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Engineering Science and Materials

Journal

2008

Articles 31 - 48 of 48

Full-Text Articles in Electrical and Computer Engineering

Preparation And Electrochemical Capacitance Of Spherical-Like Polypyrrole Doped With Heparin Sodium, Hong-Yu Mi, Xiao-Gang Zhang, Su-Dong Yang, Xiang-Guo Ye May 2008

Preparation And Electrochemical Capacitance Of Spherical-Like Polypyrrole Doped With Heparin Sodium, Hong-Yu Mi, Xiao-Gang Zhang, Su-Dong Yang, Xiang-Guo Ye

Journal of Electrochemistry

Spherical-like polypyrrole with an average diameter of 100 nm as the electrode material for supercapacitor was prepared by a self-assembly process with heparin sodium salt as the dopant at-10 ℃.The morphology and electrochemical properties were characterized by transmission electron microscopy(TEM),cyclic voltammetry(CV),galvanostatic charge/discharge and electrochemical impedance spectroscopy(EIS) measurements.The results showed that the polypyrrole doped with heparin sodium salt exhibited good capacitive behavior.The specific capacitance of single electrode was up to 338 F/g at 3 mA/cm2.

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Structure And Property Of Molecular Self-Assembled Membrane With Zirconium Ion, Tian-De Wang, Rong Wang, Xia-Qin Wu, Zhi-Gang Guo, Wei-Wei Ji May 2008

Structure And Property Of Molecular Self-Assembled Membrane With Zirconium Ion, Tian-De Wang, Rong Wang, Xia-Qin Wu, Zhi-Gang Guo, Wei-Wei Ji

Journal of Electrochemistry

According to the complex interaction between dodecyl phosphonate and stainless steel surface as well as the zirconium ion,the self-assembled monolayer and double-layer dodecyl phosphonate modified 304 type stainless steel electrode were prepared.The electrodes were characteristiced by static contact angles and electrochemical polarization methods.The results suggested that the double-layer modified stainless steel electrode had better corrosion inhibition effect than the monolayer modified electrode.

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Synthesis Of Agv_3o_8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang May 2008

Synthesis Of Agv_3o_8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang

Journal of Electrochemistry

The layered cathode material of AgV3O8 has been prepared for the lithium secondary batteries via the soft chemistry technique. The so-synthesized powders were characterized by XRD(powder X-ray diffraction),SEM(scanning electron microscope) and LPSA(laser particle size analysis).The electrochemical property was investigated by the galvanostatic discharge-charge technique.The results indicated that the particale sizes of AgV3O8 prepared were small in the distribution of narrow range,which leads to high discharge capacity.Among them,the material synthesized at 400 ℃ displayed the first discharge capacity of 760.5 mAh/g.

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The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue May 2008

The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide were prepared by sol-gel method with different annealed temperatures.The influences of annealed temperature in properties of anode coatings were characterized by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD),potential of chlorine evolution,accelerated life,cyclic voltammetry and electrochemical impedance spectroscopy(EIS) tests.The results showed that the annealed temperature affected the morphology of coatings,while the electric quantities of cyclic voltammetry and double layer capacitances of anode coatings had a tendency to fall down and the potential of chlorine evolution and accelerated life had a tendency to increase as the annealed temperature increased.

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Preparation And Photoelectrochemical Properties Of Fe-Doped Tio_2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin May 2008

Preparation And Photoelectrochemical Properties Of Fe-Doped Tio_2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The Fe-doped TiO2 nanotube arrays were fabricated in Fe(NO3)3-HF mixing solutions by electrochemical anodic oxidation method,and characterized by FESEM,Raman,XPS and DRS.The effect of Fe concentratiions on photoelectrochemical property of the arrays was also investigated.The diameters and lengths of Fe-doped TiO2 nanotube arrays were 50~90 nm and about 200 nm,respectively.Compared with the undoped TiO2 nanotube arrays,the absorption edge of Fe-doped TiO2 nanotube arrays appeared red shifting.The more Fe content,the larger red shifting,in addition,the photocurrent of Fe-doped TiO2 nanotube arrays increased obviously.

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Synthesis Of 2,2′-Dichlorohydrazobenzene Using An Ion Exchange Membrane, Chao Zhang, Pei-Jin Li Feb 2008

Synthesis Of 2,2′-Dichlorohydrazobenzene Using An Ion Exchange Membrane, Chao Zhang, Pei-Jin Li

Journal of Electrochemistry

Using an ion exchange membrane as a separator,the 2,2′-Dichlorohydrazobenzene is synthesized by the electrolytic reduction of o-chloronetrobenzene.The effects of electrode activation condition,current density,electrolyte temperature on electrolytic reduction are discussed.It was found that the optimum reaction temperature is 80 ℃.When the electrolyte concentration was 30% NaOH at the anode and 10% NaOH at the cathode,current density is 4.2A/dm2,the current efficiency reached 73% and yield is 83%.

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The Influence Of The Sputtering Power On The Structural And Electrochemical Properties Of Tin Oxide Films, Min-Zhen Cai, Jie Song, Ming-Sen Zheng, Qi-Hui Wu, Sun-Tao Wu, Quan-Feng Dong Feb 2008

The Influence Of The Sputtering Power On The Structural And Electrochemical Properties Of Tin Oxide Films, Min-Zhen Cai, Jie Song, Ming-Sen Zheng, Qi-Hui Wu, Sun-Tao Wu, Quan-Feng Dong

Journal of Electrochemistry

Tin oxide films were deposited on silicon substrates at room temperature using the radio frequency(RF) magnetron sputtering with different sputtering power.The influence of sputtering power upon the crystal structure,surface morphology and electrochemical properties of tin oxide films were then investigated.The XRD and SEM results illustrate that the phase of tin oxide thin films changed from amorphous to crystalline and the grain size augments with the increase of the sputtering power.The constant current charge and discharge cycle tests imply that the initial irreversible capacity loss of Li/tin oxide batteries increase and which capacity decrease as the sputtering power increases.The sputtering power …

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Cu Doping Lifepo_4 And Its Electrochemical Performance, Ming-Sen Zheng, Shan-Ke Liu, Shi-Gang Sun, Quan-Feng Dong Feb 2008

Cu Doping Lifepo_4 And Its Electrochemical Performance, Ming-Sen Zheng, Shan-Ke Liu, Shi-Gang Sun, Quan-Feng Dong

Journal of Electrochemistry

LiFePO4 and LiFePO4 doped with Cu2+ ions were synthesized by solid-state reactions.The structure of LiFePO4 and the Fe valence were analyzed by the XRD(X-ray diffraction) and XPS(X-ray photoelectron spectroscopy) respectively.The Cu doping position in LiFePO4 is discussed.It has found that the volume of LiFePO4 by doping Cu2+ ions is reduced.The minim Cu2+ ions doping does not almost change the binding energy of Fe2p1/2 in LiFePO4.According to the experiment results,we conclude that most of the Cu2+ ions substitute the Fe2+ ions in LiFePO4 when a small amount of Cu2+ ions doping is occurred.

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Preparation And Electrochemical Performance Of Ordered Mesoporous Titanium Phosphate As Cathode Material For Li-Ion Battery, Qiong Wang, Attia Adel, Zhi-Cong Shi, Yong Yang Feb 2008

Preparation And Electrochemical Performance Of Ordered Mesoporous Titanium Phosphate As Cathode Material For Li-Ion Battery, Qiong Wang, Attia Adel, Zhi-Cong Shi, Yong Yang

Journal of Electrochemistry

Ordered porous titanium phosphate materials were prepared by using the surfactant template combined with the sol-gel method.The samples were characterized by small angle X-ray diffraction(SA-XRD) method,N2 adsorption/desorption techniques,high resolution transmission electron microscopy(HRTEM) and element analysis.It is found that the calcination temperature is a big influence on the porous structure,and electrochemical performance of the titanium phosphate materials.,and the mesoporous titanium phosphate showed good performance in the electrochemical test,the first discharge capacity is 94 mAh/g at the current density of 150 mA/g.On the other hand,the no porous material with a low capacity of 37 mAh/g under the same charge-discharge condition.

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Effect Of Au At Different States On Electrocatalytic Performance Of Pd Catalyst For Oxidation Of Formic Acid, Xin Wang, Ya-Wen Tang, Tian-Hong Lu Feb 2008

Effect Of Au At Different States On Electrocatalytic Performance Of Pd Catalyst For Oxidation Of Formic Acid, Xin Wang, Ya-Wen Tang, Tian-Hong Lu

Journal of Electrochemistry

Using liquid-reduction or complex-redution method,four catalysts,i.e,the Au/C,Pd/C,Pd-Au/C-T and Pd-Au/C-H were preparated and which electroanalytic activities and stabilities for the oxidation of formic acid were compares.It was found that the Au/C catalyst has no electrocatalytic activity,and the Pd/C catalyst possesses the good electrocatalytic performance for the oxidation of formic acid.The addition of Au into the Pd/C catalyst can increase the electrocatalytic activity and stability.Especially,the electrocatalytic activity and stability of the Pd-Au/C-T catalyst with the alloy of Pd and Au are better than that of the of the Pd-Au/C-H catalyst,in which,Pd and Au do not form the alloy.The investigation of its reason …

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A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang Feb 2008

A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Large scale vertically aligned carbon nanotubes(ACNTs) with uniform length and diameter were prepared by the pyrolysis of iron(Ⅱ) phthalocyanine at low pressure.The ACNTs were activated by electrolyte-activation,acid-activation or electrochemical activation.The performance of the capacitor based on activated ACNTs was characterized by cyclic voltammograms which was of rectangular shape,impedence spectroscopy in which the phase is above 80° and the result specific capacitance was 16～32 F/g,which suggest that the ACNTs are the promising material for the supercapacitor.

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Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr_2o_7~(2-)/Cr~(3+) As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun Feb 2008

Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr_2o_7~(2-)/Cr~(3+) As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun

Journal of Electrochemistry

Adipic acid was synthesized by electro-oxidation of cyclohexanol taking Cr2O72-/Cr3+ as indirect oxidant.The best technological conditions were optimized by orthogonal experiment.The optimum condition are as follows: the temperature is 35℃,ratio of crude material is n(cyclohexanol)∶n(Cr2O72-)=0.4∶1 and concentration of H2SO4 is 4 mol·L-1.Under these conditions,the yield of adipic acid can reach 70.29%.Moreover,The effects of concentration of Ag2SO4,(NH4)2SO4,H2SO4and current density on the formation of Cr2O72-were also explored.The rate of Cr3+ conversion can reach 82.52%.

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Molten Salt Treatment Of Mno_2 And Investigation On Supercapacitor Properties, Ye Chen, Zun-Bo Zhang, Wei Zhang, Liang Liu, Zhi-Min Liu Feb 2008

Molten Salt Treatment Of Mno_2 And Investigation On Supercapacitor Properties, Ye Chen, Zun-Bo Zhang, Wei Zhang, Liang Liu, Zhi-Min Liu

Journal of Electrochemistry

The MnO2 prepared by solid phase method is treated by KCl-NaCl-LiCl molten salt system.The XRD patterns indicated that the crystal structures of MnO2 sample have had the α-MnO2 and γ-MnO2 phase,the crystallinity of sample is increased after treated by molten salt.The electrochemical properties were tested by cyclic voltammetry,constant current charge/discharge and AC impedance.The result shows that the supercapacitor performance of the treated material has improved.The specific discharge capacitance of the treated sample are 129.07 F·g-1,increased by 27.88% compared to 100.94 F·g-1 of untreated sample.Long cycle life and high coulombic efficiency were also demonstrated after charge/discharge 100 cycles.The value of RESR …

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Potentiometric Response Of Glucose On Mno_2-Go_X Carbon Paste Electrode, Cai-Juan Wang, Xiao-Ya Hu Feb 2008

Potentiometric Response Of Glucose On Mno_2-Go_X Carbon Paste Electrode, Cai-Juan Wang, Xiao-Ya Hu

Journal of Electrochemistry

A novel carbon paste electrode(CPE) modified with MnO2 and glucose oxidase(GOx),is reported.Different factors,such as the effect of supporting electrolyte,pH of solutions,various paste glues,the amount of MnO2 and temperature,which may influence the determination of H2O2 and glucose were tested to optimize.Based on above,potentiometric determination of glucose was achieved in neutral solution and at 35 ℃,the electrode gave a response of 36.12～34.62 mV/pGlucose between 2.0×10-5mol·L-1 and 5.2×10-3 mol·L-1 with a detection limit of 3.3×10-6 mol·L-1.Moreover,this kind of the electrode had good stability and reproducibility.Most normal anion,cation,isotol,glycerin and amide will not interfere the determination of glucose.

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Effects Of Oxidation Methods On The Stability Of Coooh Conductive Network In Foam Nickel Electrodes, Xiao-Feng Li, Yan-Wei Wei, Hui-Chao Dong Feb 2008

Effects Of Oxidation Methods On The Stability Of Coooh Conductive Network In Foam Nickel Electrodes, Xiao-Feng Li, Yan-Wei Wei, Hui-Chao Dong

Journal of Electrochemistry

Two kinds of the cobalt oxyhydroxide conductive networks in foam nickel electrodes were prepared by different methods i.e.the electrochemical-oxidation(EO) and chemical-oxidation(CO) and which redox behaviors were studied by using cyclic voltammetry and X-ray diffraction measurements.The results show that the CoOOH(CO) has better redox reversibility than CoOOH(EO) and the structure of the former can be kept when nickel electrodes are subjected to a negative potential.Thus,98.7% capacity retention is demonstrated on nickel/metal-hydride batteries with CoOOH(CO) conductive network after being imposed over-discharge state storage;on the contrary,only 83.3% capacity retention is found on the batteries with CoOOH(EO) conductive network.

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Square Wave Stripping Voltammetric Behaviors Of Rutin On Glassy Carbon Electrode And Its Application, Jun Hua, Xiao-Ying He, Fang Liao, Qing-Tao Zhu Feb 2008

Square Wave Stripping Voltammetric Behaviors Of Rutin On Glassy Carbon Electrode And Its Application, Jun Hua, Xiao-Ying He, Fang Liao, Qing-Tao Zhu

Journal of Electrochemistry

The electrochemical behaviors of rutin(Rt) at glassy carbon electrode were studied by square wave stripping voltammeter in the presence of 0.1mol·L-1HAc-NaAc buffer solution(pH=3.0).The sensitive oxidation peak of rutin was observed and which potential peak is 0.46V(vs.SCE).The experimental parameters,such as pH value,deposition potential and deposition time were investigated and selected.The peak currents were proportional to the concentration of rutin in range of 5.0×10-8 mol·L-1~1.0×10-6mol·L-1,and the linear regression coefficient equaled 0.99799,the detection limit was 1.1×10-8 mol·L-1.This method was applied to the determination of rutin content in tablet with satisfactory results.

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Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na_3alf_6-Alf_3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu Feb 2008

Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na_3alf_6-Alf_3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu

Journal of Electrochemistry

The mechanism of TiO2 electrode process has been investigated by cyclic voltammetry and chronopotentiometry on the tungsten filament in molten Na3AlF6-AlF3 salts at 990 ℃.The experimental results showed that electrochemical reduction of Ti(Ⅳ) precede were two steps,firstly Ti(Ⅳ) was reduced to Ti(Ⅱ),then Ti(Ⅱ) was reduced to Ti,namely: Ti(Ⅳ)→Ti(Ⅱ)→Ti.

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The Determination Of Vitamin C By Bromophenol Blue Modified Glassy Carbon Electrode, Shu-Lin Zhang, Min-Jiao Li, Yi Luo, Xiao-Bo Wang Feb 2008

The Determination Of Vitamin C By Bromophenol Blue Modified Glassy Carbon Electrode, Shu-Lin Zhang, Min-Jiao Li, Yi Luo, Xiao-Bo Wang

Journal of Electrochemistry

The content of ascorbic acid of(vitamin C) was analyzed by using fast cyclic voltamment with bromophenol blue(BPB) modififed GC-electrode,and which experimental conditions were optimiged.The results showed that the BPB modified GC-electrode had the good stability and anti-jamming faculty for analysing the content of ascorbic acid.A linear relationship between the peak current and concentration of vitamin C in the range of 0.0050~0.1500 g·L-1 was obtained,which related coefficient and the detection limit are-0.9991 and 0.0010 g·L-1,respeclively.The method has satisfactory results.

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