室温离子液体电解液中尖晶石LiMn_2O_4的电化学性质

应用循环伏安、恒电流充放电和电化学阻抗技术研究了尖晶石L iMn2O4于室温离子液体电解液中的电化学性质.实验表明,以室温离子液体作电解液,L iMn2O4的首次放电容量可达108.2 mAh/g、循环效率高于90%,温度和电流密度显著影响电极的电化学性能.交流阻抗测定了L i+在电极/电解液相界面迁移的活化能,为55 kJ/mol.根据界面反应的高活化能解释了L iMn2O4在该离子液体电解液中低温性能和倍率充放电性能不佳的原因.     

离子液体中2,4,6-三溴苯酚的电化学还原脱卤

<正>室温离子液体的许多独特的性质为其在化学分离、电化学传感器、电池等领域展示了广阔的应用前景[1-3]。室温离子液体作为有机反应介质,可以克服水溶液电化学窗口较窄的缺点,还可避免或减少造成二次污染的大量有机溶剂[4]。利用离子液体的导电性,可将电化学反应中的     

离子液体在氟化反应中的应用进展

离子液体作为一类新型绿色溶剂,具有制备简单、稳定性好、溶解能力强、挥发性小、安全性强等优点,因此在有机单元反应包括酯化、氧化、还原、重排反应等中的应用相当广泛,有着十分诱人的应用前景.虽然其在氟化反应中的应用研究开始得较晚,但发展很快,目前在重氮化氟化、亲核氟化、亲电氟化以及电化学氟化等方面都取得了较大的进展.本文综述了近年来离子液体在氟化反应中应用的最新进展情况,并对其未来发展方向和应用前景进行了展望.     

室温离子液体在聚合反应中的应用

室温离子液体作为一种环境友好的“绿色溶剂”,具有很多独特的物理化学性能,可以应用于自由基聚合、阳离子聚合、配位聚合、电化学聚合等反应体系。本文介绍了室温离子液体在上述反应中的应用。     

电流型电化学气体传感器电解液的研究进展

综述了电流型电化学气体传感器电解液的发展状况。 研究发现,用离子液体作电解液,与水溶液电解液相比,具有不挥发、电导率高和电化学窗口宽等优点,其与聚合物结合得到的离子液体聚合物电解质兼具离子液体和聚合物电解质的优点。 用有机溶剂作电流型电化学气体传感器电解液的研究还刚刚开始,但它是很有应用前景的。     

天然石墨阳极在室温离子液体电解液中的电化学性质

对比研究了天然石墨在室温离子液体和有机电解液中的嵌脱锂性质, 探讨了添加剂提高天然石墨在离子液体电解液中电化学性质的微观机制.     

室温离子液体中二氧化碳与环氧化合物的电催化插入反应

在温和条件下，二氧化碳在室温离子液体中可以被电化学活化。同时，活化后 的二氧化碳在室温离子液体中与环氧化合物发生插入反应生成环状碳酸酯也得到了 较好的结果。[BMIm][BF4]离子液体为反应介质，环氧丙烷为反应底物时得到最佳 反应结果。电化学活化对反应的发生是必需的。     

离子液体--一种新型的绿色化学反应介质

离子液体是室温下表现为液体的离子化合物,近年来被开发成为一种新型绿色化学反应介质。本文简要介绍了离子液体的特点、发展历史、制备、应用等方面,并对其应用前景做了展望。我们阳信,在不久的将来,离子液体会成为绿色化学工程技术中的一枝新秀。     

离子液体应用于电合成导电聚合物*

自20世纪70年代导电聚合物发现以来,聚吡咯、聚苯胺、聚噻吩、聚（3,4-乙撑二氧噻吩）、聚对苯及其衍生物等,以其特殊的电子、电化学、光学性质以及巨大应用潜力受到广泛关注。离子液体是一类在室温或接近室温时呈液态的离子化合物,作为一类环境友好的新型绿色溶剂,具有很多独特的物理化学性质。本文综述了离子液体作为反应介质、支持电解质、测试介质以及离子液体参与形成的聚集体,在导电聚合物的电化学合成以及电化学性质测试中的研究进展,并展望了发展趋势。     

分子动力学模拟离子液体（BMIM＋／PF6-）／金红石（110）界面的结构

本文用分子动力学方法研究了室温离子液体1-甲基-3-丁基咪唑六氟化磷（BMIM＋／PF6-）在金红石（110）晶面的结构性质,旨在模拟染料敏化太阳能电池中的电解液／半导体界面性质．模拟结果表明离子液体的密度函数在界面处出现最大值,并成有序的“双层”结构排列,在金红石表面区域,阳离子（BMIM＋）的侧链有明显伸长的趋势,且咪唑环倾向平行于金红石（110）晶面．     

电化学氟化的新进展

电化学氟化是利用电极反应将氟直接引入有机或无机物的一种重要方法。有机物的电化学氟化方法有两种: 一是Simons于1941年发明的, 用镍作阳极, 在无水氟化氢溶液中, 电解制备全氟化合物的方法。此方法在近年来有不少改进。另一是1970年Rozhkov提出的, 以有机溶剂(如含Et3N.3HF的MeCN)为介质, 在铂阳极上,氧化得到单氟化产物的方法。本文全面地综述了这两种方法, 并着重于最新民发展。     

(NH_4)_(42)[Mo_(132)O_(372)(CH_3COO)_(30)(H_2O)_(72)]膜修饰电极的构筑和电化学性质的研究

由于过渡金属替代的多金属氧酸盐(polyoxometalates)的催化、磁性、电化学等性质,越来越受到人们的关注~([1-7]). 目前世界上约有10亿人生活在缺碘地区,碘的缺乏严重影响人类健康.对食物、生物临床、环境及工业中碘含量检测很有实际意义.     

The Electrochemical Behavior of PPV/PEO Blend

Light-emittingelectrochemicalcellisanewpromisingdeviceforlarge-areadisplay'.Theelectrochemicaldopinginthepolymerblendofpoly(ethyleneoxide)(PEO)andpoly(l,4-phenylenevinylene)(PPV)usedintheLECplaysaveryimpo~roleinitselectroluminescence.TheaimofthisinvestigationistounderstandiftheadditionofPEOaffectstheelectrochemicalbehaviorofPPVandtheeffectsofdopantsonsuchablendsystem.Accordingtotheprocessesreportedintheliteramresl',wepreparedthepolymerblendonaPtelectrodewhichwasusedastheworkingelectrode…     

Electrochemical machining of metals: Fundamentals of electrochemical shaping

Basic problems of metal electrochemical shaping theory are considered. Exact and approxi1mate (quasi-steady-state, locally one-dimensional) methods for solving direct and inverse problems are analyzed. Experimental methods for improving the electrochemical shaping accuracy are considered.Translated from Elektrokhimiya, Vol. 40, No. 12, 2004, pp. 1438–1480.Original Russian Text Copyright © 2004 by Davydov, Volgin, Lyubimov.     

Disposable and Flexible Electrochemical Paper-based Analytical Devices Using Low-cost Conductive Ink

In this work, a simple procedure for construction of disposable electrochemical paper-based analytical devices (ePADs) by screen-printing using low-cost materials and a home craft electronic printer is proposed. The devices were constructed using liner paper as a substrate and carbon ink prepared with graphite powder and wood glue. The ePAD was evaluated as an electrochemical sensor and biosensor. The proposed conductive carbon-based ink can be easily prepared and is an eco-friendly and non-toxic material. The developed ePAD was simple to produce and can be used as a low-cost electrochemical sensor, at less than US $0.20 per device.     

纳米材料电化学与生物传感器——有机微污染物检测新途径

本文介绍了近年来纳米材料电化学与生物传感器在有机微污染物检测中的研究现状,分析了这些传感器中纳米材料修饰电极的特点,重点阐述了纳米材料在有机微污染物检测中的重要作用,列举了一些纳米材料电化学与生物传感器在有机微污染物检测中的应用。最后对纳米材料电化学与生物传感器用于有机微污染物的检测研究进行了简要评述和展望。     

Sub-millivolt amplitude potential oscillations observed in the noise of hydrogen evolution on Ag and Cu microelectrodes

A strange effect was observed while using the method of quasi-simultaneous determination of electrochemical voltage noise and impedance to obtain information on the kinetics of the hydrogen evolution reaction on Ag and Cu microelectrodes. Beyond a certain polarizing current density we found microvolt-amplitude potential oscillations on both electrodes with a frequency in the 5 Hz–5 kHz range. The oscillations were observed in every single experiment with Ag and Cu, while no oscillatory behavior was observed during the control experiments with the Pt microelectrode. The presence of the oscillations indicates that the mechanism of hydrogen evolution is more complex compared to the original assumption.      

Electrochemical behavior of single crystals of nonstoichiometric cerium(III) fluorides

The electrochemical properties of single crystals of cerium fluoride alloyed with bivalent cations Sr²⁺, Ca²⁺, Ba²⁺, Sr²⁺ + Ca²⁺, Sr²⁺ + Ba²⁺, Ba²⁺ + Ca²⁺ and also with La³⁺ and La³⁺ + Ba²⁺ cations are studied using the dynamic voltammetry and impedance spectroscopy. The conductivity of symmetrical cells with Ag electrodes is determined using the method of impedance spectroscopy in the frequency range from 450 to 5 kHz at the temperatures from 20 to 100°C: for CeF₃: Sr²⁺ (0.5 mol %) + Ba²⁺ (0.5 mol %), σ = σ₀ exp[(?0.284 ± 0.005/kT]; for CeF₃:Ca²⁺ (0.5 mol %) + Sr²⁺ (0.5 mol %), σ = σ₀ exp[(?0.292 ± 0.017/kT]. The steady-state and dynamic voltammogams of symmetrical electrochemical cells with nonpolarizable reference electrodes and CeF₃ single crystals alloyed with Sr²⁺, Ca²⁺, and Ba²⁺ bivalent cations exhibited ohmic polarization. For cells with CeF₃ containing La³⁺ as an admixture, a hysteresis was observed, which could not be eliminated by chemical and electrochemical treatment of crystals. In the dynamic voltammetric curves of asymmetric cells with nonpolarizable and silver electrode and CeF₃ crystals alloyed with Sr²⁺, Ca²⁺, and Ba²⁺, a range of ideal polarizability (from 0 to ～?2.7 V), and also cerium redox processes and silver fluorination-boundary regeneration were observed. In the dynamic voltammetric curves of asymmetric cells with CeF₃ containing La³⁺ admixture, no range of ideal polarizability was observed; however, the reactions of silver fluorination and reduction of solid-electrolyte cerium were well pronounced at the corresponding potentials.     

Miniaturized electrochemical sensors and their point-of-care applications

Most of the current analytical methods depend largely on laboratory-based analytical techniques that require expensive and bullky equipment,potentially incur costly testing,and involve lengthy detection processes.With increasing requirements for point-of-care testing(POCT),more attention has been paid to miniaturized analytical devices.Miniaturized electrochemical(MEC)sensors,including different material-based MEC sensors(such as DNA-,paper-,and screen electrode-based),have been in strong demand in analytical science due to their easy operation,portability,high sensitivity,as well as their short analysis time.They have been applied for the detection of trace amounts of target through measuring changes in electrochemical signal,such as current,voltage,potential,or impedance,due to the oxidation/reduction of chemical/biological molecules with the help of electrodes and electrochemical units.MEC sensors present great potential for the detection of targets including small organic molecules,metal ions,and biomolecules.In recent years,MEC sensors have been broadly applied to POCT in various fields,including health care,food safety,and environmental monitoring,owing to the excellent advantages of electrochemical(EC)technologies.This review summarized the state-of-the-art advancements on various types of MEC sensors and their applications in POCT.Furthermore,the future perspectives,opportunities,and challenges in this field are also discussed.     

Influence of Electrochemical Parameters on the Etching of Macropores in Silicon

The process of formation of macropores in silicon with stationary irradiation and a constant current density during the electrochemical process in dependence on the initial bias on the silicon anode, U ₀, has been studied. Stable formation of macropores began when the bias reached U _c, corresponding to a critical concentration of holes p _c at the silicon–electrolyte interface. The process of macropore formation is unstable with U ₀ > U _c.