【作者】 史鸿雁；

【导师】 宋文波；

【作者基本信息】 吉林大学 ， 分析化学， 2014， 博士

【摘要】 钛酸盐纳米管不仅具备大的比表面积、优良的导电性、良好的生物相容性，同时还具有强吸附和离子交换性质，已引起科学家们的广泛关注和研究兴趣。目前为止，钛酸盐纳米管的研究多集中在材料制备方面，关于其催化及分析传感应用的研究报道还不多见。然而，常规的粉体分散液涂膜和交替层沉积技术多得到无序的钛酸盐纳米管膜，不利于实现其功能，故开展与基底结合牢固、取向垂直的钛酸盐纳米管阵列制备技术研究具有重要意义。本文基于对水热调控钛酸盐纳米管阵列的生长研究，设计制备了几种功能杂化材料体系，系统研究了这些功能化的钛酸盐纳米管阵列的分析性能，构建了几种高灵敏度、高稳定性、响应快速的电化学传感器。论文的第一章详细介绍了钛酸盐纳米管的性质、合成方法和应用领域，并对电化学传感器进行了简单的介绍。论文第二章利用水热制备方法，在金属钛片表面直接生长钛酸盐纳米管阵列膜，考察了水热制备参数对钛酸盐膜结构及形貌的影响；并基于晶体生长动力学和形态学研究结果，初步提出了钛酸盐纳米管阵列膜的水热生长机制；并在优化水热参数的基础上，实现了钛酸盐纳米管阵列的可控制备。实验结果表明，获得的钛酸盐纳米管阵列膜与钛片基底结合力强，热稳定性高，化学性质稳定。钛酸盐纳米管呈负电性，对晶体生长具有导向作用。在第三章中，基于钛酸盐纳米管阵列的纳米限域作用，模板电沉积制备了铜纳米立方，沉积的铜纳米立方堆积成三维纳米花结构，有效增大了材料的比表面积，可提供更多的催化点位，有助于提高分析检测性能。文中通过电化学氧化将沉积的铜纳米立方转化为铜氧化物，获得了钛酸盐纳米管阵列/铜氧化物纳米立方功能杂化材料体系，系统地研究了该功能电极材料的葡萄糖检测性能。钛酸盐纳米管阵列/铜氧化物纳米立方杂化材料在葡萄糖的分析检测中，具有高灵敏度、高稳定性、宽的线性范围等优点。论文第四章将石墨烯氧化物组装到钛酸盐纳米管阵列表面，实现了一维纳米材料和二维纳米材料的有序复合；然后，通过电化学还原使石墨烯氧化物转化为还原型石墨烯氧化物，系统研究了还原型石墨烯氧化物/钛酸盐纳米管阵列复合材料对邻苯二酚和对苯二酚的同时检测性能。实验结果表明，还原型石墨烯氧化物片层通过组装堆积形成了三维结构，该结构不仅具有大的比表面积，而且其三维纳米通道利于分析物的快速吸附和催化，表现出了良好的电催化性能，而且稳定性高、重现性好，可望用于环境分析检测等领域。在第五章中，改变水热反应条件，设计合成了钛酸盐纳米管交织形成的三维多级孔结构膜，并基于钛酸盐纳米管表面的负电荷，通过聚电解质层层组装技术，将金纳米粒子修饰在钛酸盐纳米管表面，制备了具有高催化活性的金纳米粒子/钛酸盐纳米管多孔膜。然后，将具有亚铁卟啉结构的血红素引入其多孔结构膜内，对比研究了其负载血红素前后对亚硝酸盐的检测性能。实验结果表明，金纳米粒子功能化的三维钛酸盐纳米管多孔膜具有大比表面积，能够提供更多的反应活性点位，且通过血红素的负载，亚铁卟啉结构呈现了快速的电子传输性能，显著改善了亚硝酸盐的检测性能。壳聚糖含有大量的羟基和氨基等活性基团，常用来作为合成金属纳米粒子的还原剂。论文第六章中，以壳聚糖为稳定剂和还原剂，利用钛酸盐纳米管表面的负电性对金纳米粒子生长的导向作用，通过调节壳聚糖与金属盐前驱体的浓度比，一步原位还原制备了钛酸盐纳米管阵列@金复合膜，获得了尺寸均匀、分散性好的钛酸盐纳米管阵列@金，并系统研究了过氧化氢的分析性能。实验结果表明，钛酸盐纳米管阵列的特殊结构、金纳米粒子尺寸小、高分散等特点，赋予复合电极材料以较高的电催化活性，实现了过氧化氢的高灵敏、快速响应、高稳定性的检测。在第七章中，在钛酸盐纳米管阵列上将多巴胺单体聚合，以聚多巴胺为碳源进行高温碳化，同时在高温条件下，钛酸盐转化为二氧化钛相，形貌由空心的纳米管转化为实心的纳米棒，制备了TiO2@C核壳结构功能杂化材料，构建了葡萄糖生物传感器并详细研究了其性能。实验结果表明，TiO2@C核壳结构纳米棒有效的加速了反应中的电子传递，实现了葡萄糖氧化酶的活性中心和TiO2@C核壳结构功能杂化材料之间的直接电子转移。该传感器用于葡萄糖的检测，具有线性范围宽、检测限低、灵敏度高、稳定性好等优点。水热钛酸盐纳米管阵列阵列电极基电化学传感平台的研究，不仅能极大提升电化学检测的分析性能，而且有望制成快速、超灵敏、无标记的电化学检测器件，为生命科学等领域研究提供更新的方法与技术。此外，由于钒和钨氧化物、硫化物等纳米管材料具有和钛酸盐纳米管阵列相似的晶体结构，本研究结果还可为其它相似半导体纳米阵列的研究提供参考和借鉴。更多还原

【Abstract】 One-dimensional (1D) nanostructured materials are attracting great attentions inthe fields of electronics, biotechnology, catalysis and sensors due to highsurface-to-volume ratio, efficient electron transport, good chemical and thermalstabilities.1D titanate nanotubes (TNTs) are attracting great research interests,because of the advantages of cost-effectiveness, mild reaction conditions, low energyconsumption and simple equipment involved in the hydrothermal synthetic approach.These TNTs posses intrinsic multi-functionality, rising not only from combination ofthe property and application of TiO2nanomaterials with the ion exchange property oflayered titanates with tubular morphology, but also from the distinct property oftubular regions (like tube opening, inner, outer and the interstitial regions). Besides,TNTs also have great potential in catalysis via loading large amount of metal cations,based on their high cation exchange capacity, and generating hybrid nanostructurewith desirable catalytic activity. Interestingly, the morphology of hydrothermallyproduced TNTs can be modulated by tuning a large number of variable factors, andvertically aligned TNTs (VATNTs) were successfully achieved directly on Ti substrateby a modified hydrothermal process. VATNTs often exhibited an orientedmultilayered structure, consisted of vertically aligned individual nanotube with ananometer-scale inner-core cavity exposed to the outer surface. One interestingfeature of VATNTs includes uniform pore size and high available surface area, whichare ready for hybridization with functional groups or molecules. Another is the facilecharge transfer between the underlying conductive substrate and the hybridizedfunctional groups or molecules, due to the good contact of each vertically oriented TNT with Ti slide. These imply a possibility of designing VATNTs-based hybridelectrode with improved activity and signal sensitivity for catalysis and sensing.In Chapter1, the property, synthesis and application of TNTs nanomaterials werechiefly introduced. The preparation and application of electrochemical sensors werealso briefly introduced. In Chapter2, VATNTs with high available surface area anduniform pore size was directly achieved on titanium substrate by a facile yet efficienthydrothermal route. By tuning hydrothermal conditions (including the concentrationof NaOH solution, reaction temperature and time, as well as the post treatmentprocedures), the morphology and structure of the titanate nanotubes arrays wereobtained. Based on these results, a general formation mechanism of titanate nanotubesarrays via the hydrothermal route was proposed. The optimum hydrothermalconditions of formation of titanate nanotubes arrays were in10mol·L-1NaOHsolution at140°C for6h. In Chapter3, TNTs possesses unique ion-exchange abilityand presents a uniform pore size and better stability as compared to non-alignednanotubes. These features increase the available surface area and allow greaterpenetration for catalyst loading, further simplify the optimization of the hybridizationprocesses. Here, VATNTs were in situ grew hydrothermally on titanium substrate, andthe possibility of electrochemically hybridizing VATNTs with CuxO nanocubes(CONC) to achieve VATNTs/CONC hybrid nanostructure for electrocatalysis andanalytic application was firstly demonstrated. Results revealed the distinctly enhancedsensing properties of VATNTs/CONC towards glucose, showing significantly loweredoverpotential, ultrafast and ultrasensitive current response in a wide linear range. InChapter4, VATNTs were functioned with graphene oxide (GO) sheets via layer bylayer assembly, and then GO was reduced by electrochemical reduction method. TheVATNTs functionalized RGO (RGO/VATNTs) not only exhibits excellent stability,which demonstrated as good electrocatalysts for small molecules. Simultaneousdetection of catechol (CC) and hydroquinone (HQ) was demonstrated in detail,showing promising application in medical and environmental fields. In Chapter5,3DTNT network via the hydrothermal route was proposed, which possess uniqueion-exchange ability and present uniform pore size and high stability.3D TNT network decorated with Au nanoparticles was obtained by assembly process, whichwas utilized as an efficient biomolecule immobilization platform. The heme was thenintroduced into3D TNT network, which used for determination of NO-2in water. Itsporous structures can enable rapid diffusion of analytes across a large surface area andpore, resulting in reduced response time. In addition, electronic transfer center ofheme facile charge transfer, favorable for electrochemical confining AuNPsnanostructure for catalysis and sensing. In Chapter6, VATNTs possessed increasedavailable surface area and uniform pore size, as well as additional features of highion-exchange capacity and facile charge transfer, which anchoring significant Aucations on the basis of electrostatic self-assembled strategy and producing highlydispersed AuNPs catalysts via a simple one-step chemistry reduction of chitosan (CS).They were demonstrated directly as electrode materials for electrocatalytic oxidationof peroxide. The VATNTs@Au exhibited excellent electrochemical performances forperoxide oxidation, presenting a low peak potential, high current, and highcurrent-to-background ratio. This sensor is expected to play an important role in thefield of peroxide monitoring. In Chapter7, TiO2@C nanorod was prepared throughdirect carbonization of polydopamine on VATNTs. The structures and morphologiesof TiO2@C nanorods were characterized and analyzed in detail by XRD, EDX, SEMand TEM. The TiO2@C nanorod was used as a novel immobilization platform forglucose oxidase (GOD). The entrapped enzyme retains good bioactivity and exhibitssatisfied performance due to the biocompatibility and efficient electron transfer ofTiO2@C nanorod. With satisfactory selectivity, reproducibility, and stability, thenanostructure we proposed offered an alternative for electrode fabricating and glucosebiosensing.更多还原