电化学双石英晶体阻抗分析新方法

电化学石英晶体微天平已被广泛应用于电分析化学与电化学领域[1] .电化学现场的石英晶体阻抗分析法能动态实时地提供电化学扰动下石英晶体谐振的多维信息 ,已用于研究电沉积与溶出[2 ,3] 、高聚物性质[4～ 6 ] 、耗尽层内溶液粘密度效应与金电极腐蚀[7,8] 等 .然而 ,以往的石英晶体阻抗分析均只涉及到一个石英晶体 ,同时对两个晶体 (分别作为工作电极和对电极 )谐振的阻抗分析未见报道 .本文以蔗糖溶液粘密度效应和氨性介质中铜沉积 /溶出过程为例 ,研究电化学双石英晶体阻抗分析新方法 .1　实验部分电化学双石英晶体阻抗分析系统由 HP43 9…     

A Study on a Partially Immersed Gold Electrode Using an Electrochemical Quartz Crystal Impedance System

Simultaneous and fast measurement of the piezoelectric quartz crystal (PQC) impedanceduring electrochemical pertUrbations, i.e., the electrochemical quartz crystal impedancesystem (EQCIS) called by us, characterizes the PQC resonance better by providingmultidimensional in sl'tu piezoelectric information than the conventional electrochemicalquartz crystal microbalance (EQCM)'-'. The PQC impedance has been analyzed basedon the Butterworth-Van Dyke (BVD) equivalent electrical circuit com…     

Electrochemical Impedance Study of Schiff Base by Means of Self-assembled Monolayer

Schiff base and its metal complex have attracted much attention because of their wide applications in biomedicine and their specific character in photochromic field1. Up to now, reports about Schiff base mainly covered its synthesis and structure2,3. To the best of our knowledge, there is no paper dealing with Schiff base using electrochemical impedance spectroscopy technique by forming self-assembled monolayer. The complexation of Schiff base with the transition metal ions has been confir…     

电催化界面和反应的电化学阻抗谱研究：经典永不褪色

本文章综述了电催化领域电化学阻抗谱（EIS）的相关研究. 首先概述了从二十世纪初到现在这一专业领域的发展历史. 然后介绍了电催化阻抗理论的几个里程碑. 其中,着重介绍了目前分析电催化EIS数据的主流模型——Dolin-Ershler模型. 之后,具体讨论了铂金单晶的双电层电容,特别是围绕这一基础课题的实验和理论上的挑战. 我们质疑采用Dolin-Ershler模型获取稀溶液中双电层电容的合理性. 因为在稀溶液中,双电层效应使得双电层电容具有频散特性,因而双电层电容的低频部分在分析过程中可能被遗失了. 未来,我们期待看到新的实验去证明或反驳一个最近的理论预测,即铂电极在氧化物生成电位区域中具有非单调表面电荷关系和负双电层电容.     

A Study on Adsorption of Electrogenerated Cystine Precipitate onto An Electrode using Electrochemical Quartz Crystal Impedance System

Insiluquartzcrystalimpedance(QCI)measurementduringelectrochemicalperturbationshasfoundwideapplicationsininvestigatingmetalandpolymerdepositionetc'-',asitprovidesmultidimensionalinsitupiezoelectricinformation.QCIanalysishasbeenbasedontheButterworth-VanDyke(BVD)equivalentelectricalcircuitcomposedofamotionalarmandastaticarminparallel.Themotionalarmcontainsthreeequivalentcircuitelementsinseries,namely,themotionalresistanceRI,themotionalinductanceL,andthemotionalcapacitanceC,,whilethestaticar…     

双电层电容器电化学阻抗谱的实验研究

电化学阻抗谱(EIS)是一种很有用的研究电化学性能的技术. 理想的双电层电容器(EDLC)阻抗谱的尼奎斯特图由中高频的45°线和低频的与实轴垂直的直线组成, 可以用孔径分布-传输线模型来解释. 然而, 在研究工作中还发现, 在阻抗谱的高频区出现了半圆弧区域, 为此, 提出的等效模型认为半圆弧可以归因于活性材料之间的接触电阻和接触电容, 以及电极与集流体之间的接触电阻与接触电容. 还研究了充电过程、活性炭和电解液的电导率、导电添加剂和粘结剂的含量、隔膜、活性物质附载量和极片加压等因素对阻抗谱的影响. 其中, 充电截止电压、活性炭的电导率、导电添加剂的含量和极片加压对半圆弧部分影响较为显著.     

利用扫描电化学显微镜研究过氧化氢检测中电化学消除抗坏血酸

利用扫描电化学显微镜 (SECM)将微探针定位于宏观金盘基底电极的扩散层内 .通过向基底电极施加适当电位以氧化消除电活性干扰物质 (如抗坏血酸 ) ,提高探针电极检测过氧化氢的选择性 .基于此方法 ,系统研究了探针 -金基底电极间距和电极电位对铂微探针检测过氧化氢选择性的影响 .结果表明 ,当探针 -基底电极间距为 2 2 .6μm ,金基底电极和铂探针电极电位分别为 0 4V和 0 5V时 ,探针电极检测过氧化氢不受抗坏血酸 ( 0 0 5mmol·L-1)的干扰 .此时 ,过氧化氢检测的线性范围为 :4× 10 -5～ 1× 10 -3 mol·L-1.基于实验结果 ,提出了在微型化电化学器件制备过程中设计互相靠近的双工作电极 ,利用电化学法消除电活性干扰物以提高检测选择性的新方法 .     

双电层电容器电化学阻抗谱的实验研究(英文)

电化学阻抗谱(EIS)是一种很有用的研究电化学性能的技术.理想的双电层电容器(EDLC)阻抗谱的尼奎斯特图由中高频的45°线和低频的与实轴垂直的直线组成,可以用孔径分布-传输线模型来解释.然而,在研究工作中还发现,在阻抗谱的高频区出现了半圆弧区域,为此,提出的等效模型认为半圆弧可以归因于活性材料之间的接触电阻和接触电容,以及电极与集流体之间的接触电阻与接触电容.还研究了充电过程、活性炭和电解液的电导率、导电添加剂和粘结剂的含量、隔膜、活性物质附载量和极片加压等因素对阻抗谱的影响.其中,充电截止电压、活性炭的电导率、导电添加剂的含量和极片加压对半圆弧部分影响较为显著.     

钒液流电池用石墨毡电极电化学活化机理的交流阻抗研究

研究了不同氧化程度下的石墨毡在钒溶液中的吸附性、润湿性及其交流阻抗图谱(EIS), 结果发现随着氧化程度增加, 吸附性和润湿性增强; 交流阻抗谱包括两个半圆和一条直线, 高频半圆对应离子的吸脱附反应, 低频半圆对应电化学反应, 直线对应离子在溶液中的扩散过程. 随石墨毡氧化程度的增加, 低频半圆显著减小, 通过等效电路拟合及动力学参数计算, 发现电荷传递电阻显著减小.     

Electrochemical Noise Analysis and Electrochemical Impedance Spectroscopy for Pure Copper in Chloride Media

The corrosion behavior of pure copper electrode exposed to artificial seawater has been studied using electrochemical noise analysis （ENA） and electrochemical impedance spectroscopy （EIS）. A diffusion process was observed for copper exposed to chloride media as indicated by the presence of a minimum phase angle over the lowest frequency range in the impedance plots. Analysis of electrochemical noise （EN） data has been collected both in time and frequency domains. Noise resistance Rn was obtained after analyzing EN data in the time domain. A good agreement was observed between Rn values and polarization resistance Rp values obtained from EIS analysis. Localization index Ii was not found to provide information concerning corrosion mechanisms. Also skewness and kurtosis for both potential and current fluctuations did not show any mechanistic information. It was concluded that ENA could detect the corrosion rate for copper exposed to chloride media, but was not found to provide information about the corrosion mechanisms.     

电沉积Bi2Te3基薄膜的电化学阻抗谱研究

以不锈钢为基底,利用电化学沉积方法制备Bi2Te3基薄膜材料,并采用X射线衍射技术、电子探针微观分析等方法对薄膜进行结构和成分表征,通过电化学阻抗谱技术对不锈钢表面Bi2Te3的电化学沉积机理进行了初步探讨.结果表明Bi-Te和Bi-Te-Se体系具有相似的电化学沉积机理,即Bi3+和2HTeO+或H2SeO3首先被还原为Bi单质和Te或Se单质,然后Bi单质与Te或Se单质反应生成Bi2Te3基化合物,而Bi-Sb-Te体系中,2HTeO+首先被还原为Te单质,生成的Te再与Bi3+和Sb(III)反应生成Bi2Te3基化合物,三种体系的沉积都受电化学极化控制.     

Characterization of Formation Kinetics of Self-Assembled Thiol Monolayers on Gold by Electrochemical Impedance Spectroscopy

Interest in the properties of organized monolayers has grown enormously in recent years because these monolayers can provide a means to control the interface at a molecular level1. The self-assemblies of alkanethiols and their derivatives were probably the most intensively studied due to their stability, well-packed structure, ease in preparation, and flexibility in designing the tail group2. The adsorption kinetics of thiol monolayer has been studied by using several techniques, including con…     

Study on the Mutagenic Properties of Mutagen Using Piezoelectric Impedance Microbial Sensing

The characteristics of mutagenic growth of Salmonella trphimurium strain TA100 induced by sodium azide were investigated by piezoelectric impedance microbial sensing. The variation of motional resistance (ΔR₁) versus time curves during the growth of revertants in the presence/absence of NaN₃ were measured and discussed. Compared to the growth process in the absence of NaN₃, a larger ΔR₁ value was obtained after addition of NaN₃, which indicates that part of the TA100 strain recovers its growth ability due to the mutagenic property of NaN₃. Moreover, the signal size of ΔR₁ increased with the increase of NaN₃ dosage within a certain dosage range, and decreased when a higher dosage of sodium azide was used. Finally, the following new impedance response equation containing the mutagenic intensity coefficient (a) and poisonous/inhibitory intensity coefficient (b) was obtained: where the a and b values of NaN₃ were 0.6063 and 1.1998 × 10⁻³, respectively. The satisfactory value of q_r shows that this equation was suitable to reflect the effect of the properties of mutagen on microorganisms.     

Pt/C催化剂氧还原反应的交流阻抗动态研究

本文通过RDE和EIS联合技术、等效电路模型,研究了酸性体系中商业Pt/C催化剂ORR行为. 研究发现Pt/C动态界面包括两个彼此独立的过程：1）Pt表面原有PtO还原至Pt过程,2）ORR促进新PtO形成过程,为催化材料稳定性及活化性提供了关键依据;并发现动态界面促进多孔电极重构以及与传输匹配过程.在高过电位下,ORR的高反应速率可通过增加催化材料憎水性予以改善. 上述研究结果可对ORR的直流电化学研究进行有效补充,并提供建模基础.     

交流阻抗法在细胞分析中应用的研究进展

交流阻抗法作为一种新型的无标记、全程动态、实时分析方法已在细胞研究中得到了广泛应用。本文综述了基于交流阻抗法进行细胞分析的研究新进展,重点对非法拉第阻抗谱法和法拉第阻抗谱法用于细胞分析的原理及应用进行了总结,主要包括交流阻抗法在细胞形态、细胞生长、细胞增殖、细胞凋亡以及作用于细胞的药效和毒性研究中的应用,并对其发展趋势进行了展望。     

Electrochemical Impedance Spectroscopy in the Characterisation and Application of Modified Electrodes for Electrochemical Sensors and Biosensors

Electrochemical impedance spectroscopy is finding increasing use in electrochemical sensors and biosensors, both in their characterisation, including during successive phases of sensor construction, and in application as a quantitative determination technique. Much of the published work continues to make little use of all the information that can be furnished by full physical modelling and analysis of the impedance spectra, and thus does not throw more than a superficial light on the processes occurring. Analysis is often restricted to estimating values of charge transfer resistances without interpretation and ignoring other electrical equivalent circuit components. In this article, the important basics of electrochemical impedance for electrochemical sensors and biosensors are presented, focussing on the necessary electrical circuit elements. This is followed by examples of its use in characterisation and in electroanalytical applications, at the same time demonstrating how fuller use can be made of the information obtained from complete modelling and analysis of the data in the spectra, the values of the circuit components and their physical meaning. The future outlook for electrochemical impedance in the sensing field is discussed.     

钌镧氧化物涂层在NaCl 溶液中的电化学阻抗谱(EIS)研究

测量了钌镧氧化物涂层的电化学阻抗谱(EIS), 结合循环伏安(CV)及扫描电子显微镜形貌分析, 研究了钌镧氧化物涂层阳极在3.5% NaCl 溶液中电化学表面结构及电化学行为. 在非析氯反应区间, 该涂层EIS 数据的最佳拟合等效电路是R_s(R_ctQ_dl), 在析氯反应区间, 其等效电路为R_s(R_fQ_f)(R_ctWQ_dl). 高频段阻抗行为对应涂层的物理阻抗, 低频段对应涂层与溶液界面的电化学反应阻抗. 实验结果表明, 随着La 浓度增加, 氧化膜及双电层的伪电容增大, 且在La 含量30mol%时达到最大值, 与CV实验结果一致, 证明了加入La 能提高RuO₂涂层的电催化活性. 但在析氯反应区间, 涂层氧化膜的导电性在含La 大于30 mol%之后迅速下降, 在低频段产生Warburg 阻抗, 与其表面钝化和特性吸附现象有关,这是导致含La 70 mol%时电催化活性急剧下降的原因.     

基于酶催化沉积放大的电化学阻抗法用于人免疫球蛋白M的检测

提出了一种基于酶催化沉积放大的电化学免疫分析方法。先通过免疫夹心反应,将酶标抗体(羊抗人IgM-HRP)固定到电极表面。通过HRP催化双氧水氧化3,3′-二氨基联苯胺在电极表面形成不溶性沉积物,从而放大电化学检测信号。实验通过蛋白A实现抗体的定向固定。考察了包被抗体的浓度和包被溶液的pH对抗体固定的影响,以及酶标抗体的用量和沉积时间对免疫分析的影响。传感器信号响应与人免疫球蛋白M(IgM)浓度在2.1~670μg/L范围内具有良好的线性关系;检出限达0.08μg/L。     

Impedance Response of a Thin Film on an Electrode: Deciphering the Influence of the Double Layer Capacitance

The different contributions of the interfacial capacitance are identified in the case of passive materials or thin protective coatings deposited on the electrode surface. The method is based on a graphical analysis of the EIS results to determine both the passive-film capacitance in the high-frequency domain and the double-layer capacitance in the low-frequency domain. The proposed analysis is shown to be independent of the physicochemical origins of the frequency dispersion of the interfacial capacitances which results, from an analysis point of view of the experimental results, in the use of a constant-phase element However, for a correct evaluation of the thin-film properties such as its thickness, the high-frequency data must be corrected for the double-layer contribution. In particular, it is shown that if the double-layer capacitance gives a frequency-dispersed response, it is necessary to correct the high-frequency part for the double-layer constant-phase elements. This is first demonstrated on synthetic data and then used for the determination of the thickness of thin oxide film formed on Al in neutral pH solution.     

An Impedance Molecularly Imprinted Sensor for the Detection of Bovine Serum Albumin (BSA) Using the Dynamic Electrochemical Impedance Spectroscopy

A molecularly imprinted electrochemical sensor is successfully developed to detect bovine serum albumin (BSA) based on the dynamic electrochemical impedance spectroscopy (DEIS) instead of the traditional impedance spectroscopy. The sensor is prepared using chitosan and pyrrole as modified material and functional monomers, respectively, and the fast and real‐time characterization of molecular imprinting process can be obtained by DEIS. It is indicated that the removal and rebinding processes of BSA are closely related with the DEIS impedance under dynamic conditions, and the direct correlation between the resulting kinetic information and BSA concentrations can be established. As a result, the impedance changing rates in the initial 5 min of BSA adsorption are linear to the BSA concentrations ranging from 0.0001 to 0.01 ng mL^?1 and 0.01 to 1 ng mL^?1 with a detection limit of 5×10^?5 ng mL^?1 (S/N=3). In addition, the detection of BSA by DEIS does not require the system to be in equilibrium. The sensor also shows simplicity, high sensitivity, good stability and acceptable recovery in real samples, indicating its promising prospects in the fast and real‐time detection of proteins.