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Articles 1801 - 1830 of 2391

Full-Text Articles in Materials Chemistry

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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The Effect Of Ferrous Sulphate On The Electroless Depositionof Co-Fe-P Alloys, Sen-Lin Wang, Qing-Hua Li Aug 2004

The Effect Of Ferrous Sulphate On The Electroless Depositionof Co-Fe-P Alloys, Sen-Lin Wang, Qing-Hua Li

Journal of Electrochemistry

Electroless deposition of Co-P alloy and Co-Fe-P alloy from an alkaline bath, containing sodium hypophosphite as a reducer, boric acid as a buffer agent and sodium citrate as a complexing agent, was investigated respectively. The effects of process parameters, such as pH of solution and metallic salt mole ratio of CoSO4/FeSO4, on the plating rate were examined. It was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the plating rate of Co-Fe-P is lower than that of Co-P. The electrochemical polarization measurements have …

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Chemical Microetching Of Three-Dimensional Gear-Like Pattern On Nickel Surface, Zhu-Fang Liu, Li-Ming Jiang, Jing Tang, Li Zhang, Zhong-Qun Tian, Zhao-Wu Tian, Pin-Kuan Liu, Li-Ning Sun Aug 2004

Chemical Microetching Of Three-Dimensional Gear-Like Pattern On Nickel Surface, Zhu-Fang Liu, Li-Ming Jiang, Jing Tang, Li Zhang, Zhong-Qun Tian, Zhao-Wu Tian, Pin-Kuan Liu, Li-Ning Sun

Journal of Electrochemistry

The chemical micromachining on nickel surface with three-dimensional (3D) gear-like mold was realized by confined etchant layer technique (CELT). By using effective chemical etching and scavenging system (HNO3 +NaOH) and optimizing experimental parameters, such as the etching time, etching current density, concentration of the etchant or and scavenger, we obtained the etched pattern, which is close to negative copy of the mold. The etched micro-pattern characterized by SEM and AFM, demonstrates that CELT can be applied to the 3-D microstructure replication on nickel surface.

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Studies On The Electrochemical Behavior Of Copper Paratolysulfate And Its Complexes, Ji-Guo Song, Pei-Kang Shen Aug 2004

Studies On The Electrochemical Behavior Of Copper Paratolysulfate And Its Complexes, Ji-Guo Song, Pei-Kang Shen

Journal of Electrochemistry

Copper (II) paratolysulfate has been synthesized and characterized by thermo-gravimetric (TG) measurements and differential scanning calorimetric (DSC) analysis. This salt can easily lose all crystal water and the dehydrated salt does not deliquesce in the air. It is found for the first time that the complex of Cu(p-OTs)2/ethanolamine(1∶1) can catalyze the oxidation of 1,1′-bi-2-naphthol in DMSO and DMF, while the process is difficult to perform in H2O and CH3OH. The electrochemical behaviors of both Cu(p-OTs)2 and its complexes with ethanolamine have been studied on platinum electrode in DMSO, DMF, CH3OH and …

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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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Preparation And Electrochemical Performance Of New Composite Seperators For Lithium-Ion Batteries, Hu Cheng, Hong-Yan Du, Yong Yang Aug 2004

Preparation And Electrochemical Performance Of New Composite Seperators For Lithium-Ion Batteries, Hu Cheng, Hong-Yan Du, Yong Yang

Journal of Electrochemistry

New composite seperators for lithium ion batteries were prepared by coating PEO mixed with nanosize SiO2 onto microporous polypropylene(PP) seperators. Highly conductive electrolytes were prepared by soaking them in an electrolyte solution. With these composite separators, the lithium ion cell consisting of Li anode and LiNi0.8Co0.2O2 cathode were assembled. The high initial discharge capacity and good capacity retention were obtained through the cell.

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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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Preliminary Study Of Speek Membranes For Direct Methanol Fuel Cells Application, Su-Zhen Ren, Zhen-Xing Liang, Xin-Sheng Zhao, Qin Xing, Gong-Quan Sun, Xue-Feng Yang Aug 2004

Preliminary Study Of Speek Membranes For Direct Methanol Fuel Cells Application, Su-Zhen Ren, Zhen-Xing Liang, Xin-Sheng Zhao, Qin Xing, Gong-Quan Sun, Xue-Feng Yang

Journal of Electrochemistry

This paper describes the methanol permeability characterization of SPEEK membranes and their feasibility for DMFC application. The SPEEK membranes showed a significant lower methanol permeation than Nafion 115 determined from voltammetric methods. An increase in open circuit voltage was found in the performance of SPEEK membranes in DMFC. The power density of the cell using SPEEK membrane was considerably poorer than that of Nafion 115. If modified properly, the SPEEK membranes can be chosen for DMFC application based on this study.

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Fabrication Of Solid Oxide Fuel Cells And Analysis Of Their Structure And Performance, Nai-Tao Yang, Bo Meng, Ru-Jun Yu, Xiao-Yao Tan Aug 2004

Fabrication Of Solid Oxide Fuel Cells And Analysis Of Their Structure And Performance, Nai-Tao Yang, Bo Meng, Ru-Jun Yu, Xiao-Yao Tan

Journal of Electrochemistry

An intermediate temperature solid oxide fuel cell (IT-SOFC) was fabricated by co-copressing-sintering methods, and the electrolyte of Ce0.8Gd0.2O1.9 (CGO) and cathode materials of La0.6Sr0.4Co0.2Fe0.8O3-α (LSCF) were prepared by sol-gel method. The effect of preparation methods on the microstructure of the prepared fuel cells was analyzed by SEM . It shows that the cells prepared by the co-pressing/co-sintering method possess a dense electrolyte layer and a compact interface between electrolyte and anode but a curved configuration, while those prepared by the colloidal technique have a flat configuration …

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Study On An Intermediate Temperature Planar Solid Oxide Fuel Cell, Shao-Rong Wang, Wen-Xia Chen, Ting-Lian Wen, Jia-Di Cao, Zhi-Yi Lv, Da-Qian Wang Aug 2004

Study On An Intermediate Temperature Planar Solid Oxide Fuel Cell, Shao-Rong Wang, Wen-Xia Chen, Ting-Lian Wen, Jia-Di Cao, Zhi-Yi Lv, Da-Qian Wang

Journal of Electrochemistry

Tape cast method was applied to prepare green sheets of Ni/YSZ anode supported YSZ thin film. After isostatic pressure treatment and cosintering, the YSZ film on the Ni/YSZ anode was gas-tight dense, and 15~30 μm thick. The area of the composite film was over 100 cm2. A Ce0.8Sm0.2O1.9 (CSO) interlayer was sintered on to the YSZ electrolyte film to protect La0.6Sr0.4CoO3 (LSCO) cathode from reaction with YSZ at high temperatures. The LSCO cathode layer was screen printed onto the CSO interlayer and sintered at 1200 ℃ for 3 …

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Preparation Of Photo-Electrochemical Anticorrosion Tio2 Films By Anodization Method, Peng-Fei Wu, Mou-Cheng Li, Jia-Nian Shen, Mei-Qun Xiao, Dong Liu Aug 2004

Preparation Of Photo-Electrochemical Anticorrosion Tio2 Films By Anodization Method, Peng-Fei Wu, Mou-Cheng Li, Jia-Nian Shen, Mei-Qun Xiao, Dong Liu

Journal of Electrochemistry

Titanium oxide films have photo-electrochemical anticorrosion effect. We investigated the TiO2 films prepared by anodization method to protect for 45# carbon steel in man-made seawater(3%NaCl). Various parameters, including voltages, electrolytes nature and concentration of electrolyte were examined. The polarization curves and of TiO2 and coupling photo-current curve between TiO2 film and 45#  carbon steel were measured.

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Nearest-Neighbor-Atom Core-Hole Transfer In Isolated Molecules, Renaud Guillemin, Oliver Hemmers, D. Rolles, S. W. Yu, A. Wolska, I. Tran, A. C. Hudson, J. Baker, Dennis W. Lindle Jun 2004

Nearest-Neighbor-Atom Core-Hole Transfer In Isolated Molecules, Renaud Guillemin, Oliver Hemmers, D. Rolles, S. W. Yu, A. Wolska, I. Tran, A. C. Hudson, J. Baker, Dennis W. Lindle

Environmental Studies Faculty Publications

A new phenomenon sensitive only to next-door-neighbor atoms in isolated molecules is demonstrated using angle-resolved photoemission of site-selective core electrons. Evidence for this interatomic core-to-core electron interaction is observable only by measuring nondipolar angular distributions of photoelectrons. In essence, the phenomenon acts as a very fine atomic-scale sensor of nearest-neighbor elemental identity.

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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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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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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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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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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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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 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 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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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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Study On The Electrochemical Impedance Spectroscopy (Eis) Of Al-Bronze At Different Anodic Potentials, Hui Yu, Sa-Ying Dong, Hai-Bo Xu, Ming-Xian Sun Feb 2004

Study On The Electrochemical Impedance Spectroscopy (Eis) Of Al-Bronze At Different Anodic Potentials, Hui Yu, Sa-Ying Dong, Hai-Bo Xu, Ming-Xian Sun

Journal of Electrochemistry

The corrosion dissolution mechanism of Al-bronze has been investigated by Electrochemical Impedance Spectroscopy (EIS) at different anodic potentials. In the active region, the corrosion products are complex compounds of cupreous chloride and the diffusion of CuCl2- is the control process of electrochemical reaction. In the transition region, there exhibits two capacitance loops on EIS because CuCl and cupreous oxides films deposit on the electrode surface. In the limiting current region, an inductance loop appears on the EIS because the breakdown of the oxides film leads to serious pit corrosion.

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