聚合物／石墨复合材料电极及其在银离子测定中的应用

用石墨粉填充苯乙烯－丙烯腈共聚树脂（ＡＳ树脂），挤出成型，制取ＡＳ树脂／石墨复合导电材料电极．用红外光谱、循环伏安等手段表征了电极的结构及特性．电极对测定Ａｇ＋有较好的选择性、稳定性和再现性，并较一般玻碳电极更易化学修饰     

离子注入修饰电极检测硝基苯

离子注入是一种新技术，可按人们的意愿和需要，将不同的离子注入不同的基本电极表面，制成具有催化活性强，稳定性高，重现性好等特点的修饰电极。作者研究了离子注入钴和注入镍的玻碳电极在０．１ｍｏｌ／ＬＨＡｃ－ＮａＡｃ缓冲溶液中硝基苯的行为及测定。     

全固态锂离子选择性电极研究

研究了新型载体HPMBP-TOPO体系几种全固态锂离子选择性电极（涂丝电极、单层全固态电极、聚吡咯修饰层内接触电极）的性能。与传统型电极相比，固态电极响应斜率有所降低，而选择性稍有提高。其中聚吡咯修饰层内接触电极性能为最佳，该电极响应斜率为56.7mV/decade，并具有良好再现性和长期稳定性。     

辅酶Ⅰ在β－萘醌磺酸根修饰金带电极上的电化学还原

研制了聚毗咯／ＮＱＳ修饰金带电极，讨论了ＮＱＳ／ＰＰｙ的电聚合过程及实验条件对金电极上吡咯聚合物膜性质的影响；用成核及生长理论解释了阴离子ＮＱＳ对电聚合过程计时电流曲线的影响，优化了ＮＱＳ／ＰＰｙ／Ａｕ电极的制备条件．该修饰电极稳定性好，对辅酶Ⅰ在金电极上的还原有催化作用．在ｐＨ＝７．０时催化电流在４．０×１０￣（－５）～１．５×１０￣（－３）ｍｏｌ／Ｌ范围内与ＮＡＤ￣＋　浓度有线性关系，探讨了电催化作用的机制．     

聚合黄素修饰电极的制备和性质

１引言黄素是生物体内氧化还原过程中的重要辅基。黄素修饰电极的制备方法有吸附法和化学键合法。用本文研究的电化学聚合法制得的黄素修饰电极，活性中心浓度大，稳定性好，可催化还原型辅酶Ｉ（ＮＡＤＨ）的氧化，使其氧化过电位降低～２００ｍＶ。可用于ＮＡＤＨ的选择性测定。２实验部分２．１仪器与试剂ＢＡＳ１００Ａ电分析仪（美国ＢＡＳ公司）。黄素由复旦大学化学系有机化学教研室提供。Ｈ２ＳＯ４、ＮａＣＩＯ４、Ｋ２ＨＰＯ４及ＮａＨ２ＰＯ４均为分析纯，乙腈、Ｎ，Ｎ－二甲基甲酸胺（ＤＭＦ）为化学纯。水为去离子水。２．２实…     

L-半胱氨酸修饰银电极及其对铜离子的电化学测定

引　　言半胱氨酸 (ｃｙｓｔｅｉｎｅ)是自然界 2 0种基本蛋白质的重要成分之一 ,具有良好的电化学活性。同时 ,半胱氨酸 (ＣｙＳ)含有极活泼的巯基 (-ＳＨ) ,易于通过形成Ａｕ Ｓ和Ａｇ Ｓ键吸附于金、银电极表面 ,借此可将ＣｙＳ引入电极表面制成修饰电极。本文采用自组装方法制备ＣｙＳ修饰银电极 (ＣｙＳ Ａｇ/ＣＭＥ) ,并用此电极对可乐样品中Ｃｕ2 + 进行吸附伏安测定 ,取得了令人满意的结果。本方法具有简便、便捷的优点 ,检测限为 10 -9ｍｏｌ/Ｌ ,可满足某种程度上对Ｃｕ2 + 含量测定的要求 ,具有一定的实际意义。2　实验部分2 …     

硅钼杂多阴离子薄膜修饰电极的研究和应用—线性扫描伏安法测定水中可溶性

本研究了以玻碳电极为基体的１：１２硅钼杂多酸根修饰电极的制备及其电化学行为，将１２－ＭＳＡ电极应用于线性扫描伏安法测定天然水中可溶性硅酸盐，结果满意，硅浓度在８．０×１０＾－７－１．７×１０＾－３ｍｏｌ／Ｌ，相对标准偏差（ｎ＝７）为１．８５％，加标回收率为９８．２％－１０３．６％，ＳｉＭｏ１２电极具有优良的选择性和稳定性。     

复合高分子膜修饰电极直接测定大脑内源性神经递质

采用阳离子交换剂Ｎａｆｉｏｎ和醋酸纤维素复合修饰的碳纤维电极具有电荷选择性和尺雨选择性，对复杂样品具有独特的选择和抗干扰性，在动物活性伏安分析中，该复合修饰电极成功地抑制了神经递质代谢产物，抗坏血酸和尿酸等电化学活性物质在电极表面的反应，直接检测了脑内神经质多巴胺的氧化电流，该电极采用静电浸浦法多次涂布，使电极的复合膜牢固，并具有很好的分析性能，同时，对复合修饰电极的作用机理进行了探讨。     

生物分子电催化的研究：V.邻菲绕啉电化学聚合修饰电极的性质

本文用恒电位，恒电流，循环扫描等电化学方法，首次制备了邻菲绕啉（０－ｐｈｅｎ）聚合膜修饰电极，在０．０１ｍｏｌ／ＬＫＣｌＯ４水溶液中，其氧化与还原过程的峰电位分别为＋０．０４Ｖ和－０．５３Ｖ（ｖｓ．ＳＣＥ），该修饰电极在酸性，中性，碱性条件下均具有良好的稳定性，能较好地改善Ｋ３Ｆｅ（ＣＮ）６和Ｖｋ３在电极上的氧化还原性质，对维生素Ｃ和肼的氧化有很好的催化作用，其氧化峰电位分别降低２２０ｍＶ和５６２     

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…     

电位溶出法测定铅和镉

重金属铅和镉元素在环境中普遍存在并可长期蓄积,是不可降解的环境污染物,常危害人体健康.建立快速准确的测定方法具有实际意义[1].     

Hg(II) immobilized MWCNT graphite electrode for the anodic stripping voltammetric determination of lead and cadmium

The preparation of Hg(II)-modified multi walled carbon nanotube (MWCNT) by reaction of oxidized MWCNT with aqueous HgCl₂ was carried out. The Hg(II)-modified multi walled carbon nanotube (Hg(II)/MWCNT) dispersed in Nafion solution was used to coat the polished graphite electrode surface. The Hg(II)/MWCNT modified graphite electrode was held at a cathodic potential (−1.0 V) to reduce the coordinated Hg(II) to Hg forming nanodroplets of Hg. The modified electrode was characterized by FESEM/EDAX which provided useful insights on the morphology of the electrode. The SEM images showed droplets of Hg in the size of around 260 nm uniformly distributed on the MWCNT. Differential pulse anodic stripping voltammetry (DPASV) and electrochemical impedance spectroscopy were used to study the Hg(II) binding with MWCNT. Differential pulse anodic stripping voltammetry of ppb levels of cadmium and lead using the modified electrode yielded well-defined peaks with low background current under a short deposition time. Detection limit of 0.94 and 1.8 ng L⁻¹ were obtained following a 3 min deposition for Pb(II) and Cd(II), respectively. Various experimental parameters were characterized and optimized. High reproducibility was observed from the RSD values for 20 repetitive measurements of Pb(II) and Cd(II) (1.7 and 1.9%, respectively). The determination of Pb(II) and Cd(II) in tap water and Pb(II) in human hair samples was carried out. The above method of fabrication of Hg(II)/MWCNT modified graphite electrode clearly suggests a safe route for preparing Hg immobilized electrode for stripping analysis.     

PVC膜修饰粉末微电极的研制及应用

聚合物具有催化、导电和选择分离等功能,将其与电极合为一体作为新的电极材料,可为改善固体电极的灵敏度、选择性和重现性提供一种新的手段［１,２］．我们用流延法［３］制得ＰＶＣ选择性渗透膜,覆盖于粉末微电极表面,制成了ＰＶＣ膜修饰粉末微电极．该电极性能稳定...     

High dispersion and electrocatalytic properties of platinum nanoparticles on graphitic carbon nanofibers (GCNFs)

Highly dispersed platinum nanoparticles were electrodeposited on graphitic carbon nanofibers (GCNFs) by cyclic voltammetry (CV) in 7.7 mM H2PtCl6+0.5 M HCl aqueous solutions. The graphitic carbon nanofibers (GCNFs) used in this paper were grown directly on a graphite disk by chemical vapor deposition (CVD). The micrographs and element composition of Pt/GCNFs/graphite electrode were characterized by scanning electron microscopy (SEM) and electron diffraction spectroscopy (EDS). The electrocatalytic properties of Pt/GCNFs/graphite electrode for methanol oxidation have been investigated by CV and excellent electrocatalytic activity can be observed even at very low platinum loading (md=8.79 microg cm(-2)). The highest mass activity (MA) for methanol oxidation reaches 323 Ag(-1) when Pt/GCNFs/graphite electrode was cycled at a sweep rate of 50 mVs(-1) by CV in 2 M CH3OH+1 M H2SO4 aqueous solutions. This may be attributed to the small particle size and high dispersion of platinum particles coated on GCNFs and shows good potential application in direct methanol fuel cell (DMFC). Additionally, the long-term cycling stability of platinum catalysts was also investigated.     

HBF4溶液中全铅液流电池

报道了一种HBF₄水溶液中的全铅液流电池,正、负电极电解液均采用Pb（BF₄）₂的HBF₄水溶液.在酸性的四氟硼酸铅电解液中考察了石墨电极和玻碳电极作为工作电极的循环伏安性能,石墨电极较适于用作全铅液流电池的正、负电极.采用石墨电极作为电池的正、负电极并在四氟硼酸铅酸性电解液中进行充放电实验,其中Pb（BF₄）₂浓度分别为0.5、1.0和1.5 mol·L^-1,且保持游离的HBF₄浓度为1.0 mol·L^-1.该电池为单液流电池,不需要隔膜分隔正、负极的电解液,电流密度为10、20和40 mA.cm^-2,当限定充电容量为7.0 mAh.cm^-2,放电电压截止到1.0 V时,平均库仑效率大于87%,平均能量效率大于68%;当电解液采用1.0或1.5 mol·L^-1 Pb（BF₄）₂+1.0 mol·L^-1HBF₄水溶液时,在10及20 mA.cm^-2电流下的能量效率最高可超过74%.     

A coated wire-type lead(II) ion-selective electrode based on a phosphorylated calix[4]arene derivative.

The preparation of a lead-selective electrode based on 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis-(diphenylphosphinoylmethoxy)calix[4]arene (1) as an ionophore is reported. The plasticized PVC membrane containing 30% PVC, 57% ortho-nitrophenyloctylether (NPOE), 4% sodium tetraphenylborate (NaTPB) and 9% ionophore 1 was directly coated on a graphite electrode. It exhibits a nearly Nernstian slope of 28.0 +/- 0.2 mV decade(-1) over a concentration range of 1 x 10(-5) - 1 x 10(-2) mol dm(-3) with a detection limit of 1.4 x 10(-6) mol dm(-3). The response time of the electrode was found to be ca. 17 s. The potential of the sensor was independent of the pH variation in the range 3.5 - 5.0. The selectivity of the electrode performance towards lead ions over Th4+, La3+, Sm3+, Dy3+, Y3+, Ca2+, Sr2+, Cd2+, Mn2+, Zn2+, Ni2+, Co2+, NH4+ Ag+, Li+, Na+ and K+ ions was investigated. The prepared electrode was used successfully as an indicator electrode for a potentiometric titration of a lead solution using a standard solution of EDTA. The applicability of the sensor for Pb2+ measurements in various synthetic water samples spiked with lead nitrate was also checked.     

溶出伏安法同时测定矿山地下水中痕量砷铅

本文以电化学预处理的金电极为工作电极,采用线性扫描溶出伏安法实现了矿山地下水中痕量As3+、Pb2+的同时测定。研究了金电极的预处理方法、不同预富集时间和不同电解质对重金属离子测定的影响规律。研究发现,电化学预处理有利于金电极对重金属离子的响应,在最优实验条件下,As3+、Pb2+在电化学活化的金电极上分别于0.18V、-0.07V产生灵敏的溶出峰,峰高与其浓度线性相关,检测限分别可达到0.5!g/L、2!g/L。该方法操作简单、干扰小、线性范围宽、灵敏度高。     

Graphite anode reaction in the KF2HF melt

Effects of traces of water on the graphite anode reaction have been investigated in the KF2HF melt at 100 °C. Cyclic voltammetry shows that with increasing water content from 0.01% to 0.05%, anode potentials for the formation of graphite oxide and graphite fluoride films on graphite electrodes are shifted to lower potentials. This may be ascribed to increase in the reaction of discharged oxygen with graphite and the subsequent decomposition of graphite oxide film by attack of discharged fluorine, which gives ultimately graphite fluoride film on a graphite electrode. When the water content is 0.05 %, the anode effect is thus caused in a short time by graphite fluoride film with a low surface energy. However, when it is 0.01-0.02%, a stage 4 intercalation compound of graphite, C_n⁺HF₂^- was prepared. Addition of 3-6 wt% LiF to the melt gave a stage 3 C_XF(HF)_y without occurrence of anode effect.     

V(IV)在不同电极上氧化还原动力学研究

分别以导电塑料集流板、石墨棒、铂片作工作电极,应用循环伏安法和稳态极化法研究V(IV)的阳极氧化动力学过程,计算V(IV)在不同材料电极上的反应动力学参数.结果表明,以导电塑料板作电极,硫酸氧钒有较宽的水稳定区,且析氧电位较高;在石墨电极上,V(V)/V(IV)的交换电流密度较大,表现出较好的可逆性;而在铂电极上,硫酸氧钒更易析氢.     

Sensitive and Rapid Flow Injection Amperometric Hydrazine Sensor using an Electrodeposited Gold Nanoparticle Graphite Pencil Electrode

A gold (Au) nanoparticle-modified graphite pencil electrode was prepared by an electrodeposition procedure for the sensitive and rapid flow injection amperometric determination of hydrazine (N₂H₄). The electrodeposited Au nanoparticles on the pretreated graphite pencil electrode surface were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, and electrochemical impedance spectroscopy. Cyclic voltammograms showed that the Au nanoparticle-modified pretreated graphite pencil electrode exhibits excellent electrocatalytic activity toward oxidation of hydrazine because the highly irreversibly and broadly observed oxidation peak at +600?mV at the pretreated graphite pencil electrode shifted to ?167?mV at the Au nanoparticle pretreated graphite pencil electrode; in addition, a significant enhancement in the oxidation peak current was obtained. Thus, the flow-injection (FI) amperometric hydrazine sensor was constructed based on its electrocatalytic oxidation at the Au nanoparticle-modified pretreated graphite pencil electrode. The Au nanoparticle-modified pretreated graphite pencil electrode exhibits a linear calibration curve between the flow injection amperometric current and hydrazine concentration within the concentration range from 0.01 to 100?µM with a detection limit of 0.002?µM. The flow injection amperometric sensor has been successfully used for the determination of N₂H₄ in water samples with good accuracy and precision.