PtCl^2^—6接着PVP修饰电极及其对Fe^2^＋的催化氧化

研究了ＰｔＣｌ＾２＾－６接着ＰＶＰ修饰电极及其催化动力学，用循环伏安法考察了电极的电化学性质，结果表明在酸性溶液中对Ｆｅ＾２＾＋的氧化有显著的催化作用。采用旋转圆盘电极法，极化曲线法等就电极对Ｆｅ＾２＾＋氧化催化过程的控制步骤及有关动力学参数进行了测定。     

三乙醇胺在金属电沉积中的基本效应

用微分电容法、极谱法、原位表面增强拉曼光谱法和微盘电极法研究了碱性溶液中存在和不存在Ｚｎ＾２＋、Ｃｄ＾２＋、Ｃｕ＾２＋、Ｎｉ＾２＋、Ｆｅ＾３＋和Ｓｎ＾４＋等离子时三乙醇胺（ＴＥＬＡ）在电极／溶液界面上的电化学行为。结果表明，ＴＥＬＡ以平卧方式吸附，符合Ｆｒｕｍｋｉｎ吸附等温线。在碱性溶液中ＴＥＬＡ与Ｚｎ＾２＋、Ｃｄ＾２＋、Ｃｕ＾２＋、Ｎｉ＾２＋和Ｆｅ＾３＋等离子生成具有表面活性的混合配体配合物，其     

La^3＋和Ca^2＋对金电极上谷胱甘肽单分子膜离子闸门的影响

谷胱甘肽能自组装吸附到金电极上形成单分子膜。该膜能阻止Ｆｅ（ＣＮ）６离子在金电极上还原，起离子闸门的作用。当溶液中加入Ｌａ＾３＋或Ｃａ＾２＋时，了穿透膜的能力得到改善。本课题应用循环伏安法和计时库仑法，在ＰＨ５．６的溶液中研究了Ｌａ＾３＋的调控能力，与Ｃａ＾２＋比较，发现在改变谷胱甘肽单分子膜的结构和Ｆｅ（ＣＮ）６离子的扩散系数方面，Ｌａ＾３＋具有更强的能力。     

一种检测NO的修饰电极

报道了「Ｆｅ（Ｓａｌ２ｅｎ）」＾２＋的咪唑加合物对ＮＯ电氧化的影响,实验表现,它将「Ｆｅ（Ｓａｌ２ｅｎ）」＾２＋对ＮＯ的电催化氧化活性提高了２这量咪唑会降低「Ｆｅ（Ｓａｌ２ｅｎ」＾２＋对ＮＯ的催化活性,证实了ＮＯ的电催化氧化形成ＮＯ「Ｆｅ（Ｓａｌ２ｅｎ）」＾２＋中间体推断,用制得的修饰电极测定ＮＯ,当ｃ（ＮＯ）在３×１０＾－６￣２×１０＾－９ｍｏｌ／Ｌ时,有良好线性关系,相对标准偏差小于０．５％,     

流动注射固相萃取预富集原子吸收光谱测定铁的价态

研究了流动注射固相萃取预富集－火焰原子吸收光谱法测定铁价态的方法。该方法用Ｃ１８微柱萃取富集Ｆｅ＾２＋,用抗坏血酸还原溶液中的Ｆｅ＾３＋测总铁,Ｆｅ＾３＋的量可由总铁与Ｆｅ＾２＋的差求得。该方法快速、方便且灵敏度高,用于水样的分析,结果令人满意。     

不同Fe2＋／Fe3＋比的铁盐溶液对氧化铁晶型和性质的影响

改变铁盐溶液中Ｆｅ２＋．Ｆｅ３＋比，将其与氨水反应，制得铁铬催化剂的主体相氧化铁，用ＴＰＲ，ＸＲＤ和活性评价对制得的氧化铁进行表征，结果表明不同Ｆｅ／Ｆｅ＾３＋比的铁盐溶液，将得到不同性质和晶型的氧化铁。     

PtCl_6~(2-)接着PVP修饰电极及其对Fe~(2-)的催化氧化

研究了接着ＰＶＰ修饰电极及其催化动力学，用循环伏安法考察了电极的电化学性质，结果表明在酸性溶液中对Ｆｅ￣（２＋）的氧化有显著的催化作用，采用旋转圆盘电极法、极化曲线法等就电极对Ｆｅ￣（２＋）氧化催化过程的控制步骤及有关动力学参数进行了测定。     

TPR研究载Fe半焦的CO2气化行为

采用溶液浸渍法，将Ｆｅ＾３＋离子担载到扎赉诺尔脱灰煤上，并制成了８００℃半伙，ｅ＾３＋变成不原类Ｆｅ＾０，以扎赉诺尔脱灰煤半焦为原料，在热天平上，运用程序升温反应进行了ＣＯ２气化研究。从ＤＴＧ曲线上考察了Ｆｅ在煤气化过程中中的催化行为，以及升温速率对催化反应历程的影响，提出了在Ｆｅ在煤气过程中的催化作用模型。     

氯化物熔体中镝铁合金形成的电化学研究

用循环伏安法，恒电位电解断电后的电极电位－时间曲线，电位阶，跃法和Ｘ射线衍射法研究了铁电极在ＮａＣｌ－Ｋｃｌ－ＤｙＣｌ２熔体中的电化学行为，获知Ｄｙ＾３＋在Ｆｅ合金，然后才析出纯金属Ｄｙ；验证了Ｄｙ－Ｆｅ合金体系中化学计量化合物的数目。     

痕量亚硝酸根的聚氯乙烯液态膜四氯络铁(Ⅲ)离子电极测定

以新型阴离子载体Ｓ－烷基双硫腙,制备了ＦｅＣｌ＾－４阴离子选择性电极,研究了电极的性能,确定了亚硝酸催化氧化Ｆｅ＾２＋的最佳反应条件,在４ｍｏｌ／Ｌ ＮａＣｌ－０．２ｍｏｌ／Ｌ ＨＣｌ介质中反应５０ｍｉｎ时以尿素终止,反应生成的Ｆｅ（Ⅲ）以ＦｅＣｌ＾－４选择电极电位法测定。间接测定ＮＯ＾－２。线性范围为１５－３５０μｇ／ＬＮＯ＾－２,检出限为８μｇ／Ｌ。该法应用于雪水和水样中亚硝酸根的测定,结果与光度法一致。     

A glass capillary ultramicroelectrode with an electrokinetic sampling ability.

A glass capillary ultramicroelectrode (tip diameter approximately 1.2 microm) having an electrokinetic sampling ability is described. It is composed of a pulled glass capillary filled with an inner solution and three internal electrodes (Pt working and counter electrodes and an Ag/AgCl reference electrode). The voltammetric response of the capillary electrode is based on electrokinetic transport of analyte ions from the sample solution into the inner solution across the conical tip. It was found that the electrophoretic migration of analytes at the conical tip is faster than electroosmotic flow, enabling electrokinetic transport of analyte ions into the inner solution of the electrode. By using [Fe(CN)6]4- and (ferrocenylmethyl)trimethylammonium (FcTMA+) ions as model analytes, differential pulse voltammetric responses of the capillary electrode were investigated in terms of tip diameter of the capillary, sampling voltage, sampling time, detection limit and selectivity. The magnitude of the response depends on the size and charge of analyte ions. With a capillary electrode having a approximately 1.2-microm tip diameter, which minimizes non-selective diffusional entry of analytes, the response after 1 h sampling at +1.7 V is linearly related to [Fe(CN)6]4- concentration in the range of 0.50-5.0 mM with the detection limit of 30 microM. Application of a potential of the same sign as that of the analyte ion forces the analyte to move out from the electrode to the solution, enabling reuse of the same capillary electrode. The charge-selective detection of analytes with the capillary electrode is demonstrated for [Fe(CN)6]4- in the presence of FcTMA+.     

电解液对水系可充电池MnO_2正极电化学性能的影响

研究了水系电解液中Li~+、Zn~(2+)和Mn~(2+)阳离子对具有不同晶型结构和形貌的MnO_2正极电化学性能的影响,探讨其储能机理。结果表明,在不含Mn(Ⅱ)离子的水溶液中,MnO_2电极所表现的电化学性能趋同,容量低,衰减快。含有Zn~(2+)离子的水溶液中,MnO_2电极因二价锌离子的嵌入-脱出,容量明显提升,但衰减严重。当溶液中同时含有Zn~(2+)、Mn~(2+)离子时,基于Mn~(2+)和Zn~(2+)离子之间的协同作用和Mn~(2+)离子氧化/还原反应过程的作用,有效抑制MnO_2颗粒的聚集和结构塌陷,削弱碱式硫酸锌杂质不利的影响,保持了锌离子在MnO_2电极中嵌入-脱出的高容量特性(200 m Ah?g~(-1),电流密度:100m A?g~(-1)),及良好的循环稳定性。     

Removal of thiocyanates and heavy metal ions from simulated wastewater solutions by electro- and peroxyelectrocoagulation

A procedure for treatment of simulated wastewater solutions to remove Cu²⁺, Ni²⁺, and SCN^? ions using various combinations of aluminum and iron electrodes in the electro- and peroxyelectrocoagulation processes was studied. The influence exerted by the current density, pH of solution, and concentrations of impurities and hydrogen peroxide on the efficiency of removal of these ions was analyzed. Electrocoagulation using aluminum anode does not lead to a significant decrease in the thiocyanate concentration. In the peroxyelectrocoagulation process, the efficiency of removal of SCN? ions increases with an increase in the [H₂O₂]: [SCN^?] ratio. The electrocoagulation efficiency with the Fe/Fe electrode pair reaches 87% for SCN^? and 99.5% for Cu²⁺ and Ni²⁺ at a current density of 20 mA cm^–2 and electrolysis time of 20 min.     

电位滴定判断二元金属氢氧化物的复合化

尖晶石型纳米复合金属氧化物目前主要的合成方法还是共沉淀法 [1,2 ] .但是此种方法常因不能准确掌握共沉淀的 p H范围 ,而出现组分金属离子偏析 ,难制得不含杂相的纯净复合金属氧化物纳米微粒[3] .混合金属离子能否形成复合氢氧化物 ,在什么条件下形成 ,这方面的研究还未见报道 .电位滴定法通常是研究单一金属离子的水解或氢氧化物生成的有效方法 [4 ,5] ,为此 ,我们以 Al3+、Fe3+分别与 Ni2 +、Zn2 +、Cu2 +等金属离子形成的二元金属混和溶液为对象 ,使用自动电位滴定仪测定这些混合体系的电位滴定曲线 ,并通过与相应的单一金属离子的…     

Using electrophoresis to observe the interaction of nitrogenase with ions

The two protein components of nitrogenase from Klebsiella pneumoniae were shown to interact with metal ions and ADP, altering their electrophoretic mobility in polyacrylamide gel electrophoresis. Both Mg+2 and Mn+2 caused reduced mobility of Fe protein relative to other proteins. The effect was about 50% complete at concentrations around 0.2 mM. Other ions including Fe+2, Ni+2 and Co+2 had no observable effect at levels up to 1 _mM. Both Cd+2 and Zn+2 appeared to interact with the protein; Cd+2 at 0.5 mM dramatically destabilized the protein. The effects of more than a dozen different mutations of the Fe protein on Mg+2 interaction were examined. All mutated proteins appeared to interact with Mg+2 similarly to wild-type. Using relative mobility differences of charge-changed mutants it was estimated that two to three Mg+2 interact with each Fe protein monomer. The MoFe protein also showed interaction with metal ions but the alteration of mobility was much smaller than for the Fe protein because it is larger and less acidic, so that it runs much more slowly than the Fe protein in standard gels. The interaction of ADP with Fe protein was examined in the presence of Mg+2. Increasing ADP partially reversed the mobility decrease observed on Mg+2 binding, and produced a more diffuse protein band indicative of a reaction zone of interconverting conformers. No alteration of MoFe protein mobility was observed with ADP added during electrophoresis.     

Photoinduced electron transfer reactions at methylene blue adsorbed nafion and clay coated electrodes

Nafion and montmorillonite clay adsorbed methylene blue coated onto platinum electrode were prepared. These dye modified electrodes were used as photoelectrodes in a photogalvanic cell in the presence of Fe²⁺ ions. The photoelectrochemical investigations showed that the dye coated electrodes behaved as cathode upon irradiation whereas the plain platinum electrode dipped in a homogeneous solution containing methylene blue and Fe²⁺ ions behaved as anode. It is suggested that the intermediate complex formed between the photoreduced methylene blue and ferric ion lead to the reductive reaction at the coated electrode.     

Ag(I)与Co(II)离子对阳极析氧过程的电催化作用

Influence of Ag(Ⅰ), Co(Ⅱ) and Ni(Ⅱ) ions on oxygen anodic evolution at Pt and Ti/Pt/PbO2 electrodes was investigated in surphuric acid solutions. The oxygen evolution reaction at Ti/Pt/PbO2 electrode in surphuric acid solutions is characterized by two linearφ~ lgi relationships. At low c.d. it is close to 2.303RT/(1+β)F, whereas at high c.d. it is close to 2.303RT/βF. In the presence of Ag(Ⅰ) or Ni(Ⅱ) ions in the electrolytic solution the Tafel slope of oxygen evolution tends to be low, 2.303RT/(1+β)F (withβ=0.5). However, the oxygen evolution reaction at Pt electrodes in H2SO4 or CoSO4﹢H2SO4 solutions is characterized by one linearφ~ lgi relationship. The Tafel slope is close to 2.303RT/βF. In the presence of Ag(Ⅰ) or Ni(Ⅱ) ions in the electrolytic solution the Tafel slope of oxygen evolution tends to be low, 2.303RT/(1+β)F. The oxygen anodic evolution reactions are catalyzed by Ag(Ⅰ), Co(Ⅱ) and Ni(Ⅱ) ions in the electrolytic solution. When Ag(Ⅰ) or Ni(Ⅱ) was mixed with Co(Ⅱ), a promising catalyst for oxygen anodic evolution with higher catalyst activity than either of them alone was found. A comparison of the PbO2 electrode and the Pt electrode has also been given.     

Fe3O4 and gamma-Fe2O3 nanoparticles for the adsorption of Co2+ from aqueous solution

The adsorption of Co2+ ions from nitrate solutions using iron oxide nanoparticles of magnetite (Fe3O4) and maghemite (gamma-Fe2O3) has been studied. The adsorption of Co2+ ions on the surface of the particles was investigated under different conditions of oxide content, contact time, solution pH, and initial Co2+ ion concentration. It has been found that the equilibrium can be attained in less than 5 min. The maximum loading capacity of Fe3O4 and gamma-Fe2O3 nanoparticles is 5.8 x 10(-5) and 3.7 x 10(-5) mol m(-2), respectively, which are much higher than the previously studied, iron oxides and conventional ion exchange resins. Co2+ ions were also recovered by dilute nitric acid from the loaded gamma-Fe2O3 and Fe3O4 with an efficiency of 86 and 30%, respectively. That has been explained by the different mechanisms by including both the surface and structural loadings of Co2+ ions. The surface adsorption of Co2+ on Fe3O4 and gamma-Fe2O3 nanoparticles has been found to have the same mechanism of ion exchange reaction between Co2+ in the solution and proton bonded on the particle surface. The conditional equilibrium constants of surface adsorption of Co2+ on Fe3O4 and gamma-Fe2O3 nanoparticles have been determined to be log K=-3.3+/-0.3 and -3.1+/-0.2, respectively. The structural loading of Co2+ ions into Fe3O4 lattice has been found to be the ion exchange reaction between Co2+ and Fe2+ while that into gamma-Fe2O3 lattice to fill its vacancy. The effect of temperature on the adsorption of Co2+ was also investigated, and the value of enthalpy change was determined to be 19 kJ mol(-1).     

Carbon Xerogel Nanostructures with Integrated Bi and Fe Components for Hydrogen Peroxide and Heavy Metal Detection

Multifunctional Bi- and Fe-modified carbon xerogel composites (CXBiFe), with different Fe concentrations, were obtained by a resorcinol–formaldehyde sol–gel method, followed by drying in ambient conditions and pyrolysis treatment. The morphological and structural characterization performed by X-ray diffraction (XRD), Raman spectroscopy, N₂ adsorption/desorption porosimetry, scanning electron microscopy (SEM) and scanning/transmission electron microscopy (STEM) analyses, indicates the formation of carbon-based nanocomposites with integrated Bi and Fe oxide nanoparticles. At higher Fe concentrations, Bi-Fe-O interactions lead to the formation of hybrid nanostructures and off-stoichiometric Bi₂Fe₄O₉ mullite-like structures together with an excess of iron oxide nanoparticles. To examine the effect of the Fe content on the electrochemical performance of the CXBiFe composites, the obtained powders were initially dispersed in a chitosan solution and applied on the surface of glassy carbon electrodes. Then, the multifunctional character of the CXBiFe systems is assessed by involving the obtained modified electrodes for the detection of different analytes, such as biomarkers (hydrogen peroxide) and heavy metal ions (i.e., Pb²⁺). The achieved results indicate a drop in the detection limit for H₂O₂ as Fe content increases. Even though the current results suggest that the surface modifications of the Bi phase with Fe and O impurities lower Pb²⁺ detection efficiencies, Pb²⁺ sensing well below the admitted concentrations for drinkable water is also noticed.     

二氧化钛和三氧化二铁复合纳米晶电极的光电化学性质

研究了以不同方式相互修饰的Fe2 O3和TiO2 纳米晶电极的光电化学行为 (包括离子的相互掺杂 ) .在不同的入射光波长下 ,瞬态光电流谱显示Ti4 掺杂的Fe2 O3电极呈现n型半导体的特性(阳极光电流 ) ;以不同方式经Fe2 O3包覆的TiO2 电极由于能级的不匹配 ,在整个的波长测量范围内没有光响应 ;而对Fe3 离子掺杂的TiO2 电极和经TiO2 修饰 (包覆或偶联 )的Fe2 O3纳米晶电极则呈现出p n共存特性 ,甚至个别的电极表现出纯粹的p型半导体的特性 .这些现象可以从p型微区的形成得到解释 .