å, respectively. Oxidation of naphthalene at 723 K for 4 h in MCM-41 leads to structural perturbation of the clusters (e.g., Cu–O: −0.02 Å and Cu–Cu: +0.02 Å) with little change in their coordination numbers. 相似文献
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Sebastian Kunze Liviu C. Tnase Mauricio J. Prieto Philipp Grosse Fabian Scholten Lucas de Souza Caldas Dennis van Vrden Thomas Schmidt Beatriz Roldan Cuenya 《Chemical science》2021,12(42):14241
Oxidized copper surfaces have attracted significant attention in recent years due to their unique catalytic properties, including their enhanced hydrocarbon selectivity during the electrochemical reduction of CO2. Although oxygen plasma has been used to create highly active copper oxide electrodes for CO2RR, how such treatment alters the copper surface is still poorly understood. Here, we study the oxidation of Cu(100) and Cu(111) surfaces by sequential exposure to a low-pressure oxygen plasma at room temperature. We used scanning tunnelling microscopy (STM), low energy electron microscopy (LEEM), X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and low energy electron diffraction (LEED) for the comprehensive characterization of the resulting oxide films. O2-plasma exposure initially induces the growth of 3-dimensional oxide islands surrounded by an O-covered Cu surface. With ongoing plasma exposure, the islands coalesce and form a closed oxide film. Utilizing spectroscopy, we traced the evolution of metallic Cu, Cu2O and CuO species upon oxygen plasma exposure and found a dependence of the surface structure and chemical state on the substrate''s orientation. On Cu(100) the oxide islands grow with a lower rate than on the (111) surface. Furthermore, while on Cu(100) only Cu2O is formed during the initial growth phase, both Cu2O and CuO species are simultaneously generated on Cu(111). Finally, prolonged oxygen plasma exposure results in a sandwiched film structure with CuO at the surface and Cu2O at the interface to the metallic support. A stable CuO(111) surface orientation is identified in both cases, aligned to the Cu(111) support, but with two coexisting rotational domains on Cu(100). These findings illustrate the possibility of tailoring the oxidation state, structure and morphology of metallic surfaces for a wide range of applications through oxygen plasma treatments.A low-pressure oxygen plasma oxidized Cu(100) and Cu(111) surfaces at room temperature. The time-dependent evolution of surface structure and chemical composition is reported in detail for a range of exposure times up to 30 min. 相似文献