Materials Science and Engineering Commons^™

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge: 1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves, 2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states, and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.

Photoelectric Property For Zinc Phthalocyanine Of Doping C60 On Inp Electrode, Mengxiong Zhan, Rongqing Yu, Biaolian Zhen, Dadian Cheng, Lansun Zheng

Journal of Electrochemistry

The curves of spectral and photovoltaic responses to zinc phthalocyanine of doping C₆₀ were determinted. The photovoltaic property for zinc phthalocyanine of doping C₆₀ wereinvestigated on the InP single crystal in the photoelectrochemical cell.The results have shown that: 1)The photovoltaic effect and the in tensities of the spectral response and of the photovoltaic responsefor ZnPc of doping C₆₀ were greater than those of ZnPc; 2)had better redox couple in the cells.

Theory Of Cyclic Voltammetry At Microdisk Electrode For Reversible Systems, Qiankun Zhuang, Hongyuan Chen

Journal of Electrochemistry

By means of a new approach, the current equations of cyclic voltammetry which describes two cases of quasi-steady-state and fast linear scan at microdisk electrode for reversiblesystem were presented and verified experimentally. It has been shown that the features of this currentessentially depend on the ration of, which is described in detail. ln extreme cases, the equationsare the same as those listed in literatures for large plane and spherical electrodes. Using the quasi-steady-state equation, the causes and conditions for forming steady state, quasi-steady state andhysteresis current for linear sweep voltammetry are all explained and discussed. The width of the ″hysteresis …

Progress In R&D Of Lithium Rechargeable Batteries In China, Jiqiang Wang

Journal of Electrochemistry

No abstract provided.

Electrodeposition Of Cobalt And Rare Earth-Cobalt In Urea-Nabr-Kbr Melt, Qiqin Yang, Kairong Qiu, Derong Zhu, Lichang Sa

Journal of Electrochemistry

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Studies On The Bright Zinc-Nickel Alloy Palting In Alkaline Baths, Jiale Cai, Shaomin Zhou

Journal of Electrochemistry

The electrochemical properties of the Zn-Ni plating baths and the structure andperformance of the obtained deposits were investigated. The results show that the nickel content of theobtained deposits is incereased with decreasing of Zn²⁺/Ni²⁺ ratio in the baths and with increasing of cathodic current density; The cathode current efficiency is increased with increasing of Zn[Ⅱ] content in the bath and with decreasing of cathodic current density. The ZN-11 additive used is thereaction product of heterocyclic compound and polyamines with epichlorohydrin, it has a higheradsorptivity on Hg-electrode at potential between -0.16～-1.68 V (vs. Hg/HgO, 1 mol·L^-1 KOH). …

Study On The Surface States Of Zinc Sulfide Thin Film Doped With Erbium And Their Effect On The Relaxation Luminance, Yujiang Wang, Zhaohong Liu, Zhenxiang Chen

Journal of Electrochemistry

X-ray photoelectron spectrum and characteristics of the capacity, versus thevoltage of the thin film devices are measured to study the surface states of the zinc sulfide thin film.The transient electroluminescence excited by pulses shows the relaxation luminance peaks during anon-exponential decay process of the characteristic transitions activated by Er³⁺ in the ZnS directcurrent thin film electroluminescence (DCTFEL) devices.The surface structures of ZnS:Cu, Cl, Erfilm with the absorption of oxygen, and the effect of the surface states on the relaxation luminance ofthe devices are discussed.

Comparison Of Time-Domain Reflectometry Performance Factors For Several Dielectric Geometries: Theory And Experiments, S. V. Maheshwarla, R. Venkatasubramanian, Robert F. Boehm

Electrical & Computer Engineering Faculty Research

We propose three nontraditional dielectric geometries and present an experimental and theoretical analysis and comparison of time domain reflectometry (TDR) performances for them. The traditional geometry (the probes inserted in material of essentially infinite extent) is compared to three nontraditional geometries where the probes are affixed outside of a core sample, inside of a bore, or flat on the surface of a semi-infinite solid. Our derivation relates the velocity of electromagnetic wave propagation to the complex permittivities and permeabilities of the media and the geometry for the three nontraditional configurations. Experimental results for air, styrofoam, dry sand, wet sand of …

37th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 37th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 23-27, 1995.

Electrochcmical Reaction Of Redox Proteins Speeded Up By The Dye Modified Electrodes, Ting Chen, Shaojun Dong, Yuanwu Xie

Journal of Electrochemistry

The electron transfer reaction of redox proteins faciliated by dye medifiedelectrode was reviewed in this paper. The medification metheds and the properties of dye modifiedelectrode were discussed. Several different studying metheds,such as voltammetry, flow analysis and spectroelectrochemical method, were reviewed. Areversible electrocatalytic reaction mechanism was proposed and verified by comparing the digital calculation results with the experimental results.

Laser Scanning In-Situ Photoelectrochemical Microscopictechnique And Its Applications, Zugeng Lin, Jinkua You, Xiangdong Zhuo, Chun Zhang, Yong Yang

Journal of Electrochemistry

The main factors of the laser scanning in-situ photoelectrochemical microscopic measurement system which is set up in our lab have been discusaed in this paper. Some applications of this technique for in-situ study of modification and processing of semiconductor electrodes, monitoring of electro deposition process of semiconducting material and redox reaction occurring at metal oxide electrodes have also been presented. The results have shown that the technique is very powerful that for studing local photoelectrochemical properties of semiconductors and metal oxide electrodes. These provide important information on the micro structural and electronic properties in the solid/electrolyte interface.

Studies Of The Black Molybdate Conversion Film On Stainless Steel, Jingli Fang, Liuqin Liuqin, Keping Han, Yaohui Chen

Journal of Electrochemistry

A black conversion film was formed on stainless steel with cathodic electrode position method from a molybdate-phosphate solution. This film displayed good themcotability. The results of XPS and AES analysis showed that the thickness of the film was 820 nm and that Mo existed as Mo(Ⅵ) in the surface of the film, while existed as Mo(Ⅵ) and Mo(Ⅳ) in the internal layer of the film. The relative atomic percent content (A.C.% of the film obtained from the elemental composition constant region of the depth profile curves by AES was O 50.9%, Mo 29.4%, P 12.6% and Fe 7.1% respectively. The …

Studies On Low Temperature Performance Of Rechargeable Mh-Ni Batteries, Wenkuan Zhang, Jingxian Shi, Yuwan Lou, Qiusheng Duan

Journal of Electrochemistry

The Dependence of low temperature performance on the alloy composition and electrolyte component for rechargeable MH-Ni batteries is studied, the suitable composition of alloy and electrofyte are founds.

An Indirect Electrochemical Oxidation Of Toluene──Anodic Oxidation Of Mn(Ⅱ) On The Lead Electrode, Zhonghua Wang, Qingmin Hua, Guacai Chen, Zhongquan Wang, Yunan Qiu, Xingguo Yan

Journal of Electrochemistry

The electrochemical oxidation of Mn(Ⅱ) to Mn(Ⅱ) in concentrated H₂SO₄ (2 ~ 8 mol⋅L^-1) at lead electrode has been studied. It is found that the electrode surface is oxidized to PbO₂ in a direct electrochemical reaction, then PbO₂ formed reacts with Mn(Ⅱ) in a chemical reaction. Some effects involves current density, concentration of H₂SO₄, temperature and conversionwere evaluated. The rule of electrogenerated Mn(Ⅲ) in flow electrolysis cell were determined at several conditions. The current efficiency at greater than 90% is obtained in general.

Electrochemically Modified Glassy Carbon Electrode And Determination Of Copper By Anodic Stripping Voltammetry, Jinrui Xu, Yie Liu, Xiurun Zhuang, Tomoo Miwa, Toyohide Takeuchi

Journal of Electrochemistry

This paper reported the glassy carbon electrode modified by cyclic voltammetrybetween -0.1 and +1.5 V (vs. SCE) in an aqueous solution containing catechol, for maldehyde and talium hydroxide. The modified electrode can be applied to the determination of copper(Ⅱ) in water, and its sensitivity is about 35 times higher than that of unmedified glassy carbon electrode, The quantitative limit with this modified electrode is 0.1 ng/ml.

Photoelectrochemical And Spectroelectrochemical Studies Oniron Oxide Ultrafine Particles, Maizhi Yang, Yongjun Ji, Wen Zhang, Shengmin Cai, Xiaojiang Lu, Zhongqun Tian, Jin Luo

Journal of Electrochemistry

In this paper, Raman spectra, photocurrent and the UV-VIS reflectance aremeasured for studying the α-Fe₂O₃ ultrafine particles adsorbed on Pt electrode. The blue shifts of Raman peaks demonstrate the size quantization effect for the particles of 50 nm in diameter ascompared with the bulk material. With the changing of the potential, the photocurrent decrcases as the UV-VIS reflectance increases, and vice-versa. Therefore, the potential not only affects the hargetransfer direcdtion in the interface of electrode/redox couple, but also influences the light absortion onthe surface of particles. According to the results of photoelectrochemistry, we suggest that the cathodic …

Horseradish Peroxidase/Poly-O-Phen Ylenediamine Mem Brane Electrode: Preparation And Properties, Dong Wei, Huihuang Wu

Journal of Electrochemistry

A horseradish peroxidase (HRP)/poly-o-phenylenediamine (PPD) membrane electrode was prepared by electropolymerization of o-phenylenediamine on glassy carbon in pH 7.0 phosphate buffer, the process of the enzyme immobilization was studied. The enzyme electrode obtained exhibits the activity to catalyze the electroreduction of hydrogen peroxide in the absence of any electron transfer mediator. The red uction reaction occurs in the potential range of PPD redoxprocess, it was believed that the polymer participates in electron transfer of the enzyme. The enzyme reaction kinetics at rotating HRP/PPD electrode was analysed, and the factors influencing kinetic parameters were discussed.

The Electrochemical Reduction Of 2-Ethylanthraquinone (2eaq), Yaobin Zhu

Journal of Electrochemistry

The process of electrochemical reduction of 2EAQ in DMSO is studied using CVand ESR methods in this work, Pt, Pd and some implanted materials are used as electrodes. The quasi-rever-sible property of two electron transfer steps and their following homogeneous chemical reactions are illustrated. The mechanism of the electrochemical red uction of 2EAQ and the kinetic parameters of the related steps are obtained. Having measured the influence of water content in the system, the effect of the proton donor is discussed. After comparising the experimental results with each other these experiments gives us the idea that the replacement of metal …

The Reduction Of Oxygen To Hydrogen Peroxide At The Poly(O-Phenylenediamine)-Filmed Electrode, Zhaoe Lu, Tiangeng Zhong, Guanyong Zhang

Journal of Electrochemistry

The poly(o-phenylenediamine) (PPD) filmed graphite electrode was formed by electro-polymerization of o-phenylenediamine in acidified (pH=1) 0.2 mol·L^-1 Na₂SO₄ solution using the cyclic voltammetric methed. The catalytic effect of the electrcareduction of oxygen in acid olution was demonstrated by the voltammogram of the electrode in the oxygen saturated acid solutionof Na₂SO₄. The current efficiency of the reduction of oxygen to hydrogen peroxide was determined by the electrolysis in a divided cell under the condition of constant current. The various effectsinfluencing the accmulation of H₂O₂ in the catholyte were discussed.

Studies On Coordination Behavior Of Dimethyl Sulfoxide In Complex Of Rare Earth With Cryptand, Shichang Liu, Tianpei Zhu

Journal of Electrochemistry

Electrochemical reduction reaction in the course of the titration of Eu(2.2.2) and Eu(2.2) using strong bonding solvent, DMSO, in C₂H₄Cl₂ has been investigated by cyclic voltammetry. The greater the concentration of strong bonding solvent, the more negative the half-wave potentials for the reduction reaction are. The coordination number of Eu(2.2.2) and Eu(2.2) which are 2 and 3 respectively, with DMSO can be calculated, according to the relations between half-wave potentials and the variety of concentration of DMSO.

Thermal Effects On Y2O3:Eu3+ For Fiber Optic Temperature Sensing, Arnel C. Lavarias

Electrical & Computer Engineering Theses & Dissertations

Fiber optic methods have gained acceptance in the past several years as non­ intrusive optical techniques of measuring environmental variables, particularly under hostile conditions. Fiber optic temperature sensors are required for many applications which have a large operating range. One way to implement this sensor is to introduce rare earth-doped materials into a fiber showing temperature-dependent optical emission characteristics. The thermal effects on optical emission characteristics of Y₂O₃:Eu³⁺ were studied. The thermal broadening and temperature dependence of the lifetime (τ) of the 611.4 nm emission due to the ⁵D₀ ➔ 7F …

Identification And Characterization Of The Iron-Zinc Intermetallics Formed In Galvanneal Steel, Richard Frederick George Grant

Physics Theses & Dissertations

The demand to improve the corrosion resistance of steel sheet, particularly for use within the automotive industry, has led to a dramatic increase in the use of coated steels in place of cold-rolled sheet steel. Galvanneal steel results from the post annealing of the zinc-coated steel sheet, in which iron and zinc are interdiffused to form an iron-zinc alloy coating. Within this alloy coating, four main iron-zinc phases, Zeta, Delta, Gamma-1, and Gamma may be present. Manufacture of the most suitable coating requires identifying which phases form during the galvannealing process, an understanding of the properties of each phase and …

Studies Of Elecctrochcmical Oscillation Of Au/Hcl In Presence Of ″Positive Feedback″Of Substrate Electrodes, Bin Ren, Bingwei Mao, Xiongwei Cai, Tao Jiang, Jiqian Mu

Journal of Electrochemistry

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A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang, Ping Wei, Di Quarto F., Piazza S., Sunseri C.

Journal of Electrochemistry

A photoelectrochemical investigation has been carried out on zirconium initialoxide film and its oxide film grownanodically at constant rate up to different thickness. Both anodicand cathedic photocurrents on the photocurrent spectrum depended on the potential, but had littlerelation with the forming anedic films or measuring solutions. Photocurrent spectrum and photocurrenttransients suggested that the oxide films on zirconium were duplex layers structure. The internal layerwas ZrO₂ and the external layer ZrO₂·(H₂O)_n. The photocurrent included photogenerated carrier ininternal and external oxide films, as well as internal photoinjection process for electrons from thesubstrate metal into the …

Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo, Renxin Liu, Weidong Tian

Journal of Electrochemistry

To improve the anti-corrosion performance of electrocoating, organic andinorganic inhibitors are applied in an anodic electrophoretic-coating. The results show that the deposition of polymer with zinc phospate exhibits a high inbihition efficiency. The inhibition mechanism of the inhibitor in electrocoating has been studied.

A Investigation Of Hydrogen-Storage Alloy As Catalytic Electrode For Hydrogenation Of Nitrobenzene, Shigang Lu, Hanxi Yang, Changfa Wan

Journal of Electrochemistry

Since hydrogen-storage alloy ean not only absorb hydrogen atoms to form highlyreactive metal hydride as hydrogen source by electrolysis but also possesses a certain catalytic activityfor hydrogenation,it is thus feasible to utilize the allov as a novel electrode for electrolvtichydrogenation in organic electroreduction. This work employed misch metal AB₅ type alloy as acatalytic electrode and studied the electrochemical hydrogenation of nitrobenzene.

The hydrogen-storage electrode (MH) was a plastic bonded electrode sheet made from a paste of Mm(NiCoMnAl)₅ alloy powder and teflon emulsion. The electrolysis was performed at constantcurrent and controlled potential in a three electrode cell of H-type …

Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/AlXGa(1-X)As Electrode, Liu Yao, Xurui Xiao, Yuan Lin, Yiping Zeng, Dianzhao Sun, Haiqun Zheng

Journal of Electrochemistry

Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well (MQW)GaAs/Al_0.3)Ga_0.7 As electrodes were studied in the 1 ×10^-2 mol·dm^-3 ferrocene([Fc⁰]/[Fc⁺]=9/1)-0.1 mol·dm^-3 tetrabutylammonium tetrafluoroborate acetonitrile solutionin order to examine the relaxation photoprocesses and to evaluate kinetic parameters of superlattice electrodes.

GaAs/Al_0.3Ca_0.7 As MQW electrode consisting of 10 periods with each of GaAs well (5.3 nm) and Al_0.3Ga_0.7. As barrier (10 nm) showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum, corresponding to the …

Synthesis Of LiXCoo2 And Its Behaviour In Rechargeable Lithium Battery, Mingfeng Guo, Ruimin Yang, Zebo Zhang, Jincao Ye

Journal of Electrochemistry

The Variations of crystal lattice parameters of Li_xCoO₂ during charge anddischarge have been st ud ied by XRD and AAR spectroscopy. It was found that the Li_xCoO₂ crystalvolume expanded during charge and contracted during discharge. The crystal lattice structure was broken because of the formation of Co₃O₄ when deeply charge.The variation of lattice parameter C₀ value in cycling process was similar to that in charge process.The variation of 006 peak was the mostsensitive in every case. In case of preheating for 20 hours at 700℃ before operating high temperature, the …

Self Assembly Via Layer By Layer Surface Reaction On Gold Electrodes And The Electrochcmical Characterization, Xiandui Dong, Juntao Lu, Chuanxin Cha

Journal of Electrochemistry

The self-assembled monolayers,which were built by spontaneous adsorption of ω-carboxylic acid thiols on gold surface,were used as substrate for further modification through later bylayer amide surface reactions. At each stage of modification,the gold surface was characterizedelectochemieally. The results demonstrated that the strategies of layer by layer self assembly is ofsignificant potential for fabrieating functionalized ultrathin layers.

Electroreduction Of The Nittobenzene On Titanium Electrode Implanted With Palladium, Zhongda Wu, Xianjun Zhu, Hongsen Wang

Journal of Electrochemistry

The titanium substrates were bombarded with 1×10¹⁷～5×10¹⁷ ions·cm^-2 ofpalladium at the room temperature. The surface composition of implanted electrode and concentration-depth profiles of various elements were measured by AES. The electrored uction processes ofnitrobenzene (NB) in 0.1 mol/L NaOH solution at Pd/Ti electrodes have been investigated by cyclicvoltaivimetry. The results show that the palladium implanted titanium electrodes exhibit a high catalyticactivity in the electroreduction of NB. The NB radical anion, which is the product of one-electronelectroreduction of NB, was detected by ESR in-situ in conjunction with electrochemical methods. Aniline was also detected as a product of …