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Articles 3781 - 3810 of 4488

Full-Text Articles in Chemistry

Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing-Guo Liu Nov 2000

Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing-Guo Liu

Journal of Electrochemistry

The synthesis and electrochemical characteristics of lithium cobalt nickel oxide as cathode materials for rechargeable lithium batteries were investigated. It was clarified from these investigations that lithium cobalt nickel oxide has been produced from basic cobalt carbonate,basic nickel carbonate, lithium carbonate, and citrate. LiNi0.8Co 0.2O2 prepared under the stream of oxygen gas showed a higher cycling capacity of (～190 mAh·g-1).

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A Study Of The Adsorption Behaviors On The Surface Of Gold Electrode By In-Situ Electrochemical Raman Spectroscopy, Xia-Qin Wu, Xiao-Wei Cao, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang Nov 2000

A Study Of The Adsorption Behaviors On The Surface Of Gold Electrode By In-Situ Electrochemical Raman Spectroscopy, Xia-Qin Wu, Xiao-Wei Cao, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang

Journal of Electrochemistry

The results of in-situ measurements with Raman spectroelectrochemical thchnique on bare gold electrode and adenine modified gold electrode were reported. The adsorption behaviors of adenine and superoxide dismutase (SOD) and their interactions with gold electrode were analyed. The mechanism of promoted electron transfer process of SOD in the presence of adenine at gold electrode surface is discussed.

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Electrochemical Polymerization Of Biphenyl And P-Terphenyl In Organic Solvent, Sheng-Yun Cui Nov 2000

Electrochemical Polymerization Of Biphenyl And P-Terphenyl In Organic Solvent, Sheng-Yun Cui

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L-1 NaOH+0.1 mol·L-1 CH3CH2OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH3COO-, only very small amount of CH 3CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

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Effect Of High Concentration Lithium Bromide Solution On Electrochemical Behavior Of Low Alloy Steel At High Temperature, Jian-Wei Guo, Cheng-Hao Liang Nov 2000

Effect Of High Concentration Lithium Bromide Solution On Electrochemical Behavior Of Low Alloy Steel At High Temperature, Jian-Wei Guo, Cheng-Hao Liang

Journal of Electrochemistry

By electrochemical measurements and weight loss experiments, the effect of MoO42- on low alloy steel's electrochemical behaviors was investigated at high temperature in 55%LiBr+0.07 mol/L LiOH solution. The results showed that MoO42-, as an anodic inhibitor, formed passive film rapidly and impeded both anodic and cathodic procedures. Moreover, Na2MoO4 prevented corrosion effectively in 55%LiBr+0.07 mol/L LiOH solution when its concentration is more than 200 mg/L. The pitting potential increased accompanying to the arising of Na2MoO4 concentration. Some elements of alloy strengthened resistance to corrosion, shch as chromium and nickel, …

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Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou Nov 2000

Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L-1 NaOH+0.1 mol·L-1 CH3CH2OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH3COO-, only very small amount of CH 3CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

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Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise Oct 2000

Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise

Chemistry & Biochemistry Theses & Dissertations

As early as 1950, Raman spectroscopy was proposed as a method to determine aromatics and olefins in hydrocarbon mixtures. Until recently, extensive use of Raman spectroscopy in the characterization of hydrocarbons has not been practical due to several limitations. One early limitation to Raman analysis was the absence of a high intensity and stable excitation source. This problem has been overcome with the advent of lasers. Another limitation was the presence of fluorescence in hydrocarbon fuels when excited by visible lasers. However, the development of Fourier-transform Raman spectrometers now allows Raman spectra to be collected using near-IR lasers (e.g …

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Three-Dimensional Microfabrication On Gaas Using A Regular Patterns Mold, Hai-Gou Huang, Jian-Jun Sun, Xiong-Ying Ye, Li-Min Jiang, Jin Luo, Ze-Sheng Lu, Shen Dong, Zhong-Qun Tian, Zhao-Ying Zhou, Zhao-Wu Tian Aug 2000

Three-Dimensional Microfabrication On Gaas Using A Regular Patterns Mold, Hai-Gou Huang, Jian-Jun Sun, Xiong-Ying Ye, Li-Min Jiang, Jin Luo, Ze-Sheng Lu, Shen Dong, Zhong-Qun Tian, Zhao-Ying Zhou, Zhao-Wu Tian

Journal of Electrochemistry

Electrochemical etching of single crystal GaAs (111) was performed with a regular mold which resembles the micro-gear patterns. The etched patterns on GaAs was very consistent with the negative copies of the mold when the confined etchant layer technique (CELT) was used. However when the scavenger chemical of H3AsO3 was not added in the etching solution, the regular micro-gear patterns of the mold could not be obtained. In addition, the procedure of fabricating a electrochemical mold is introduced and the characteristics of the mold are briefly discussed.

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Electrochemical Investigations Of Semiconductor Silicon Wafers, Xuan Cheng, Chang-Jian Lin Aug 2000

Electrochemical Investigations Of Semiconductor Silicon Wafers, Xuan Cheng, Chang-Jian Lin

Journal of Electrochemistry

Electrochemical characteristics of semiconductor silicon wafers were investigated in dilute hydrofluoric acid solutions using DC polarization and AC impedance techniques under both illuminated and dark conditions. Both techniques were extremely sensitive to the trace amount (10-9 wt% level) of copper presented in solutions, but only sensitive to the 10-6 wt% level of non ionic surfactant OHS contained in solutions. The results revealed that the electrochemical reactions took place favorably and became predominated at silicon/solution interface under illuminated condition.

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The Effect Of Cerium On The Anodic Behavior Of Pb-Ca-Sn Alloy In Sulfuric Acid Solution, Hou-Tian Liu, Jiong Yang, Hai-He Liang, Ji-Hua Zhuang, Wei-Fang Zhou Aug 2000

The Effect Of Cerium On The Anodic Behavior Of Pb-Ca-Sn Alloy In Sulfuric Acid Solution, Hou-Tian Liu, Jiong Yang, Hai-He Liang, Ji-Hua Zhuang, Wei-Fang Zhou

Journal of Electrochemistry

The cyclic voltammograms for Pb - 0.5 at% Ca - 1.5 at% Sn and Pb - 0.5 at% Ca - 1.5 at% Sn containing a certain amount of cerium in 4.5 mol·dm-3 H2SO4 at 20℃ were measured between 0.6 V and 1.4 V(vs. Hg/Hg2SO4). The growth rate of the anodic Pb(Ⅱ) films formed on the mentioned alloy electrodes at 0.9 V in the same sulfuric acid medium was investigated using the Linear Sweep Voltammetry. The variation with electrode potential of the real part of the impedence (Z’) for the anodic Pb(Ⅱ) films …

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The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo Aug 2000

The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo

Journal of Electrochemistry

A linear polarization method was applied to measure corrosion rate of reinforcing bar of concrete in situ. Generally in the experiment, the area and shape of the reinforcing bar as a working electrode can be changed and adjusted according to our needs. But polarization area cannot be defined when reinforcing bar is polarized in situ, so that a real Rp can't be obtained. Thus the purpose of present work is to improve the measurement system. We used the double-ring auxiliary electrodes made by ourselves. The size of the double-ring auxiliary electrodes was adjusted repeatedly until the real polarization area …

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Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li Aug 2000

Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li

Journal of Electrochemistry

We described a novel cathodic indirect epoxidation system in which O2 was first cathodically reduced to H2O2. Then VO(acac)2 was oxidized by H2O2 homogeneously to VO(acac)2OOH which was used to epoxidize some olefine such as maleic, fumaric and crotonic acids. Many affecting factors on the current efficiency were optimized. The research will contribute to the developments of organic electrosynthesis.

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The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu Aug 2000

The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu

Journal of Electrochemistry

The coherent electroplates were prepared by electro depositing Pd on supporting materials glassy carbon. The surface morphology of the electrodes was examined by SEM. The electro oxidation of HCOOH in HClO4 solution was investigated by using cyclic voltammetry. The results show that the deposited conditions in the preparation of electrodes by electro depositing Pd affect the electrodes electro catalytic activity to the oxidation of HCOOH. The platinized Pd electrode on GC substrates using large current density is of higher catalytic activity to the oxidation of HCOOH than Pd electrode. The electro catalytic activity of PdO formed on the Pd …

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The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang Aug 2000

The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang

Journal of Electrochemistry

Lithiated titanium composite oxides Li4Ti5O12 were prepared from Li2CO3 and TiO2. The XRD results of this composite oxides indicated that the compound had a spinel structure. The electrochemical behavior of lithiated titanium composite oxides was examined. The results showed that this material had an excellent cyclic capability and reversibility for lithium insertion, and had high specific capacity: the initial discharge capacity was 300 mAh·g-1 , and the reversible capacity was 100 mAh·g-1 . The discharge plateau (about 1.5 V) and the charge plateau (about 1.6 V) were very …

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Studies Of The LialYNi1-YO2 As Cathode Materials For Rechargeable Lithium Ion Batteries, Xiao-Gan Li, Wei-Hua Qiu, Chuan-Gang Lin, Qing-Guo Liu Aug 2000

Studies Of The LialYNi1-YO2 As Cathode Materials For Rechargeable Lithium Ion Batteries, Xiao-Gan Li, Wei-Hua Qiu, Chuan-Gang Lin, Qing-Guo Liu

Journal of Electrochemistry

In this paper, we have synthesized series of single-phase LiAlyNi1-yO2 (differentive in value-y) by solid reaction. Through examining their electrothemical properties, found that, under a proper sintering condition, LixAl0.25Ni0.75O2 solution for cathode materials of rechargeable lithium ion batteries showed more pleasing properties in overcharge-resist and cycling life (vs LiNiO2). When x>1, the capacity can be kept 125mAh/g after 30 cycles under higher charged/discharged voltages ranging from 3.0 V to 4.8 V, whereas that of pure LiNiO2 has only 61 nAh/g after 25 cycles. The …

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Electrochemical Characteristics Of Sb Irreversibly Adsorbed On Pt(100), Pt(110), Pt(111) And Pt(320) Electrodes, Yi-Yun Yang, Zhi-You Zhou, Qi-Hui Wu, Shi-Gang Sun Aug 2000

Electrochemical Characteristics Of Sb Irreversibly Adsorbed On Pt(100), Pt(110), Pt(111) And Pt(320) Electrodes, Yi-Yun Yang, Zhi-You Zhou, Qi-Hui Wu, Shi-Gang Sun

Journal of Electrochemistry

The electrochemical behaviors of irreversibly adsorbed antimony on Pt(100), Pt(110), Pt(111) and Pt(320) were studied by using cyclic voltammetry. The results revealeds that the Sb adatoms are stable on Pt(100), Pt(110), Pt(111) and on Pt(320) when electrode potentials are below 0.45 V(SCE) and 0.40 V, respectively. It was demonstrated that various coverages of Sb ad can be conveniently obtained by controlling the number of potential cycling and varying the upper limit of potential scan. The electrochemical behaviors of irreversibly adsorbed antimony varied with the surface atomic arrangement of Pt single crystal electrodes. Based on quantitative results of the relationship between …

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A Study On Stochastic Resonance For The Process Of Active-Passive Transition Of Iron In Sulfuric Acid, Hong-Bo Ding, Bao-Yun Xia, Chun-Sheng Yin, Zhong-Xiao Pan, Renato Seeber Aug 2000

A Study On Stochastic Resonance For The Process Of Active-Passive Transition Of Iron In Sulfuric Acid, Hong-Bo Ding, Bao-Yun Xia, Chun-Sheng Yin, Zhong-Xiao Pan, Renato Seeber

Journal of Electrochemistry

The bistable characteristics of the process of active passive transition of iron in sulfuric acid was described and the stochastic resonance phenomenon in the process was simulated.

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Corrosion Behavior Of Reinforcing Steel In Concrete, Rong-Gui Du, Rong-Gang Hu, Zu-De Feng, Jiang-Guang Tan, Chang-Jian Lin Aug 2000

Corrosion Behavior Of Reinforcing Steel In Concrete, Rong-Gui Du, Rong-Gang Hu, Zu-De Feng, Jiang-Guang Tan, Chang-Jian Lin

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete in chloride free and chloride contaminated simulated concrete solutions was studied by electrochemical technique. The results showed that the reinforcing steel exhitibted different corrosion characteristics in the different solutons. In general, the steel in concrete was protected in the test solutions with no salt or the lower concentration of NaCl. When the concentration of NaCl is larger than 70%, however, the corrosion behavior of the steel varied considerably, and the corrosion rate increased as pH fell and the concentration of Cl- increased.

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A Study On The Cylindrical Zinc-Air Battery, Sheng-Sian Li, Gui-Mao Zhou, Xin-Ping Ai, Han-Xi Yang Aug 2000

A Study On The Cylindrical Zinc-Air Battery, Sheng-Sian Li, Gui-Mao Zhou, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

The zinc air battery has advantages of high specific energies and low cost, therefore attracts much interests. However, its application is limited only in prismatic and button type.This paper reported a novel design of cylindrical zinc air batteries and the performances of the batteries tested at various conditions. The results showed that when discharged at the current of 40 mA at 20 °C, the capacity of AA size and AAA size batteries reached 4000mAh and 1400mAh respectively, corresponding to the energy densities 280 Wh/kg and 200 Wh/kg. The effects of the discharge current, temperature and humidity on the performances of …

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Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu Aug 2000

Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu

Journal of Electrochemistry

The cathode materials Li1+xMn2O4 were prepared with citric acid complexing and solution impregnating methods. Structure characterization and specific surface area test were performed by means of XRD, BET methods, the influences of calcination temperature, Li/Mn molar ratio and raw materials on the structure and electrochemical capacity of samples have beem examined. The results showed that the Li/Mn molar ratio and calcimation temperature were the key factors affecting the electrochemical capacity of cathode materias. The optimum conditions for synthesis of  Li1+xMn2O4 cathode material were 0≤x≤0.05 and calcined at 750°C. The initial …

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Mechanisimic Study Of Fes Electrode Process, Cong-Sheng Guan, Shu-Zhen Duan Aug 2000

Mechanisimic Study Of Fes Electrode Process, Cong-Sheng Guan, Shu-Zhen Duan

Journal of Electrochemistry

The mechanism of FeS electrode process has been investigated by using linear cyclic voltammetry. The electrode porcess of FeS is accompanied with the formation and dissolution of insoluble FeS and controlled by ohmic resistance. The peak currents and potentials on the cyclic voltammograms are dependent lineally on the square root of the scan rates. According to this, an ohmic resistance controlling model of FeS electrode has been put forward, and the relative functions between peak currents or potentials and scan rates have been deduced. The theoretical deduction is corresponding to the results of the experiments.

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Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang Aug 2000

Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang

Journal of Electrochemistry

By investigating the polarization curves of pure Ni-P alloy, Ni-P alloy coation and carbon steel in nitric acids with different concentrations, the sutable concentration of nitric acid for the evaluation of the porosity of Ni-P alloy coatings has been determined and the coatings with different thickness have been evaluated. The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method. The polarization curve of Ni-P alloy coating in 10% nitric acid can accurately reveal the porosity. With the decrease of the porosity of the coating, …

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The Electrochemical Polymerization Of Erythrosin And The Fluorescence Spectra Of Polyerythrosin, Hong-Ping Zhu, Shao-Lin Mu Aug 2000

The Electrochemical Polymerization Of Erythrosin And The Fluorescence Spectra Of Polyerythrosin, Hong-Ping Zhu, Shao-Lin Mu

Journal of Electrochemistry

The solution used for the electrolysis consisted of 0.03 mol·dm-3 erythrosin, 0.05 mol·dm-3 sodium tetraborate and 0.5 mol·dm-3 KCl with pH 8.50. Polyerythrosin film with red color has been electrochemically synthesized using repeated potential cycling between -0.20 and 1.10 V (vs.SCE). The film growth and the electrochemical property of polyerythrosin are affected by electrolytic conditions. Two main absorption peaks of polyerythrosin at 326 nm and 370 nm appear in the UV-visible spectrum, which are different from that of the monomer. Polyerythrosin in dimethyl sulfoxide or dimethylformamide has a strong fluorescence intensity and the fluorescence intensity of polyerythrosin …

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Pulse Potential Modulated Electrochemical Gas Sensors, Zhong-Bai Zhou, Liang-Dong Feng, Wen-Jun Liu Aug 2000

Pulse Potential Modulated Electrochemical Gas Sensors, Zhong-Bai Zhou, Liang-Dong Feng, Wen-Jun Liu

Journal of Electrochemistry

The current popular electrochemical gas sensors are mostly stable with regard to their operating states. As a result, the further improvement of sensor charcateristics is restricted by such a "steady state". Based on the transient electrochemistry principle, a kind of all new transient electrochemical multi component gas sensors— "pulse potential modulated electrochemical gas sensors" was established by combining computer controlled fast modulated potential technique with microelectrode method.This novel approach provided a real time and dynamic sensor technique integrated with acquisition, treatment and display of signals for rapid simultaneous detecion of multicomponent gases, as illustrated by the case of monitoring of …

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The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan Aug 2000

The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan

Journal of Electrochemistry

Solid oxide fuel cells with supported yttria stabilized zirconia electrolyte films on anode substrates of various thickness have been fabricated. The electrochemical performances of the SOFCs have been examined. The results showed that the cell performance was limited by the anodic overpotential, which is caused mainly by a concentration polarization when the anode substrate is thick. The anodic overpotential was reduced obviously as the thickness of anode substrate was decreased. As a result, the performance of the SOFC cell was improved. With a 0.5 mm anode substrate, a SOFC cell produced a power density about 0.19 W/cm2 at 800 …

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A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu Aug 2000

A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu

Journal of Electrochemistry

Research and development on low platinum loading electrode is very important in reducing the cost of proton exchange membrane fuel cell(PEMFC) stack. This paper has put forward a new method to prepare the electrode of PEMFC. The pore forming substances were used in this methd. The low platinum loading electrodes (0.02 mgPt⋅cm-2) have already been prepared with the method. Compared with the traditional method, the new method is simple, cheep, and easy to scale up. The superior composition of the electrodes is catalyst: pore forming substance: Nafion= 3:3:1. The performance of a single cell using this …

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Electrocrystallization Mechanism And Grain Sizes Of Ni-W-B Alloy Eletrodeposits, Fang-Zu Yang, Gang-Min Cao, Xiao Hu, Shu-Kai Xu, Shao-Min Zhou May 2000

Electrocrystallization Mechanism And Grain Sizes Of Ni-W-B Alloy Eletrodeposits, Fang-Zu Yang, Gang-Min Cao, Xiao Hu, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

The electrodeposition characteristics and grain sizes of Ni-W-B alloy have been studied by cyclic voltammetry, potentiostatic step and X-ray diffraction (XRD). The results showed that Ni-W-B alloy electrodeposit obtained from the solution containing ammonium citrate as a complexing agent was presented in the lower electrochemical activity compared with Ni-W alloy. Based upon the i～t curves of potentiostatic step, it was revealed that electrocrystallization of Ni-W-B alloy on glassy carbon followed the mechanism of instantaneous nucleation and three dimensional growth with diffusion controlled. The crystal nucleus number on the surface of electrode was raised by the increase of overpotential. According to …

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A Review On Impressed Current Anodes Of Cathodic Protection For Underground Structures, Li-Kun Xu, Ting-Yong Wang, Liang-Qian You, Rong-Chun Qian, Guang-Zhang Chen May 2000

A Review On Impressed Current Anodes Of Cathodic Protection For Underground Structures, Li-Kun Xu, Ting-Yong Wang, Liang-Qian You, Rong-Chun Qian, Guang-Zhang Chen

Journal of Electrochemistry

The requirements of impressed current anodes for the protection of underground structures were presented in this paper according to the analysis of working conditions. The characteristics and performance of various anodes such as scrap steel, graphite, high silicon cast iron, magnetite, platinized anode, conductive polymer cable anode and mixed metal oxide anode were reviewed. The development trend of impressed current anodes for underground applications was also discussed.

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Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu May 2000

Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu

Journal of Electrochemistry

Li-ion secondary batteries negative electrodes were prepared by low temperature (<1 000 ℃) pyrolysis of commercial phenol-formaldhyde resin. A thermogravimetric analysis (TGA) and an X-ray diffraction (XRD) studies were peoformed for the pyrolytic carbonaceous materials. The results indicated that these samples are amorphous polyacenic structure materials. With increasing pyrolytic temperature, these materials become structurally order, and the first charge-discharge special capacities reduce. The specific capacities base on pyrolytic temperature, involving lithium storage nanometer cavities.

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Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma May 2000

Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma

Journal of Electrochemistry

A sensitive and stable amperometric enzyme electrode was constructed, based on the immobilization of tyrosinase in potentiostatically electropolymerized polypyrrole film at a platinum electrode. The influence of pH and potential on immbilization was discussed. SEM micrographs and CV curves of films obtained before and after incorparation of tyrosinase molecular were analyzed and compared each other. The enzyme electrode responds linearly to p-cresol over a concentration range of 5×10 -8 ～1×10-6 mol/L with an optimum pH of 6.6, It exhibited kinetic characteristics of the typical enzyme-catalyzed reaction with an apparent Michaelis constant of 2.2 ×10-5 mol/L.

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Electrochemical Codeposition Of Palladium And Glucose Oixdase In The Presence Of Glycine As Complexing Agent, Kan Zhu, Hui-Huang Wu May 2000

Electrochemical Codeposition Of Palladium And Glucose Oixdase In The Presence Of Glycine As Complexing Agent, Kan Zhu, Hui-Huang Wu

Journal of Electrochemistry

Glycine and Pd(NH3)2Cl2 consist of a solution for the electrochemical codeposition of Pd and glucose oxidase (GOD) to prepare a metallized enzyme electrode. The experiments by UV/V spectroscopy show that the complexing of Pd ion with glycine can occur, which makes the plating bath has relatively stable chemical composition in a certain pH range. The voltammetric experiments indicate that the presense of glycine decreases the potential of Pd deposition ,facilitating to prevent the formation of palladium hydride. The appropriate conditions for the electrochemical codeposition of Pd and GOD are discussed.

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