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Journal of Electrochemistry

1998

Articles 61 - 70 of 70

Full-Text Articles in Chemistry

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 …

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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 …

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Spectroscopic Investigation Of Ion Transport Mechanisms In Polyacrylonitrile Based Electrolytes, Zhaoxiang Wang, Biying Huang, Rongjian Xue, Xuejie Huang, Liquan Chen Feb 1998

Spectroscopic Investigation Of Ion Transport Mechanisms In Polyacrylonitrile Based Electrolytes, Zhaoxiang Wang, Biying Huang, Rongjian Xue, Xuejie Huang, Liquan Chen

Journal of Electrochemistry

Raman, IR, X-ray photoelectron (XPS), and NMR spectra of components in polyacrylonitrilebased electrolytes have been studied. It is found that there are strong interactions among the components though different systems show different interaction characteristics. A concept of competition is proposed between the polymer matrix and the plasticizer on associating with the Li~+ ions. By analyzing the important functions of the plasticizer, a possible mechanism of the ions transport in the polymer electrolyte is suggested.

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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 …

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Investigation On The Ellipsometry For The Detection Of Nickel Through Anodic Stripping Voltammetry, Wei Zhu, Yuru Yang, Zongqing Huang Feb 1998

Investigation On The Ellipsometry For The Detection Of Nickel Through Anodic Stripping Voltammetry, Wei Zhu, Yuru Yang, Zongqing Huang

Journal of Electrochemistry

The ellipsometry with a new parameter Vop  and anodic stripping voltammetry are used to analyze the nickel ions solutions with different concentration of 10-6～10-9 mol/L. It is shown that the results given by both methods are identical and the sensitivity and accuracy of ellipsometry are higher than anodic stripping voltammety.

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The Migration Of Samarium(Ⅲ)Across Oil/Water Interface, Junwei Di, Xiaoxing Xu, Ying Wu, Ruixi Fan Feb 1998

The Migration Of Samarium(Ⅲ)Across Oil/Water Interface, Junwei Di, Xiaoxing Xu, Ying Wu, Ruixi Fan

Journal of Electrochemistry

The migration of Samarium(Ⅲ)across water/nitrobenzene (w/nb) interface facilitated by diantipyrylmethane (DAM) and the electrochemical behaviour affected by emulsifier OP in the nb phase have been studied by normal and convolute cyclic voltammetry. It is concluded that the formation of the complex occurs at w/nb interface and the mechanism of the samarium(Ⅲ)transfer across w/nb interface facilitated by DAM is E mechanism.

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The Time Dependent Red Shift Phenomenon Of Visible Electroluminescence Of Porous Silicon, Rongqiu Wang, Jingjian Li, Shengmin Cai, Zhongfan Liu Feb 1998

The Time Dependent Red Shift Phenomenon Of Visible Electroluminescence Of Porous Silicon, Rongqiu Wang, Jingjian Li, Shengmin Cai, Zhongfan Liu

Journal of Electrochemistry

The electroluminescence (EL) of ntype porous silicon (PS) in a persulphate solution under cathodic polarization was studied. A significant red shift in the luminescence spectra with the increase of polarization time, as well as a blue shift with the increase of cathodic polarization, have been found. FTIR, MicroRaman, AFM and photoelectrochemical techniques have been used to investigate the structure of PS before and after the electroluminescence emission. All these results show that the surface of PS has been oxidized by the persulphate during the EL emission, and accompanied by the stripping of small silicon nanocrystallite, which leades to the red …

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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.

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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.

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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 …

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