合成电势对Li／聚吡咯正极性能的影响

为了简便真实的分析聚合电势对叫聚吡咯电池正极电化学行为的影响，同时寻找最佳聚合电势，在pt微盘电极上用恒电位法合成聚吡咯（PPy），通过循环伏安，计时电势方法对电化学行为进行检测，结果表明：当聚合区间为3．8-4．2V（VSLi／Li^＋）时，PPy膜电极均具有较好的可遗陛和电化学容量。选择4．0V（VS Li／Li^＋）电位聚合，PPy微电极的电化学陛能更佳。通过SEM测试技术进一步分析表明，不同电位直接影响聚吡咯的形貌，这是导致电池可逆性不同的直接原因；选择4．0V电势进行聚合，可以得到满足二次电池充放电性能要求的PPy膜电极。     

ITO表面PANI纳米纤维膜的电化学聚合与表征

以盐酸为掺杂剂,采用循环伏安和恒电位2种电化学聚合法在氧化铟锡(ITO)表面制得导电性良好的纳米纤维状聚苯胺(PANI)薄膜,对ITO和PANI薄膜进行表征。研究表明,在ITO电极表面,苯胺循环伏安电聚合行为电位扫描速率和循环次数增加,对应的氧化-还原峰电位差增加,PANI氧化还原可逆性变差;恒电位聚合过程中,苯胺单体浓度对其在ITO表面聚的合诱导期有显著影响,当盐酸和苯胺浓度均为0.1mol/L,扫描速率为20mV/s,恒电位为0.9V时,制得的PANI膜的厚度为3.47μm,电导率最大达到49.48S/cm,性能较好。     

铜表面有机镀膜及薄膜性能研究

通过有机镀膜的方法,利用一种自设计合成的三嗪硫醇化合物(TTN)在铜表面制备有机薄膜.通过循环伏安法解释了TTN在纯铜表面的反应及有机薄膜(PTT)的生长过程,并在0.05mA/cm2的电流密度下进行恒电流有机镀膜.通过电化学方法对薄膜的性能进行了评价,测试结果显示有机镀膜方法能在铜表面获得均匀致密的有机膜,为有机介电薄膜的制备提供研究基础.     

新型噻吩单体的合成与电化学聚合

以3,4-二溴噻吩(DBrT)为原料,通过亲核取代和醚交换反应制备了带有羟基的双烷氧基取代噻吩,再采用开环-取代反应引入磺酸官能团,得到新型取代噻吩单体EDOT-S。采用红外光谱、紫外光谱和核磁共振氢谱、碳谱对此单体进行了表征。采用循环伏安法进行电化学聚合制得PEDOT-S,该聚合物的氧化电位和还原电位分别为442mV和371mV(vs.SCE)。PEDOT-S膜具有可逆的电致变色性能,在氧化态呈蓝绿色,还原态呈紫红色。     

Ta/BDD薄膜材料电极在检测苯胺中的应用

制作钽衬底掺硼金刚石薄膜材料电极(Ta/BDD),并利用此薄膜材料电极为工作电极通过阴极溶出伏安法检测水中的苯胺.用热丝化学气相沉积(HFCVD)方法沉积Ta/BDD薄膜电极,扫描电镜和拉曼光谱表明电极具有良好的物理性质,循环扫描测试表明电极具有宽的电势窗口4.1V(-1.8～+2.3V vs SCE)和低背景电流,此特性对于电化学检测有着明显的优势.发现苯胺在氧化处理的Ta/BDD电极上有可逆的氧化还原峰,检测过程中未发生电极钝化现象.Ta/BDD电极在酸性介质中苯胺检测效果较明显,苯胺在1～40靘ol/L范围内浓度与溶出峰电流值有较好的线性关系.     

纳米α-MnO_2的固相制备及电化学性能

用KMnO4和醋酸锰为原料,在室温下固相反应经过热处理和酸处理制备纳米-αMnO2,采用X射线衍射技术和扫描电子显微镜(SEM)分析了MnO2的结晶结构及表面形态;通过循环伏安法、恒流充放电和交流阻抗测试研究了样品的电化学行为。合成的α-MnO2在1.0mol/L Na2SO4电解液中,-0.1~0.8V(vs.SCE)范围内,电流密度为300mA/g,3mV/s的扫描速度下的比电容可达222.7F/g,经1000次循环后,容量保持85%以上,有着较好的循环性能和电容稳定性。     

钕在[BMP]Tf_2N离子液体中的阳极行为

本文研究了稀土金属钕(Nd)在1-丁基-1-甲基吡咯烷双(三氟甲磺酰)亚胺盐([BMP]Tf_2N)离子液体中的阳极行为。采用循环伏安法测定了[BMP]Tf_2N的电位窗,通过线性伏安扫描、恒电流极化以及恒电位极化研究了Nd在[BMP]Tf_2N中阳极溶解,利用恒电流溶解计算了Nd的溶解价态,最后采用SEM考察了恒电流溶解之后Nd的表面形貌。结果表明:电极电位超过1.4V(vs.Pt)之后,Nd表面氧化膜发生破坏,之后Nd电极开始活性溶解;Nd溶解之后的产物为[Nd(Tf_2N)_x]_((x-3)-);在较低的电流密度下,如0.1mA/cm~2,Nd表面氧化膜发生局部破坏,出现局部溶解的形貌;在较高的电流密度下,如1mA/cm~2,Nd表面氧化膜完全被破坏,出现均匀溶解形貌。     

碳纳米管修饰碳糊电极测定铜离子

制备了碳纳米管修饰碳糊电极,并研究了铜离子在该电极上的循环伏安行为,建立了一种测定铜离子的新方法.结果表明,在pH=3.4的B-R缓冲溶液中,该电极在铜离子标准溶液中富集Cu2+,在-0.072V处产生一个还原峰,回扫时在0.059V处产生一个氧化峰,电极反应是可逆的.Cu2+浓度对数在1.0×10-7～1.0×10-4mol/L内与电位呈良好的线性关系,其检测下限为5.4×10-8mol/L.     

水热电化学法制备LiCoO2薄膜和粉末

采用水热电化学法同时制备出LiCoO2粉末和薄膜.LiCoO2粉末是由菊花状晶粒组成,LiCoO2薄膜由0.2～0.4μm左右的颗粒堆积而成.LiCoO2薄膜电极首次循环伏安过程在3.85V和4.3V左右出现强氧化峰,在3.6V左右出现还原峰;LiCoO2粉末的首次循环伏安过程在4.3V左右出现强氧化峰,在3.5V左右出现还原峰;在随后的循环中,氧化和还原峰对应的电位和强度衰减程度小,表明该方法制备的LiCoO2正极材料具有良好的循环伏安性能.     

H6PMo9V3O40/PANI复合电极材料的电容特性研究

采用超声氧化聚合法,以自制杂多酸H6PMo9V3O40作为质子酸掺杂剂兼辅助氧化剂,配合过硫酸铵(APS)氧化剂,合成了聚苯胺基复合电容材料H6PMo9V3O40/PANI。以此复合材料为活性物质制备电极,在0.5mol/L H2SO4电解液体系中,通过循环伏安、恒电流充放电和交流阻抗等技术研究其电化学性能。结果表明,H6PMo9V3O40/PANI电极体现出优良的法拉第赝电容特征,循环稳定性能良好,且大电流下充放电特征明显。在-0.1~0.7V(vs.SCE)电压和1.5A/g电流密度下,首次充电比电容量160.643F/g,放电比电容量153.225F/g,充放电效率95.38%,500次循环后,充电比电容量140.543F/g,衰减率12.51%,放电比电容量139.528F/g,衰减率8.94%,充放电效率99.27%。     

Sb-Fe合金的电沉积及其结构与磁性能

以柠檬酸为络合剂、硼酸为缓冲剂的酸性镀液中电沉积Sb-Fe合金,循环伏安实验显示在镀液pH值为3.2时合金的起始共沉积电位约-0.855V(vs·SCE)。借助扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)和振动样品磁强计(VSM)研究了沉积条件对Sb-Fe镀层结构和磁性能的影响。结果表明,在镀液pH值为3.2时,随着阴极电流密度从20mA·cm-2增加到40mA·cm-2,镀层中铁含量从2at%增加到24at%;当阴极电流密度大于40mA·cm-2,镀层中铁含量又下降。Sb-Fe镀层含有Sb-Fe固溶体(R-3m)相以及少量的铁(Im3m)相。随着Sb-Fe镀层中铁含量的增加,镀膜的矫顽力减少而饱和磁化强度则增加。镀膜的矫顽力在1.2～1.7kA·m-1范围,属软磁材料。     

Electrodeposition of black chromium spectrally selective coatings from a Cr(III)-ionic liquid solution

In the present study, black chromium coatings were electrodeposited from a 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF₄]) solution containing Cr(III) under potentiostatic control on copper substrates. The electrochemical behavior of the electrolyte was studied by cyclic voltammetry. The reduction of Cr(III) species in the solution is a two-step process, from Cr(III) to Cr(II) and from Cr(II) to Cr(0). The potential of each reaction shifts positively with the increase of the electrolyte temperature. The parameters for the electrodeposition of black chromium films were optimized. Homogeneous black chromium films with spectrally selective optical properties were produced by applying a potential of −1.5 V for 1800 s, at an electrolyte temperature of 85 °C. The coatings consist of a mixture of chromium oxide/hydroxide and metallic chromium. They are amorphous and present a sub-micrometric granular structure.     

电沉积与铁基体电位活化的增强拉曼光谱研究

为探讨电沉积初始过程对电镀层结合强度的影响,采用循环伏安法和表面增强拉曼(SERS)光谱研究了光亮铁电极在5%KCl溶液中表面氧化物随电位负移的还原过程,并应用循环伏安法和恒电流电位-时间法研究了氰化物镀铜体系铁基体的电位活化现象和电沉积初始过程.结果表明,在电位-0.9 V时,特征波数为424 cm-1和499 cm-1的Fe3O4谱峰消失,电位-1.2 V时,特征波数671 cm-1的FeO、谱峰明显降低,说明Fe3O4和FeO在不同电位下依次实现还原过程.循环伏安曲线在-0.9 V及-1.2 V附近也依次出现了铁氧化物的还原电流平阶.在氰化物镀液中,铜的析出电位(约-1.4 V)负于铁表面氧化物的还原电位,电极过程首先实现铁表面氧化物的还原,随后铜沉积在活化的铁基体上.     

镁合金硫酸镍体系化学镀镍工艺及镀层性能研究

采用酸性钼酸盐酸洗、碱性钼酸盐活化工艺,研究了AM60镁合金上硫酸镍溶液体系化学镀镍的方法.采用扫描电子显微镜(SEM)观察镀层表面形貌,电子探针(EDX)分析镀层成分,电化学方法研究镀层腐蚀性能,锉刀试验测试镀层与基体结合力.结果表明,所得镀层为Ni-P合金镀层,磷质量分数为10%～14%;镀层均匀致密,无明显缺陷;镀层的自腐蚀电位接近-0.4 V(vs SCE),阳极极化曲线有明显的钝化区;Ni-P镀层耐蚀性好,与基体结合牢固.     

Electrochemistry and electrocatalytic properties of hemoglobin in layer-by-layer films of SiO2 with vapor-surface sol-gel deposition

In this paper, layer-by-layer {Hb/SiO2}n films assembled by alternate adsorption of positively charged hemoglobin (Hb) and vapor-surface sol-gel deposition of silica at 50 degrees C onto a glassy carbon electrode were reported. The result films were characterized with cyclic voltametery, electrochemical impedance spectroscopy, UV-vis spectroscopy, and SEM, and the direct electrochemical and electrocatalytic properties of Hb in these layer-by-layer films were investigated. A pair of well-defined quasi-reversible cyclic voltammetric peaks were observed, and the formal potential of the heme FeIII/FeII redox couple was found to be -0.330 V(vs SCE). The electron-transfer behavior of Hb in {Hb/SiO2}n films was dependent on the vapor temperature, the number of layers, and the pH of the Hb solution, based on which a set of optimized conditions for film fabrication was inferred. The hemoglobin in{Hb/SiO2}n films displayed good electrocatalytic activity to the reduction of hydrogen peroxide, and H2O2 had linear current response from 1.0 x 10(-6) to 2.0 x 10(-4) M with a detection limit of 5.0 x 10(-7) M (S/N = 3). The apparent heterogeneous electron-transfer rate constant (ks) was 1.02 +/- 0.03 s(-1), and the apparent Michaeli-Menten constant (Kmapp) was 0.155 mM, indicating a potential application in the third-generation biosensor.     

Cu-In合金硒化法制备CuInSe_2薄膜

采用三电极体系恒电压电沉积法制备了Cu-In薄膜,经硒化退火生成CuInSe_2薄膜.采用循环伏安法研究了电沉积Cu-In的循环伏安特性,确定其最佳沉积电位在-0.75V左右,Cu与In的化学计量比为1.1,达到了理想前驱体的Cu与In的化学计量比.研究了不同沉积电位下材料组成、结构与性能的影响.硒化后,Cu与In的化学计量比为1,1时形成了比较单一的CuInSe_2黄铜矿相结构.     

Electrochemical processing of high-T c Bi(Pb)-Sr-Ca-CuO thin films

Superconducting thin films of Bi(Pb)-Sr-Ca-CuO system were prepared by depositing the film onto silver substrate by d.c. electrodeposition technique with dimethyl sulphoxide bath in order to examine the effect of Pb addition to the BSCCO system. The films were deposited at the potential of -0.8 V vs saturated calomel electrode (SCE) onto the silver substrate. The different preparative parameters such as deposition potential, deposition time were studied and optimized. These films were then oxidized electro-chemically at room temperature in an alkaline (1 N KOH) solution, and also at 600°C temperature in an oxygen atmosphere. The films showed the superconducting behaviour, with T_c values ranging between 85 K and 96 K, respectively.     

不锈钢表面电化学合成导电聚苯胺膜的研究

在酸性电解液中分别用电化学恒电位法和恒电流法在不锈钢基材上成功制备了导电聚苯胺膜，该膜在空气中呈绿色，稳定、完整致密，为结晶态结构，与基体的结合情况较好。在氯化钠溶液中测定试样的阳极极化曲线后发现，表面覆盖聚苯胺膜后的不锈钢，其点蚀电位比无膜时升高1000mV左右，表明导电聚苯胺膜可显著提高不锈钢的抗点蚀性能，具有良好的点腐蚀防护效果。     

LY12铝合金电解着黑色方法及机理的研究

为了解决LY12铝合金电解着黑色存在的着变色和掉色问题,研究了LY12铝合金电解着黑色的工艺方法,观察了电解着黑色膜层的形貌,分析了膜层表面的成分,并用线性电位扫描法和循环伏安法探讨了电极反应过程中金属离子的电化学反应行为.结果表明,LY12铝合金在NiSO4-SnSO4盐溶液中电解着色能得到黑色膜层,元素镍和锡沉积于氧化膜孔内,其沉积反应过程为扩散控制.     

Growth of different shape Cu2O micro structures using PEDOT coated ITO electrode

Crystalline cuprous oxide (Cu2O) particles were successfully deposited on poly(3,4-ethylenedioxythiophene) [PEDOT] coated indium tin oxide (ITO) glass. PEDOT film was first prepared on ITO glass by electrochemical polymerization. Crystalline Cu2O particles were then deposited on the PEDOT film by applying various electrochemical synthesis methods using a copper sulfate precursor. The effects of applied electrochemical methods on the compositions, grain sizes and shapes, and surface morphologies of the electrodeposited films were investigated. The micro structures of Cu2O particles were confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). When the cyclic voltammetry (CV) and chronoamperometry (CA) were applied, fine Cu2O particles of cubic and pyramidal phase were formed, respectively. However, bare ITO electrode was used, metallic copper particle was obtained. It shall be assumed that PEDOT might act as a buffer layer in electrochemical reduction of cuprous ion. The details of PEDOT behavior will be the topic of future studies.