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Electrocatalytic Oxidation of Calcium Folinate on Carboxyl Graphene Modified CuxO/Cu Electrode 下载免费PDF全文
Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene (CG) was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate (CF) at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0 μA·(μmol/μL)-1cm-2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10-7 mol/L to 2.0×10-5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10-8 mol/L (S/N=3). In addition, the proposed sensor was successfully applied in determination of CF in drug sample. 相似文献
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采用常压化学气相沉积法(APCVD),分别以金属镓(Ga),铟(In)和氨气(NH3)为镓源,铟源和氮源,在Si衬底上利用催化剂Au成功合成了不同形貌的InxGa1-xN纳米材料。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM),X射线光电子能谱(XPS)和光致发光谱(PL)对比研究了InxGa1-xN(x=0,0.25)纳米材料在形貌,化学成分,晶体结构以及发光特性的变化。分析结果表明:当没有催化剂时,所生成的InxGa1-xN样品形貌由片状结构自组装成花状结构,而在催化剂Au的作用下,生成的InxGa1-xN纳米晶的形貌变为以纳米线为轴在其上生长的片状的"塔"状结构;虽然在催化剂Au的作用下生成的InxGa1-xN(x=0.25)形貌发生了很大变化,但晶体结构未发生改变,均为六方纤锌矿结构;PL分析结果显示InxGa1-xN纳米结构的发光性能随着In含量的增加,发光谱的强度增加且同时出现了蓝光区,在催化剂Au的作用下生成的InxGa1-xN的发光强度最强。最后对不同形貌InxGa1-xN其生长机理做简单分析。 相似文献
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Oliver Clemens Melanie Kuhn Robert Haberkorn 《Journal of solid state chemistry》2011,184(11):2870-2876
The oxyfluorides La1−xSrxFeO3−xFx have been prepared by fluorination of the precursor oxides La1−xSrxFeO3−δ via a low temperature route using poly(vinylidene fluoride) (PVDF). The structures of the oxides and oxyfluorides were investigated in detail by the Rietveld analysis of powder diffraction data. The oxyfluorides crystallize in the space group Pnma for 0<x≤0.9 (SrFeO2F itself is cubic, space group Pm-3m) and show a sort of two-step structural distortion for decreasing x. Furthermore, a structural comparison of the oxyfluorides with the oxides is given, revealing an increase of the volume per La1−xSrxFeX3 unit during fluorination, of which the magnitude highly depends on the value of x. 相似文献
5.
采用水热法制备了Al掺杂的锂二次电池正极材料LiV3-xAlxO8,并用X射线衍射和扫描电镜对材料的晶体结构和形貌进行了表征.以50 mA·g-1进行恒流充放电测试,结果表明Al掺杂能够明显改善材料的电化学性能.在掺杂改性的LiV3-xAlxO8材料中,LiV2.93Al0.07O8的初始容量最高,达到325 mAh·g-1.当掺杂量为x=0.04时,材料的循环性能最佳.LiV2.96Al0.04O8经20次循环后仍保持179 mAh·g-1的比容量,且充放电效率始终维持在98%左右. 相似文献
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M. Jiménez-Ruiz C. Prieto J.L. Mart?&#x;nez J.M. Alonso 《Journal of solid state chemistry》1998,140(2):3442
The NiK-edge XANES of reduced Nd2−xSrxNiO4samples shows an increase of Ni3+content with Sr3+concentration. The appearance of mixed valence Ni2+/Ni3+produces a change in the magnetic properties of the system. The Nd3+sublattice orders antiferromagnetically atTN∼13–20 K forx=0.4, 0.5, and 0.6, due to the interactions of Ni–Nd sublattices. Forx=0.8 this order begins to disappear because of the effect of the low spin state Ni3+created at the NiO4planes. Additionally, the reduced family Nd2−xSrxNiOy(y<4) shows the disappearance of Ni3+, the decrease of Ni2+with respect to the nonreduced form, and the appearance of Ni+. All the compounds of the reduced family show AF order at low temperature. 相似文献
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本文采用溶胶凝胶法制备了一系列不同Ca含量的钙钛矿型氧化物La1-xCaxMnO3(x=0~0.4)纳米颗粒, X射线粉末衍射及精修、扫描电镜表征显示其相纯度和结晶度高, 颗粒平均粒径约40 nm。在0.1 mol·L-1 KOH水溶液中进行的氧还原电催化性能测试显示, La0.7Ca0.3MnO3样品催化活性最高, 表观电子转移数接近4, 还原电流密度与Pt/C催化剂相当, 而催化稳定性优于Pt/C。进一步研究了La1-xCaxMnO3样品中Mn价态、晶胞参数的改变对氧还原催化活性的影响, 结果表明当x=0.3时, 催化剂中Mn处于混合价态, Mn-O键长适中, 最有利于电催化反应。 相似文献
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本文采用溶胶凝胶法制备了一系列不同Ca含量的钙钛矿型氧化物La1-xCaxMnO3(x=0~0.4)纳米颗粒,X射线粉末衍射及精修、扫描电镜表征显示其相纯度和结晶度高,颗粒平均粒径约40 nm。在0.1 mol.L-1KOH水溶液中进行的氧还原电催化性能测试显示,La0.7Ca0.3MnO3样品催化活性最高,表观电子转移数接近4,还原电流密度与Pt/C催化剂相当,而催化稳定性优于Pt/C。进一步研究了La1-xCaxMnO3样品中Mn价态、晶胞参数的改变对氧还原催化活性的影响,结果表明当x=0.3时,催化剂中Mn处于混合价态,Mn-O键长适中,最有利于电催化反应。 相似文献
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《Electrochemistry communications》2000,2(6):404-406
A novel composite InxGa1−xAs/GaAs|GaAs/AlxGa1−xAs multiple quantum well material with different well widths was studied as a new kind of photoelectrode in a photoelectrochemical cell. The photocurrent spectrum and photocurrent–electrode potential curve were measured in ferrocene nonaqueous solution. Pronounced quantization effects and strong exciton absorption were observed in the photocurrent spectrum. The effects of surface states and interfacial states on the photocurrent–electrode potential curve are discussed. 相似文献
10.
S. V. Murashov V. G. Yarzhemsky V. I. Nefedov E. N. Muravev 《Russian Journal of Inorganic Chemistry》2007,52(8):1243-1247
The band structures of pure semiconductors CdGeAs2 and CuGaTe2, as well as magnetic semiconductors Cd1 − x
Mn
x
GeAs2 and Cu1 − x
Mn
x
GaTe2 (x = 0.0625), have been calculated by the density functional theory method. In both compounds, the Mn3d orbitals form a narrow band near the Fermi level. In the case of Cd1 − x
Mn
x
GeAs2, the Mn3d orbitals are slightly involved in chemical bonding. In the case of Cu1 − x
Mn
x
GaTe2, the same orbitals are considerably involved in chemical bonding. The relationship of these results with the properties of
the compounds and ferromagnetism models is discussed.
Original Russian Text ? S.V. Murashov, V.G. Yarzhemsky, V.I. Nefedov, E.N. Murav’ev, 2007, published in Zhurnal Neorganicheskoi
Khimii, 2007, Vol. 52, No. 8, pp. 1327–1331. 相似文献
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J. M. Lloris B. León C. Pérez Vicente J. L. Tirado M. Womes J. Olivier Fourcade J. C. Jumas 《Journal of Solid State Electrochemistry》2004,8(8):521-525
In order to gain a better understanding of the parameters affecting the capacity and performance of spinel electrode materials, the chemical composition and cation distribution of three members of the LiCuxMn2–xO4 and LiCu0.5–yAlyMn1.5O4
series have been studied by chemical analysis, X-ray diffraction and X-ray absorption spectroscopy. The synthesis used stoichiometric and lithium-excess precursors. The results evidence that lithium is always incorporated in lower contents than expected from the nominal stoichiometry, owing to the occurrence of significant amounts of copper in the tetrahedral sites of the structure. Manganese displays an oxidation state below 4+ in all these solids, while the lithium-excess synthesis leads to a slightly higher average oxidation state. The electrochemical results evidence the lack of improvement in capacity by using lithium-excess synthesis, while a significant increase in capacity is obtained by aluminium doping, reaching values of 100 mAh/g. 相似文献
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This paper is devoted to the investigation of the tolerance of glucose oxidation on NiO x /MnO x /GC binary catalyst to poisoning by halide ions. NiO x /MnO x /GC electrode was prepared by the consecutive electrodeposition of MnO x followed by the deposition of NiO x nanoparticles atop the previously deposited MnO x nanoparticles. The electrode was characterized electrochemically and morphologically. Interestingly, experimental results showed that the NiO x /MnO x /GC electrode shows a superior electrocatalytic activity compared with the NiO x /GC electrode and a behavior comparable to the NiO x /GC electrode regarding tolerance to poisoning by halides, even in the presence of high concentrations of Cl? and Br? up to 0.3 M. On the other hand, it was found that iodide ions have a significant effect on glucose electrooxidation under the prevailing operating conditions and even at concentrations lower than those of the other two halide ions. 相似文献
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Zhuang QuanChao Xu JinMei Fan XiaoYong Wei GuoZhen Dong QuanFeng Jiang YanXia Huang Ling Sun Shigang 《中国科学B辑(英文版)》2007,50(6):776-783
The storage behavior and the first delithiation of LiCoO2 electrode in 1 mol/L LiPF6-EC:DMC:DEC electrolyte were investigated by electrochemical impedance spectroscopy (EIS). It has found that, along with the
increase of storage time, the thickness of SEI film increases, and some organic carbonate lithium compounds are formed due
to spontaneous reactions occurring between the LiCoO2 electrode and the electrolyte. When electrode potential is changed from 3.8 to 3.95 V, the reversible breakdown of the resistive
SEI film occurs, which is attributed to the reversible dissolution of the SEI film component. With the increase of electrode
potential, the thickness of SEI film increases rapidly above 4.2 V, due to overcharge reactions. The inductive loop observed
in impedance spectra of the LiCoO2 electrode in Li/LiCoO2 cells is attributed to the formation of a Li1−x
CoO2/LiCoO2 concentration cell. Moreover, it has been demonstrated that the lithium-ion insertion-deinsertion in LiCoO2 hosts can be well described by both Langmuir and Frumkin insertion isotherms, and the symmetry factor of charge transfer
has been evaluated at 0.5.
Supported by the Special Funds for Major State Basic Research Project of China (Grant No. 2002CB211804) 相似文献
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《中国化学快报》2020,31(4):984-987
In this study,two-dimensional V_2CT_x MXene has been prepared by selectively etching Al layers from V_2 AlC MAX phase by NaF+HCl etching at 90℃ for 72 h and its performance as supercapacitor(SC)electrode were tested using simulating seawater as electrolyte.V_2CT_x MXene-based electrodes shows a good capacitance of 181.1 F/g,which is in accordance with the volumetric specific capacitance of 317.8 F/cm3,and with 89.1% capacitance retention even after 5000 cycle.Compared with other MXenes,V_2CT_x have better electrochemical performance as SC electrode.This work provides an innovative strategy to apply V_2CT_x MXene as SC electrode in safety and effective seawater electrolyte. 相似文献
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以乙酰丙酮金属盐为前驱体,三乙二醇为溶剂,采用多元醇法制备了镍锌不同配比的Ni_xZn_(1-x)Fe_2O_4(x=0,0.3,0.5,0.7和1.0)铁氧体,并通过X射线衍射仪(XRD),透射电子显微镜(TEM)和振动样品磁强计(VSM)等对样品的结构、形貌、磁性能和磁热性能进行了表征。结果表明:Ni_xZn_(1-x)Fe_2O_4铁氧体分散性较好,尺寸均一,形状近似球形,平均粒径为4~5 nm。Ni_xZn_(1-x)Fe_2O_4纳米颗粒在室温下表现出亚铁磁性,饱和磁化强度随着镍含量的增加先增大后减小,当x=0.5时达到最大值29.38 emu·g~(-1)。在382k Hz交变磁场作用下,Ni_(0.5)Zn_(0.5)Fe_2O_4铁氧体温度可升温至313 K,表现出较好的磁热性能。 相似文献
16.
不同形貌Cu_xCd_(1-x)S光催化剂光腐蚀性能差异研究 总被引:1,自引:0,他引:1
利用溶剂热法和水热法,合成出不同形貌的CuxCd1-xS光催化剂,并考察了它们的抗光腐蚀性能。荧光实验表明适量的铜掺杂取代后得到的CuxCd1-xS晶体具有良好的光生电子-空穴对的分离性能,有利于光生载流子的快速转移;不同形貌是导致样品抗光腐蚀性能不同的重要原因;此外铜掺杂量和晶体结晶度都对催化剂光腐蚀性能有重要影响。 相似文献
17.
Thermodynamic properties of a solid solution, MgyU1−yO2+x, at low magnesium concentrations have been investigated using the solid galvanic cell technique. The emf values were found to vary linearly with temperature in the range 850 1050 °C, from which the linear temperature dependence of partial molar free energy of oxygen,
, and the temperature independence of
and
were derived. These thermodynamic quantities were obtained as a function of x and y. Agreement of these values with those from theoretical considerations was examined. The effect of magnesium incorporation on
was expressed using
of UO2+x as
. 相似文献
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19.
J. Navrtil T. Plech
ek J. Hork S. Karamazov P. Lo
t'k J. S. Dyck W. Chen C. Uher 《Journal of solid state chemistry》2001,160(2):474
The paper reports on the temperature dependence of the electrical and thermal conductivity, Hall constant, and Seebeck coefficient of Bi2−xInxSe3 (x=0, 0.2, 0.4) single crystals measured over the temperature range from 2 to 300 K. One single-valley conduction band model is used to interpret relations among transport coefficients. The data analysis relies on the use of a mixed carrier scattering mechanism consisting of acoustic scattering and scattering on ionized impurities. The effect of In incorporation into the Bi2Se3 crystal lattice on the individual components of thermal conductivity is evaluated and discussed. 相似文献
20.
In the context, SrxY10−x(SiO4)y(PO4)6−yO2 doped with 1 mol%Eu3+ (x = 2, y = 6; x = 4, y = 4; x = 5, y = 3; x = 8, y = 0) were synthesized by using 3-aminopropyl-triethoxysilane (APES) as the sources of the silicate network. X-ray diagrams confirm that SrxY10−x(SiO4)
y(PO4)6−yO2: Eu3+ solid solutions are formed as a pure apatitic phase. The SEM picture shows that there exist some novel unexpected coral like morphological structures. The luminescent intensity is the strongest for the host composition of Sr4Y6(SiO4)4(PO4)2O2 although the effect of the composition on the luminescent intensity is little. 相似文献