以乙基紫为活性物质的聚氯乙烯膜氰化亚金电极的研制和应用

以碱性染料为活性物质制备２０余种不同组分ＰＶＣ膜Ａｕ（ＣＮ）２＾－电极，确定较佳膜组成为乙基紫０．９９％，邻苯二甲酸二丁酯６９．２％，ＰＶＣ粉２９．８％。该电极对Ａｕ（ＣＮ）２＾－浓度在５．０×１０＾－７￣１．０×１０＾－２ｍｏｌ／Ｌ范围内接近能斯特响应；斜率为５５．７ｍＶ（３０℃）。稳定性与选择性较好。该电极制备简单，使用方便，已成功用于氰化镀金液中金的测定。     

互通多孔碳/二氧化锰纳米复合材料的原位水热合成及电化学性能

以互通多孔碳（IPC）为载体，水热条件下在碳表面原位反应生成纳米结构的二氧化锰（MnO₂），制备互通多孔碳/二氧化锰纳米（IPC/MnO₂）复合电极材料. 采用扫描电镜（SEM），透射电镜（TEM），X射线衍射（XRD），热重分析（TGA）对其结构进行表征；采用循环伏安法、恒流充放电和交流阻抗对其电化学性能进行研究. 结果表明：生成的MnO₂均匀地负载在碳的表面，形成多层次结构，并且随着温度的升高IPC表面负载的MnO₂由纳米颗粒变为纳米片状结构；MnO₂纳米片具有典型的K-Birnessite 型晶体结构；复合物中MnO₂的含量约为34%（w）. 在100 ℃制备的IPC/MnO₂复合材料在三电极系统中最高比电容达到了411 F·g^-1；随着反应温度的升高,比容量先增长后基本保持不变. 以IPC/MnO₂为正极，活性炭（AC）为负极，1 mol·L^-1 Na₂SO₄溶液为电解液组装成IPC/MnO₂//AC 混合超级电容器，发现IPC/MnO₂电极的电容器其电位窗口从1 V扩展到1.8 V，容量可达86F·g^-1，且表现出良好的电容特性和大电流放电性能.     

Renewable sol-gel carbon ceramic electrodes modified with a Ru-complex for the amperometric detection of l-cysteine and glutathione

A renewable three-dimensional chemically modified carbon ceramic electrode containing Ru [(tpy)(bpy)Cl] PF₆ was constructed by sol-gel technique. It exhibits an excellent electro-catalytic activity for oxidation of l-cysteine and glutathione at pH range 2-8. Cyclic voltammetry was employed to characterize the electrochemical behavior of the chemically modified electrode. The electrocatalytic behavior is further exploited as a sensitive detection scheme for l-cysteine and glutathione by hydrodynamic amperometry. Optimum pH value for detection is 2 for both l-cysteine and glutathione. The catalytic rate constants for l-cysteine and glutathione were determined, which were about 2.1×10³ and 2.5×10³ M⁻¹ s⁻¹, respectively. Under the optimized condition the calibration curves are linear in the concentration range 5-685 and 5-700 μM for l-cysteine and glutathione determination, respectively. The detection limit (S/N=3) and sensitivity is 1 μM, 5 nA/μM for l-cysteine and 1 μM, 7.8 nA/μM for glutathione. The relative standard deviation (RSD) for the amperogram's currents with five injections of l-cysteine or glutathione at concentration range of linear calibration is <1.5%. The advantages of this amperometric detector are: high sensitivity, good catalytic effect, short response time (t<3 s), remarkable long-term stability, simplicity of preparation and reproducibility of surface fouling (RSD for six successive polishing is 3.31%). This sensor can be used as a chromatographic detector for analysis of l-cysteine and glutathione.     

铅笔芯修饰聚苯胺制作微型复合pH电极的性能

在0.3mm直径的铅笔芯上电修饰聚苯胺,封入玻璃毛细管中,并与Ag/AgCl电极组合成复合微型pH电极.经实验测试,该电极的pH响应特性良好,在pH1～11的线性范围内,能斯特斜率为(-56.4±0.5)mV/pH,线性相关系数不小于0.996.作为参比的Ag/AgCl电极性能稳定.由于电极是复合微型化的,所以可用于活体微区测定.     

Polarization Dependence of a Hydrophobized Electrode for Electrosynthesis of a Soluble Product

An equation for a polarization curve of a hydrophobized electrode is proposed for electrosynthesis of a soluble electroactive product in an inner-kinetic mode. The equation contains the concentration of the target product (TP) in an explicit form. The shape of the curve depends on the biquadratic root of the TP concentration and the square root of the ratio between exchange currents of the side and target reactions.     

邻菲啰啉对固定尿酸酶催化反应动力学的影响

The activation energy of the enzyme-catalyzed reaction for uric acid decreases markedly in the presence of o-phenanthroline, which activates the bioelectrochemicla activity of the polypyrrole uricase electrode. The response current of the enzyme electrodeis independent of the concentration of o-phenanthroline. Based on the experimental results, the mechamsm of the enzyme-catalyzed reaction for uric acid in the presence of o-phenanthroline is presented as follows: E+A→EA, EA+S EAS, EAS→EA+P, where E, A, S and P are the enzyme, activator, substrate and product, respectively. The effects of pH value, potential and the uric acid concentration on the response currents of the uricase electrode have been studied in the presence of o-phenanthroline. In the presence of o-phenanthroline, the response current of the enzyme electrode increase linearly with increasing concentration of uric acid in the region of 0.07 to 0.67 mmol·L~(-1), therefore the polypyrrole uricase electrode which has once lost its activity can be activated and used again to determine the substrate concentration.     

电化学方法研究I3^—和Ti^3＋在铂上的异相催化

用电化学方法研究了Ｉ－３和Ｔｉ３＋在还原铂表面上的电极反应，由此计算出Ｉ－３与Ｔｉ３＋在还原铂表面上的混合催化反应速率（νｍｉｘ）．当混合催化电位（Ｅｍｉｘ）位于极限电流区时，νｍｉｘ对［Ｔｉ３＋］为零级反应，对［Ｉ－３］为一级反应，且正比于电极旋转速率的平方根，Ｈ＋浓度影响不大．由动力学方法研究的结果证实了电化学研究结果的正确性，致使可用电化学方法解释溶液中的异相催化问题     

KCl-LiCl-H2O体系热力学性质的研究

用K-ISE、Li-ISE和Cl-ISE测定了25 ℃时体系中KCl、LiCl的平均活度系数, 溶液的离子强度从0.1～4.0 mol·kg~(-1), 组成范围从纯的KCl到纯的LiCl。将Pitzer方程应用于测定结果, 用多元线性回归方法求出了Pitzer参数。     

Comparative EIS study of a paste electrode containing zinc powder in neutral and near neutral solutions

The corrosion and passivation of Zn powder particles dispersed in a paste electrode immersed in 0.5 M Na₂SO₄ and 5×10^–3 M Na₂HPO₄ solutions were studied mainly by electrochemical impedance spectroscopy. The role played by diffusion in the mechanism of anodic oxidation of zinc powder particles has been shown. It was demonstrated that the anodic reactionof Zn powder in neutral or near neutral media involves at least two adsorbed intermediates. By simulating the porous structure of the electrode, some information about porous nature of zinc electrode could be extracted. Electronic Publication