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由于电解池时间常数和iR降的限制,传统上绝大部分电化学实验的时间尺度是在秒或毫秒的范围,超微电极的应用使得快速电化学动力学测量成为可能。考虑一个盘电极,双电层电容Cd以及瞬态电流i都与电极面积即半径平方成正比,而溶液内阻R_u则与电极半径成反比,因此,电解池时间常数R_uC_d和iR_u降都随着电极尺寸的缩小而减小。一个半 相似文献
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薄层电解池流动注射法测定铜 总被引:1,自引:0,他引:1
薄层电解池做高压液相色谱鉴定器的报道较多。但不用分离装置的简单薄层电解池流动注射法国内似尚未见正式报道,国外报道也很少。Alexandra等曾以管状金电极流动注射安培法测定氯。我们分别以大面积银、铜、玻璃碳、铜面镀金为工作电极装配电解池,试验发现以玻璃碳为最佳。本文报道薄层电解池的结构及用薄层电解池流动注射法测定铜的试验条件及结果。 相似文献
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设计了原位电解池用于生物材料/活细胞界面电化学交流阻抗谱(EIS)的测量, 原位观测了钛/MG63细胞界面EIS行为及其随时间的变化. 原位电解池中引入Ag/AgCl作为参比电极, 解决了EIS测量过程中高频部分信号失真的问题. 钛/MG63细胞界面EIS研究初步结果表明: 活细胞在钛电极表面附着, 可改变界面双电层结构和电极的表面状态, 进而影响界面的电化学性质. 实验发现, 由于钛电极表面氧化层的阻抗信号处于中低频段, 而细胞膜层自身的电化学阻抗响应位于高频范围, 由此, 可分别分析不同的电极过程, 解析其相互关系, 研究活细胞在生物材料表面的作用机理. 相似文献
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采用真空镀膜技术制得了超薄型红外光透极电极,设计了适用于水溶液体系和多种固体电极体系的红外光透薄层电解池,通过亚铁氰化钾水溶液/金电极体系和亚硫酰氯/碳电极体系的现场红外光谱电化学测试证明:该电解池具有结构简单,光谱响应灵敏,适用范围较宽等优点。 相似文献
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电化学检测池的结构与装置 LCEC系统可以简化成图1。一般由四部分组成:样品注入、溶剂传输、色谱分离和电化学检测。本文将主要介绍LCEC仪器中的电分析化学原理。由于电分析检测方法种类繁多,电解池装置(包括电极材料、形状及电解池结构等)的设计也有相当的数量。我们将试图对LCEC系统中电极材料的选择和电解池结构的设计等的一般性原则作出总结。 相似文献
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普鲁士兰修饰电极的现场X射线衍射研究 总被引:4,自引:0,他引:4
利用X射线衍射仪-电化学装置-两台微机联机组成的X射线衍射差谱全自动电化学测量系统,并结合特制的电解池,现场测定了普鲁士兰修饰电极薄膜在电化学变过程中的X射线衍射差谱。结果证实在变色过程为了平衡体系电荷而进入和脱出修饰薄摸的K^+导致了薄膜晶体结构的转变。理论计算的X射线衍射差谱与实测结果基本一致。 相似文献
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电化学沉积制备纳米结构铜电极及其葡萄糖检测性能 总被引:1,自引:0,他引:1
利用电化学沉积法制备了高电活性的纳米结构铜电极材料, 采用扫描电子显微镜和电化学方法分别对电极表面形貌和电化学性能进行了表征, 研究了实验参数对葡萄糖电氧化活性的影响. 结果表明, 改变沉积条件可以调控沉积铜的形貌及电催化活性. 在最佳条件下制备的铜纳米结构电极对葡萄糖检测的灵敏度为1310 μA·L/mmol, 检出限为5.0×10-7 mol/L(S/N=3). 相似文献
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Polovov IB Volkovich VA Charnock JM Kralj B Lewin RG Kinoshita H May I Sharrad CA 《Inorganic chemistry》2008,47(17):7474-7482
Soluble uranium chloride species, in the oxidation states of III+, IV+, V+, and VI+, have been chemically generated in high-temperature alkali chloride melts. These reactions were monitored by in situ electronic absorption spectroscopy. In situ X-ray absorption spectroscopy of uranium(VI) in a molten LiCl-KCl eutectic was used to determine the immediate coordination environment about the uranium. The dominant species in the melt was [UO 2Cl 4] (2-). Further analysis of the extended X-ray absorption fine structure data and Raman spectroscopy of the melts quenched back to room temperature indicated the possibility of ordering beyond the first coordination sphere of [UO 2Cl 4] (2-). The electrolytic generation of uranium(III) in a molten LiCl-KCl eutectic was also investigated. Anodic dissolution of uranium metal was found to be more efficient at producing uranium(III) in high-temperature melts than the cathodic reduction of uranium(IV). These high-temperature electrolytic processes were studied by in situ electronic absorption spectroelectrochemistry, and we have also developed in situ X-ray absorption spectroelectrochemistry techniques to probe both the uranium oxidation state and the uranium coordination environment in these melts. 相似文献
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M. S. Vasil’eva V. S. Rudnev O. E. Sklyarenko L. M. Tyrina N. B. Kondrikov 《Russian Journal of General Chemistry》2010,80(8):1557-1562
Nickel-copper compositions for catalytic oxidation of carbon(II) oxide to carbon(IV) oxide were prepared by impregnation of
oxide films on titanium surface, obtained by plasma electrolytic oxidation followed by annealing. Plasma electrolysis oxide
coatings with a layer thickness of 5 to 50 μm were generated using different electrolytes. The compositions were studied by
X-ray powder diffraction, X-ray spectral analysis, and electron microscopy, and moisture absorption of the initial plasma
electrolytic structures was estimated. A linear correlation was found between the overall concentration of nickel and copper
(4 to 25 mol %) in the surface layer of ∼2–5-μm compositions and their catalytic activity. The overall concentration of nickel
and copper was found to increase in parallel with the moisture absorption of plasma electrolytic oxidation coatings. Nickel-copper
compositions based on plasma electrolytic oxidation coatings generated in a silicate electrolyte displayed the best catalytic,
mechanical, and adhesion properties. 相似文献
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《Analytical letters》2012,45(7):671-676
Abstract The method of electrolytic dissolution in organic solvents (saturated with NH1Cl) followed by atomic absorption spectroscopy was applied to the determination of Fe and Cu impurities in niobium metal. It was found that a previously reported decrease in sensitivity could be attributed to precipitation of NH4Cl on the walls of the feeding chamber of the spectrometer and could be avoided by diluting the solution before measurement. 相似文献
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M. Z. Muldakhmetov A. M. Gazaliev I. V. Kirilyus S. D. Fazylov 《Russian Journal of Applied Chemistry》2007,80(7):1087-1089
An electrolytic method was suggested for the synthesis of nipecotic acid ethyl ester in a diaphragm electrolytic cell on a copper cathode in aqueous alcoholic alkali solution. 相似文献
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Electrochemical Deposition and Spectroelectrochemical Response of Bromophenol Blue Films on Gold
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Bromophenol blue (BPB) was electropolymerized onto a Au substrate. The effects of voltammetric cycle number, BPB concentration, and pH on film thickness, density, optical absorption, and electrochemical susceptibility were evaluated, and favorable deposition conditions were identified. Quantitative measurement of the film mass via quartz crystal microbalance enabled determination of the molar volume and revealed a strong dependence of film density with deposition pH. Finally, electrochemical control of the optical properties of BPB films was demonstrated via in situ spectroelectrochemistry. We believe this is the first demonstration of electropolymerization of pure BPB on Au, and thus the first demonstration of poly(BPB) as an electrochemically switchable optical coating. 相似文献
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《Journal of Inorganic and Nuclear Chemistry》1979,41(11):1595-1599
The oxidation of uranium (III) in acid solutions has been studied by spectrophotometric measurement in an inert gas atmosphere. Uranium (III) obtained by reduction of uranyl salt with zinc amalgam was oxidized more rapidly than that prepared by dissolution of uranium amalgam or electrolytic reduction of uranyl ion. The oxidation is strongly catalysed by copper or lead ion contained as a trace impurity in zinc. The autoxidation and the metal surface catalysed oxidation of uranium (III) are discussed. 相似文献
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XIE Qing-Ji PANG Xiao-Yong NIE Li-Hua YAO Shou-Zhuo Department of Chemistry Chemical Engineering Hunan University Changsha Hunan China 《中国化学》1994,12(5):425-431
Piezoelectric transmission spectroelectrochemistry (PTSEC), i.e., the combination of electrochemistry and spectroelectrochemistry (SEC) with electrochemical quartz crystal microbalance (EQCM) technique is reported by using a normal piezoelectric quartz crystal (PQC) as an optically-transparent electrode (OTE). A theoretical relationship between the PQC response and the spectroelectrochemical response is derived and used to estimate the apparent molar absorptivity of the absorbing species deposited on the OTE on the PQC surface. The complex of copper with aspartic acid is used to test this new PQC-SEC technique. Results show that the combination of three such diverse techniques provides a very useful methodology for studying electrode processes and electrode surface characteristics in situ. 相似文献