有序二氧化硅纳米通道薄膜的电化学研究
发布时间:2018-05-07 01:06
本文选题:二氧化硅纳米通道薄膜 + 电化学整流 ; 参考:《浙江大学》2015年博士论文
【摘要】:纳米通道是一种孔径在1-100nm范围,并且孔道深度大于孔径的孔状或管状结构,具有尺寸可控、比表面积大、表面易修饰等优点,已成为化学、材料、生命科学等领域中的重要研究对象。纳米通道在分析、分离、单分子检测、药物传递、仿生离子通道模拟以及其它纳米材料的合成等方面均有良好的应用前景。受天然生物纳米孔道的启发,科学家们利用各种前沿的物理化学技术制备了多种人工固体纳米通道。垂直有序的二氧化硅纳米通道为一种较新的固体纳米孔道,具有制备方法简单、重现性好、物理化学性质稳定等优点。本论文以有序二氧化硅纳米通道为基础,研究了分子在二氧化硅纳米通道中的传输以及电活性物质在其中的负载。开展的工作具体如下:依据二氧化硅纳米通道的表面性质,研究了二氧化硅纳米通道薄膜的选择渗透性。二氧化硅纳米通道表面带有羟基,等电点为2-3,在pH大于3的溶液中二氧化硅表面带负电荷。以三种带不同电荷的探针分子为例,考察了表面电荷对分子在纳米通道中传输的影响。通过修饰胺基使二氧化硅表面带正电荷,此时带不同电荷的探针分子在其通道中的传输情况发生翻转。此外,二氧化硅纳米孔的直径为2-3 nm,在此纳米尺度上表面双电层发生重叠。低离子强度下,与二氧化硅表面带相同电荷的分子在其通道中的传输受到明显地影响。利用金电极上硫醇二茂铁分子自组装膜的整流效应构建了AND逻辑门。首先在含有垂直二氧化硅纳米通道薄膜的金电极表面组装硫醇二茂铁分子。由于硫醇二茂铁分子的氧化电位高于溶液中的亚铁氰化钾(Fe(CN)64-)探针分子,因此产生阳极整流。整流的程度用阴极峰电流与阳极峰电流的比值来评价,当阴极峰电流消失时为完全整流。实验发现,随着Fe(CN)64-浓度的增大,硫醇二茂铁的整流效应越来越明显。当探针分子的浓度大于90μM时,发生完全整流。由于双电层重叠,能够进入二氧化硅纳米通道与硫醇二茂铁发生反应的Fe(CN)64-的量受电解质浓度的控制。在Fe(CN)64-浓度一定的情况下,随着电解质浓度的增加,整流效应越来越明显;当NaClO4的浓度接近0.1 M时,Fe(CN)64-可自由的进入二氧化硅纳米通道,发生完全整流。利用探针分子和电解质的浓度对硫醇二茂铁整流效应的影响构建了AND逻辑门。制备了聚苯胺-介孔二氧化硅纳米复合材料。以具有垂直于电极表面纳米通道的二氧化硅为硬模板,用电化学聚合的方法在孔道中沉积聚苯胺。通过调节电聚合时间与苯胺单体的浓度,可以控制苯胺的电聚合只发生在二氧化硅纳米通道内。得到的聚苯胺-介孔二氧化硅复合物对抗坏血酸(AA)的电化学氧化有较好的催化活性,可用于AA的定量分析,在0.1-1.0mM范围内氧化峰电流与AA的浓度有较好的线性关系。该复合物还可以用作pH传感器,在pH 3~9范围内电极电势与pH呈能斯特响应。研究了金属纳米颗粒在二氧化硅纳米通道内的负载及其电催化和电分析性能。通过在二氧化硅通道中修饰可与金属前驱体发生相互作用的基团,将金属前驱体引入到二氧化硅通道中,最后经过化学还原将二氧化硅通道中的金属前驱体还原为金属纳米颗粒。通过在介孔二氧化硅通道中修饰可与金前驱体发生静电吸引作用的氨基基团,合成了粒径分布较窄且不含有机保护基团的金纳米颗粒。在第三章工作的基础上,利用铂前驱体与聚苯胺骨架结构中仲胺和叔胺的相互作用,在二氧化硅通道内同时引入了聚苯胺与铂纳米颗粒两种活性基团。该复合材料具有良好的电催化活性,可检测较宽浓度范围(1.0 μM-2.0 mM)内的H2O2,并且具有较高的灵敏度(50μA mM-1)和较低的检测限(0.24 μM,S/N=3)。
[Abstract]:Nanoscale is a porous or tubular structure with aperture in the range of 1-100nm, and the pore depth is larger than the aperture. It has the advantages of size controllable, large surface area and surface modification. It has become an important research object in the fields of chemistry, material, life science and so on. The nanoscale channel is analyzed, separated, single molecule detection, drug delivery, bionic ion The channel simulation and the synthesis of other nanomaterials have good application prospects. Inspired by the nanoscale nanomaterials, scientists have prepared various artificial solid nanoscale channels by various frontiers of physicochemical technology. The vertical ordered silica nanochannel is a new solid nano channel, which is prepared. The method is simple, reproducible and stable in physical and chemical properties. In this paper, the transport of molecules in silica nanoscale and the load of electroactive substances in silica nanochannels are studied on the basis of ordered silica nanoscale. The work of this paper is as follows: Based on the surface properties of the two oxygenated silicon nanochannels, the two oxygen is studied. Selective permeability of silicon nanoscale thin films. The surface of silicon dioxide nano channel with hydroxyl group, isoelectric point is 2-3, the surface of silicon dioxide with negative charge in pH more than 3. Three kinds of probe molecules with different charge are used as an example to investigate the effect of surface charge on the transport of molecules in nanoscale. By modifying the amine group, two oxidation is made. In addition, the diameter of the silicon dioxide nanopore is 2-3 nm, and the surface double layer overlaps on the nanoscale. Under the low ion intensity, the molecules with the same charge with the silicon dioxide surface are transmitted in the channel. The AND logic gate is constructed by the rectification effect of the mercaptan two ferrocene molecular self assembled film on the gold electrode. First, the thiol two ferrocene molecules are assembled on the surface of the gold electrode containing the vertical silicon dioxide nanoscale membrane. The oxidation potential of the thiol two ferrocene molecule is higher than the potassium ferrocyanide (Fe (CN) 64-) probe molecule in the solution. This produces an anode rectifier. The degree of rectification is evaluated by the ratio of the peak current to the anode peak current. When the cathode peak current disappears, the rectification effect is completely rectified. It is found that the rectification effect of the thiol two ferrocene is becoming more and more obvious with the increase of the concentration of Fe (CN) 64-. The amount of Fe (CN) 64- that can enter the silica nanoscale and thiol two ferrocene is controlled by the electrolyte concentration. With the concentration of Fe (CN) 64-, the rectifying effect becomes more and more obvious with the increase of the concentration of electrolyte. When the concentration of NaClO4 is close to 0.1 M, Fe (CN) 64- can enter the silicon dioxide nanoscale freely. The AND logic gate was constructed with the influence of probe molecules and electrolyte concentration on the rectifying effect of thiol two ferrocene. Polyaniline mesoporous silica nanocomposites were prepared. The silica was a hard template with nano channels perpendicular to the surface of the electrode and deposited in the channel by electrochemical polymerization. Aniline, by adjusting the time of electropolymerization and the concentration of aniline monomer, can control the electropolymerization of aniline only in the silica nanoscale. The polyaniline mesoporous silica composite has a good catalytic activity against the electrochemical oxidation of AA, and can be used for the quantitative analysis of AA and the oxidation of peak power in the range of 0.1-1.0mM. The flow has a good linear relationship with the concentration of AA. The complex can also be used as a pH sensor, and the electrode potential in the pH 3~9 range is in the nerster response to pH. The load of metal nanoparticles in the silica nanochannel and its electrocatalytic and electroanalytical properties are investigated. By modifying the two oxygen silicon channel, it can be used with the metal precursor. The metal precursor is introduced into the silica channel by the group of the interaction. Finally, the metal precursor in the silicon dioxide channel is reduced to a metal nanoparticle by chemical reduction. The amino group that can be used in the electrostatic attraction with the gold precursor is modified by modifying the mesoporous silica channel. On the basis of the third chapter, on the basis of the work of the third chapter, two active groups of Polyaniline and platinum nanoparticles are introduced in the silica channel by the interaction of the platinum precursor and the tertiary amine in the polyaniline framework. The composite has good electrocatalytic activity and can be used to detect the wide concentration. The H2O2 in the range (1 M-2.0 mM) has a high sensitivity (50 A mM-1) and a lower detection limit (0.24 M, S/N=3).
【学位授予单位】:浙江大学
【学位级别】:博士
【学位授予年份】:2015
【分类号】:O613.72;TB383.1
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