聚吡咯/聚砜复合膜修饰电极的制备及其对对苯二酚的电化学催化性能

采用循环伏安法电化学聚合制备了聚吡咯(PPY)/聚砜(PSF)复合膜修饰电极.结果发现:复合膜的正面(与工作电极接触的一面)是黑色的;而反面(与溶液接触的一面)是白色的.复合膜的表面形态和化学组分分别用SEM和FTIR表征,用电化学循环伏安法对PPY/PSF复合膜修饰电极的电化学催化性能进行了研究.实验结果表明:所得复合膜修饰电极电化学可逆性好并且对对苯二酚有显著的催化效果,其氧化峰电流在5～30mM的范围内与对苯二酚的浓度呈线性关系,表明该复合膜修饰电极在对苯二酚H2Q的监测方面将有潜在的用途.     

铂粒子修饰的聚苯胺/醋酸纤维素复合膜电极对甲醛的催化氧化

采用循环伏安法在酸性溶液中成功的制备出聚苯胺(PANI)/醋酸纤维素(CA)复合膜,原子力显微镜显示:复合膜具有不对称的微孔结构,正面是不规则微孔结构的聚苯胺层,反面是海绵状的醋酸纤维素层.用电沉积法将铂沉积到PANI/CA复合膜上,研究发现Pt修饰的PANI/CA复合膜电极对甲醛有较高的催化活性和稳定性.     

复合酸掺杂聚苯胺电极膜的制备及其电化学性能的研究

采用了恒电压法在不同的电解液中分别制备出硫酸(H2SO4)和复合酸(SSA+H2SO4)掺杂的聚苯胺(PAn)电极膜.通过循环伏安法(CV)、电化学阻抗谱(EIS)和塔菲尔曲线(TAF),对H2SO4和复合酸掺杂聚苯胺电极膜的电化学稳定性、导电性以及耐腐蚀性进行了研究与表征.结果表明,复合酸掺杂的PAn电极膜具有较好的电化学稳定性、导电性以及较强的耐腐蚀性,更能满足实际应用的要求.     

聚苯胺/TiO2复合纳米膜电极的制备及其光电性能

采用原位化学氧化法,在酸性TiO2溶胶中未加分散剂制备了聚苯胺修饰的TiO2稳定溶胶,并以涂刮法在柔性导电塑料薄膜上成膜。利用FT-IR、XRD、TEM、选区电子衍射、紫外-可见光谱、光电流-电压曲线对所制备的复合溶胶及复合膜进行了表征。结果表明TiO2与聚苯胺之间实现了结构上的复合,聚苯胺的引入改善了TiO2膜对太阳光的利用率,提高了TiO2膜的光电响应性能。这种用复合溶胶制备聚苯胺/TiO2复合膜的方式扩大了成膜基底的范围。     

掺杂聚苯胺锂电池正极材料的性能研究

用化学氧化聚合制备了十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺(PANI)材料,采用恒流充放电、循环伏安和交流阻抗等电化学方法对其作为锂离子电池正极材料的电化学性能进行了研究,并利用红外光谱对聚合物循环前后的结构进行表征.结果表明,聚苯胺正极具有较高的放电容量,首次放电容量达63.3mAh/g,20次充放电循环后保持在48.5mAh/g.循环伏安曲线及交流阻抗谱表明聚苯胺具有较好的电化学活性.红外光谱测试表明,聚苯胺正极在20次充放电循环后结构基本保持不变.     

铂钌/聚苯胺/聚砜复合膜电极的制备及对甲醇的电催化氧化

利用电化学聚合分别制备了铂(Pt)及其铂钌(PtRu)/聚苯胺(PAN)/聚砜(PSF)复合膜电极。采用循环伏安法和电化学交流阻抗对复合膜电极的甲醇电催化氧化性能进行了比较与分析。结果表明:PtRu/PAN/PSF电极对甲醇的电催化活性比Pt/PAN/PSF电极的高,铂钌的沉积不仅改变了催化剂表面对氢的吸附性质,而且使氧化物还原峰电位向阴极方向移动。另外,对在不同浓度下沉积的铂钌电极对甲醇的催化效果也做了讨论,验证了RPt∶Ru=2∶1时,复合膜电极具有最好的催化活性。     

镧离子电化学掺杂聚苯胺薄膜电极及其电容性能

采用循环伏安法(CV)制备了聚苯胺(PANI)和掺杂镧离子的聚苯胺(PANI/La~(3+))薄膜电极。利用傅里叶红外光谱、X射线衍射、场发射扫描电镜和X射线能谱仪对其结构和形貌进行了分析。通过循环伏安、恒流充放电(CP)及交流阻抗(EIS)等测试其电化学性能。结果表明,在0.5mol/L H_2SO_4电解液中,当电流密度为5mA/cm~2时,掺杂镧离子的聚苯胺比电容相对聚苯胺薄膜电极提高了100F/g,且镧离子掺杂后的聚苯胺循环稳定性明显改善。     

循环伏安法制备聚吡咯/聚砜复合膜

采用循环伏安法电化学聚合制备了聚吡咯(PPY)/聚矾(PSF)复合膜,结果发现:复合膜的正面(与工作电极接触的一面)是黑色的,而反面(与溶液接触的一面)是白色的.复合膜的表面形态和化学组分分别用扫描电子显微镜(SEM)和红外光谱(FTIR)进行了表征,讨论了吡咯和聚砜的含量对复合膜性能的影响,分析了复合膜的形成过程.     

聚苯胺/TiO_2纳米复合膜的制备及表征

利用溶胶-凝胶法和浸渍-提拉法于载玻片表面沉积了TiO2纳米薄膜,然后通过化学氧化法得到了聚苯胺/TiO2纳米复合膜。借助XRD、AFM、UV-Vis、XPS等方法对复合膜进行了表征。结果表明,所得TiO2薄膜由规则立方体外形的纳米TiO2组成,颗粒直径为20nm。包覆后所得聚苯胺/TiO2复合膜由不规则球形颗粒组成,颗粒直径增大为35nm。薄膜的UV-Vis光谱分析表明,聚苯胺/TiO2复合膜的吸收带边约为390nm,对可见光的吸收显著增强。XPS分析结果表明,复合膜中N+/N之比高达0.63,高于块体聚苯胺的0.57和理想的本征态盐中的0.5,表明掺杂程度高。     

温度对固相聚合反应盐酸掺杂聚苯胺的影响

利用固相聚合反应法制备了盐酸掺杂聚苯胺,并以红外光谱(FT-IR),电子扫描显微镜(SEM)、X射线衍射(XRD)、循环伏安(cyclic voltametry)等测试,对聚苯胺进行了表征。结果表明,固相反应法合成的聚苯胺颗粒要比液相法合成的聚笨胺颗粒相对小,并表现出良好的结晶性,而低温(0℃)固相聚合反应法制备的盐酸掺杂聚苯胺要比室温固相聚合反应法制备的聚苯胺颗粒分布均匀,晶化率好,还具有良好的电导率。循环伏安测试表明,固相反应法合成的聚苯胺有较好的电化学活性。     

新型TiO2（B）/碳复合纳米线负极材料电化学特性研究

以锐钛矿TiO2粉末为原料,通过简单的两次水热及氩气气氛下热处理工艺,制备出新型TiO2(B)/碳一维复合纳米线材料。研究结果表明该复合纳米线主要是由TiO2(B)所组成,其外层包覆一层无定形碳以形成特殊的一维壳/核结构;这种特殊一维壳/核结构和化学组成在诸多领域都将会有着极其广泛应用。本文锂离子电池测试结果证实该复合纳米线电极具有超高的可逆循环电池容量和倍率充放电容量,在30 mAg-1充放电速率下,该TiO2(B)/碳一维壳核结构材料100圈循环后容量高达560 mAhg-1;在750 mAg-1充放电速率下,充放电容量达到200 mAhg-1。鉴于其优良的电化学性能,该一维复合结构材料有望成为下一代最有前途的锂离子电池电极材料。     

铝合金表面三嗪二硫醇和硅烷纳米复合薄膜的制备及表征

通过电化学方法,在铝合金表面制备6-N,N-二丁基胺-1,3,5-三嗪-2,4-二硫醉单盐(DBN)的纳米聚合薄膜(PDB),然后采用自组装技术对铝合金表面PDB膜进行十六烷基三甲氧基硅烷化处理,形成疏水性的高分子纳米复合薄膜(CPDB).通过循环伏安法解释了DBN在铝合金表面的反应及PDB的生长过程,同时分析了CPD...     

The effects of substrate and annealing on structural and electrochemical properties in LiCoO2 thin films prepared by DC magnetron sputtering

LiCoO2 thin films were fabricated by direct current magnetron sputtering method on STS304 and Ti substrates. The effects of substrate and annealing on their structural and electrochemical properties of LiCoO2 thin film cathode were studied. Crystal structures and surface morphologies of the deposited films were investigated by X-ray diffraction and field emission scanning electron microscopy. The as-deposited films on both substrates have amorphous structure. The (104) oriented perfect crystallization was obtained by annealing over 600 degrees C in STS304 substrate. The LiCoO2 thin film deposited on Ti substrate shows the (003) texture after annealing at 700 degrees C. The electrochemical properties were investigated by the cyclic voltammetry and charge-discharge measurement. The 600 degrees C-annealed LiCoO2 film deposited on STS304 substrate exhibits the inithial discharge capacity of 22 uAh/cm2 and the 96% capacity retention rate at 50th cycles. The electrochemical measurement on annealed films over 600 degrees C was impossible due to the formed TiO2 insulator layer using Ti substrate. As a result, it was found that the STS304 substrate seems to be more suitable material than the Ti substrate in fabricating LiCoO2 thin film cathode.     

Enhanced oxidation of estrone at multi-wall carbon nanotubes film electrode: direct evidence for the advantage of carbon nanotubes over other carbonaceous materials

The electrochemical behaviors of estrone at various carbonaceous nanomaterials-dihexadecyl hydrogen phosphate (DHP) composite films coated glassy carbon electrodes were investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronocoulometry (CC) and electrochemical impedance spectroscopy (EIS). Comparing with the composite films of acetylene black (AB) and carbon nanofiber (CNF), multi-wall carbon nanotubes (MWCNTs)-DHP film showed the best electrochemical performance towards the oxidation of estrone, reflected by the significantly enhanced oxidation current in the voltammograms as well as the apparently reduced charge transfer resistance in EIS. Studies on the active surface area, the surface coverage and EIS suggested that the apparently improved electrochemical responses of estrone at MWCNTs should arise from their large surface area, good conductivity and the ability to facilitate the charge transfer process. The reaction mechanisms of estrone oxidation at the three composite films were also discussed, which were expected to follow a process involved the total loss of two electrons and two protons.     

纳米TiO2/还原石墨烯复合修饰电极用于食品中 柠檬黄的检测

为了检测食品中柠檬黄的含量,利用滴涂法和电化学还原法制备纳米TiO_2/还原石墨烯复合修饰玻碳电极(TiO_2-Er GO/GCE)。采用透射电子显微镜和X射线粉末衍射仪对TiO_2和TiO_2-GO两种修饰电极材料进行表征;通过循环伏安法观察了柠檬黄在不同电极上的电化学行为,并对检测条件如p H值、富集电位、富集时间进行了优化。实验结果表明:TiO_2-Er GO/GCE增大了电极的电化学活性面积,提高了柠檬黄的电化学氧化响应;最优的检测条件为p H值为3.7、富集电位为-0.20 V、富集时间为180 s;在最优的检测条件下,采用线性扫描伏安法检测柠檬黄的线性范围为2.0×10-8~2.0×10-5 mol/L,检测限为8.0×10-9 mol/L(信噪比为3)。     

Synthesis of TiO2/GO composite film via an electrochemical route

A nano-structured film composed of TiO2 and reduced graphite oxide (GO) was synthesized on ITO glass via a typical electrochemical route. A mixed solvent of Ti(SO4)2 and GO was prepared, with the addition of H2O2, HNO3 and DMF at different ratio. A setup of two electrodes of ITO glass in a plastic cell and an electrochemical analyzer is used for the film forming. The film is characterized with a microstructure of GO plates being perpendicular to the glass substrate, since GO in the electrolyte solvent is separated as small plates at about several nanometers in diameter. TiO2 is found being deposited between these GO plates. This microstructure is quite different from the film formed by normal deposition, where the GO plates are generally parallel to the substrate. The oxygen containing groups of C=O, C-O-C and C-OH on the GO surface are reduced because of neighboring to TiO2, it means two phases being bonded to each other at the interface. The photoelectric current of the composite film is compared with the pure TiO2 film, the former one is almost one time higher than the latter one. The degradation of methyl orange of two kinds of film is also analyzed under the irradiation of ultraviolet light. The photocatalytic activity of two kinds of film presents the same trend of variation as that of photoelectric current. These results suggest that the photoexcited electrons of TiO2 may quickly transfer to the glass substrate through the reduced GO neighbor, that owns a better conductivity, and so far decrease the recovery of excited electron-hole. The unordinary microstructure of the composite film may favor both to the electron transmission between the GO and ITO glass substrate, and to the light excitation of TiO2. The microstructure of different films was studies by AFM, XPS, FESEM. The photo-electrochemical property was measured by an electrochemical instrument Model CHI660C with Blupoint4 as a UV light source.     

Preparation, characterization and anion exchange properties of polypyrrole/carbon nanotube nanocomposites

In this study, polypyrrole (PPy) thin films were electrodeposited on carbon nanotube (CNT) backbones by applying a constant deposition potential in 0.1 M pyrrole solution with different electrolytes, such as NaCl, NaNO3, or NaClO4. The hybrid films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, and cyclic voltammetry. SEM images revealed the nanostructrure of PPy films generated on CNT surface. The electrochemical and anion exchange properties of the PPy-CNT composite films have been investigated. Nanostructured composite thin films of PPy-CNTs were studied by cyclic voltammetry between 0.4 and -0.8 V in aqueous solution to evaluate their cycling stability and capacity for electrically switched anion exchange. The presence of the CNT backbone greatly improved the anion exchange capacity and stability of the PPy-CNT composite film, which may be attributed to the high surface area of CNT matrix, nanostructure of the PPy film, and the interaction between CNTs and PPy.     

MnO_2-CNTs复合材料的合成及其超级电容器性能研究

采用液相沉淀法在碳纳米管（CNTs）的表面沉积MnO2纳米颗粒,制得了MnO2-CNTs复合材料。通过扫描电子显微镜（SEM）、X射线衍射（XRD）对材料的微观结构及成分进行了表征。利用电化学循环伏安和恒电流充放电对材料进行电化学性能测试,表明MnO2-CNTs复合材料结合了MnO2较高的质量比电容和CNTs较好的电化学稳定性的优点,质量比电容为220F/g。并将MnO2-CNTs复合材料与活性炭（AC）组装形成非对称超级电容器,发现MnO2-CNTs与AC质量比为0.75：1时,质量比电容达到最高,为306F/g。非对称电容器性能较对称电容器有较大幅度的提高,并且具有良好的电化学稳定性。     

Introduction of gold nanoparticles into myoglobin-Nafion film for direct electrochemistry application

An effective myoglobin-Nafion film is prepared by introducing gold nanoparticles in through a simple procedure by ion-exchange combined with electrochemical reduction. Gold nanoparticles are highly dispersed in myoglobin-Nafion film with an average size of 2.3 +/- 0.2 nm. The electrochemical behavior of myoglobin entrapped in the film has been carefully investigated with cyclic voltammetry. The results show that the introduction of gold nanoparticles into myoglobin-Nafion film makes the direct electron transfer of myoglobin efficient. A pair of well-defined redox peaks for myoglobin heme Fe(II)/Fe(III) is observed with a formal potential of -0.150 V in 0.1 M phosphate buffer (pH 7.0). The electrochemical parameters of myoglobin in the composite film are further calculated with the results of the electron-transfer rate constant (k(s)) as 0.93 s(-1) and the charge transfer coefficient (alpha) as 0.69. The experimental results also demonstrate that the immobilized myoglobin retains its electrocatalytic activity for the reduction of hydrogen peroxide and the catalytic reduction peak of myoglobin appear in a linear relationship with H2O2 concentration in the range of 10.0-235.0 microM with correlation coefficient of 0.9970. Thus fabricated Au/Mb/Nafion electrode should give a new approach for developing redox protein or enzyme-based biosensors.