共查询到19条相似文献,搜索用时 93 毫秒
1.
原位电化学拉曼光谱是一种重要的光谱电化学技术.基于超微电极的原位电化学拉曼光谱将拉曼光谱反映的结构信息与电极表面的电化学过程从实验上严格对应和关联,为深刻理解电化学反应机理提供依据.本文综述了采用超微电极作为工作电极的原位电化学拉曼光谱的研究方法和应用进展,总结了应用超微电极作为工作电极开展电化学拉曼光谱实验的方法和具有表面增强拉曼活性的超微电极制备方法,展示了如何利用在超微电极表面获得的拉曼光谱与界面电化学过程的严格关联研究单个锌颗粒电化学氧化过程、吡啶分子在Au电极表面的电化学吸附过程,以及如何利用该技术能以高的信噪比和灵敏度同时测量光电流与分子反应这一特性研究对巯基苯胺选择性光氧化反应.采用超微电极作为工作电极的原位电化学拉曼光谱技术极大拓展了拉曼光谱技术的研究范围,有望成为探索(光)电化学反应的有力工具. 相似文献
2.
3.
计算机化的多功能超微电极电化学仪器 总被引:4,自引:1,他引:3
报道了一种计算机化的多功能超微电极电化学仪器.它具有12种基本功能和正确的电流、电位性质及很高的灵敏度.能用于超微电极的电化学研究和测试,也适用于常规电极. 相似文献
4.
5.
6.
7.
由于个体的差异性和异质性作用,整体平均测量掩盖了个体的本征性质和电化学性能之间的关联.单体碰撞电化学作为一种强大而方便的电化学方法,已被用于研究超微电极上自由扩散的单个个体随机碰撞过程中的电化学行为.然而,个体的动态行为与其电化学反应过程息息相关.因此,对于单体动态电化学行为的研究可实时获取单体在电极界面上的动态电化学反应信息,也将有助于理解电极界面电荷或电子的动态转移过程.本文重点围绕单体动态电化学行为的研究,通过单个纳米颗粒在电极表面碰撞事件中产生的瞬时电流响应追踪其动态电化学反应过程,进而推广到其他单体动态电化学行为的研究.同时,单体电化学方法结合光学显微成像技术作为高时空分辨的研究手段提供了充分信息全面地反映了单个实体的动态电化学反应动力学过程和反应机制,最后讨论了该领域面临的科学挑战并展望了未来的研究方向. 相似文献
8.
微流控芯片中超微电极的制作及其在芯片-电化学检测中的应用 总被引:8,自引:0,他引:8
设计并制作了集成有超微电极的玻璃微流控芯片.在电化学检测芯片1(EC-1)中,以光刻方法制作13μm宽的Pt超微电极,距分离管道末端30μm,优化电极体系和分离电压,检测了电泳分离的神经递质.在电化学检测芯片2(EC-2)中,制作7μm宽的超微电极,在其上游集成城墙式的膜结构,进一步腐蚀后的膜厚度为10μm,具有良好的导电性和散热性能,成功地将高压电场截至在超微电极之前,具有进一步应用于电化学检测的能力. 相似文献
9.
超微盘电极上苯胺的循环扫描伏安法电化学聚合 总被引:1,自引:0,他引:1
本文对超微盘电极上苯胺的循环扫描伏安法电化学聚合进行了研究。对研究过程的伏安曲线性质以及峰电流和单体浓度,循环扫描次数和速率及电位之间的关系作了详细的探讨,还给出了峰电流的经验式。 相似文献
10.
11.
《Electroanalysis》2004,16(19):1583-1591
Micro‐wire electrodes were made from gold and silver wires (diameter: 25 μm; length: 3–21 mm) and sealed in a polyethylene holder; micro‐disk electrodes were made from the same wires and polished. The gold electrodes were electrochemically coated with mercury before use; the silver wires were used without coating. Comparative measurements demonstrated that the micro‐wire electrodes had much higher sensitivity, and a much (10–100×) lower limit of detection, than micro‐disk electrodes, and the sensitivity increased linearly with the area and length of the electrodes. Using a gold micro‐wire electrode of 21 mm and a deposition time of 300 s the limit of detection was 0.07 nM Pb in seawater of natural pH, compared to a limit of detection of 10 nM Pb (more than 100×greater) using a gold micro‐disk electrode of the same diameter. Using the silver micro‐wire electrode the limit of detection of lead was improved by a factor of 10 to 0.2 nM in acidified seawater. It is expected that the improved sensitivity of micro‐wire electrodes will lead to successful in situ detection of metals in natural waters. 相似文献
12.
The stripping voltammetry ofteIlurium(IV) in 0.1 M perchloric acid at gold electrodes is described. Detection limits for solid gold, in situ gold-plated and externally gold-plated rotating glassy carbon disk electrodes are presented. There is no significant increase in sensitivity for the use of solid gold electrodes; 0-25 ppm teIIurium(IV) can be determined by anodic stripping voltammetry at an in situ gold-plated rotating glassy carbon disk electrode. The determination of tellurium in NBS SRM 1632a (Trace Elements in Coal) is described. 相似文献
13.
《Electroanalysis》2006,18(1):89-94
The fabrication and characterization of very cheap disposable gold disk electrodes with reproducible area is reported. The innovation of the proposed procedure is the use of toner masks to define reproducible areas on uniform gold surfaces obtained from recordable compact disks (CD‐R). Toner masks are drawn in a laser printer and heat transferred to gold surfaces, defining exactly the electrodes area. The electrochemical behavior of these disposable electrodes was investigated by cyclic voltammetry in Fe(CN)64? solutions. The relative standard deviation for signals obtained from 10 different gold electrodes was below 1 %. The size of the disk electrodes can be easily controlled, as attested by voltammetric responses recorded by using electrodes with radii varying from 0.5 to 3.0 mm. The advantages of using this kind of electrode for analytical measurements of substances that strongly adsorb on the electrode surface such as cysteine are also addressed. 相似文献
14.
We report on a dropcasting method to fabricate lightweight and mechanically flexible electrodes from gold nanorods. The nanorod electrodes possess extremely high electroactive areas, which lead to greatly enhanced electrocatalysis towards oxygen reduction reaction and methanol oxidation reaction when compared to conventional gold disk electrodes. 相似文献
15.
Ivar Kruusenberg Jaan Leis Mati Arulepp Kaido Tammeveski 《Journal of Solid State Electrochemistry》2010,14(7):1269-1277
Electroreduction of oxygen in alkaline solution on glassy carbon (GC) electrodes modified with different carbon nanomaterials
has been studied. Electrochemical experiments were carried out in 0.1 M KOH employing the rotating disk electrode and rotating
ring-disk electrode methods. The GC disk electrodes were modified with carbon nanomaterials using polytetrafluoroethylene
as a binder. Four different carbon nanomaterials were used: multiwalled carbon nanotubes, carbon black powder, and two carbide-derived
carbons (CDC). For the first time, the electrocatalytic behavior of CDC materials toward oxygen reduction is explored. Electrochemical
characterization of the materials showed that all the carbon nanomaterial-modified GC electrodes are highly active for the
reduction of oxygen in alkaline solutions. 相似文献
16.
Cyclic voltammetric and electrochemical impedance spectroscopic investigations of screen-printed, thick-film gold electrodes reveal significant differences when compared with conventional polished gold disk electrodes of comparable size. The rough and porous structure of the thick-film electrode surface leads to an actual electrode area which is increased six-fold compared to polished disk electrodes. Due to the catalytic properties of these surface structures it is possible to perform the electrochemical oxidation of reduced nicotinamide adenine dinucleotide (NADH) at relatively low overpotentials, i.e. +0.145 V vs. SCE. By operating electrodes at this potential, electrode fouling processes and interference from electroactive species, e.g. acetaminophen, are minimized. An amperometric glucose sensor based on polymer matrix-entrapped glucose dehydrogenase with a working potential of +0.145 V vs. SCE was successfully incorporated into a flow injection analysis (FIA) system. 相似文献
17.
Dr. Alexander Oleinick Feng Zhu Dr. Jiawei Yan Prof. Dr. Bingwei Mao Prof. Dr. Irina Svir Prof. Dr. Christian Amatore 《Chemphyschem》2013,14(9):1887-1898
Recessed generator–collector assemblies consisting of an array of recessed disks (generator electrodes) with a gold layer (collector electrode) deposited over the top‐plane insulator reportedly allow increased selectivity and sensitivity during electrochemical detection of dopamine (DA) in the presence of ascorbic acid (AA), a situation which is frequently encountered. In sensor design, the potential of the disk electrodes is set to the wave plateau of DA, whereas the plane electrode is biased at the irreversible wave plateau of AA before the onset of the DA oxidation wave. Thus, AA is scavenged but DA is allowed to enter the nanocavities to be oxidized at the disk electrodes, and its signal is further amplified by redox cycling between disk and plane electrodes. Several different theoretical approaches are elaborated herein to analyze the behavior of the system, and their conclusions are successfully tested by experiments. This reveals the crucial role of the plane‐electrode area which screens access to the recessed disks (i.e. acts as a diffusional Faraday cage) and simultaneously contributes to amplification of the analyte signal through positive feedback, as occurs in interdigitated arrays and scanning electrochemical microscopy. Simulations also allow for the evaluation of the benefits of different geometries inspired by the above design and different operating modes for increasing the sensor performance. 相似文献
18.
用溅射、光还原及电沉积法在n-TiO2单晶电极表面上形成了大颗粒金岛,测量了这些电极和纯金电极在H2SO4溶液以及含有Fe[3+]/Fe[2+]的酸溶液中的光电化学极化行为。通过分析和比较这些曲线,确定了大颗粒金岛与n-TiO2单晶的接触具有欧姆结性质。并借助于可换盘旋转环盘电极,在含Ce[3+]的酸溶液中测量了裸TiO2电极及载金TiO2电极上Ce[3+]的竞争光电化学氧化。证实了以大岛形式在TiO2电极表面上分布的催化剂只能催化暗反应,而不能催化光电化学反应。 相似文献
19.
A technique for polishing the surface of carbon-fiber ultramicroelectrodes to a bevelled tip is described which simplifies electrode preparation. The bevelled surface has an active area that is more than twice that of a disk electrode fabricated from the same material. This results in larger faradaic currents. It is found that the chronoamperometric current at these electrodes is equal to that calculated for a disk of equivalent area to the elliptical area of the electrode. While the area is increased, the residual current is not, and thus quantitative applications of these electrodes as in vivo probes as facilitated. Furthermore, the bevelled tip results in an electrode that minimizes tissue damage during insertion into brain tissues. 相似文献