以1,3-二(4-邻羟基苯亚胺次甲基)苯氧基丙烷为载体的铁离子(Ⅲ)电极的研究

以1,3-二(4-邻羟基苯亚胺次甲基)苯氧基丙烷为中性载体制备了PVC膜Fe3+离子选择性电极。该电极对Fe3+呈现出良好的选择性和近Nernst电位响应性能。电极斜率为21mV/dec,线性范围为3.0×10-5～1.0×10-1mol/L,检出限为1.0×10-5mol/L。采用交流阻抗技术研究了电极的响应机理,并将电极作为指示电极初步用于EDTA的电位滴定。     

基于2,4-二羟基苯甲酸铜(Ⅱ)为载体的硫氰酸根电极的电位响应

制备了基于一种简单的金属铜配合物2,4-二羟基苯甲酸铜(Ⅱ)(Cu(Ⅱ)DHBA)为载体的PVC膜硫氰酸根离子(SCN-)选择性电极。该电极在1.0×10-1～1.0×10-6mol/LSCN-浓度范围内呈现斜率为-59.5mV/dec的近Nernst电位响应,检测下限为9.1×10-7mol/L。利用紫外可见光谱及交流阻抗技术初步探讨了电极对SCN-呈现的选择性电位响应机理。该电极作为直接电位分析法的指示电极,成功运用于实验室废水中硫氰酸盐含量的测定。     

Electrochemical investigation of the iron-containing and no iron-containing AB5-type negative electrodes

The electrochemical behaviour of LaNi_3.55Mn_0.4Al_0.3Co_0.75−xFe_x (x = 0, 0.15, 0.55, 0.75) intermetallic compounds has been studied and presented [C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, Int. J. Hydrogen Energy 29 (2004) 307–311; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 360 (2003) 266–271; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 384 (2004) 249–253]. It has been deduced that the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound has interesting electrochemical properties. In this paper we present the electrochemical study of LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound properties compared with the parent LaNi_3.55Mn_0.4Al_0.3Co_0.75 compound. Several techniques, such as, the chronopotentiometry, the constant potential discharge (CPD), the cyclic voltammetry (CV) and the linear polarization (LP) were applied to characterize these electrochemical properties. The electrochemical discharge capacity of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 alloy increases to reach 294 mAh g⁻¹ after few cycles only (five cycles). However, the activation of the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy takes more than 20 cycles to be achieved and the obtained maximum discharge capacity is 194 mAh g⁻¹. The hydrogen diffusion coefficient D_H was determined by constant potential discharge and cyclic voltammetry techniques. The obtained values of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compounds are 6.29 × 10⁻¹¹ and 7.62 × 10⁻¹¹, and 2 × 10⁻⁸ and 7.5 × 10⁻⁸ cm² s⁻¹ by CPD and CV techniques, respectively. The exchange current density values, determined by a linear polarization technique, are 44 and 27 mA g⁻¹, respectively, for LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloys.     

二元稀土系AB5型贮氢电极合金的放电容量与晶胞体积和4f电子浓度的关系

制备了6个系列通式为AαA‘1-αB5的RE(NiCoMnTi)5贮氢电极合金(其中，AαA‘1-α为La，Ce，Pr，Nd4个元素中任意2个的组合)，测定了它们在100次循环中的最大放电容量Cmax及部分合金的晶胞体积Vcell．结果表明：Cmax主要由Vcell决定，Cmax先随Vcell的增大而增加，在Vcell≈85．66x10^-^3。nm^3时达到一极大值，然后又随Vcell的增大而减小；同时，Cmax还与4f电子浓度ne4f／naRE有关，A侧具有相同4f电子浓度的合金其Cmax随4f电子浓度的变化趋势相似．     

用丝束电极研究混凝土中钢筋腐蚀的不均匀性

用8×8阵列丝束电极模拟研究了混凝土中钢筋的腐蚀.将混凝土试样浸泡在10 %NaCl溶液中,通过测量铁丝束电极的自腐蚀电位和极化电阻,获得了在相同埋置深度和不同埋置深度时,铁丝腐蚀的电位、极化电阻和腐蚀速度分布等信息,研究了混凝土结构和氯离子浓度对它们的影响.结果表明,混凝土中铁丝腐蚀不均匀.自腐蚀电位和极化电阻较分散,电位随时间负移、极化电阻变小,丝束之间的电位差增大.随铁丝埋入深度增加,电位负移量、氯离子浓度和腐蚀速度都减小、极化电阻增加     

IrO2-pH微电极的研制及钢筋/混凝土界面pH的测量

采用电化学阳极氧化和高温碳酸盐氧化两种方法制备 IrO2-pH微电极，其特点是对氢离子响应快、线性范围宽、机械性能好、具有长期稳定性 .考察了该电极的pH响应特性、化学成分、机械性能等.结果表明，这种IrO2-pH微电极 适用于钢筋/混凝土界面pH值的原位测量.     

Kinetics of synthesis of Li4Ti5O12 through solid-solid reaction

1. Introduction The solid-solid reaction used in synthesizing various kinds of electrochemical materials has many advantages, such as simple process, without using solvent, saving energy, friendly to the environment and easy to obtain good quality materials like nano-size materials. Recently, the manufacturing of electrochemistry materials has been paid more atten- tion due to its increasing needs. Therefore it is a natural interest to study the synthesis of electro- chemical materials by usin…     

锂电极表面膜的组成和阻抗行为

介绍了锂电池中锂电极的表面膜的组成和阻抗行为，并根据其表面膜的阻抗行为提出了电化学模型。     

Activity of gold towards methylamine electrooxidation

The kinetics of methylamine oxidation at a gold electrode in contact with an alkaline electrolyte solution was studied. The adsorptive behaviour of substrate molecules was determined by changes in the differential capacitance of the double layer at the electrode/solution interface. The electrooxidation of methylamine occurs only in the potential range of gold oxide layer formation. The general reaction pathways of methylamine oxidation on the gold electrode is proposed.     

Electropolymerization of chlorinated phenols on a Pt electrode in alkaline solution. Part II: An electrochemical quartz crystal microbalance study

Electropolymerization of phenol and mono-, di-, tri-, pentachlorophenols was studied using EQCM on a Pt electrode at 0.78 V (SHE) in 1 M NaOH solution containing 0.1 M of the corresponding phenol. The highest electropolymerization rate was found for ortho-substituted chlorophenols indicating a weak fouling of the electrode. Low electropolymerization rates for para-substituted chlorophenols suggest a low permeability of the polymer film, resulting in rapid electrode fouling. The EQCM data suggest that electropolymerization of chlorophenols occurs without Cl-elimination for the monomers with unsubstituted ortho and para positions. Dechlorination is most pronounced for electropolymerization of para-substituted isomers. The mechanism of electropolymerization of chlorophenols is discussed.