锡阴电极的制备及析氢性能的研究

为了提高锡电结晶过电位,改善锡镀层表面形貌和制备较好的镀锡电极,通过电镀技术在室温条件下制备了不同电镀液条件下的锡镀层,运用线性伏安法、交流阻抗法和电势阶跃法等电化学方法和SEM技术研究了酸性镀锡体系中明胶对锡沉积的影响。阴极极化曲线和交流阻抗曲线表明,明胶能增大锡沉积反应的电荷传递内阻,提高锡电沉积过电位,延缓锡电沉积反应。电势阶跃表明,锡的电结晶过程遵循扩散控制瞬时成核和三维生长方式的结晶机理。SEM分析结果表明,添加明胶能使锡镀层光滑致密、晶粒细小。电极的极化曲线表明,镀锡电极能提高析氢电位,其中添加明胶所得的锡电极的析氢效果最好。     

交流阻抗谱研究钙磷陶瓷电沉积层的结构

用交流阻抗技术研究了不同电沉积时间的钙磷陶瓷沉积层。结果表明，沉积时间不同的陶瓷沉积层的交流阻抗谱存在显著的差别。采用双层结构物理模型，对不同沉积时间陶瓷沉积层的交流阻抗谱进行计算机拟合，得到的等效电路各元件拟合值显示：电极表面钙磷陶瓷为内密外疏型梯度沉积层。在陶瓷电沉积过程中，钙磷晶粒同时沉积于距电极表面不同距离的部位，沉积层厚度增加的同时内层密度也在逐渐增加，整个 只层的梯度结构处于动态变化之中。     

添加剂对单膜双室同槽电解膜电积工艺的影响

采用单膜双室膜电积工艺在MnSO₄+(NH₄)₂SO₄电解液体系中电沉积金属锰,同时阳极联产电解二氧化锰并富集回收硫酸,研究了两种典型无机、有机复合添加剂亚硒酸、聚丙烯酰胺+硫脲对膜电积工艺效果的影响。结果表明,单膜双室同槽电解工艺中添加剂的使用对产锰率、酸回收率以及能耗等都有较大改善。无机添加剂亚硒酸的最适浓度在0.3g/L时,其产锰率可达84.9%,酸回收率为79.5%,能耗为5545kW·h/t;有机复合添加剂聚丙烯酰胺浓度为0.01g/L、硫脲浓度为0.02g/L时,其产锰率可达75.1%,酸回收率为76.5%,能耗为6034kW·h/t,此时电沉积锰表面白皙光亮、均匀细致,其形貌、质量都有很大的改观。     

量子点敏化太阳电池FTO/CoS/CuS对电极的制备与性能

摘要：本文采用恒电位电沉积方法在FTO导电玻璃表面依次沉积CoS和CuS,形成 FTO/CoS/CuS复合对电极用于量子点敏化太阳电池。确定了电沉积电位和电沉积时间,并研究了电沉积温度对电极形貌及电催化活性的影响。对电极的表面形貌和微观结构采用SEM和TEM方法进行表征;对电极的光反射性能采用紫外可见分光光度计进行测试;对电极的电化学性能通过测试交流阻抗、Tafel极化曲线以及J-V曲线进行表征。研究结果表明,FTO/CoS/CuS对电极与电解液界面处的电荷转移阻抗较低,具有更高的光反射率及电催化活性。与Au片、FTO/CoS和FTO/CuS对电极相比,光电转化效率分别提高了132.9%,46.6%,26.9%。     

镧系元素对铬酸镀铬电解液性能的影响

报导了在镀铬电解液中添加镧系元素（镧和铽）后，使该电解液电沉积金属铬的覆盖能力及阴极电流效率显著提高。研究中采用微分电容，交流阻抗测试技术以及Ｘ光电子能谱测定，探明了镧和铽是以特性吸附的方式参与了阴极膜的形成，使阴极膜电阻增大，表征电极表面状态变化的极化曲线的电流峰值下降，析出金属铬的电位正移，使铬能在较低的阴极电流密度下沉积，因而显著地改善了覆盖能力。添加镧和铽后使阴极电流效率提高，这可能是因为     

电沉积参数对钛沉积层耐蚀性的影响

为了确定NaCl-KCl-NaF-TiO_2熔盐体系中直流电沉积参数对碳钢表面钛沉积层耐蚀性的影响,分别选取不同的沉积时间和沉积电流进行电沉积钛实验。将沉积后的试样进行交流阻抗测试。通过分析交流阻抗的等效电路可知:在沉积时间1.0h、沉积电流1.5A的条件下获得的钛沉积层的耐蚀性最好。能谱分析表明:钛沉积层的耐蚀性与其表面钛的质量分数有关。     

硒酸钠对锌锰合金电沉积影响的研究

本文旨在探讨硒酸钠提高锌锰合金电沉积电流效率的机理。通过阴极极化曲线、循环伏安曲线及分电流曲线的测量研究了硒酸钠对锌锰合金电沉积的影响。硒酸钠能提高锰沉积的分电流，降低析氢的分电流，而对锌沉积的分电流影响不大。这是由于硒酸钠的加入增大了析氢过电位，抑制了氢的析出，从而提高了阴极大电流效率。     

氯离子对酸性镀铜电沉积的影响

旋转圆盘电极动电位扫描(RRDE)、交流阻抗(EIS)、原子力显微镜(AFM)等方法研究氯离子与添加剂AQ对酸性镀铜电沉积过程的影响,从沉积机理的角度解释氯离子必不可少的原因.结果表明,加入的氯离子改变了吸附络合物的放电形式,表现在氯离子通过离子桥机理形成三维网状结构的[Cl…AQCu(I)…Cl]放电以阻碍整个放电过程,增加反应电阻,从而使镀层表现出很好的性能.     

一种良好的玻璃着色剂和脱色剂

本文介绍用亚硒酸锌与硒进行着色对比试验的情况,说明亚硒酸锌具有与硒相同的着色性能,并且具有挥发损失小,着色稳定等优点,是一种代替硒的优良的玻璃着色剂和脱色剂。     

亚硒酸铀酰中铀的容量测定法

取硫酸铀酰水溶液,加入1.5～2倍的亚硒酸水溶液,和必需量的绝对酒精,使其浓度约等于50%。然后加5%的醋酸铵水溶液,至pH=4～5,在几小时后,将析出的沉淀过滤,以绝对酒精洗涤至剩馀的亚硒酸除尽,然后将亚硒酸铀酰溶解在浓盐酸中,利用碘定量法,应用硫代硫酸盐的淀粉,测定其中的亚硒酸。因为,一克分子量的铀结合一克分子量的亚硒酸。     

The high‐frequency alternating electrical properties of silver powder and its rubber composites

Electromagnetic shielding materials are widely used in alternating electric fields. As a result, the alternating current (AC) conductivity is vital to the electromagnetic shielding effectiveness. In this article, we designed a kind of test method about powder conductive properties and studied AC conductivity of silver powder and the silicon rubber composite, which presented that a sharp peak of impedance would take place in the both systems during the high frequent electric flow. Through the design of the equivalent circuit and the test of the system parameters such as the dielectric constant, this article displayed the impedance model of the silver powder and the silicon rubber composite. The calculated results and the experimental data match very well. POLYM. COMPOS. 37:1122–1127, 2016. © 2014 Society of Plastics Engineers     

十八硫醇自组装膜对银的缓蚀作用

在银电极表面制备了十八硫醇自组装膜,采用极化曲线、交流阻抗等电化学方法研究了不同浓度的十八硫醇对银的缓蚀作用的影响。结果表明:在温度50℃,自组装时间4h,十八硫醇0.05mol/L的条件下,缓蚀效率达到97.1%,覆盖度达到97.8%,十八硫醇在银电极表面形成了致密的自组装膜,有效地抑制了银的腐蚀。     

甘草硒多糖的制备研究

根据有机硒化合物的合成原理,以天然甘草多糖为原料,与亚硒酸硒化,制备甘草硒多糖。利用单因素实验和正交实验探讨最佳工艺条件。实验结果表明,最佳工艺条件为反应温度60℃,反应时间8 h,甘草多糖与亚硒酸的质量比为1∶1,催化剂BaCl2的质量1.0 g。此条件下,甘草硒多糖的收率为27%。红外光谱对甘草硒多糖进行结构表征可知,甘草硒多糖中含有Se O键和Se—C键,实现了甘草多糖的硒化。原子发射光谱对甘草硒多糖中硒质量分数进行测定,甘草硒多糖中硒质量分数为6.59 mg/g。     

Nanoflakes to nanorods and nanospheres transition of selenious acid doped polyaniline

Morphology transition of selenious acid doped polyaniline from nanoflakes to nanorods and nanospheres was explored by changing the selenious acid-aniline (dopant-monomer) mole ratio in the aniline polymerization. The transition of polyaniline nanospheres to nanorods occurred when the dopant-monomer mole ratio was between 1 and 0.5. The formation of polyaniline nanorods was dominant when the dopant-monomer mole ratio is 0.5. At mole ratio 0.5, nanorods were obtained with the diameter at around 150 nm. At mole ratio 1, both the nanorods and nanospheres were formed and formation of the nanosphere is favored when the mole ratio is more than 1. When the mole ratio was low (0.125-0.03), polyaniline showed flakes like morphology. The morphology transition was studied by scanning electron microscopy and the molecular structure was confirmed by X-ray diffraction, FTIR and UV-vis spectroscopy. A simple and practical route to synthesize polyaniline nanostructures was demonstrated using selenious acid as effective dopant. The mechanism governing the formation of the polyaniline nanostructures is discussed.     

交流阻抗技术及其在腐蚀科学中的应用

交流阻抗技术作为一种重要的电化学测试方法目前被广泛应用。本文概括了交流阻抗技术的基本原理,同时对交流阻抗技术在腐蚀科学领域的应用及其应用优势进行了阐述和探讨。交流阻抗技术的发展必将使其获得更广泛的应用,同时也促使其技术更加完善。     

A study of polymer-modified mortars by the AC impedance technique

Cement mortar can be regarded as a composite consisting of the cement paste, fine aggregate, and the interfacial transition zone (ITZ). In this paper, the formation and development of the ITZ of polymer-modified mortar (PMM) was studied by alternating current impedance spectroscopy (ACIS). The test results showed that the AC impedance spectra of the PMMs had the following characteristics: (1) the AC impedance spectra of the fresh PMMs were almost parallel to the imaginary axis; (2) The AC impedance spectra of the hardened PMMs showed a high-frequency part not connected to the intermediate frequency part. This characteristic was maintained over a rather long period, and then obvious changes appeared in the AC impedance spectra. The age at which the impedance spectra of the mortars changed appeared to shorten with an increase of the sand volume fractions (SVFs). These characteristics of the AC impedance spectra of the PMMs were related to the close contact, the packing, and the formation of a mechanically rigid film of the polymer particles.     

A review of AC impedance modeling and validation in SOFC diagnosis

In this paper, over 150 journal papers were reviewed with respect to AC impedance modeling and validation in solid oxide fuel cell (SOFC) diagnosis. Different models based on experimental AC impedance data and their advantages and disadvantages in data interpretation were discussed. The challenges currently faced by AC impedance modeling and validation were identified and possible directions and approaches in addressing these challenges were suggested.     

饮用水深度净化载银活性炭研究进展

介绍了活性炭（AC）在净水过程中微生物的繁殖,概述了银抗菌机理的研究进展。阐述了载银AC（AC/Ag）的制备现状,指出负载纳米银的AC/Ag具有更强的抗菌性能。归纳了银的价态、银颗粒尺寸等因素对AC/Ag抗菌的影响,总结了AC孔结构、AC表面化学性等因素对AC/Ag的影响,展望了AC/Ag的发展趋势。     

基于直流内阻和交流阻抗特性的PEMFC水管理状态分析

基于Randles等效电路,研究质子交换膜燃料电池(PEMFC)操作温度和湿度耦合关系,建立电堆直流内阻和交流阻抗特性模型。通过两种方法相结合,研究不同操作条件下的电化学阻抗谱图和U-I输出特性曲线的变化规律,以及不同水管理状态在直流内阻和交流阻抗变化规律中体现出的对应关系,进而分析水管理状态对电堆输出性能的影响作用。仿真和实验结果表明,温湿度耦合关系下的不同水管理状态,在电化学阻抗谱图和U-I特性曲线中具有一致的变化规律和对应的量化关系;电堆输出性能中的膜干、水淹等现象,在直流内阻值和交流阻抗图的变化中具有明显的表现特征;通过研究水管理状态对两者的影响,能够实现操作条件的优化和电堆输出性能的优化控制。     

Effect of Inorganic Silver Nanoparticles on Structural and Electrical Properties of Polyaniline/PVC Blends

Dodecylbenzenesulfonic acid (DBSA) doped polyaniline (PANDR) has been synthesized by redoping method. Inorganic silver nanoparticles were incorporated in THF solution of PANDR (PANDS) and then mixed with PVC solution to prepare PANDS/PVC nanocomposites. FTIR spectroscopy indicated that silver nanoparticles reside more close to imine nitrogen of PANDS. Transmission electron microscopy (TEM) confirmed the formation and dispersion of silver nanoparticles in polymer matrix having average size of ~20 nm. Incorporation of inorganic metal silver nanoparticles has improved the mechanical properties of nanocomposite films as compared to pure polymer blends. Addition of silver nanoparticles in the blends reduces the charge trapping centres and increases the conducting channels; as a result a decrease in the real part of impedance has been observed.