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Full-Text Articles in Materials Science and Engineering

Studies On Impedance Of Acidcopper Electroplating System, Wen Deng, Zhao Liu, Xiangmin Lin, Hetong Guo May 1998

Studies On Impedance Of Acidcopper Electroplating System, Wen Deng, Zhao Liu, Xiangmin Lin, Hetong Guo

Journal of Electrochemistry

The impedance characteristics of elementary solution (0.3 mol/L CuSO_4+1.94 mol/L H_2SO_4) and that with the addition of 60 mg/L Cl~-, 300 mg/L OP_21, 30 mg/L PEG, 10 mg/L 2thiazolinyldithiopropane sulfate(self-synthesized additive) are investigated and interpreted in terms of equivalent circuit. The results indicated: (1) Cl~- ion can increase cathodic polarization. (2) A twostep reaction mechanism corresponds to Cu~2+ reduction, that is: Cu~2+→Cu~+, Cu~+→Cu(adsorption)→Cu(lattice), Cu~2+ react in different forms of complex ion in sulfuric acidcupric sulfate solution with or without Cl~- ion. (3) cupric redution impedance shows dispersion effect in the solution that contains Cl~- ion.


Influences Of Ptfe On Electrochemical Properties Of FoamType Ni(Oh)_2 Electrodes, Zhen Zhou, Jie Yan, Xianyou Wang, Jinyuan Huatang Lin, Deying Song, Yunshi Zhang May 1998

Influences Of Ptfe On Electrochemical Properties Of FoamType Ni(Oh)_2 Electrodes, Zhen Zhou, Jie Yan, Xianyou Wang, Jinyuan Huatang Lin, Deying Song, Yunshi Zhang

Journal of Electrochemistry

Research work was performed for the influences of PTFE on the electrochemical properties of foamtype Ni(OH)_2 electrodes by constant current discharge. CV and EIS method. Experimental results exhibit that the existence of PTFE would decrease the reversibility of electrode reaction and increase the reaction resistance of the electrode; thus lower the discharge potential and capacity, so PTFE should be added as little as possible during the preparation of pastetype electrodes.


Study Of The Mechanisms Of The Electrochemical Reactions Of The Soluble Polyimides, Yin Zhu, Wei Xing, Hui Zhao, Guizheng Shi, Yuesheng Li, Mengxian Ding May 1998

Study Of The Mechanisms Of The Electrochemical Reactions Of The Soluble Polyimides, Yin Zhu, Wei Xing, Hui Zhao, Guizheng Shi, Yuesheng Li, Mengxian Ding

Journal of Electrochemistry

For the first time, the electrochemical behaviors of the three soluble polyimides were studied in the organic and aqueous solutions. It was found that the electrochemical behaviors of PI in the organic solutions are significantly different from that in the aqueous solution. Using the IR spectroscopy and semiempirical molecular orbital calculation and combining the results of the electrochemical measurements, the mechanisms of the electrochemical reactions of polyimides were demonstrated.


A Novel Pt(Ir) Plated Stainless Steel Electrode, Jingying Shi, Xiufeng Xiao, Zeshan Zhu May 1998

A Novel Pt(Ir) Plated Stainless Steel Electrode, Jingying Shi, Xiufeng Xiao, Zeshan Zhu

Journal of Electrochemistry

A novel Pt(Ir) plated stainless steel electrode have been developed, to be applied underpotential deposition and anchor effect. The electrode is provided with the excellent electrochemical characteristic, lt is possible to use the matter as micro-sensor.


Studies On The Transport Properties Of Zn~2+ In The Zn/V_2o_5 Secondary Battery With Aqueous Medium, Jiahong Zhou, Kuanhong Xue, Guping Pan May 1998

Studies On The Transport Properties Of Zn~2+ In The Zn/V_2o_5 Secondary Battery With Aqueous Medium, Jiahong Zhou, Kuanhong Xue, Guping Pan

Journal of Electrochemistry

The transport properties and the reaction mechanism of Zn~2+ in the cathode material of Zn/V_2O_5 secondary battery with aqueous medium were studied by use of intermittent titration experiments and X-Ray diffraction analysis. The relations of some kinetic parameters to the discharge depth were discussed. The results of the experiments show that the cathodic discharge reaction is an intercalation process.


Investigation Of Pb/Pb~2+And Polypyrrole Electrodes By Use Of Ac ElectrochemicalThermal Method, Jihua Zhuang, Jie Zhang, Liangjun Dong, Hong Xie, Zhiyu Jiang May 1998

Investigation Of Pb/Pb~2+And Polypyrrole Electrodes By Use Of Ac ElectrochemicalThermal Method, Jihua Zhuang, Jie Zhang, Liangjun Dong, Hong Xie, Zhiyu Jiang

Journal of Electrochemistry

The values of entropy change for Br/Br_2 and Pb/Pb~2+ electrode reactions were measured by use of the ac electrochemicalthermal method. The influence of alkaline pretreatment on the electrochemical behavior for a polypyrrole electrode was also investigated by this method. It was found that after alkaline pretreatment the eletrochemical activity of polypyrrole electrode was decreased obviously, but it kept partly electrochemicalthermal characteristic as same as that before pretreatment.


Electrode Process Of Lithium Ions On Aluminum Electrode In Molten Licl-Kcl, Shuzhen Duan, Congsheng Guan, Qingrong Shi, Xindong Wang May 1998

Electrode Process Of Lithium Ions On Aluminum Electrode In Molten Licl-Kcl, Shuzhen Duan, Congsheng Guan, Qingrong Shi, Xindong Wang

Journal of Electrochemistry

The Deposition mechanism of Lithium on aluminium electrode was studied by using linear sweep voltammetry and potential step method. The formation of α-solid solution was controlled by the diffusion of lithium within the aluminium substance. The formation of β-LiAl alloy was limited by the rate of forming the alloy at the legining, and by diffiusion of lithium through the β- LiAl alloy layer was limited by the rate of forming the alloy at the begining, and by the diffusion of lithium through the β-LiAl alloy later. Neucleation polarization for the formation of β-LiAl alloy was observed. This polarization is an …


Molecular Inclusion Of Cyclodextrin Polymer And Its Application To Enzyme Electrodes, Huihuang Wu, Baozhang Wu May 1998

Molecular Inclusion Of Cyclodextrin Polymer And Its Application To Enzyme Electrodes, Huihuang Wu, Baozhang Wu

Journal of Electrochemistry

The inclusion complexation of α-cyclodextin prepolymer host with benzoquinone guest was studied by voltametry. The spectroscopic measurements show that the polycondensation of CD with glutaric dialdehyde forms the polymer (PCD) with pending carbonyl, the latter brings about covalent immobilisation of glucose oxidase (GOD) to polymer chains. Owing to the inclusion complexation of CD, the benzoquinone(BQ) as mediator of GOD can be collected in the enzymecontaining PCD membrane, resulting in high concentration of BQ in the membrane while decreasing its amount in solution. TTF was tested to prepare the immobilised enzyme together with mediator in PCD. The enzyme loading in PCD …


Study On The Substitution Of Chromium Alloy Electroplating From Trivalent Plating Bath For The Hard Chromium Plating, Huidong Li, Min Li, Huiqi Li May 1998

Study On The Substitution Of Chromium Alloy Electroplating From Trivalent Plating Bath For The Hard Chromium Plating, Huidong Li, Min Li, Huiqi Li

Journal of Electrochemistry

Recently, a vast amount of exploring experiments have been made to solve many deadly defect of existing trivalent chromium plating processes and promote to finally substitute the trivalent chromium for the hexvalent chromium plating. Technical scheme which we substitute the amorphous chromium alloy deposition for the pure chromium is determined step by step and process of amorphous CrFeC alloy plating from trivalent chromium plating bath has been developped successfully. The deposition maintains standard of traditional hexvalent chromium deposition in properties of wearresistance and corrosive wear resistance. Moreover, it completely eliminates serious enviromental pollution and has certain advantages of technological property …


Influence Of Buffers On The Electrodeposition Of Nickel From A Watts Bath, Canzh Gao, Yuli Lu, Rutao Liu, Fang Chen, Shuben Li May 1998

Influence Of Buffers On The Electrodeposition Of Nickel From A Watts Bath, Canzh Gao, Yuli Lu, Rutao Liu, Fang Chen, Shuben Li

Journal of Electrochemistry

The electrochemical reactions occurring during the deposition of nickel from Watts bath have been examined using the voltammetric technique. The important reactions taking place at the anode and cathode have been identified. The influence of buffers HAc,H_3BO_3 and NH_4Cl on the rate of nickel deposition was marked in the lower concentration (0.01-0.05 mol/L) of buffers. The reason why buffers make the rate of nickel deposition increase were discussed.


Progresses In Surface Electrochemistry And Electrocatalysis ——A Review On The 1997 Joint International Meeting Of Electrochemistry And 97′ International Meeting Of Surface Electrochemistry, Shigang Sun Feb 1998

Progresses In Surface Electrochemistry And Electrocatalysis ——A Review On The 1997 Joint International Meeting Of Electrochemistry And 97′ International Meeting Of Surface Electrochemistry, Shigang Sun

Journal of Electrochemistry

The progresses in surface electrochemistry and electrocatalsis reported in the 1997 joint international meeting of electrochemistry and in the 97′ international meeting of surface electrochemistry were reviewed. The main trends described in this paper consisted of 7 aspects: 1) the studies employing single crystal electrodes, 2) the development of in situ methods of diverse spectroscpoy, 3) the innovation of new research techniques, 4) the preparaton of electrocatalyst of high performances, 5) the quantitative studies on kinetics of electrocatalytic reactions, 6) the investigation on the dynamic processes of surface by timeresolved methods, and 7) the theoretical modeling and simulation of surface …


A Preliminary Study On Thin Film Plasticizing Lithium Ion Battery, Quanfeng Dong, Hanxi Yang, Xingping Ai, Xiaohong Hu, Shengxian Li Feb 1998

A Preliminary Study On Thin Film Plasticizing Lithium Ion Battery, Quanfeng Dong, Hanxi Yang, Xingping Ai, Xiaohong Hu, Shengxian Li

Journal of Electrochemistry

A dry polymer electrolyte was made by plasticizing a copolymer matrix and further filling with liquid electrolyte. A thinfilm lithium ion battery based on the dry polymer electrolyte was manufactured and its electrochemical properties were measured. It is found that the thin film lithium ion battery exhibits similar discharge properties to liquid electrolyte battery, and shows strong high rate capability. 


A Study Of Adsorption Kinetics Of Β-Phenylaminopropiophenone On Iron In Acid Solution, Dihua Wang, Xianzhang Bu, Jinyun Zou, Fuxing Gan Feb 1998

A Study Of Adsorption Kinetics Of Β-Phenylaminopropiophenone On Iron In Acid Solution, Dihua Wang, Xianzhang Bu, Jinyun Zou, Fuxing Gan

Journal of Electrochemistry

The adsorption kinetics of β-phenylaminopropiophenone (PAP) on iron electrode in 0.5 mol/L H_2SO_4 solution with or without Cl~- were investigated by chronoamperometry. According to the following adsorption kinetic equation dθ/dt=kaCen-1(1-θ)nexp(fθ/2)-kdθexp(-fθ/2)The rate constants ka, kd as well as the adsorption free energy parameter f of PAP in sulfuric acid soltuion was calculated by used a computerized curve fitting program, the calculated ka, kd are in the order of 10~-1 mol/L s~-1 and 10~-3 s-1, respectively, f>0 in the concentration region of 5×10~-5 to 1×10~-3 mol/L of PAP. While in the 0.5 mol/L H_2SO_4 solution with 0.1 mol/L Cl-,the values of …


A Study On Heterogeneous Indirect Electrosynthesis Of Benzaldehyde, Daobao Chu, Changjian Lin, Huashui Lin, Jianguang Tan Feb 1998

A Study On Heterogeneous Indirect Electrosynthesis Of Benzaldehyde, Daobao Chu, Changjian Lin, Huashui Lin, Jianguang Tan

Journal of Electrochemistry

Heterogeneous indirect electrosynthesis process of benzaldehyde has been investigated using cyclic voltammetry and polarization curves. An optimum condition for preparation of benzaldehyde by indirect electrooxidation of toluenc with redox Mn~3+/Mn~2+ is given in this paper. Electrolytic regeneration Mn~3+ are made at Pt/Ti anode in “slurry” MnSO_4/H_2SO_4 medium. Current efficiency for electrolytic regeneration Mn~3+ was maintained over 88% by “double cyclic way”.


Investigation Of Methanol Anode Electrooxidation Catalysts, Gangyao Wen, Ying Zhang, Zhenglong Yang, Changzhi Li Feb 1998

Investigation Of Methanol Anode Electrooxidation Catalysts, Gangyao Wen, Ying Zhang, Zhenglong Yang, Changzhi Li

Journal of Electrochemistry

A series of catalysts, Pt-WO_3/C, Pt/Ru/C and Pt-Ru-WO_3/C were prepared by chemical reduction deposition. Electrocatalytic oxidation of methanol on different catalyst/Nafion membrane electrodes was studies by cyclic voltammetry and currentpotential polarization. The results indicated that the catalytic activity order of different catalysts is as follows: Pt-Ru-WO_3/C>Pt-Ru/C>Pt-WO_3/C. At the same time, influences of methanol concentrations and catalyst proportion on performances of anodes were also studies.


Study On Nano Electrode Material Of Lithium Ion Batteries, Jinkua You, Yong Yang, Dong Shu, Shenghui Wu, Yingchun Zhang, Zugeng Lin Feb 1998

Study On Nano Electrode Material Of Lithium Ion Batteries, Jinkua You, Yong Yang, Dong Shu, Shenghui Wu, Yingchun Zhang, Zugeng Lin

Journal of Electrochemistry

In this paper, the structure and morphology of the nano phase electrode materials have been characterized with XRD and TEM. The performances of electrochemical intercalation and deintercalation of lithium ions have been studied by using cyclic voltammograms and galvanostatic charge discharge techniques. The results show that the nano materials posses advantage of micro structure and Li+ ions intercalation performances. The observed high capacity and large charge discharge current density of the nano phase materials seem to have resulted from three kinds of effects: 1) an increase in the space for Li+ ions intercalation; 2) a decrease in the distance for …


Studies Of Surface Electrochemistry And Electrocatalysis At Atomic And Molecule Level, Shigang Sun Feb 1998

Studies Of Surface Electrochemistry And Electrocatalysis At Atomic And Molecule Level, Shigang Sun

Journal of Electrochemistry

The main progresses achieved during last few years in our research group concerning studies of surface electrochemistry and electrocatalysis were reviewed in this present paper. Four topics were described: 1) the surface electrochemistry and model electrocatalysis of metal single crystal planes, 2) the electrocatalytic reaction mechanism and the control of reaction pathways at molecule level, 3) the reaction kinetics of electrooxidation of small organic molecules, and 4) the relationship between the properties and the surface chemical states of electrocatalyst. This review lays in emphasis on the demonstration of the results as well as the research direction of surface electrochemistry and …


Gold Electrodeposition On Microelectrodes, Lihua Xiong, Caihui Shi, Xiaoqin Li, Bingwei Mao Feb 1998

Gold Electrodeposition On Microelectrodes, Lihua Xiong, Caihui Shi, Xiaoqin Li, Bingwei Mao

Journal of Electrochemistry

The initial stage electrodeposition behaviors of gold onto glassy carbon and platinum microelectrodes are studied in an acid solution containing AuCl_3using cyclic voltammetry and potential step techniques. The results suggest that gold nucleation on microelectrodes requires a higher driving force with high probability. Within the range of the microelectrode dimension that have been used in the present work, large amount of gold nucleus could be formed at short time scale at overpotentials higher than a threshole value. The It curves from the platinum microelectrode are in consistence with the continuous nucleation model. It has been found that the deosition history …


Microelectrode Studies On The Pitting Corrosion Process Of Stainless Steel, Changjian Lin, Lijian Chen, Ronggui Du, Zude Feng, Jianguang Tang, Hongping Dai Feb 1998

Microelectrode Studies On The Pitting Corrosion Process Of Stainless Steel, Changjian Lin, Lijian Chen, Ronggui Du, Zude Feng, Jianguang Tang, Hongping Dai

Journal of Electrochemistry

Abstract Differing with the scanning microelectrode techniques, which scan microelctrode closely to the interface of electrode/electrolyte and make electrochemical imaging in a lateral spatial resolution, the technique of microelectrode with a micron diameter is of very high timeresolution and ratio of signal/noise in electrochemical measurements. The microelectrode technique allows doublelayer capacitance and background current for a microelectrode to be drastically reduced due to the exposed area of a microelectrode is usually 6~8 orders of magnetite lower than that of a conventional electrode with largescale exposed area. Microelectrode was recently developed as a new powerful electrochemical technique and widely used in …


The Investigations Of Surface Treatment Methods And Characterization Of Oxide Films On Ab_5Based Metal Hydride Electrodes Ⅰ. New NiRich Treatment Methods And Photoelectrochemical Characterization Of Oxide Films, Junmin Nan, Yong Yang, Jun Li, Zugeng Lin Feb 1998

The Investigations Of Surface Treatment Methods And Characterization Of Oxide Films On Ab_5Based Metal Hydride Electrodes Ⅰ. New NiRich Treatment Methods And Photoelectrochemical Characterization Of Oxide Films, Junmin Nan, Yong Yang, Jun Li, Zugeng Lin

Journal of Electrochemistry

Two simple and efficient surface treatment methods for AB_5type hydrogen storage alloys were developed. The results of X-ray photoelectron spectroscopy (XPS) and cyclic voltammetric (CV) experiments showed that the hydrogen storage alloys treated by two different methods had Nirich surface layer so that the performances of the electrodes were improved after treatment. The characterization of the oxide films which formed on the surface of electrodes through potentiodynamic oxidation with the help of photoelectrochemical microscopy (PEM) were done. The anodic photocurrent and the cathodic photocurrent related to the oxidation of hydrogen and the reduction of oxygen on the surface layer were …


Electrochemical Impedance Of Molten Salts Induced Hot Corrosion, Chaoliu Zeng, Weitao Wu, Jianqing Zhang Feb 1998

Electrochemical Impedance Of Molten Salts Induced Hot Corrosion, Chaoliu Zeng, Weitao Wu, Jianqing Zhang

Journal of Electrochemistry

Electrochemical impedance technique was employed to study corrosion behaviors of Ni-3Al, IN100 and IN738 alloys in molten (Na, K, Li)_2SO_4 at 700 ℃. The Nyquist plots for Ni-3Al and IN100 alloys have the characteristics of diffusioncontrolled reaction. But, the corrosion reaction for IN738 alloy is not controlled by the diffusion of oxidants. The equivalent circuits were proposed, and the parameters in circuits were also calculated. Ni-3Al and IN100 alloys suffer from catastrophic corrosion due to the formation of a porous corrosion layer. IN738 alloy has excellent corrosion resistance because of the formation of a protective oxide scale.


Study On The Synthesis And Electrochemical Behavior Of Poly (QuinonoidDisulfide), Xiaohui Tang, Xiuwu Sun, Yongfang Li, Shibi Fang Feb 1998

Study On The Synthesis And Electrochemical Behavior Of Poly (QuinonoidDisulfide), Xiaohui Tang, Xiuwu Sun, Yongfang Li, Shibi Fang

Journal of Electrochemistry

Organic polydisulfide containing quinonoid structure was synthesized by chloromethylation, oxidation by nitric acid, and condensation polymerization with sodium disulfide. The effect of quinonoid structure on the electrochemical behavior of organic polydisulfide was investigated with cyclic voltammetry and chargedischarge measurement. The result shows that quinonoid struture mainly affects the positions of redox peaks of organic polydisulfide, open circuit voltage and discharge platform voltage of cell with the organic polydisulfide as cathode.


Anchor Effect Of Iron And Cobalt To Platinum On Carbon Substrates, Zidong Wei Feb 1998

Anchor Effect Of Iron And Cobalt To Platinum On Carbon Substrates, Zidong Wei

Journal of Electrochemistry

The cathodic reduction of oxygen is studied on porous carbonbased electrodes carrying platinumiron and/or cobalt alloy catalysts. Electrodes using such electrocatalysts, particularly when used as cathodes in acidic electrolytes, remain stable for longer periods. The cathodic polarization of oxygen reduction on such electrodes is 20 mV to 40 mV lower than that on the conventional electrode on which only platinum alone is used as an electrocatalysts. An accelerated aging test (AAT) is used to evaluate the corrosion resistance and sintering resistance of each catalyst. The dissolution of the catalyst in the AAT filtrate is analysed and provides a measure of …