ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Dong-Fang Li,Jin-Chuan Mao,De-Li Chen,Fang Chen,Hong Ze-Wen,Xiao-Yi Zhou,Ya-Hao Wang,Xiao-Shun Zhou,Zhen-Jiang Niu,Emmanuel Maisonhaute
The single-molecule conductance of 1,4-dicyanobenzene (DCB), 1,4-benzenediamine (BDA) and 4,4'-biphenyldicarbonitrile (BPDC) with Ag and/or Cu electrodes is measured by electrochemical jump-to-contact STM-break junction. All single-molecule junctions present three sets of conductance values revealing different contact geometries. We observe that the single-molecule conductance of Ag-BDA-Ag junction is larger that of Ag-DCB-Ag junction, and DCB with Ag contacts are more conductive than that with Cu ones. This is related to a different electronic coupling between the molecules and the electrodes. Tunneling decay constants of 1.70 and 1.68 per phenyl group were found for Ag and Cu electrodes, respectively. The present study therefore shows that nitrile and amino groups can also be used as effective anchors for other metals than gold.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2015
·
IF 3.091
Guangren Yu,Lin Zhang,Ibrahim A. Alhumaydhi,Ahmed A. Abdeltawab,Abdulaziz A. Bagabas,Hamid A. Al-Megren,Salem S. Al-Deyab,Xiaochun Chen
Ionic liquids (ILs) coupled with Ag + or Cu + salts to form a new kind of reactive absorbent have been studied to separate light olefin from paraffin recently. In this work, we prepared two halogen-free alkylimidazolium thiocyanate ILs with cheaper cuprous thiocyanate, i.e., [Bmim]SCN–CuSCN and [Emim]SCN–CuSCN (Bmim, 1-butyl-3-methylimidazolium; Emim, 1-ethyl-3-methylimidazolium) and investigated their absorption capability for propylene, propane and mixture of both at 1–7 bar and 298–318 K. The effects of operating parameter including cation nature, temperature, pressure, Cu + concentration and reuse of absorbent were investigated. Propylene shows a chemical absorption while propane does a physical one, and increasing Cu + concentration effectively improves the absorption capability for propylene and the selectivity of propylene/propane. [Bmim]SCN–CuSCN has higher absorption capability and selectivity for propylene than [Emim]SCN–CuSCN, e.g., [Bmim]SCN–CuSCN-1.5 M can absorb 0.12 mol of propylene per liter while 0.012 mol of propane per liter at 1 bar and 298 K, with a selectivity of 10, which is comparable to some other ILs-Ag + salts and better than pure ILs. Such absorbents can be regenerated through temperature and pressure swing without remarkable activity loss. This work shows that alkylimidazolium thiocyanate ILs with Cu + salts are promising reactive absorbents to separate propylene from propane.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2013
·
IF 1.164
Xiaochun Chen,Shuimin Ming,Xinying Wu,Chang Chen,Charles Asumana,Guangren Yu
The absorption of propylene and propane in Cu(I)-based ionic liquids, i.e., 1-butyl-3-methylimidazolium chloride/CuCl ([Bmim][Cl]/CuCl), N-Methyl pyrrolidone chloride/CuCl ([HNMP][Cl]/CuCl), and tricaprylmethylammonium thiocyanate/CuSCN ([A336][SCN]/CuSCN), are investigated in this work. It is observed that such Cu(I)-based ionic liquids, especially Bmim-based ionic liquids, present good absorption capability for propylene and good selectivity over propane, e.g., 1.0 kilogram [Bmim][Cl]/CuCl is able to absorb 0.08 mol propylene while only 0.006 mol propane at 25°C and 1.3 bar with the selectivity of 13. The effects of pressure, Cu+ concentration, and temperature on the absorption are investigated; in addition, the absorption kinetics of propylene by [Bmim][Cl]/CuCl is obtained. The much higher absorption capability for propylene than propane is ascribed to the π-complexation between propylene and Cu+. This work shows that the absorption by Cu(I)-based ionic liquids is an potential alternative method for traditional cryogenic distillation with high energy cost to separate propylene and propane.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Chemistry
·
2015
·
IF 0.772
Hao Zhou,Dong-Yao Xu,Hai-Qing Zuo,Wei Liu,Shuang Lin
Urchin-like Cu-W18O49 and flower-like Cu-WO3 structures were successfully synthesized using a hydrothermal process followed by calcination. The synthesized products were characterized using XRD, SEM, and TEM. The results revealed that the as-prepared urchin-like and flower-like samples with monoclinic structures, which were approximately 1 μm and 1-2 μm, respectively, possessed microflower architecture assembled by the nanosheet. In addition, the gas sensing properties of monoclinic-structured Cu-WO3 to acetone were measured using a static state gas sensing test system. The sensor based on the flower-like Cu-WO3 nanostructures, which were calcined at 600°C, exhibited high sensitivity toward 10 ppm acetone at an optimum temperature of 110°C, and the maximum sensitivity reached 40, which was approximately four times higher than that of urchin-like WO3 that was annealed at 300°C. The sensitivity was improved by increasing the acetone concentration. The detection limit was as low as 1 ppm. Using linear fit, the sensor was determined to be sufficiently sensitive to detect acetone in a detection range of 1 to 10 ppm even in the presence of interfering gases, which suggests that this type of sensor has excellent selectivity and has the potential for use in acetone gas sensors in the future.
✓ 已验证
产品关联
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2017
·
IF 4.164
Wenjun Zhao,Jiayi Jin,Huimin Wu,Shengfu Wang,Chuanqi Fneg,Shuijin Yang,Yu Ding
The Cu@Pt/C nanocomposites have been synthesized via two-step reduction method. Electrochemical observations showed that the Cu@Pt/C had better electrocatalytic activity for the reduction of hydrogen peroxide than Pt/C, with a wide linear range between 0.50 μM and 32.56 mM, a high sensitivity of 351.3 μA mM − 1 cm − 2 , and a low detection limit of 0.15 μM (signal/noise = 3). Furthermore, the sensor based on Cu@Pt/C has potential applications due to its excellent long-time stability, good reproducibility and acceptable selectivity.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 84
·53135-53144
·
IF 3.108
Changjiang Yu,Miao Wang,Xinyu Dong,Zaifeng Shi,Xiaopeng Zhang,Qiang Lin
Magnetic microspheres (MM) were prepared using calcium alginate (CA) encapsulated biochar (BC) and Fe3O4 as a high-performance green absorbent for Cu(II) removal from aqueous solution. The effects of the initial Cu(II) concentration, initial pH value of the Cu(II) solution and equilibrium contact time were investigated. The results revealed that the adsorption capacity of MM was approximately 3 times higher than that of the magnetic biochar (MBC). The adsorption of Cu(II) by the MM was in good agreement with pseudo-second-order kinetics. The overall orders for fitting the isotherm models are Langmuir > Freundlich for Cu(II). Mechanism studies showed that coordination and ion exchange were the major mechanism for Cu(II) removal by the MM. Moreover, the presence of the magnetic particles in the microspheres allowed easy separation of the material from aqueous solutions. This study provides an effective method for biochar modification.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Jiale Liu,Zhennan Wu,Ye Tian,Yanchun Li,Lin Ai,Tingting Li,Haoyang Zou,Yi Liu,Xindong Zhang,Hao Zhang,Bai Yang
Aggregation-induced emission (AIE) and self-assembly induced emission (SAIE) effects have been employed to tune the emission properties of metal nanoclusters (NCs). However, it is still not possible to further enhance the photoluminescence quantum yields (PLQYs) and control the emission colors of the NCs using AIE and SAIE. On the basis of our recent work studying the contribution of Cu(I) defects in the SAIE of Cu NCs, in this article, Au(I) was doped into Cu NC self-assembled nanosheets (NSASs) to construct a more stable Au(I)-centered state. As a result, the PLQYs, emission stability, and tunability of emission colors of the Cu NSASs were significantly improved. Detailed studies reveal that the doped Au(I) induces a Au(I)–Cu(I) metallophilic interaction, which leads to a ligand-to-Cu–Au charge transfer, which facilitates the relaxation of excited electrons via a radiative pathway, thereby enhancing the emission intensity. The charge transfer from Cu to Au lowers the energy, thus leading to the red-shift of PL emission. Au(I) is likely doped into the Cu NSASs rather than in individual NCs, because 0.3% Au doping is enough to alter the emission properties. By mixing Au(I)-doped Cu NSASs with different emission colors (due to different Au doping percentages) as color conversion materials on commercially available 365 nm GaN chips, a white light-emitting diode prototype is fabricated.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Junjie Li,Xing Yu,Tielin Shi,Chaoliang Cheng,Jinhu Fan,Siyi Cheng,Tianxiang Li,Guanglan Liao,Zirong Tang
In this paper, we proposed a depressing bonding temperature method for Cu Cu bonding with nanoparticle paste. The paste was prepared by composting dominant Cu nanoparticles with Ag nanoparticles of lower sintering temperature , where the average nanoparticle size of Cu and Ag was 61.02 and 69.25 nm, respectively. The reliable bonding was successfully achieved at the temperature of 250 °C, the pressure of 1.12 MPa and the protection of Ar-H 2 gas mixture comparing with pure Cu nanoparticles paste. An optimal resistivity of sintered Cu-Ag composite nanoparticle paste can achieve 1.99 × 10 −7 Ω m with the 2:1 molar ratio of Cu to Ag, and the largest shear strength of the bonded Cu-Cu joint can reach 25.41 MPa. The underlying sintering mechanism of the composited nanoparticles was discussed. It suggests the compositing with Ag nanoparticles is a practical strategy towards lowering the bonding temperature for Cu-based interconnect. The experimental process can be easily implemented, the bonding temperature and the performance can satisfy the packaging requirements of current 3D-IC. The developed Cu-Ag composite nanoparticle paste is also promising for packaging of other thermal and force sensitive chips.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2016
·
IF 4.312
Xuesong Liu,Xiaodong Wu,Duan Weng,Zhichun Si,Rui Ran
Cu-modified SAPO-34 molecular sieves with different Cu loading amounts were prepared by ion-exchange and impregnation methods. Both series of catalysts were hydrothermally treated at 750 °C in 10 vol% H 2 O/air for 24 h. The catalysts were characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), NH 3 temperature-programmed desorption (NH 3 -TPD) and diffused reflectance infrared flourier transform spectroscopy (DRIFTS). All the fresh catalysts show high activity toward the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) at low temperatures regardless of preparation method. Generally, the hydrothermal aging shifts the operation window of the catalysts towards high temperatures. The improvement in high-temperatures activity is attributed to the migration of surface CuO clusters into the ion-exchanged sites as isolated Cu 2+ during ageing, which suppresses the competitive oxidation of NH 3 . The loss of low-temperatures activity is also related to the decrease in the amount of active surface CuO clusters, inhibiting the oxidation of NO to NO 2 and fast SCR reaction. Interestingly, the amount of Lewis acid sites increase linearly with the increasing isolated Cu 2+ , while the Brønsted acidity is weakened.
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Xueye Wang,Zhiwei Wang,Haiqin Chen,Zhichao Wu
Efficient removal of toxic metals using low-pressure membrane processes from contaminated waters is an important but challenging task. In the present work, a conducting microfiltration membrane prepared by embedding a stainless steel mesh in the active layer of a polyvinylidene fluoride membrane is developed to remove Cu(II) ions from contaminated waters. Results showed that the conducting membrane had favorable electrochemical properties and stability as cathode. Batch tests showed that Cu(II) removal efficiency increased with the increase of voltages and leveled off with the further enhancement of electric field. The optimal voltages were determined to be 1.0 V and 2.0 V for the influent Cu(II) concentrations of 5 mg/L and 30 mg/L, respectively. X-ray photoelectron spectroscopy and X-ray diffraction results demonstrated the presence of Cu(0) and Cu(OH) 2 on the membrane surface. The removal mechanisms involved the intrinsic adsorption of membrane, electrosorption of membrane, adsorption of deposited layer, chemical precipitation of Cu(OH) 2 and deposition of Cu(0) which were aided by electrophoresis and electrochemical oxidation-reduction. Long-term tests showed that the major contributors for Cu(II) removal were the deposition of Cu(0) by electrochemical reduction-oxidation (47.3% ± 8.5%) and chemical precipitation (41.1% ± 0.2%), followed by electrosorption, adsorption by the fouling layer and membrane intrinsic sorption.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jiaming Li,Jiawei Hu,Quan Jiang,Huan Yu,Wen Xiao,Diab Khalafallah,Fang Yu,Chao Liu,Feng Zhang,Qinfang Zhang
The construction of highly efficient photocatalysts for generating high-purity hydrogen (H 2 ) through a sustainable water decomposition system is a feasible option to replace conventional non-renewable energy resources. Here, we report a simple chemical reduction approach to embed Cu–Pt alloy nanocrystals on the C 3 N 5 (CN) matrix, creating a Schottky heterojunction. The structural morphology, crystal phase, light-harvesting capacity, and photo-electrochemical properties of as-prepared heterostructures were investigated. The uniformly anchored Cu–Pt alloy nanocrystals improve the photocatalytic H 2 evolution (PHE) activity by promoting the separation and transfer of photogenerated carriers and inhibiting recombination. Meanwhile, the alloyed nanocrystals strengthen the absorption of incident light energy, inducing photothermal energy. This improves the charge carrier separation and promotes the surface reaction kinetics. The PHE performance of as-developed catalysts could be adjusted by optimizing the molar ratio of Cu/Pt ions. Among them, the optimal Cu 1 Pt 3 /CN photocatalyst yields a higher PHE performance (672.85 μmol g −1 h −1 ). Notably, the Cu 1 Pt 3 /CN catalyst also reveals an enhanced photocatalytic activity for H 2 evolution in natural seawater. The possible PHE mechanism in CuPt/CN heterostructures is discussed toward the role of CuPt alloy deposition in boosting photocatalytic efficiency.
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Shikai Liu,Chuqiao Shi,Chaokai Xu,Haichuan Zhang,Wenqi Li,Valentín Briega-Martos,Qian He,Yimo Han,Yao Yang
CO2 reduction reaction (CO2RR) facilitates the sustainable synthesis of fuels and chemicals. Although copper (Cu) enables CO2-to-multicarbon product (C2+) conversion, Cu-based electrocatalysts, particularly nanocatalysts, face challenges in poor selectivity and stability owing to the highly dynamic nature of Cu atoms under reaction conditions. Core–shell structures present a promising approach to address these issues by modulating the Cu overlayer–substrate interactions with atomic-level precision. Here, we report on Pd@Cu core–shell structures with atomically thin and nanometer-thick Cu overlayers on single-crystal Pd nanocubes with {100} facets promoting the CO2-to-C2+ conversion. The microstructures and surface compositions at the atomically sharp Pd/Cu interface were investigated by atomic-scale scanning transmission electron microscopy (STEM) imaging and electron energy-loss spectroscopy (EELS). Our results reveal that atomic-layer Cu epitaxially grows on Pd and adapts to the lattice of the Pd substrate. The reaction-driven migration of atomic-layer Cu is effectively suppressed on Pd due to the strong Cu–Pd interaction. While Pd only reduces CO2 to C1 products, atomic-layer Cu on Pd can initiate the C2+ production during the CO2RR. Thick Cu overlayers (∼15 nm) on Pd further enhance the C2+ faradaic efficiency while undergoing significant structural reconstruction, with only the 2–3 nm Cu layers near the Pd surface remaining stable and resistant to Cu migration after the CO2RR. We anticipate that Pd@Cu core–shell structures with intermediate Cu shell thickness hold significant potential for enhancing C2+ selectivity while maintaining high stability of nanocatalysts for CO2 reduction to liquid fuels.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）