[SiNi(H2O)W11O39]6-多层组装膜修饰电极及其电化学行为

采用电化学生长法制备包含杂多酸[SiNi(H2O)W11O39]6-(SiNiW11)和聚合物阳离子PDDA的多层膜修饰电极, 利用循环伏安法研究其电化学行为、 pH的影响及其对BrO3-和NO2-体系还原的电催化性能;并对多层膜电化学过程机理进行了初步探讨. 结果表明: 多层膜的增长均匀, 峰电流随层数的增加而增加;多层膜的峰电流随扫速的增加而增加;还原峰的峰电位随pH的增加而负移.     

[SiMn(H2O)W11O39]6-在玻碳电极上的多层组装膜修饰电极及电化学行为

采用电化学生长法制备包含杂多酸[SiMn(H2O)W11O39]6-(SiMnW11)和聚合物阳离子PDDA的多层膜修饰电极,利用循环伏安法研究其电化学行为、扫描速率的影响及其对BrO3-和NO2-体系还原的电催化性能.结果表明:SiMnW11多层膜增长均匀,峰电流随层数的增加而增加;多层膜的峰电流随扫速的增加而增加;SiMnW11修饰电极对BrO2-和NO2-的还原具有良好的电催化作用.在最佳的实验条件下,BrO3-的还原峰电流与其浓度在0.345～5.28 mmol·L-1范围内呈良好的线性关系,相关系数r=0.998,检出限8.8×10-5mol·L-1.     

2:18磷钼杂多酸的过氧化氢传感器

１引言 有关Ｄａｗｓｏｎ型磷钼杂多酸修饰电极的研究报道甚少,本文按文献方法合成Ｄａｗｓｏｎ型磷用杂多酸Ｈ６Ｐ２Ｍｏ１８Ｏ６２（简写为Ｐ２Ｍｏ１８）。采用电化学方法制得 Ｐ２Ｍｏ１８／ＧＣ膜修饰电极,研究其在 ０．５ｍｏｌ／Ｌ Ｈ２ＳＯ４溶液中的电化学行为,发现Ｐ２　Ｍｏ１８／ＧＣ膜修饰电极对酸性水溶液中的Ｈ２Ｑ２有较灵敏的催化活性,因而在ＧＣ上研制了Ｐ２Ｍｏ１８／ＧＣ的 Ｈ２Ｏ２传感器,初步探讨了电催化还原机理。２实验部分２．１仪器与试剂ＸＪＰ－８２１（Ｂ）型新极谱仪（中国科学院长春应用化学研究所,…     

双-Keggin型四元杂多化合物[Nd(SiMo7W4O39)2]13-多层膜在化学修饰玻碳电极上的组装及电催化

报道双-Keggin型四元杂多化合物K10H3[Nd(SiMo7W4O39)2]XH2O(简称[Nd(SiMo7W4)2]^13-）聚合物的交替组装多层膜在4-氨基苯甲酸修饰玻碳电极上的制备及其电化学特性。各层的循环伏安行为证明膜的均匀增长，峰电流随层数的增加而增加，与溶液中的电化学行为相比，位于多层膜中的杂多化合物的氧化还原特征峰随着多层膜层数的增加，具有一定程度的形变。该电极具有较高的稳定性。并讨论了pH对其氧化还原行为的影响，考察了该多层膜修饰电极对BrO3^-、HNO2和H2O2等的电催化性能。     

磷钼钒杂多酸—聚吡咯膜修饰电极测定污沙哑业硝酸根 …

采用电化学方法以导电基体玻碳电极上制备出磷钼钒杂多酸－聚吡咯膜修饰电极,研究了ＮＯ２＾－在该电极上的电化学行为。结果表明,磷钼钒杂多酸－聚吡咯膜修饰电极对酸性水溶液中的ＮＯ２＾－具有良好的电催化还原作用,与空白玻碳电极相比,降低过电位１０００ｍＶ以上,而且ＮＯ２＾－的浓度在５．０×１０６－６￣１．０×１０＾－２ｍｏｌ·Ｌ＾－１范围内,催化峰电流与ＮＯ２＾－浓度呈良好的线性关系,检出限可达１．０×１     

锰取代Keggin型杂多酸[ZnW11O39Mn(H2O)]8-在化学修饰玻碳电极上的多层组装及电催化性能研究

在4-氨基苯甲酸修饰的玻碳电极上制备了过渡金属取代杂多酸[ZnW₁₁O₃₉Mn(H₂O)]^8-(ZnW₁₁Mn)多层膜.各层的循环伏安行为证明膜的增长均匀,峰电流随层数的增加而增加.与其在溶液中的氧化还原行为相比,多层膜中的ZnW₁₁Mn显示出一些特殊的性质.还讨论了pH对其氧化还原行为的影响.该多层膜对BrO₃^-和H₂O₂的还原及抗坏血酸的氧化具有较好的电催化性能.     

[SiZn(H2O)W11O39]6-在玻碳电极上的多层组装及电催化性能

采用循环伏安法研究一取代硅钨杂多酸在酸性水溶液中的电化学行为及pH的影响.制备了包含杂多酸[SiZn（H2O）W11O39]%6-（SiZnW11）和聚合物阳离子-聚二烯丙基二甲基氯化铵（PDDA）的多层膜修饰电极,研究了其电化学行为.逐层的循环伏安行为表明膜的增长均匀,峰电流随膜层数的增加而增加,与其在液中的氧化还原行为相比,多层膜中的SiZnW11显示出一些特殊的性质.对BrO3^-和NO2^-体系的还原具有良好的电催化性能.     

硅钼钨杂多阴离子-聚吡咯膜修饰电极的制备及其电化学性质研究

用电位扫描方法将混配型杂多阴离子α－ ＳｉＭｏ３ Ｗ９Ｏ４０４－ （ 简写为α－ ＳｉＭｏ３Ｗ９） 催化剂固定在导电聚吡咯膜电极上,从而制得具有表面功能的α－ ＳｉＭｏ３Ｗ９ 掺杂的聚吡咯膜修饰玻碳电极．该电极具有良好的电化学活性和稳定性,并对ＮＯ２－ 的还原起电催化作用．实验结果表明,α－ ＳｉＭｏ３Ｗ９ 在膜中的还原过程由溶液中的三步单电子还原转化为一步双电子和一步单电子还原．     

第四周期过渡金属磷钼三元杂多酸聚吡咯薄膜修饰电极及其电催化性…

合成了第四周期过渡金属磷钼三元杂多酸类化合物，采用电化学聚合法研制了该类杂多酸－聚吡咯薄膜修饰电极，该电极制备过程简便，快速，研究了膜电极的电化学行为，发明掺杂膜电极性能稳定，对酸性水溶液中的Ｈ２Ｏ２，ＮＯ２，ＣｌＯ３，ＢｒＯ＾－３，ＩＯ３等物质具有较好的电催化还原作用，初步探讨了电催化还原机理。     

γ—Mo2N合成过程中的热变化及中间产物的研究

采用ＤＴＡ技术，通过改变升温速率研究了γ－Ｍｏ２Ｎ合成过程中的热变化，并经ＸＲＤ，ＢＥＴ及ＩＲ测试，对ＤＴＡ曲线中的谱峰进行归属，考察了中间产物，ＤＴＡ结果表明，在ＭｏＯ３和ＮＨ３程序升温反应过程中有放热峰及吸热峰出现，且随升温速率的长高，放热峰面积与吸热峰面积之比逐渐减小，结合ＸＲＤ及ＩＲ结果可知，ＤＴＡ曲线听放热峰可归属为由ＭｏＯ３变化为ＭｏＯ２的还原峰，吸热峰则归属为由ＭｏＯ２变化为Ｍｏ２Ｎ     

钒取代多金属氧酸盐/聚酰胺-胺多层膜的制备及其电催化性能

用层接层自组装的方法制备了过渡金属钒取代的多金属氧酸盐PMo11VO4-40/聚酰胺-胺多层纳米复合膜. X射线光电子能谱(XPS)、紫外-可见光谱(UV-Vis)、循环伏安(CV)测定和分析结果表明, PMo11VO4-40和聚酰胺-胺通过静电相互作用形成了纳米交替多层膜,且膜的增长均匀. 复合膜的循环伏安图呈现出四对氧化还原峰(一个V的单电子和三个Mo的双电子), 峰电流与扫描速率成正比, 其式量电位随着pH 的增加而线性负移, 表明电极过程属于表面控制过程, 电荷传递很快且有氢离子参与多金属氧酸盐的氧化还原反应. 该方法制备的多层膜修饰电极稳定性好, 对NO-2、BrO-3及H2O2具有良好的催化还原活性.     

Layer-by-layer assembly of silicotungstate multilayer films modified on glassy carbon electrode and their electrochemical behaviors

A new electrode was modified by multilayer films composed of heteropolyanion (SiW12) and cationic polymer poly(diallyldimethylammonium chloride) through electrochemical growth. The modified electrode electrochemical behavior, the effect of solution pH and electrocatalytic response to the reduction of BrO3- and NO2- have been investigated. The result shows that the electrochemical process of multilayer films modified electrode including SiW12 is a reversible process by electrochemical step. One-electron process has no proton participation in the first step, and one-electron process is accompanied by one proton participation in the second step and two-electron process is accompanied by two protons participation in the third step. The films grow uniformly, and the peak currents increase with increasing layer numbers. The peak currents increase with scan rate, and the reduced potentials of multilayer films shift negatively with increasing pH. The electrochemical mechanism of multilayer films was suggested.     

Assembly of Electroactive Ordered Multilayer Films of Cobalt Phthalocyanine Tetrasulfonate and Polycations

Films with alternating layers of the anion cobalt phthalocyanine tetrasulfonate (CoIIPcTS4-) and cationic polydimethyldiallylammonium chloride (PDDA) were prepared by electrostatic layer-by-layer adsorption. Quartz crystal microbalance and optical studies demonstrated formation of smooth ultrathin films with a linear increase in thickness with the number of deposition steps. Films containing 1, 2, 3, 4, and 5 bilayers of CoIIPcTS4-/PDDA on a gold electrode gave reversible, reproducible steady state cyclic voltammetry for the CoII/CoI redox couple with midpoint potential at -0.28 V vs a saturated calomel reference electrode. Voltammetry was controlled predominantly by charge transport processes in the film, even for films containing only a bilayer of PDDA/CoIIPcTS4-. The peak reduction current increased with the number of layers and showed a tendency to saturation after a deposition of 4-5 bilayers. Copyright 1999 Academic Press.     

十八胺/杂多阴离子杂化LB膜的制备与表征

采用界面吸附法制备了５种十八／杂多阴离子杂化ＬＢ膜ＯＤＡ／ＨＰＡ（ＨＰＡ＝ＰＷ１２,ＰＭo12,MPo12,PW6Mo6,PW9Mo3,P2Mo18).对５种本合物在空气／水界面上单分子膜的行为进行了研究,它们有较高的崩溃压４６．０－４８．０mN,m^-1,均能开稳定的单分子膜,用红外光谱,紫外光谱,小角Ｘ射线衍射（ＬＸＲＤ）和荧光光谱对ＬＢ膜的沉积特性与结构进行了鉴定,结果表明,制备的ＬＢ膜具有中心对称性,其层状结构由杂多阴离子的单层与表面活性剂双层交替组成。     

双长链烷基Dawson结构钼磷酸复合薄膜的制备、结构及光致变色性质

近年来 ,无机 -有机复合材料由于其独特的结构和特殊的光、电和磁功能特性而引起科研工作者的广泛关注 [1,2 ] .杂多化合物为均一的无机多聚物 ,具有笼状结构 ,结构中均有 M3O13三金属氧簇 ,能够接受电子生成杂多蓝或杂多棕 ,加之其在水和有机溶剂中的溶解性和稳定性 ,使其在光电变色材料领域中具有潜在的应用价值 [3～ 5] .但这类化合物难于加工成实际应用的器件 ,因而限制了其进一步的应用 .利用有机组分调控的超分子自组装技术可构建光致变色同多酸或杂多酸纳米薄膜材料 ,从而为开发变色响应快、稳定性好、变色可调控的新型光电变色高密…     

Electrostatic synthesis and electrochemical properties of a composition comprising ultrathin layers of silicododecamolybdate anions and poly(allyl ammonium) cations

A layer-by-layer (LbL) composition comprising ultrathin anionic layers of silicododecamolybdate and cationic layers of poly(allyl ammonium) is synthesized. The synthesis is realized by means of successive immersion of a glassy-carbon rod into aqueous sulfuric acid solutions of silicododecamolybdic acid and poly(allyl ammonium) hydrochloride. Cyclic voltammetry shows that the silicododecamolybdate anion in the composition undergoes three steps of reversible reduction with formal potentials of 0.34, 0.22, and 0.02 V (SCE). It is established that in the course of synthesis one can obtain a sixfold increase in the currents of redox conversions as compared with currents of a monolayer of the anion chemisorbed on glassy carbon. The LbL composition exhibits catalytic activity during electrochemical reduction of NO ₂ ^? : the cathodic current of the third redox transition considerably increases and the peak in the reverse run of a cyclic voltammogram disappears. The calculated Michaelis constant of 5 × 10^?2 M speaks of a high catalytic activity of the electrode.     

Electrochemically deposited thiophene-based polymers as protective agents for Prussian Blue thin films

A composite material based on overlapped layers of electrochemically synthesized Prussian Blue (PB) and terthiophene-derived polymer is described, aiming at enhancing the stability of the hexacyanoferrate thanks to the protective action of the polymer. Two bilayer configurations and deposition methods (for the polymer component) were tested. The morphology and electrochemical behavior in organic solvent and in aqueous solutions containing different supporting electrolytes were carried out. The best performances of electrodes modified with films of the composite material as to increased stability of PB were achieved with the potentiostatically deposited polymer covering the PB layer, in acetate buffer at pH 5.5. As for potential cycling stress, the anodic and cathodic peak currents due to PB were not decreased after 20 cycles. Conversely, PB alone displayed the anodic peak currents relevant to PB/Prussian White (PW) and PB/Berlin Green (BG) systems decreased by about 30 %. The stability to local pH increase was assessed by cyclic voltammetry after electrochemical reduction of H₂O₂. For example, the anodic peak currents were decreasing by 15 % and 5 % for the two PB redox systems, while for PB alone the same currents decreased by 35 % and 10 %. The response sensitivity to hydrogen peroxide was improved by 54 %, with respect to PB alone, as evaluated by chronoamperometry.     

血红素修饰电极及其催化氧还原性质

金属大环络合物（卟啉、酞箐、维生素Ｂ_(１２)等）修饰电极对氧、一氧化氮和其它生物物质的催化作用［１－３］引起了化学工作者的极大兴趣,血红素是一种重要的铁卟啉化合物,是血液中血红蛋白的重要组成部分,承担携氧的任务,由于其特殊的生理功能,研究血红素修饰电极的性质和作用对进一步研究开发燃料电池具有很重大的意义．卟啉在电极上的修饰有多种方法,当卟啉或金属卟啉环侧链上具有苯氨基、苯酚基、乙烯基或吡咯等取代基时［３］,可采用电氧化聚合法制备聚卟啉膜．本文采用循环伏安法在水溶液中制备了聚血红素膜电极,研究了聚…     

Preparation and photochromism of Keggin-type molybdphosphoric acid/silica mesoporous composite thin films

Using tetraethoxysilane and 3-aminopropyltriethoxysilane as the silica sources, amino-functionalized organic/inorganic hybrid mesoporous silica thin films with 2-dimensional hexagonal structure have been synthesized by evaporation induced self-assembly process in the presence of cetyltrimethyl ammonium bromide templates under acid conditions. The Keggin-type molybdphosphoric acid (PMo) is incorporated into the mesoporous silica thin films with amino-groups by wetness impregnation, and the PMo/silica mesoporous composite thin films are obtained. The results of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and Fourier transform infrared (FTIR) spectra indicate the PMo molecules maintain Keggin structure and are homogeneously distributed inside mesopores. The composite thin films possess excellent reversible photochromic properties, and change from colorless to blue under ultraviolet irradiation. The photochromic mechanism of the composite thin films is studied by ultraviolet-visible (UV-vis), electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) spectra. It is shown that intervalence charge transfer (IVCT) and ligand-to-metal charge transfer (LMCT) are the main reasons of photochromism. PMo anions interact strongly with amino-groups of the mesoporous suface via hydrogen bond and electrostatic force. After ultraviolet irradiation, the charge transfer occurs by reduction of heteropolyanions accompanying the formation of heteropolyblues with multivalence Mo(VI, V), and the bleaching process of composite thin films is closely related to the presence of oxygen.