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Articles 1411 - 1440 of 1920

Full-Text Articles in Materials Science and Engineering

Nucleation And Crystal Growth Of Pt Electrodeposition On Poly Crystal Au Microdisc Electrode, Zhi-Yong Tao, Pei-Fang Liu Aug 2004

Nucleation And Crystal Growth Of Pt Electrodeposition On Poly Crystal Au Microdisc Electrode, Zhi-Yong Tao, Pei-Fang Liu

Journal of Electrochemistry

Based on the Fleischmann's model of nucleation and crystal growth for electrodeposition combined with the Barradas-Bosco's adsorption-nucleation model for electrochemical phase formation, the chronoamperometry was well fitted for Pt deposition on polycrystalline Au micro disc electrodes (30 μm in diameter) in different H2PtCl6 concentrations at different over-potentials. The initial stage of Pt deposition in dilute H2PtCl6 could be interpreted by the model of H2PtCl6 adsorption combined with instantaneous nucleation and two-dimensional cylindrical growth. The rate constant of the two-dimensional growth increased linearly with overpotential. Then the deposit grew layer by layer …

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Synthesis Of (S)-3-Phenylpropane-2-Tert-Butoxycarbonylamino-1-Thiol And Its Electrochemical Behavior Self-Assembled On Gold, Ru Sun, Jian-Feng Ge, Mei Wang, Ren-Ao Gu Aug 2004

Synthesis Of (S)-3-Phenylpropane-2-Tert-Butoxycarbonylamino-1-Thiol And Its Electrochemical Behavior Self-Assembled On Gold, Ru Sun, Jian-Feng Ge, Mei Wang, Ren-Ao Gu

Journal of Electrochemistry

The synthesis of (S)-3-Phenylpropane-2-tert-butoxycarbonylamino-1-thiol(N-Boc-APT) from L-phenylalanine was reported. L-Phenylalanine was reduced to the corresponding amino alcohol, protection of the amino group using tert-butyl pyrocarbonate gave (S)-2-tert-butoxycarbonylamino-3-phenylpropane-1-ol, which was then O-mesylated and treated with potassium thioacetate in DMF to give 3-phenylpropane-2-tert- butoxycarbonylamino-1-etylmercapto. After the acetyl group was removed with ammonia in alcohol, the desired target molecular was obtained. The structure of intermediate and target molecular was conformed by IR and 1HNMR. We made N-Boc-APT self-assemble-modificated gold electrode and investigated its electrochemical behavior. The CV results of methylene blue on nano-Au/N-Boc-APT SAM/Au electrode showed that nano-Au could speed this electron transfer …

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Synthesis And Electrochemical Behavior Of Layered-Structure Limn1-XCrXO2, Jie Xiao, Hui Zhan, Yun-Hong Zhou Aug 2004

Synthesis And Electrochemical Behavior Of Layered-Structure Limn1-XCrXO2, Jie Xiao, Hui Zhan, Yun-Hong Zhou

Journal of Electrochemistry

The Layered-structure LiMn1-xCrxO2(x=0, 0.15) solid solution has been prepared by the rheological phase method. From the XRD results, undoped LiMnO2 crystallized almost entirely in the orthorhombic phase while the structure of LiMn0.85Cr0.15O2 belongs to monoclinic phase. TEM investigation shows that the final powder product consists of ultrafine spherical particles which are distributed homogeneously, with the average diameter ranging from 60 to 300nm. The initial discharge capacity of LiMn0.85Cr0.15O is much higher than that of undoped LiMnO2. After 40 cycles, the capacity retention …

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Lithium Insertion Into Tio2(B) Nanobelts Synthesized By The "Soft Chemical" Method, Cha-Geng Nie, Zheng-Liang Gong, Lan Sun, Juan Zuo, Yue-Kun Lai, Chang-Jian Lin Aug 2004

Lithium Insertion Into Tio2(B) Nanobelts Synthesized By The "Soft Chemical" Method, Cha-Geng Nie, Zheng-Liang Gong, Lan Sun, Juan Zuo, Yue-Kun Lai, Chang-Jian Lin

Journal of Electrochemistry

TiO2(B) Nanobelts were synthesized by using the "Soft chemical"method. The products were characterized by means of transmission electron microscope(TEM), X-ray diffraction(XRD), Raman spectrum and energy dispersive spectrum(EDS). Galvanostatic charging and discharging tests showed that lithium-ion intercalation/deintercalation occurred reversibly in the TiO2(B) nanobelts electrode, and a high capacity (265 mAh·g-1) can be obtained. The results suggested that TiO2(B) Nanobelts might be a promising negative electrode material of second Lithium battery.

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Preparation, Characterization And Photoelectrochemical Activities Of Cu-Tio2/Ito Films, Dong Shu, Chun He, Han-Xia Zhang, Ya Xiong May 2004

Preparation, Characterization And Photoelectrochemical Activities Of Cu-Tio2/Ito Films, Dong Shu, Chun He, Han-Xia Zhang, Ya Xiong

Journal of Electrochemistry

Cu-TiO2/ITO films were prepared by direct photo-reduction deposition of Cu2+ on TiO2/ITO films. The nanocomposite films were characterized by UV-vis diffuse reflectance spectra (DRS), XRD spectra, Scanning Electron Microscope (SEM) technology, and photovoltage measurement. The feasibility of improving the photocatalytic activity of TiO2 film by combining the modification of Cu nanoparticles with the application of anodic bias was investigated. The experimental results showed that the deposited Cu has an apparent enhancement effect with respect to suppressing the recombination between the photogenerated charge carriers and enhancing the photocatalytic oxidation of formic acid. The combination could …

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Investigation Of Adsorption And Oxidation Behavior Of Isosafrole On A Smooth Pt, Xiao-Hong Zhang, Xiao-Jing Su, Qi-Ling Zhong, Lei Zhang, De-Sheng Mei, Bin Ren, Zhong-Qun Tian May 2004

Investigation Of Adsorption And Oxidation Behavior Of Isosafrole On A Smooth Pt, Xiao-Hong Zhang, Xiao-Jing Su, Qi-Ling Zhong, Lei Zhang, De-Sheng Mei, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

The electro-oxidation of isosafrole on a smooth platinum electrode was investigated in the non-aqueous solution. The CV curve shows two oxidation peaks and one reduction peak in the potential region between -0.5 V and 1.95 V. The relation between the oxidation and reduction peaks has been determined also by CV. The adsorption behavior of isosafrole on Pt was also investigated.

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Stability And Electrochemical Performance Of Nio Cathode Modified By Zno Additive For Mcfc In Molten Carbonates, Bo Huang, Fei Li, Qing-Chun Yu, Gang Chen, Ke-Ao Hu May 2004

Stability And Electrochemical Performance Of Nio Cathode Modified By Zno Additive For Mcfc In Molten Carbonates, Bo Huang, Fei Li, Qing-Chun Yu, Gang Chen, Ke-Ao Hu

Journal of Electrochemistry

The ZnO/Ni composite cathode was fabricated by tape-casting method, which microstructures and phases were studied. The electrochemical behaviors of ZnO impregnated NiO cathodes were also evaluated in molten 62 mol%Li2CO3 + 38 mol%K2CO3eutectic at 650 ℃ by electrochemical impedance spectroscopy (EIS) as a function of ZnO content and immersion time. The ZnO impregnated nickel cathodes showed the similar porosity, pore size and morphology to the reference nickel cathode. The stability tests of ZnO impregnated NiO cathodes showed that the ZnO additive could dramatically reduce the solubility of NiO in a eutectic carbonate mixture …

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Structures And Redox Activities Of Poly(M-Methoxyaniline), Yun-You He, Yi-Ting Xu, Li-Zong Dai, Jean-Yves Gal, Hui-Huang Wu May 2004

Structures And Redox Activities Of Poly(M-Methoxyaniline), Yun-You He, Yi-Ting Xu, Li-Zong Dai, Jean-Yves Gal, Hui-Huang Wu

Journal of Electrochemistry

Poly(m-methoxyaniline), PmMAn, was prepared in the presence of HCl, p-toluene-sulfonic acid and perchloric acid. By using cyclic voltammetry, the effect of different acid dopant on electrochemical activities of PmMAn was studied. The results showed that perchloric acid is the best acid to prepare PmMAn with good electrochemical activities The FTIR spectra indicate that the acid radical anions have embedded into PmMAn molecularchain as counter-ion during synthetic process, and this great influences the redox activities of PmMAn. SEM and XRD measurements illustrate that PmMAn is characterized by its typical molecular crystalline being monoclinic.

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Study On Reduction Process Of Electrolyic Manganese Dioxide In Situ By Ultraviolet-Visible Absorption Spectroscopy, Li-Cai Zhu, Zhong-Zhi Yuan, Wei-Shan Li May 2004

Study On Reduction Process Of Electrolyic Manganese Dioxide In Situ By Ultraviolet-Visible Absorption Spectroscopy, Li-Cai Zhu, Zhong-Zhi Yuan, Wei-Shan Li

Journal of Electrochemistry

The concentrationsof soluble Mn(Ⅲ) species, during the reduction ofelectrolytic MnO2 (EMD) in alkaline solution,have been monitored in situ by UV-visible spectroscopy. The concentration of Mn(Ⅲ) ion in solution changes with discharge time. The first electron discharge process of EMD can be described by three different steps: 1) the reduction of Mn4+ ions on the surface of EMD particles and the structural defect regions within the EMD, 2) the reduction of Mn4+ ions in ramsdellite, 3)the reduction of Mn4+ ions in pyrolusite. During the second electron discharge of EMD, the soluble Mn(Ⅲ) is reduced to Mn(Ⅱ) , …

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Study Of Anti-Corrosion Property On Poly(An-Co-Oas)/Epoxy, Qing-Wu Wang, Geng-Chao Wang May 2004

Study Of Anti-Corrosion Property On Poly(An-Co-Oas)/Epoxy, Qing-Wu Wang, Geng-Chao Wang

Journal of Electrochemistry

Polyaniline, polyanisidine and their copolymer poly(An-co-oAs) were synthesized via the solution chemical oxidative polymerization of aniline and anisidine in an acidic aqueous medium, and their properties and structure were characterized. The electrochemical method were applied to evaluate the corrosion behavior of tined iron uncoated or coated by polyaniline, poly(An-o-oAs), polyanisidine and poly(An-co-oAs)/epoxy blend in acid or saline aqueous solution. The result showed that with the increase of anisidine content, the solubility of polymers is improved apparently but their oxidation extent decreases accordingly. It is also founded that polyaniline, poly(An-co-oAs) and polyanisidine all have good anti-corrosion properties, and their anti-corrosion capacity …

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The Matching Study Of Electrodes In C/Ni(Oh)2 Hybrid Capacitor, Yue-Feng Su, Feng Wu May 2004

The Matching Study Of Electrodes In C/Ni(Oh)2 Hybrid Capacitor, Yue-Feng Su, Feng Wu

Journal of Electrochemistry

The energy storage mechanisms of electrochemical double-layer capacitor (EDLC) and C/Ni(OH)2 hybrid capacitor had been studied. The results proved that,the difference between the capacity of EDLC and C/Ni(OH)2 hybrid capacitor was detemined by the effectiveness usage of the activated carbon negative electrode, which is a criterion to estimate or design the theoretic capacity of the C/Ni(OH)2 hybrid capacitor. The electrochemical availability of activated matter in Ni(OH)2 electrode was introduced, and the quantity of the activated matter in Ni(OH)2 electrode should be compatible with the capacity of carbon electrode. When the capacities of Ni(OH)2 electrode …

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Electrodeposition Of Copper Into Trenches Under Rotating Hydrodynamic Condition, Jian-Jun Sun, Bu-Gao Xie, Wen-Hui Yin, Guo-Nan Chen May 2004

Electrodeposition Of Copper Into Trenches Under Rotating Hydrodynamic Condition, Jian-Jun Sun, Bu-Gao Xie, Wen-Hui Yin, Guo-Nan Chen

Journal of Electrochemistry

Silicon chips patterned with treneches were fixed onto a rotating electrode. Copper was electrodeposited into the trenches under rotating hydrodynamic conditions The sizes of the trenches are 1 m in height and 0.35 m, 0.50 m and 0.70 m in width, respectively. The effects of rotating of the chip, the current density and the concentration of Cu2+ on the filling of thetrenches were studied. It is found that lower current density and moderate concentration of Cu2+ resulted in a void free filling of the trenches.

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Two Kinds Of Polarons Observedin Polyaniline In Aqueous H2So4, Qin Zhou, Lin Zhuang, Jun-Tao Lu May 2004

Two Kinds Of Polarons Observedin Polyaniline In Aqueous H2So4, Qin Zhou, Lin Zhuang, Jun-Tao Lu

Journal of Electrochemistry

Simultaneous electrochemistry electron spin resonance (ESR) conductance measurements were carried out on electropolymerized polyaniline and ESR spectra were obtained with high signal/noise ratio. Spectral simulation revealed that in the early stage of polymerization, there were two kinds of polarons. According to the potential dependence of the ESR line width and the corresponding conductivitychange of the polymer, the two polarons are thought to be in ordered and disordered domains, respectively. With increasing doping level, the two polarons underwent similar transfer from Curie spin to Pauli spin and both polarons were charge carriers in the conducting polymer. This deduction was further supported …

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Studies Of Infrared Optical Properties Of Palladium Nanoparticles With Different Sizes And Dispersed States, Yan-Xia Jiang, Hong-Gang Liao, Wei Chen, Shi-Gang Sun May 2004

Studies Of Infrared Optical Properties Of Palladium Nanoparticles With Different Sizes And Dispersed States, Yan-Xia Jiang, Hong-Gang Liao, Wei Chen, Shi-Gang Sun

Journal of Electrochemistry

Pd nanoparticles with different sizes and dispersed states were prepared. Their infrared optical properties were studied with CO molecule probe. The infrared spectroscopic investigation revealed that Pdn of 6.6 nm and Pdn(cube)of 100～150nmexhibit normal IR absorption. The center of IR bands are around 1970 cm-1 and 1910cm-1. Pdnis introduced into the surface of electrode, and is induced by interface electric fieldto form the aggregation of nanoparticles Pdn(ag). The Pdn(ag) has a different IR optical property from Pdn. The direction of IR absorption band of Pdn …

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Electrochemical Lithium Insertion Of Nanosized Tio2, Ying Lan, Jian-Wen Liu, Xue-Ping Gao, Xing-Di Zhou, Jin-Qiu Qu, Feng Wu, De-Ying Song May 2004

Electrochemical Lithium Insertion Of Nanosized Tio2, Ying Lan, Jian-Wen Liu, Xue-Ping Gao, Xing-Di Zhou, Jin-Qiu Qu, Feng Wu, De-Ying Song

Journal of Electrochemistry

The protonic titanate nanotubes with the diameter of 10～15 nm were synthesized via hydrothermal method in NaOH solution and the calcined nanotubes at 500 ℃ were transferred to anatase nanorods with the diameter of 12～20 nm due to dehydration.The electrochemical behavior of the anatase nanorods as lithium insertion materials was examined. The results showed that the nanorod electrode had the high initial discharge capacity of 232 mAh/g and second reversible capacity of 198 mAh/g. The capacity of nanorod electrode maintained 152mAh/g after 20 cycles.

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Electrocatalytic And Lifetime Studies Of Commercial Catalystsin A Pemfc, Cheng Xuan, Yan-Yun Ma, Li Qi, Cheng Peng, Ling Chen, Jun Zhao, Ying Zhang, Qin-Bai Fan May 2004

Electrocatalytic And Lifetime Studies Of Commercial Catalystsin A Pemfc, Cheng Xuan, Yan-Yun Ma, Li Qi, Cheng Peng, Ling Chen, Jun Zhao, Ying Zhang, Qin-Bai Fan

Journal of Electrochemistry

A particularly designed H-type cell was used to simulate the operating condition of a hydrogen-air proton exchange membrane fuel cell (PEMFC). The electrocatalytic activity, morphology, structure and lifetime of commercially available catalysts, carbon support platinum (Pt/C) and unsupported platinum-ruthenium (Pt-Ru), were preliminary studied by carrying out electrochemical measurements and by SEM, XRD techniques. The catalysts were simultaneously tested in the H-cell under operation, and also separately tested in a conventional electrochemical cell for comparison. It was found that the characteristic peaks of hydrogen adsorption/desorption on cyclic voltammograms shifted considerably to a more positive direction for Pt/C, while a more negative …

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Preparation And Optical Properties Of Highly Ordered Cds Nanowire Arrays, Lan Sun, Chang-Jian Lin May 2004

Preparation And Optical Properties Of Highly Ordered Cds Nanowire Arrays, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Highly ordered CdS nanowire arrays have been prepared by using dc electrodeposition in the porous anodic aluminum oxide template. Scanning electro microscopy (SEM) and transmission electron microscopy (TEM) reveal that the nanowires are uniform and highly ordered. The measurements of X-ray diffraction and high-resolved electron microscopy (HRTEM) show that the nanowires are hexagonal structure with the crystallographic c-axis preferentially oriented along the length of the pore. The UV-Vis absorption spectra of CdS nanowire arrays show that the absorption edges of the nanowire arrays shift towards short wavelength with the decrease of the nanowire size. The photoluminescence measurements show that the …

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Direct Electron Transfer Of Redox Proteins And Enzymes Promoted By Carbon Nanotube, Chen-Xin Cai, Jing Chen May 2004

Direct Electron Transfer Of Redox Proteins And Enzymes Promoted By Carbon Nanotube, Chen-Xin Cai, Jing Chen

Journal of Electrochemistry

The redox proteins (enzymes), such as hemoglobin (Hb), horseradish peroxidase (HRP) and glucose oxidase (GOx) were immobilized on the surface of the carbon nanotube modified with glassy carbon (CNT/GC) electrode, respectively. The experimental results showed that the redox proteins (enzymes) underwent effective and stable direct electron transfer reaction at the surface of CNT/GC electrode with a pair of nearly symmetrical redox peaks in phosphate buffer solution. The formal redox potential, E0' , is almost independent on the scan rates, the average value of E0'  for Hb, HRP and GOx is -0.343±0.001, -0.319±0.002 and -0.456±0.001 V (vs.SCE,pH 6.9), respectively. …

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Exceptional Electrochemical Activities Of Amorphous Fe-B And Co-B Alloy Particles Used As High Capacity Anode Materials, Ya-Dong Wang, Xin-Ping Ai, Han-Xi Yang May 2004

Exceptional Electrochemical Activities Of Amorphous Fe-B And Co-B Alloy Particles Used As High Capacity Anode Materials, Ya-Dong Wang, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

Ultrafine amorphous alloy particles (UAAP) of Fe-B and Co-B were synthesized and tested for possible use as electroactive anode materials. It is found that unlike their parent elements, the alloy particles of transition metal (TM) and boron, the Fe-B and Co-B showed superior electrochemical activities when used as anodic materials in aqueous alkaline solution. The discharge capacities of Fe-B and Co-B electrodeswere observed to be 1200 mAh/g and 1100 mAh/g at moderately high rate of 100 mAh/g, respectively, much higher than the theoreticalcapacity of currently used zinc metal (820 mAh/g). The exceptional high capacities of the boride alloys were probably …

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Study On Electrochemical Properties Of Peo-Based Composite Polymer Electrolytes, Hong-Yan Du, Hu Cheng, Yong Yang May 2004

Study On Electrochemical Properties Of Peo-Based Composite Polymer Electrolytes, Hong-Yan Du, Hu Cheng, Yong Yang

Journal of Electrochemistry

Composite polymer electrolytes were prepared by introducing nano-scale SiO2 into PEO8-LiClO4 matrix. The ionic conductivity, lithium transference number and the electrochemical stability windows were measured. The phase component was evaluated with DSC techniques. The results showed that the introduction of nano fillers enhanced the ionic conductivity. It reached 4.3×10-5 S·cm-1 at 22 ℃. The conductivity enhancement of the composite polymer electrolytes is analyzed and proposed.

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Study On Electrochemical Performance Of Electroless Cobalt Coating For Microencapsution Of Hydrogen Storage Alloys, Tong-Chi Xia, Sheng-Li Zhang, Shu-Xin Wang, Kun Huang, Wen-Zeng Tian May 2004

Study On Electrochemical Performance Of Electroless Cobalt Coating For Microencapsution Of Hydrogen Storage Alloys, Tong-Chi Xia, Sheng-Li Zhang, Shu-Xin Wang, Kun Huang, Wen-Zeng Tian

Journal of Electrochemistry

The chemical cobalt plating method is used to treat on the hydrogen storage alloys. Effect of the surface treatment on the electrochemical performance of MH eletrodes was investigated by carrying out experimental methods of CV, AC and charge/discharge cycle tests. The results showed that after microencapsulation with cobalt, the impedance of electrochemical reaction on the surface and polarization during chare/discharge process was markedly decreased; and the electrocatalytic activity on the surface, discharge capacity, charge efficiency was improved. It was also indicated that the anode reaction of MH electrode treated was controlled by diffusion process.

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Progress In Research For Biofuel Cell, Yue Bao, Xia-Qin Wu Feb 2004

Progress In Research For Biofuel Cell, Yue Bao, Xia-Qin Wu

Journal of Electrochemistry

In this article, research progresses of the biofuel cell in recent years were summarized. The operation principle and classification of the biofuel cells were described. The role of the mediator for promoting electron transfer in biofuel cells and the techniques for improving the electric properties of biofuel cells, such as output potential, were discussed with some attracting research instances. Finally, the choke points for research of biofuel cell were explored, and the application prospect of biofuel cells was forecasted.

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Preparation, Structure And Electrochemical Hydrogenation Of Carbon Nanotubes Supported Platinum Catalysts, Qing-Gang He, Xiao-Zi Yuan, Xian-Xia Yuan, Zi-Feng Ma Feb 2004

Preparation, Structure And Electrochemical Hydrogenation Of Carbon Nanotubes Supported Platinum Catalysts, Qing-Gang He, Xiao-Zi Yuan, Xian-Xia Yuan, Zi-Feng Ma

Journal of Electrochemistry

In this paper, Pt/CNTs catalyst was prepared and its electrocatalytic property was studied by obtaining cycling voltammetry curves (C-V) and Tafel curves. In addition, the XRD,XPS and TEM tests were carried out to determine the structure and composition of the catalysts. It can be found that the platinum loading has been increased significantly using a carbon nanotubes support. Dispersion of Platinum was better and gave more active sites. The electrochemical characteristic of Pt/CNTs was also more desirable than that of Pt/C catalys t(Johnson Matthey). In conclusion, carbon nanotubes can played a conspicuous role in "electrogenerative" processes of PEMFC hydrogenation reactor.

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The Interaction In Doping Lithium Of Carbonaneous Anode In Lithium Ion Battery, Chang-Guo Chen, Hong-Min Zhang, Jia Chen, Dan-Mei Yu Feb 2004

The Interaction In Doping Lithium Of Carbonaneous Anode In Lithium Ion Battery, Chang-Guo Chen, Hong-Min Zhang, Jia Chen, Dan-Mei Yu

Journal of Electrochemistry

The quantum chemical DV-Xα method was used to calculate the lithium-doped models from one-Li-dopant to LiC6 and LiC2. It was found that Li+ has an tendency to attract electrons from the carbon plane through the C6 hexagons lying above or below it by the graph of charge-density difference. It was shown that LiC6 can exist steadily,while LiC2 can not exist steadily.

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Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu Feb 2004

Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu

Journal of Electrochemistry

In this paper, a chitosan modified glassy carbon electrode was prepared by the method of covalent-bond reaction, and the anodic stripping voltammetric characteristics of iodine on the modified electrode was studied. The results showed that the modified electrode has higher adsorption and selectivity for I- , and the sensitivity for I-  has been much improved in 0.1 mol·L-1 KH2PO4 solution (pH=4.0). The anodic stripping peak current of I- on the modified electrode varied linearly with I-  concentration in the range of 2.0×10-6～2.0×10-3 mol·L-1, and the detection limit …

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Study Of Electrochemical Properties Of The Hydride Alloy Electrode Zrcr0.4Mn0.2V0.1Co0.1Ni1.2 At High Temperature, Song Li, Shi-Jun Ji, Jun-Cai Sun Feb 2004

Study Of Electrochemical Properties Of The Hydride Alloy Electrode Zrcr0.4Mn0.2V0.1Co0.1Ni1.2 At High Temperature, Song Li, Shi-Jun Ji, Jun-Cai Sun

Journal of Electrochemistry

Electrochemical properties of the hydride alloy electrode ZrCr0.4Mn0.2V0.1Co0.1Ni1.2 at the different temperature have been investigated. The results showed that the alloy electrodes possessed the maximum discharge capacities 336 mAh/g and 298 mAh/g at 25 ℃ and 70 ℃ respectively. The activation process of the alloy at 70 ℃ became faster, and the alloy reached its maximum capacity in less than 4 cycles, while in 13 cycles at 25 ℃. The high rate capability increased from 55 % at 25 ℃ to 71% at 70 ℃ at 300 mA/g. It was worth …

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Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang Feb 2004

Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang

Journal of Electrochemistry

The ferrate(Ⅵ) was synthesized by electrochemical anodic oxidation. The effects of preparation conditions on the current yield of ferrate(VI) synthesis have been studied in this work. The experimental results showed that grey cast iron as an anodic material is suitable for electrochemical synthesis and NaOH solution as an electrolyte results in a higher current yield than KOH solution. The highest current yield was obtained at a current density (4.54) mA·cm-2, temperature 20 ℃ and 14 mol·dm-3 NaOH. In this case, a current yield of 68.5% was obtained by electrolysis for 1 h.

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Substrates Made By Electrodeposition For Measuring Electrical Properties Of One Dimensional Nanomaterials, Jin-Xuan Liu, Juan Xiang, Zhong-Qun Tian, Bing-Wei Mao Feb 2004

Substrates Made By Electrodeposition For Measuring Electrical Properties Of One Dimensional Nanomaterials, Jin-Xuan Liu, Juan Xiang, Zhong-Qun Tian, Bing-Wei Mao

Journal of Electrochemistry

A method to prepare alternating conducting/insulating substrates by electrodeposition-oxidation was established to facilitate I-E measurements of one-dimensional nanomaterial by CT-AFM. The prepared Au/CuO and HOPG/CuO substrates showed low roughness as well as high uniformity of the alternating conducting/insulating structure, Qualitative I-E measurements were performed on a single carbon nanotube attached to the two above-mentioned substrates, both showing metallic characteristics at room temperature and in air.

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Studies On The Mechanism Of Electroreduction Of Oxalic Acid, Yu-Zhan Li, Xin Liu, Rui-Sheng Hu, Deng-Ping Gu Feb 2004

Studies On The Mechanism Of Electroreduction Of Oxalic Acid, Yu-Zhan Li, Xin Liu, Rui-Sheng Hu, Deng-Ping Gu

Journal of Electrochemistry

The electroreduction mechanism of oxalic acid on Pb electrode in Na2SO4 solution were investigated using high scan rate cyclic voltammetry and chronoamperometry. The dynamic parameters for the first step electron transter reaction of oxalic acid electroreduction by were determined. The corresponding reduction peak potentials of oxalic acid, glyoxylic acid and glycolic acid in the cyclic voltammogranis obtained in the same condition were compared, and the intermediate reduction products of oxalic acid were suggested. The results showed that oxalic acid is weakly absorbed on the lead electrode.

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An Electrochemical Study Of The Effects Of Chelating Agents And Additives On Electroless Copper Plating, Xin Gu, Zhou-Cheng Wang, Chang-Jian Lin Feb 2004

An Electrochemical Study Of The Effects Of Chelating Agents And Additives On Electroless Copper Plating, Xin Gu, Zhou-Cheng Wang, Chang-Jian Lin

Journal of Electrochemistry

In this study, ethylenediaminetetraacetic acid disodium salt (Na2EDTA), triethanolamine(TEA), and 2,2′-dipyridine were adopted as chelating agents or additives in the electrolyte for electroless copper plating, and formaldehyde (HCHO) was as the reducting agent. Linear sweep voltammetry was applied to analyze the polarization behavior. The peak current of formaldehyde oxidation which increased by the addition of 2,2′-dipyridine is beneficial to formaldehyde oxidation in a specific range of concentration, While TEA decreased the peak current of formaldehyde oxidation. Two cathodic peaks due to copper(Ⅱ)reduction of TEA chelatation and copper(Ⅱ)reduction of EDTA chelatation were examined. EDTA increased the reduction peak current …

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