RSC Advances
·
2015
·Vol. 5
·期 56
·45320-45330
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IF 3.84
Guannan Wang,Limin Chen,Yuhai Sun,Junliang Wu,Mingli Fu,Daiqi Ye
Methanol synthesis from CO2 hydrogenation in a fixed-bed plug flow reactor was investigated over Cu–ZrO2 catalysts supported on CNTs bearing various functional groups. The highest methanol activity (turnover frequency 1.61 × 10−2 s−1, space time yield 84.0 mg gcat−1 h−1) was obtained over the Cu/ZrO2/CNTs catalyst (CZ/CNT-3) with CNTs functionalized by nitrogen-containing groups and Cu loading only about 10.3 wt% under the reaction conditions of 260 °C, 3.0 MPa, V(H2) : V(CO2) : V(N2) = 69 : 23 : 8 and GHSV of 3600 h−1. The catalysts were fully characterized by N2 physisorption, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR) and temperature-programmed desorption of H2 (H2-TPD) techniques. The excellent performance of CZ/CNT-3 is attributed to the presence of nitrogen-containing groups on the CNTs surface, which increase the dispersion of copper oxides, promote their reduction, decreases the crystal size of Cu, and enhances H2 and CO2 adsorption capability, thus leading to good catalytic performance towards methanol synthesis.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2015
·
IF 4.513
Zhi-Chao Liu,Jian-Wen Qi,Chun Hu,Li Zhang,Wei Song,Ru-Ping Liang,Jian-Ding Qiu
Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive detection of Cu 2+ is very important to prevent over-ingestion, and visual detection is preferred for practical applications. In this work, we developed a simple and environmental friendly approach to synthesize hyperbranched polyethyleneimine-protected copper nanoclusters (hPEI-Cu NCs) with great stability against extreme pH, high ionic strength , thiols etching and light illumination, which were then conjugated to the surface of silica coated CdSe quantum dots (QDs) to design a ratiometric fluorescence probe. In the presence of different amounts of Cu 2+ ions, the fluorescence of Cu NCs can be drastically quenched, while the emission from QDs stayed constant to serve as a reference signal and the color of the probe changed from yellow-green to red, resulting in ratiometric and visualization detection of Cu 2+ ion with high accuracy. The detection limit for Cu 2+ was estimated to be 8.9 nM, much lower than the allowable level of Cu 2+ in drinking water (∼20 μM) set by U.S. Environmental Protection Agency. Additionally, this probe can be also applied for the determination of Cu 2+ ion in complex real water samples.
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Yong Cui,Zhe Zhang,Xu Du,Wei Liu,Shi Liu,Yulin Deng,Xiaogu Huang,Gang Wang
Hybrid solution process is a powerful liquid deposited strategy merging the advantage of molecular precursor solution and nanocrystals ink. A novel hybrid solution approach is presented to fabricate Cu(In,Ga)(S,Se) 2 (CIGSSe) absorber layer using fully dissolved CIGS precursor solution and the CIGS nanocrystals. Such attractive strategy could significantly improve the single deposited thickness and enhance the quality of as-prepared CIGS film compared with the pure CIGS molecular precursor solution and the CIGS nanocrystals ink. Photovoltaic absorber layers based on CIGSSe chalcopyrite structure show the high-quality microstructural performance and are incorporated into solar cells with power conversion efficiency of 10.19%. The high performance of resulted optoelectronic devices represents a chance to extend the hybrid solution process to other inorganic semiconductor thin film solar cells.
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高影响因子
ELECTROANALYSIS
·
2016
·Vol. 29
·期 4
·965-974
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IF 2.471
Yingqiao He,Guodong Wei,Junhong Lin,Mingxu Sun,Ziheng Li
A novel non-enzymatic carbohydrates sensor which was an indium tin oxide (ITO) glass electrode modified by nickel and copper nanoparticles (Cu/Ni/ITO) was developed by an electrochemical method. The crystallinity, morphology, electrochemical measurements and amperometric response of the as-prepared ITO modified electrode were examined by the X-ray diffraction (XRD), scanning electron microscopic (SEM), cyclic voltammetry (CV) and chronoamperometry, respectively. The Cu/Ni/ITO electrode had better electroactivity for glucose oxidation than that obtained using Cu/ITO, Ni/ITO, and Ni/Cu/ITO. The logistic regression equation, I pa = ( A 1 – A 2 )/[1 + ( C glucose / x 0 ) p ] + A 2 , was used to fit the calibration curves of glucose aqueous solution concentrations and responsive current intensity. In research of other saccharides, such as fructose, lactose, sucrose, and maltose, which were detected by the Cu/Ni/ITO electrode, it was obvious that the Cu/Ni/ITO electrode was more sensitive to monosaccharides than disaccharides. Monosaccharides and disaccharides can be detected because the saccharides themselves had aldehyde group or be isomerized to an isomer having an aldehyde group in alkaline environment, and then aldehyde group produced carboxylic acid in the catalytic oxidation of the electrode, which lead to the change of electrode surface conductivity and the appearance of oxidation peak, and the alkaline environment further promotes the above reaction.
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高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2016
·
IF 2.357
Cuicui Wang,Heyi Ge,Yueying Zhao,Shanshan Liu,Yu Zou,Wenbo Zhang
The folic acid functionalized magnetic graphene oxide (FA-mGO) as a new adsorbent has been synthesized in this work for the elimination of Cu(II) from waste water. The as-prepared FA-mGO was tested by SEM, TEM , particle size analyzer, FTIR, XRD, Roman spectrum, TGA and magnetic properties analyzer. Some factors, such as adsorbent dose, pH, contact time, initial concentration of adsorbate and temperature were explored. The results showed that the FA-mGO had the better adsorption performance than mGO. After 40 min, the adsorption equilibrium could be reached. Furthermore, the adsorption property obeyed the pseudo-second order kinetic model and the Temkin isotherms well. The maximum adsorption capacity was 283.29 mg/g for Cu(II) from Pseudo-second-order model at pH=5 and 318 K. The chelation action between FA and Cu(II) along with electrostatic incorporation between GO and Cu(II) determined the favourable adsorption property. Besides, thermodynamic studies results ∆G 0 <0, ∆H 0 >0, ∆S 0 >0 suggested that the adsorption mechanism was an endothermic and spontaneous process essentially. Finally, desorption and reusability studies imply FA-mGO has an excellent reproducibility and is benefit to environmental protection and resource conservation.
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高影响因子
RSC Advances
·
2016
·Vol. 6
·期 94
·91394-91400
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IF 3.289
Jie Xue,Jizhong Song,Yousheng Zou,Chengxue Huo,Yuhui Dong,Leimeng Xu,Jianhai Li,Haibo Zeng
Compared to monometallic counterparts, core–shell structured nanowires may possess additional performances or even new properties because of synergistic effects between two components. Particularly, the alloying shell may bring the advantage that we can adjust its components and sizes to achieve the desired performance. Here, we mainly study Ni-dependent electric stability and opto-electrical performances of Cu@CuNi NW electrodes. And we find that the increase of nickel content has little effect on optical performance, but effectively improves the stability of Cu@CuNi NW electrodes. We can also achieve ideal performance through regulating the nickel content and outstanding performance may come from the particular structure. Hence we studied Ni-dependent microstructure variations of Cu@CuNi NWs with the corresponding properties. The high stability NWs with a high nickel content have smooth CuNi alloying shells which effectively protect the NWs from oxidation. At the same time, the large length diameter ratio and high degree of crystallinity of Cu@CuNi NWs are the reasons for good transparent conductive properties. These demonstrations of controlling the composition of alloying shells for oxidation resistance of the NWs could bring forth great opportunities for transparent, flexible, stretchable, and wearable electronic and optoelectronic devices.
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高影响因子
Materials Research Express
·
2016
·Vol. 3
·期 6
·065018
·
IF 0.968
Pinhua Zhang,Guangliang Cui,Chuanhai Xiao,Mingzhe Zhang,Li Chen,Changmin Shi
We fabricated an Ag decorated Cu (Ag@Cu) nano/microstructure ordered array by facile template-free 2D electrodeposition combined with a galvanic reduction method for SERS applications. The Cu nano/microstructure ordered arrays were first synthesized by a 2D electrodeposition method, then Ag nanocubes were decorated on the arrays by galvanic reduction without any capping agent. The pollution-free surface and edge-to-face heterostructure of Ag nanocubes and Cu nano/microstructure arrays provide the powerful field-enhancements for SERS performance. The results verified that the Ag@Cu nano/microstructure ordered arrays have excellent activity for 4-Mercaptopyridine, and the sensitivity limit is as low as 10−8 M. Therefore, this facile route provides a useful platform for the fabrication of a SERS substrate based on nano/microstructure ordered arrays.
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高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2017
·Vol. 12
·期 3
·422-431
·
IF 0.836
Yuan Wang,Wei Zhu,Shengya Sang,Lijing Gao,Guomin Xiao
Aqueous-phase processing of biomass-derived furfural is one of the promising ways to convert biomass into useful chemicals. Supported metal catalysts are crucial in the aqueous-phase hydrogenation of furfural. Understanding the effect of acid and basic properties of supports on the performance of the catalysts will help understand the reaction pathways and develop more efficient catalysts. Here, a series of Cu-based catalysts with different supports (Al 2 O 3 , ZnO, SiO 2 , MgO, and ZSM-5) have been investigated in hydrogenation of furfural in aqueous phase. The properties of the supports have been characterized by X-ray diffraction, N 2 adsorption–desorption, transmission electron microscope, H 2 temperature-programmed reduction, and CO 2 and NH 3 temperature-programmed desorption. The results show that pure acid support leads to the formation of oligomers and pure basic support results in furfuryl alcohol as the main product. And the mass balance in reaction system catalyzed by Cu-based catalysts with higher acidity amount is lower. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2017
·Vol. 46
·期 7
·4676-4681
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IF 1.579
Han Wensong
Third-generation hyperbranched polyester (HBPE3) was synthesized by stepwise polymerization with N , N -diethylol-3-amine methylpropionate as AB 2 monomer and pentaerythritol as core molecule. Then, Cu particles were prepared by reduction of copper nitrate with ascorbic acid in aqueous solution using HBPE3 as template. Finally, Cu/SiO 2 particles were prepared by coating silica on the surface of Cu particles. The structure and morphology of the samples were characterized by Fourier-transform infrared (FT-IR) spectrometry, x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results confirmed the formation of the silica coating on the surface of Cu and that the Cu/SiO 2 particles had spherical shape with particle size in the range of 0.8 μ m to 2 μ m. Compared with pure Cu, the synthesized Cu/SiO 2 core–shell particles exhibited better oxidation resistance at high temperature. Moreover, the oxidation resistance of the Cu/SiO 2 particles increased significantly with increasing tetraethyl orthosilicate (TEOS) concentration.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2017
·
IF 2.686
Jinshui Liu,Bin Wang,Meijiao Xu,Lizhen Wang,Zihan Zhou
Polyethyleneimine-capped Cu nanoclusters (PEI-CuNCs) with a mean diameter of 2.5 nm and that emitted blue light at 485 nm were synthesized. The fluorescence of PEI-CuNCs was strongly quenched when Au(III) ions were present. Because of this specific response, a PEI-CuNC-based fluorescent turn-off sensor was developed. Under optimum conditions, a good linear relationship (R 2 =0.993) was found between the relative fluorescence intensity ( F 0 / F ) and the Au(III) ion concentration between 0.5 and 15 µM. The detection limit for Au(III) ions was 0.06 µM. The quenching mechanism was assessed by performing X-ray photoelectron spectroscopy spectra studies. The fluorescence quenching was ascribed to photo-induced electron transfer from the PEI-CuNCs to the AuCl 4 − occur. Using The method described is a new way of quantifying Au(III) ions.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 12
·13280-13287
·
IF 1.798
Liu Jingdong,Ji Hongjun,Wang Shuai,Li Mingyu
In this study, we present a new simple method using formic acid pretreatment to achieve low temperature sintering of Cu nanoparticles, and the Cu nanoparticles have been successfully prepared with a modified polyol method. For formic acid pretreatment, the spherical Cu nanoparticles with an average size of 30 nm were saturated with a mixed solution of formic acid and absolute ethanol directly. The surface composition analysis indicated that the initial oxide on the surface of Cu nanoparticles was completely removed, and formate was generated as a by-product which could decompose at low temperature. According to the thermal analysis results, it was found that the sintering temperature of Cu nanoparticles with formic acid pretreatment was reduced to 160 °C. And the corresponding microstructures further demonstrated that the emerging small exothermic peak of thermal curve over the temperature range between 120 and 160 °C was caused by the formation of sintering necks. The formic acid treated Cu nanoparticle films sintered at 260 and 320 °C exhibited an electrical resistivity of 6.1 and 3.6 μΩ cm respectively.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Yi Cao,Baoping Lin,Ying Sun,Hong Yang,Xueqin Zhang
La x Sr 1 − x Cu 0.1 Mn 0.9 O 3 − δ (LNF- x ) (0.1 ⩽ x ⩽ 1) nanofibers are prepared by electrospun method. The structure of LNF- x and the electrochemical properties of LNF- x in 1 M Na 2 SO 4 aqueous electrolyte are investigated. As a result, LNF- x nanofibers present a perovskite structure, and the LNF-0.5 sample exhibits the highest specific capacitance value of 464.5 F g − 1 at a current density of 2 A g − 1 . The maximum energy density of 64.5 W h kg − 1 are achieved at a power density of 2 kW kg − 1 for the symmetric supercapacitor prepared by La 0.5 Sr 0.5 Cu 0.1 Mn 0.9 O 3 − δ nanofibers. More importantly, this symmetric supercapacitor also shows an excellent cycling life after 2000 charging and discharging cycles. Those results offer a suitable design of electrode materials for high-performance supercapacitors.
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高影响因子
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