电化学方法制备铜钴纳米多层膜

采用旋转圆盘电极、双脉冲电位法从单一的含有铜离子和钴离子的镀液中电沉积Ｃｕ－Ｃｏ纳米多层膜、并用ＴＥＭ．ＡＥＳ和Ｘ－射线衍射研究镀层的形貌和组成。结果表明：多层膜结构为纯铜和含有少量铜的铜钴合金层交替组成,铜在钴层中的含量,随镀液中的铜含量的增大和转速的提高而提高。     

电化学方法制备铜钴钠米多层膜

要用旋转圆盘电极，双脉冲电位法从单一的含有铜离子和钴离子的镀液中电沉积Ｃｕ－Ｃｏ纳米多层膜，并用ＴＥＭ．ＡＥＳ和Ｘ－射线衍射研究镀层的形貌和组成。结果表明：多层膜结构为纯铜和含有少量铜的铜钴合金层交替组成。铜在钴层中的含量，随着液中的铜含量的增大和转速的提高而提高。     

5,5′-二甲基乙内酰脲体系电沉积金(英文)

开发了以5,5′-二甲基乙内酰脲(DMH)为配位剂的无氰电镀金工艺。利用扫描电镜(SEM)和线性扫描伏安曲线对电镀时间和添加剂(由丁炔二醇、糖精和十二烷基硫酸钠组成)对镀金层表面、断面形貌和镀液性能的影响进行了测试,结果表明随着电镀时间的延长镀金层表面形貌几乎没有发生变化,光亮剂的加入增大了阴极极化同时使镀金层结晶变得细致均匀,在由HAuCl4,DMH,K3PO4和KH2PO4组成的基础镀液中金的沉积速度可达0.3μm.min-1,镀液中添加剂的加入没有影响金的沉积速度。利用X射线衍射技术(XRD)和X射线光电子能谱技术(XPS)对镀金层性能进行了测试,结果表明镀金层沿着(111)晶面择优生长并且由纯金组成。利用循化伏安曲线和旋转圆盘电极对Au(Ⅲ)在镀液中的电化学还原机制进行了研究,结果表明当研究电极为玻碳电极(GCE),镀液温度为45℃时,镀液中金的电沉积过程是受扩散控制的不可逆的过程。同时利用循环伏安曲线对镀金液的稳定性进行了分析。     

电解煤浆制氢钛基阳极铂铁合金催化剂的制备及电催化活性研究

将预处理后的钛片作为电极基体, 采用恒电流法沉积Pt和Fe, 通过高温热处理得到Ti/Pt-Fe电极, 通过扫描电镜(SEM)、X射线衍射(XRD)、电子能谱(EDS)以及等离子发射光谱(ICP)等方法对所制备电极表面形貌、组分的合金化程度、催化层成分组成以及电极寿命等进行了表征; 在煤浆电解过程中, 采用两电极体系, 对所制备电极的电催化活性进行了测试. 结果表明: 所制备的电极表面呈层状结构, 且有大量峰形突起, 催化层形成了PtFe合金, 合金化程度较高, 与同面积的铂片电极、Ti/TiO₂Pt-Ru电极相比, 大大提高了电催化活性, 降低了电极成本.     

PAFC空气电极催化层相界面结构分析

提出一个考虑了催化层中电压不均匀分布,可以在任意气体压力p、输出电流密度I工作条件下,表征PAFC空气电极行为的数学模型.发现表征“气/液”相界面比表面的参数AB与I在不同的p下呈不同的线性关系.其中在较低的压力下AB对I有较深的依赖关系,而在较高的压力p下,AB趋向与I无关.表征“液/固”界面的参数AI在不同p、I下基本保持不变.利用所构建的数学模型对PAFC空气电极中催化反应层内O2电化学还原速率进行了定量分析.结果表明,大电流下运行的空气电极,其主要的电极反应发生在“扩散层/催化层”交界处的催化反应层中,意味着厚的催化反应层是不必要的.     

钛基氧化物阳极中间层的研究进展

钛基氧化物阳极是国内外电化学领域应用广泛的优良阳极材料. 为提高电极导电性、延长电极使用寿命、增强钛基体和金属氧化物活性层之间稳定性,可以在钛基体和金属氧化物活性层之间添加氧化物等中间过渡层. 本文评述了钛基氧化物阳极中间层的研究进展,指出了钛基氧化物电极存在的问题,展望了中间层氧化物电极的发展趋势.     

共价键合四磺酸基铁酞菁有序多层膜电极

以玻碳电极为基础电极,经静电自组装方法将带负电荷的四磺酸基铁酞菁与带正电荷的含重氮基团的重氮树脂在电极表面进行层-层自组装,然后经紫外光照射,使铁酞菁的磺酸基与重氮树脂的重氮基发生交联反应,使层与层之间的离子键转为共价键,从而使铁酞菁在电极表面形成稳定、有序且处于分子水平的层-层构筑.用UV-Vis和IR光谱表征了组装过程,用CV方法研究了该电极的电化学性能及其对三氯乙酸的电催化还原.同时用计时电流法测定了三氯乙酸通过该类膜的扩散系数.     

共价键合铁卟啉有序多层膜电极的组装及其对H2O2的电催化还原

以玻碳电极为基础电极,先用静电自组装方法将带负电荷的四磺酸基苯基铁卟啉和带正电荷的含重氮盐基团的重氮树脂在电极表面进行层-层组装,然后在紫外光的照射下,使铁卟啉的磺酸基与重氮树脂的重氮基引发交联反应,使层与层之间的离子键变成共价键,从而使铁卟啉在电极表面形成稳定、有序、分子水平的层-层构筑.用UV-Vis和IR光谱表征了组装过程,用CV方法研究了该电极的电化学性能.结果表明,该电极不但具有非常优异的稳定性,而且对H₂O₂的电还原反应也表现出很好的催化活性.     

PAFC空气电极催化层相界面结构分析

提出一个能够在任意运行条件下 (气体压力 P、输出电流密度 I)正确表征 PAFC空气电极行为的数学模型。该模型中表征“气 /液”相界面比表面的 AB与 I在不同的 P下是不同的线性关系。其中在低压下有较深的依赖关系 ,而在高压下 AB趋向与 I无关。表征“液 /固”界面的 AI在不同 P、I下基本保持不变。利用所构建的数学模型对 PAFC空气电极中催化反应层内 O2 电化学还原速度进行了定量分析 ,结果表明 ,高效的反应速度发生在“扩散层 /催化层”与“催化层 /电解质”层界面交界较近的催化反应层中 ,为贵金属催化剂的有效利用提供了理论依据。     

反射式薄层可见光谱电解池的制作与性能测试

设计制作了一种反射式薄层可见光谱电解池。该电解池采用光亮铂片作为工作电极,将铂丝辅助电极和Ag AgCl参比电极组装在一起。薄层池中间的溶液薄层是通过光亮铂片和覆盖其上的玻璃片之间的塑料薄膜垫圈加以控制,当液层厚度为0.2mm时,液层容积为16μL。由于采用双平行反射的光路,使入射光与出射光保持在一直线上,可以在不变更光路系统下的各种光度计上使用。在K3Fe(CN)6 K4Fe(CN)6体系中,用循环伏安法、恒电位现场光度法进行性能测试。实验结果表明,该电池具有良好的薄层光谱电化学性能,可用于薄层可见光谱电化学研究。     

Dynamics of copper electrodeposition onto fibrous carbon electrodes

Distribution of copper electrodeposited from a sulfuric acid solution onto fibrous carbon electrodes, copper deposition rate, and current efficiency by the metal were studied in relation to the electrolysis duration, electrical conductivity of the electrode, geometric current density, and solution flow rate. The variation of the electrode thickness on which copper ions discharge at the limiting diffusion current at various solution flow rates and the electrode thickness on which the whole amount of oxygen dissolved in the electrolyte is reduced were calculated in relation to the solution flow rate and geometric current density. The main factors governing the distribution of copper across the electrode thickness and the electrolysis parameters from the beginning of the process till ??clogging?? of a part of the electrode by the metal were determined.     

Checking of applicability of conditions for reaching the limiting-current mode to flow-by porous electrodes

For the flow-by porous electrodes, which differ in thickness, specific surface area, solution flow rate, and a ratio between the phase conductivities, the conditions providing the limiting-current mode over the entire electrode surface at nearly 100% current efficiency are determined using the method of successive refinement of total current and profile of its distribution along the solution flow. The used values of electrode thickness L are compared with available estimates for the limiting thickness of porous electrode L _lim derived for the ideal limiting-current mode and calculated using real values of the width of the limiting-current plateau of overall polarization curve, solution conductivity, and the diffusion limiting current in the zone of solution input into the electrode. It is found that these values are close to each other in all cases. The largest error of estimation of L _lim does not exceed 10% indicating that it can be used for preliminary estimation of the conditions for reaching the limiting-current mode for the flow porous electrodes of this type.     

Oxygen reduction on polycobaltprotoporphyrin film: I. Catalytic activity and stability of polycobaltprotoporphyrin film toward oxygen reduction

The catalytic activity of polycobaltprotoporphyrin (PCoPP) was compared with adsorbed cobaltprotoporphyrin monolayer. The results have shown that PCoPP film shows higher catalytic activity and stability than monolayer on glass carbon electrode in both alkaline and acid solution. Catalytic activity of PCoPP goes through a maximum with increase of film thickness. A model was proposed to explain such dependence. The effect of film thickness and solution pH on the stability of PCoPP film was studied.     

Dynamics of copper electrodeposition onto fibrous carbon electrodes with electrical conductivity varying across their thickness

Distribution of copper in its electrodeposition from a sulfuric acid solution onto fibrous carbon electrodes with electrical conductivity varying across their thickness, the deposition rate of copper, and the current efficiency by copper were studied in relation to the electrolysis duration, electrical conductivity of the electrode, geometric current density, and solution flow rate. The main factors governing the distribution of copper across the electrode thickness and the electrolysis parameters beginning from the process onset till the “clogging” of a part of the electrode by the metal were determined.     

Synthesis, characterization, and electrochemical properties of self-assembled leaf-like CuO nanostructures

A simple hydrothermal process was used to synthesize the assembled leaf-like copper oxide (CuO) from copper hydroxide and urea in aqueous solution. The field emission scanning electron microscopy revealed that the individual CuO leaf-like nanostructure has a dimension of about 0.5–1.5 μm in length, 50–70 nm in thickness, and 80–110 nm in width, respectively. These CuO nanostructures were structurally characterized by X-ray diffraction and Raman spectroscopy, which showed that the CuO nanostructures prepared from the hydrothermal process have high crystalline properties with a monoclinic structure. X-ray photoelectron spectroscopy studies confirmed that the as-prepared sample is composed of CuO, which is consistent with X-ray diffraction patterns. The CuO nanostructures were used as electrode materials for lithium-ion batteries, demonstrating electrochemical properties of a high initial discharge capacity of approximately 1,028 mAh/g along with good cycle stability.     

Experimental verification of the properties of ion-selective electrodes for low concentration determination

The influence of several ion-selective electrode properties on electrode response and selectivity at low concentration levels has been investigated experimentally. The properties investigated were the composition of inner electrode solution, the composition of the membrane, the presence of interfering ions in the sample, and the thickness of diffusion layer in the sample solution. All the results obtained confirmed theoretical considerations.     

The tube electrode and e.s.r.

The convective diffusion equation for the downstream distribution of products and intermediates produced on a tube electrode under conditions of laminar flow is solved. For distances which are large compared to the thickness of the electrode, an analytical solution in real space can be found. The solution of the equation has been applied to an apparatus in which the intermediates and products are detected by e.s.r. The species are transported by laminar flow from the electrode through an e.s.r. cavity. Results are presented for two systems and are found to be in good agreement with the theory.     

具有阳极氧化膜的镁合金电极性能的研究

镁合金电极上生成阳极氧化膜的保护技术，使电极耐大气腐蚀的性能大大优于用铬酸盐膜保护的镁电极。阳极氧化工艺条件不同。镁电极的耐腐蚀性和电压滞后性能不同，本文讨论了膜的组成，形态，厚度等对性能的影响。     

银电极表面氧化物的形成与转变

金属银是碱性电池的重要电极材料,人们已对它在碱性水溶液中的电化学反应进行广泛的研究,但其阳极氧化过程的分析以及氧化产物的鉴定至今仍是众说不一。为此,本文采用现场电化学X-射线衍射技术并配合循环伏安实验进行了研究。现场X-射线衍射实验在一个特制的有机玻璃电解池中进行。整个电解池系统犹如普通粉末样品架一样安放干衍射仪的样品台上,其中透射X-射线的窗片为聚酯薄膜。研究电极是将15×10×2mm~3的银片(纯度为99.99%)用环氧树脂灌封而成,并使用饱和甘汞电极     

Effect of Cathodic and Anodic Polarization in a Lithium Sulfate Solution on the Electrical Conductivity of Carbonized Fibrous Carbon Materials

The effect of cathodic and anodic polarization of carbonized fibrous carbon materials of the KNM and NT-1 types in a Li₂SO₄ solution on their properties: electrical conductivity, steady-state electrode potential, electrical conductivity profile across the electrode thickness in relation to the electrolysis time, current density, Li₂SO₄ concentration, electrode thickness, and current reversal, was studied. The stability of the resulting electrical conductivity profile across the electrode thickness with time and in the course of the subsequent electrolysis was assessed. The reduction of Fe³⁺ in the ferri-ferrocyanide system on electrically iso- and nonisoconducting fibrous carbon electrode was considered.