可直接还原银纳米粒子的儿茶酚基聚合物膜的制备及抗菌性能研究

将预先合成的聚合物PVA-DOPA与PVA共混制备聚合物膜PVA/PVA-DOPA;由于含儿茶酚基的3,4-二羟基苯丙氨酸(DOPA)具有氧化还原活性,可直接利用PVA/PVA-DOPA聚合物还原银纳米粒子并使其负载在PVA/PVA-DOPA膜表面。紫外可见光谱表明,PVA-DOPA与Ag+作用时,发生氧化还原反应,酚羟基被氧化成醌,在415nm处出现特征吸收峰。通过扫描电子显微镜和透射电子显微镜,可观察到聚合物膜表面Ag纳米粒子的形态;并通过热失重分析计算出PVA/PVA-DOPA/Ag0膜中Ag的负载量。抗菌性研究测试表明制得的聚合物膜具有良好的抗菌性。因而,PVA/PVA-DOPA聚合物膜可用作抗菌性包装材料、涂层材料和生物医用材料等多种功能材料。     

硫化亚锡敏化纳晶TiO2膜的制备及光电性能研究

采用简单的离子交换沉积法制备了SnS敏化的纳晶TiO₂光阳极。通过SEM、XRD、UV-Vis等手段对光阳极的表面形貌, 晶态结构, 紫外-可见吸收和散射性能进行表征。并分别以聚苯胺和铂为催化剂制备对电极, 以含碘氧化还原电对和硫氧化还原电对溶液为电解质, 组装SnS敏化太阳能电池, 对其光电性能进行研究。通过比较不同光阳极、电解质和对电极的组合, 发现用光阳极为离子交换沉积9次SnS的纳晶TiO₂膜, 对电极为聚苯胺不锈钢网压片膜, 电解质为含硫氧化还原电对溶液组装的太阳能电池光电性能最佳, 其短路电流、开路电压、填充因子和光电转换效率分别达到4.59 mA/cm²、0.547 V、0.505和1.27%。     

柔性TiO2薄膜电极的制备方法及其对光电性能的影响

分别采用水热法和紫外处理低温烧结法制备了柔性TiO2薄膜电极。通过傅立叶变换红外吸收光谱仪（FTIR）、紫外可见光仪（UVSP）、场发射扫描电镜（FESEM）对两种方法制备的TiO2薄膜电极进行表征，同时，测试了不同电极组装柔性染料敏化太阳能电池的光电性能。结果表明：两种方法制备的电极均为一种多孔结构，不含有机物；紫外处理低温烧结法制备电极组装柔性电池的短路电流为4.9mA，其光电转换效率为1．28％。而水热法制备电极组装柔性电池的稳定性较好，虽然其短路电流为2．60mA，光电转换效率为1．32％。     

聚吡咯-二氧化钛自组装复合膜的制备及其光电转换性质

通过原位自组装技术制备了聚吡咯-二氧化钛纳米复合膜,利用紫外-可见光谱、红外光谱、原子力显微镜、电化学循环伏安等方法对所制备的复合膜进行了表征.与利用原位自组装技术制备的聚吡咯膜相比较,由于在复合膜中聚吡咯和TiO2纳米粒子之间的相互作用,复合膜π→π*跃迁吸收峰发生蓝移,氧化还原峰的位置向负电位方向移动.沉积在导电玻璃ITO表面的该纳米复合膜在可见光下表现出一定的光电转换性质.     

2种苯并咪唑衍生交替共聚物的合成及性能

以苯并噻二唑作为初始原料,通过Sonogashira、Suzuki反应将4,7-二溴-2-己基-1,3-苯并咪唑单体分别与带有不同烷氧基链的对苯乙炔、9,9-二辛基芴进行交替共聚,得到了聚[2-己基-1,3-苯并咪唑-1,4-二乙炔基-2,5-二辛氧基苯](P1)、聚[2-己基-1,3-苯并咪唑-1,4-二乙炔基-2,5-二(十二烷氧基)苯](P2)和聚[2-己基-1,3-苯并咪唑-9,9-二辛基芴](P3)。采用红外光谱、核磁共振等手段对单体和共聚物的结构进行了表征,利用紫外-可见吸收光谱、荧光量子效率测试和循环伏安法对聚合物的光、电化学性能进行了探讨。结果表明,共聚物P1、P2均在445 nm处出现紫外-可见吸收峰,共聚物P3在376 nm处出现紫外-可见吸收峰。P2、P3共聚物的相对荧光量子效率分别为80%,66.7%,所得共聚物都有较强的荧光性能。P2共聚物在1.3 V处出现氧化掺杂峰,在-1.3 V处出现还原掺杂峰,P3共聚物在0.48 V处出现氧化掺杂峰,0.34 V处出现脱掺杂峰。     

三苯胺类染料用于染料敏化太阳能电池光敏剂的理论研究

为了揭示三苯胺分子为敏化剂的染料敏化太阳能电池(DSSCs)的物理机制,采用含时密度泛函理论(TDDFT)方法计算了三苯胺染料分子1、2、3的紫外-可见吸收光谱和能级结构。结果表明,在电子给体和电子受体不变的情况下,改变π桥结构将明显改变染料的光谱性质。分子3的紫外-可见吸收光谱比分子1、2的吸收光谱有明显的红移。分子2、3的摩尔吸光系数也明显高于分子1的摩尔吸光系数,因此具有更高的捕获太阳光的能力。计算结果还表明,有机染料的合成需要综合考虑染料的吸收光谱特性、染料能级与半导体电极电位及氧化还原电解液电位的匹配及电子注入等内在因素,从而提高DSSCs的能量转化效率。     

聚鲁米诺膜修饰金电极上对苯二酚的电化学行为

在强酸性溶液中,鲁米诺能在金电极上电氧化聚合得到聚鲁米诺刚性膜,该膜有一对峰形良好的氧化还原峰。该聚鲁米诺膜修饰电极可用于电催化氧化对苯二酚。在0.5molL-1H2SO4溶液中,该修饰电极上对苯二酚氧化电流的线性范围为5.0×10-6~2.0×10-4molL-1。     

水溶性C_(60)-环糊精包络化合物的合成及其光、电化学性质研究

以羟丙基-β-环糊精为主体,C60为客体形成了C60-羟丙基-β-环糊精包络化合物,并对包络化合物进行了红外和紫外光谱的表征。通过循环伏安法研究了包络化合物在水溶液中的电化学性质,发现其在电极上的反应是准可逆的氧化还原反应。在紫外光光照条件下形成了C.-60-羟丙基-β-环糊精,利用它的还原性对Ag+和AuCl-4等进行了还原,形成了水溶性的Ag和Au纳米颗粒,并对其进行了透射电镜和紫外可见光谱表征。     

新型太阳能材料C60Pt（dppp）配合物的合成及性能

以C60及双齿膦dppp为配体,在氮气氛下合成出C60Pt(dppp)配合物,采用质谱、元素分析、红外光谱、紫外可见光谱以及光电子能谱等手段对产物进行表征.同时研究了产物的光电性能及氧化还原性能.光伏效应研究结果表明:产物具有优良的光电转化性能,尤其是在BQ/H2Q介质电对中,光生电压最大达到371mV;当C60Pt(dppp)薄膜厚度为1μm时,光伏效应值最大.     

金属氧化物超大容量电容器电极材料的研究进展

超大容量电容器是一种介于传统电容器和电池之间的新型储能元件,它比传统电容器具有更高的比电容和能量密度,比电池具有更高的功率密度,因而具有广阔的应用前景.简要介绍了超大容量电容器的储能机理、特点,综述了金属氧化物超大容量电容器电极材料的发展状况,以及改善氧化钌基电容器的方法和廉价材料(如氧化镍、氧化钴、氧化锰、氮化钼等)替代氧化钌电极的研究进展情况,展望了其发展趋势.     

Bis(2,2'-bipyridine)(5,6-epoxy-5,6-dihydro-[1,10]phenanthroline)ruthenium: synthesis and electrochemical and electrochemiluminescence characterization

In this work, an electrochemiluminescence (ECL) reagent bis(2,2'-bipyridine)(5,6-epoxy-5,6-dihydro-[1,10]phenanthroline)ruthenium complex (Ru-1) was synthesized, and its electrochemical and ECL properties were characterized. The synthesis of Ru-1 was confirmed by IR spectra, element analysis, and (1)H NMR spectra. For further study, its UV-vis absorption and fluorescence emission spectra were investigated. Ru-1 also exhibited quasi-reversible Ru (II)/Ru (III) redox waves in acetonitrile solution. The aqueous ECL behaviors of Ru-1 were also studied in the absence and in the presence of tripropylamine. The complex was fabricated on a gamma-(aminopropyl) triethoxysilane (APTES) pretreated indium tin oxide (ITO) substrate via aminolysis reaction between the 5,6-epoxy-5,6-dihydro-[1,10]phenanthroline ligand and APTES. The resulting Ru-1 modified ITO substrate exhibited a broad absorption band in the visible region (350-600 nm) and its fluorescence emission spectrum was centered at 622 nm. The Ru-1 modified ITO electrode showed relative low ECL response. To improve the solid-state ECL response, a gold nanoparticles (GNP)/Ru-1 modified ITO electrode was constructed. The mixing of GNP and Ru-1 could produce the aggregates, which were further immobilized onto a 3-mercaptopropyltrimethoxy-silane (3-MPTMS) pretreated ITO substrate via Au-S interactions to construct the GNP/Ru-1 modified electrode.     

Electrochemical oxidation of oxalic acid at highly boron-doped diamond electrodes

Electrochemical oxidation of oxalic acid has been investigated at bare, highly boron-doped diamond electrodes. Cyclic voltammetry and flow injection analysis with amperometric detection were used to study the electrochemical reaction. Hydrogen-terminated diamonds exhibited well-defined peaks of oxalic acid oxidation in a wide pH range. A good linear response was observed for a concentration range from 50 nM to 10 microM, with an estimated detection limit of approximately 0.5 nM (S/N = 3). In contrast, oxygen-terminated diamonds showed no response for oxalic acid oxidation inside the potential window, indicating that surface termination contributed highly to the control of the oxidation reaction. An investigation with glassy carbon electrodes was conducted to confirm the surface termination effect on oxalic acid oxidation. Although a hydrogen-terminated glassy carbon electrode showed an enhancement of signal-to-background ratio in comparison with untreated glassy carbon, less stability of the current responses was observed than that at hydrogen-terminated diamond.     

Chromatographic detection of nitroaromatic and nitramine compounds by electrochemical reduction combined with photoluminescence following electron transfer

The oxidizing agent tris(bipyridyl)ruthenium(III), or Ru-(bpy)(3)3+, is used as a postcolumn reagent for the detection of nitroaromatic and nitramine explosive compounds. After separation, the explosives are reduced electrochemically to oxidizable products such as hydroxlamines and nitrosamines, and these products react readily with Ru-(bpy)(3)3+ and Ru(bpy)(3)2+. The photoluminescence from the latter is used for detection. A porous carbon electrode was used for on-line analyte reduction following chromatography. Another porous carbon electrode was used to generate the nonluminescent Ru(bpy)(3)3+ from Ru(bpy)(3)3+ on-line at high efficiency. The two streams were combined, and the Ru(bpy)(3)2+ produced by oxidation of the reduced analytes was detected by laser illumination and light detection. Reductive hydrodynamic voltammograms of nitrobenzene, 2,4,6-trinitrotoluene, and hexahydro-1,3,5-trinitro-1,3,5-triazine indicated that a potential of - 1500 mV vs Ag/AgCl was sufficient to achieve a maximum signal from the reduced analytes. HPLC with a water/acetonitrile gradient on a C-18 reversed-phase column was then used to determine these three compounds plus the four additional examples, 1,3,5,7-tetrazocine, 2,4-dinitrotoluene; 2,6-dinitrotoluene, and 4-nitrotoluene. For both hydrodynamic voltammetry and HPLC detection, the photoluminescence following electron-transfer signal was calibrated using the one-electron standards ferrocene and ferrocenecarboxylic acid. Detection limits were in the low-nanomolar range for 20-microL injections of nonpreconcentrated nitro compounds.     

碳纳米管/聚苯胺化学修饰电极的制备及其对抗坏血酸的检测

通过恒电压沉积法将纳米金属镍沉积于石墨电极表面, 经化学气相沉积法在石墨电极表面原位生长出碳纳米管(CNTs), 通过电化学聚合法在CNTs表面原位聚合聚苯胺, 从而获得化学修饰电极。采用扫描电子显微镜对所得电极形貌结构进行表征, 并研究CNTs与PNAI复合电极对抗坏血酸(AA)的检测效果。研究结果表明: 制备的CNTs都能均匀地生长在石墨电极表面, 纳米中空管状结构都保持完好; PANI均匀地包覆在CNTs管壁上, 复合材料呈现出典型的三维网状结构。所制备的CNTs/PANI修饰电极对AA具有良好的电化学响应, 其中管径较小CNTs的修饰电极对AA的电化学响应更强: 具有更宽的检测范围和更低的检出限。其检测线性范围为1.0×10^-6~4.5×10^-4 mol/L, 检出限为1.0×10^-7 mol/L (S/N = 3)。且具有良好的稳定性、重复性和可靠性。     

碳纳米管电极电催化氧化降解染料溶液的研究

研究了经高温焙烧结合高速球磨处理后的碳纳米管的结构及形貌, 测定了其相应的比表面积. 对碳纳米管冷压成形制得的电催化电极的表面形貌进行了分析. 分别以活性炭、石墨、碳纳米管作为电催化阳极, 处理模拟染料废水活性艳红X-3B溶液, 实验结果表明: 碳纳米管电极电催化稳定性较好, 经电催化氧化反应20min后, X-3B染料的降解率达到96.55%, 其电催化降解效率明显优于活性炭和石墨电极.     

Direct electrochemistry and electrocatalytic activity of cytochrome c covalently immobilized on a boron-doped nanocrystalline diamond electrode

Cytochrome c (Cyt c) was covalently immobilized on a boron-doped nanocrystalline diamond (BDND) electrode via surface functionalization with undecylenic acid methyl ester and subsequent removal of the protecting ester groups to produce a carboxyl-terminated surface. Cyt c-modified BDND electrode exhibited a pair of quasi-reversible and well-defined redox peaks with a formal potential (E(0)) of 0.061 V (vs Ag/AgCl) in 0.1 M phosphate buffer solution (pH 7.0) and a surface-controlled process with a high electron transfer constant (ks) of 5.2 +/- 0.6 s(-1). The electrochemical properties of as-deposited and Cyt c-modified boron-doped microcrystalline diamond (BDMD) electrodes were also studied for comparison. Investigation of the electrocatalytic activity of the Cyt c-modified BDND electrode toward hydrogen peroxide (H2O2) revealed a rapid amperometric response (5 s). The linear range of response to H2O2 concentration was from 1 to 450 microM, and the detection limit was 0.7 microM at a signal-to-noise ratio of 3. The stability of the Cyt c-modified BDND electrode, in comparison with that of the BDMD and glassy carbon counterpart electrodes, was also evaluated.     

钌-生物质碳人工酶的制备及在比色检测杀虫剂毒死蜱残留中的应用

金属纳米材料人工酶以其高稳定性和低成本的特点而被广泛用于生物传感与催化领域。本研究采用[1-甲基-3- 乙基咪唑][二氰胺]离子液体([EMIM][DCA])与氯化钌反应形成[EMIM]₃[Ru(DCA)₆]离子液体, 将蚕丝溶解于[EMIM]₃[Ru(DCA)₆]后经高温碳化得到钌-生物质碳纳米材料。结果显示, 钌-生物质碳纳米材料具有优异的分散性, 平均直径为7.5 nm的钌纳米粒子可均匀地分散在碳片表面, 表现出较强的类氧化酶活性。基于杀虫剂毒死蜱对钌-生物质碳酶活性的抑制作用, 建立了一种测定毒死蜱的比色方法。钌-生物质碳酶能催化3,3′,5,5′-四甲基联苯胺氧化生成蓝色产物。毒死蜱能抑制钌-生物质碳人工酶的活性, 从而导致蓝色产物的吸光度下降。当毒死蜱浓度在10~80 ng/mL之间, 反应体系的吸光度随毒死蜱浓度增大而线性下降, 检出下限为6.5 ng/mL。本方法的灵敏度和稳定性明显优于现有技术, 已成功应用于桃果实中毒死蜱农药残留的快速测定。     

Comparison of different methodologies for integration of molecularly imprinted polymer and electrochemical transducer in order to develop a paraoxon voltammetric sensor

In this work a paraoxon voltammetric sensor was introduced. Different methods for integration of molecularly imprinted polymer (MIP) and electrochemical transducer were investigated. Three techniques including MIP particles embedding in the carbon paste (CP) (MIP-CP), coupling of MIP with the glassy carbon electrode (GC) surface by using poly epychloro hydrine (PECH) (MIP/PECH-GC) and MIP/graphite mixture thin layer attachment onto the glassy carbon electrode (MIP/Graphite-PECH-GC) were tested. The prepared electrodes were applied for paraoxon measurement by using a three-step procedure including analyte extraction in the electrode, electrode washing and electrochemical measurement of paraoxon. The washing of electrodes, after paraoxon extraction, led to high selectivity of electrode for paraoxon. It was found that MIP-CP electrode had higher response to paraoxon in comparison to other tested electrodes. Besides, the washing process decreased response magnitude of MIP/PECH-GC and MIP/Graphite-PECH-GC but, the response of MIP-CP was not affected considerably by the washing. Parathion was chosen to evaluate the selectivity of MIP based sensors. It was proved that the MIP-CP had better selectivity, wider linear range and lower detection limit in comparison to other tested electrodes. The developed MIP-CP electrode was used as a high selective sensor for paraoxon determination in water and vegetable samples.     

Supercapacitance of ruthenium oxide deposited on titania and titanium substrates

Titanium planar sheet formed by a chemical polishing process and titania nanotube array formed by an electrochemical anodization process are used as electrode substrates, on which electroactive ruthenium oxides are deposited by an electroreduction and electrooxidation process for supercapacitor applications. Morphological characterization and electrochemical properties of the electrode substrates and ruthenium oxide electrodes have been investigated. Crystalline titania nanotube array shows a much higher electric double layer capacitance than titanium planar sheet due to its high surface area of nanotube walls. Additionally, the well-defined ruthenium oxide–titania/titanium nanotube array electrode exhibits a much higher redox supercapacitance and a lower capacitance decay than ruthenium oxide/titanium planar film electrode. Such a superior energy-storage performance of ruthenium oxide–titania/titanium is ascribed to highly accessible nanotube channels for the reversible redox reaction of ruthenium oxide. The modification strategy of ruthenium oxide electrode by introducing highly ordered nanotube array structure instead of planar film structure can significantly improve specific capacitance as well as cyclic charge-discharge stability.     

Ruthenium complex containing block copolymer for the enhancement of carbon nanotube photoconductivity

We report the synthesis of a multifunctional block copolymer incorporated with pyrene and ruthenium terpyridyl thiocyanato complex moieties by reversible addition-fragmentation chain transfer polymerization. The pyrene block in the copolymer facilitates the dispersion of multiwalled carbon nanotubes in DMF solution because of the strong π-π interaction between the pyrene moieties and nanotube surface. On the other hand, the ruthenium complexes greatly enhance the photosensitivity of the functionalized nanotubes in the visible region. The photocurrent responses of the nanotubes at different wavelength measured by conductive AFM spectrum strongly agree with the absorption spectrum of the ruthenium complex. The results demonstrate a new and versatile approach in enhancing and fine-tuning the photosensitivity or other opto-electronic properties of carbon nanotubes by multifunctional block copolymers.