乙醇氧化酶电极的研究

1 引言 本文在Clark 1972年工作基础上,以自制的铂电极为工作电报,采用简单的预处理方法,并且调整乙醇氧化酶(AOD),牛血清白蛋白,缓冲液的比例,以戊二醛为交联剂,将(AOD)固定在铂电极上,制成AOD电极,并且研究了该电极的性能,用于测定啤酒,白酒中乙醇含量,结果证明此电极具有响应快,灵敏度高,稳定性好,测试方便等优点。     

新型的不锈钢镀Pt（Ir）电极

应用欠电位沉积与锚定效应，研制了一种新型的不锈钢镀Ｐｔ（Ｉｒ）电极，此电极具有优越的电化学特性，可望用于微传感器。     

1—（2—吡啶偶氮）—2—萘酚修饰的铅笔芯电极上铜的阳极溶出伏安特性

１引言我们曾用２Ｂ型铅笔芯制成电极并经实验证明它具有与玻碳电极类似的良好伏安特性。也曾用它作为基体电极，修饰８－羟基喹啉，研究了铜和锌的阳极溶出特性。本文研究了ｌ－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）修饰的铅笔芯电极上铜的阳极溶出伏安特性，并用以测定了人发中的微量铜。探讨了铜在此电极上的预富集与溶出机理。２实验部分２．１仪器与试剂ＭＥＣ－１２Ａ型电化学分析仪，以ＰＡＮ修饰电极为工作电极，饱和甘汞电极为参比电极，铂电极为辅助电极，组成三电极体系。所有试剂均为分析纯试剂。水为二次去离子水。２．２电极…     

煅烧温度对纳米TiO2光电响应的影响

自从Graetzel及其合作者在液结太阳能电池研究方面取得重大突破以来,纳米晶多孔膜电极越来越引起人们的兴趣。TiO2纳米结构电极是由纳米粒子烧结在一起的三维海绵状结构,电解液可渗透到电极内部,因而电荷的传输较复杂。如何提高纳米结构电极的光电转换效率是一个值得大力研究的问题。本文探索了煅烧温度对TiO2纳米结构电极电荷传输特性的影响,旨在为提高太阳能转换中光电转换效率而寻找有效途径。     

聚吡咯修饰乳酸氧化酶电极的研制

根据聚吡咯修饰电极掺杂和去掺杂原理，将乳酸氧化酶固定在玻碳电极表面形成一种新型的乳酸酶电极，该电极灵敏度高，稳定性好，易于制作。本文报道了该电极的研制过程，探讨了影响电极响应的各种因素，找出了最佳实验条件。将此电极用于实际样品中乳酸含量的测定，结果令人满意。     

表面活性剂对聚氯乙烯膜修饰电极电化学行为的影响

采用循环伏安法考察了所制备的聚氯乙烯(PVC)膜修饰电极的稳定性,结果表明,该修饰电极性能稳定,电极反应过程为扩散控制的过程。以循环伏安法、计时库仑法、稳态极化曲线法和交流阻抗法分别考察了阳离子(十六烷基三甲基溴化铵,CTMAB)、阴离子(十二烷基硫酸钠,SDS)和非离子(脂肪醇聚氧乙烯醚,AEO9)3种不同类型的表面活性剂对PVC膜-Ag[B(ph)4]修饰电极反应过程的影响。结果表明:加入CT-MAB或SDS后,PVC膜中Ag[B(ph)4]氧化态和还原态的扩散系数分别比电极在0.1mol/LKOH支持电解质中的扩散系数小,PVC膜修饰电极的反应过程受扩散控制的特征变得更明显,表明在此条件下膜中的电子转移速度加快,CTMAB或SDS对PVC膜修饰电极的电极反应过程有增敏作用。而加入AEO9后,PVC膜中的Ag[B(ph)4]氧化态和还原态的扩散系数比电极在0.1mol/LKOH支持电解质中的扩散系数大,并使电极反应的控制步骤从扩散控制转向含电子转移控制的扩散控制,表明在此条件下膜中的电子转移速度变慢,AEO9对PVC膜修饰电极的电极反应过程有抑制作用。     

一种新的硫酸根离子敏感电极

探索新的材料制备离子敏感电极,研究这些电极的响应特性和响应机理,是离子电极研究的一个新方向［'－"．硫酸根离子敏感电极一直是离子电极研究中的一个难点·本文采用电沉积方法,在铜、钻、玻璃碳和低碳钢体表面沉积了Ni－P系非晶合金硫酸根离子敏感电极,电极对硫酸根离子在卫X10－'～IX10－'mol／L浓度范围内呈Nernst响应,检测下限可达4X10'mol／L,具有良好的重现性和稳定性．该硫酸根离子电极对常见阴离子具有良好的选择性,与迄今所报道的SO广离子敏感电极比较显示了较优异的特性．1实验部分将金属铜（99％,4-5mm）、金属钻…     

维生素B12修饰电极及其催化氧还原性质的研究

发现给生素Ｂ１２能吸附在经阳极化处理的玻碳电极上，从而制成稳定的维生系Ｂ１２修饰玻碳电极详细研究了此电极的电化学性质。并发现此修饰电极能有效地催化分子氧的二电极还原。     

用离子选择性电极测定环氧树脂中的氯含量

本文利用环氧树脂可溶于二氧六环的性质,在二氧六环-水混合体系中,采用离子选择性电极,能分别测定环氧树脂中的游离氯离子和有机结合氯的含量。由于市售氯离子选择电极都用塑料套管封结,在二氧六环中易溶解,所以作者用电解法自制了氯离子选择电极。该电极在二氧六环-水混合体系中的线性范围为1×10~(-1)—3×10~(-5)M,测定下限为6×10~(-6)M, 斜率为58,5mV,转换系数为99％。     

纳米结构TiO2/3-甲基噻吩和2-噻吩甲酸共聚物复合膜电极光电化学性能

用光电流作用谱、光电流-电势图等光电化学方法研究了ITO/3-甲基噻吩和2-噻吩甲酸共聚物(CTCMT)膜电极和ITO/TiO₂/CTCMT复合膜电极的光电转换性质.结果表明,CTCMT膜为p型半导体,禁带宽度为2.36eV,价带位置为-5.52eV.在ITO/TiO₂/CTCMT复合膜电极中存在p-n异质结,在一定条件下异质结的存在有利于光生电子-空穴对的分离.CTCMT膜修饰ITO/TiO₂电极可使光电流增强,光电流起始波长红移至600nm以上,使宽禁带半导体电极的光电转换效率得到改善.     

n型碲化镉单晶光电化学电池的研究II:金属离子修饰与光电化学催化

n-CdTe单晶表面用H2PtCl6或RuCl3溶液浸渍,显著提高了电池的效率及稳定性.除选择金属离子种类外,电极预处理及浸渍时间对修饰作用也有很大影响.固体表面分析表明,在PtCl6^2^-溶液中短时间浸渍的电极表面上有大量铂岛,能减少表面缺陷并催化界面反应.在RuCl3溶液中浸渍,将可使Ru^3^+离子吸附于电极表面,有利于光电化学反应.PdCl2溶液浸渍或长时间PtCl6^2^-溶液处理均得到不利的结果.     

Characterization of Electrode/Electrolyte Interface of ECIS Devices

Electric cell‐substrate impedance sensing requires low electrode/electrolyte interface impedance for effective biomedical and biophysical applications. Thus a complete understanding of physical processes involved in the formation of an electric double layer is required to design a low interface impedance device. This paper presents the numerical simulation of the impedance for the electrode/electrolyte interface of three‐electrode devices along with the practical realization for the effective workout of impedance sensing devices. The three‐electrode based impedance sensing devices along with phosphate buffered saline as electrolyte is simulated using COMSOL Multiphysics to evaluate the impedance of the electrode/electrolyte interface. Microfabrication technology is used to realize three‐electrode impedance sensing devices with diverse configuration which are used to measure the electrode/electrolyte interface impedance. The measured impedance data were then compared with the COMSOL simulated results and it is found that both the data sets fitted well with less than 5 % RSE. The results obtained from simulation and experiments indicate that the impedance due to double layer diffusion dominates in the low frequency region up to few kHz whereas electrolytic bulk resistance plays a major role in the higher frequency range. The experimental impedance data were further interpreted by electrochemical impedance spectroscopy analysis software to model the equivalent circuit of the electrochemical system.     

电化学阻抗谱法测定固态聚合物电解质的本体电阻

采用电化学阻抗谱法,对阻抗谱中的聚合物电解质本体电阻（Rb）与膜厚（L）的关系和固体聚合物电解质/惰性电极间的界面阻抗随直流电压的变化趋势进行了研究.结果表明,阻抗谱中聚合物电解质本体电阻（Rb）含有一定的阻塞电极/聚合物电解质间的界面阻抗;由于界面双电层电容的变化,在直流电压0.15～3 V范围内,界面阻抗随电压的增大而减小.     

Development of long-term stable reference electrode with fluoric resin liquid junction

A porous polytetrafluoroethylene (PTFE) junction reference electrode with an air-tight inner solution chamber containing saturated potassium chloride (KCl) was developed for flow analysis. This reference electrode is not influenced by a change in the sample pressure, and is not necessary to supply the KCl inner solution. The pore size of the porous PTFE junction is about 150 mum, although the conventional porous ceramic junction is 0.1 ~ 0.3 mum. The large pore size of the porous PTFE junction promotes the continuous exudation of KCl from the liquid junction and the higher surface tension of PTFE is effective to prevent the overflow of KCl. The porous PTFE was made by putting 74% of PTFE powder and 26% of KCl powder in a mold, pressing with a pressure of 200 kgf cm(-2), and sintering at 365 degrees C. The quantity of KCl exuded from the disposable reference electrode is closely related to the life of the electrode. The relationship between the diffusion rate of the PTFE reference electrode and its characteristics was investigated. The quantity of KCl exuded from this reference electrode was initially of the order of 10(-5) mol h(-1) and decreased to the order of 10(-6) mol h(-1) after a year. This is approximately one-tenth of that exuded in a conventional reference electrode with a ceramic junction. The junction potential of the developed reference electrode was stable in the pH range 2 ~ 12 with a total ionic strength of more than 10(-3) mol l(-1). This reference electrode containing 8 ml of the KCl inner solution was able to be used continuously for one or two years.     

Studies of a Model Mesh Electrode O2,Pt/O2- under Galvanostatic Polarization

The impedance of model platinum mesh electrode in contact with a doped zirconium-dioxide-based single-crystal electrolyte is studied by impedance spectroscopy under constant-current polarization. The electrode is distinguished for its readily determinable geometrical characteristics of the metal/electrolyte interface, in particular, the length of the triple-phase boundary and the electrode contact area. Three different orientations of the electrolyte face are studied. The impedance dispersion is discussed in terms of the electrode prehistory, orientation, and potential.     

玻碳电极界面的阻抗谱数学表达及定量分析

玻碳电极（GCE）是各类电化学传感器常用的基础电极,其界面特征直接影响检测性能。本文详细考察了电极体系的电化学过程,针对GCE传感界面,探讨了一个等效电路中电解质电阻、电荷输运电阻、扩散阻抗、电化学（氧化/还原）反应阻抗、表面吸附阻抗和双电层电容等电学元件的物理意义,并给出了对应的数学模型。通过改变模型中5个参数值,模拟了不同状态下的阻抗谱,分析了电极系统各参数对GCE阻抗谱的贡献规律。最后,采用该数学模型对裸GCE和修饰GCE在铁氰化钾溶液中的阻抗谱进行分析,拟合结果与实验数据吻合度高;基于拟合获得参数,定量对比分析了修饰前后电极表面的特征变化。     

电极材料对含水花岗岩阻抗谱的影响

本文研究了不同电极材料对含水花岗岩阻抗谱的影响。在相同实验条件下,分别用铜、含氧化膜的钛片及钛/二氧化钛纳米管作为电极材料进行交流阻抗实验,结果表明,电极材料主要对阻抗谱的低频有影响,其中钛/二氧化钛纳米管电极的微观结构增大了其与岩石的接触面积,使有效导电通路增加,从而减小了测试阻抗,在同样的测试频率范围内得到更丰富的阻抗信息。     

Comparison of Planar and 3‐D Interdigitated Electrodes as Electrochemical Impedance Biosensors

It has been reported that the introduction of a dielectric barrier between adjacent digits of an interdigitated electrode array can improve the sensitivity of the array as an electrochemical impedance biosensor. Here we present an in‐depth analysis of the impedance in planar interdigitated electrodes and 3‐D interdigitated electrodes (with dielectric barriers). The analysis indicates that the planar geometry not only provides lower impedance but also a higher change impedance as a result of molecular immobilization on the electrode array surface.     

Li/SOCl_2、BCX电池放电电压滞后研究

应用交流阻抗法研究Li/SOCl2、BCX电池放电过程碳、锂电极阻抗变化并测试外加电压和并联超电容对电池放电初期电压的影响.测试表明,锂电极阻抗在放电初期迅速减小了80%~90%,直到放电末期,阻抗几乎不变;碳电极阻抗至放电末期才迅速增大;BCX电池有较高开路电压可改善放电电压滞后;电池并联超级电容器可抑制放电电压滞后.     

Kinetics of Adsorption of Neutral Molecules from a Thin Layer on a Rough Electrode

A theoretical model for the generalized finite adsorption impedance of a rough electrode is offered. A complex function of the roughness of the electrode surface is introduced and its frequency dependence is studied. The frequency characteristics of constituents of the adsorption impedance are shown to depend on the electrode roughness and the diffusion layer thickness. The frequency dependences of the phase angle and impedance components are found to considerably differ from the Frumkin–Melik-Gaikazyan result for an ideal smooth electrode.