中空、多孔贵金属纳米结构的构筑及其机理、性能研究

发布时间：2018-05-17 09:02

本文选题：贵金属纳米结构 + 伽伐尼反应　；参考：《温州大学》2015年硕士论文

【摘要】：贵金属纳米结构因其独特的物理、化学性质、丰富的形貌而具有广泛的应用前景。众所周知,贵金属纳米结构的性质由一系列物理参数来决定,这些参数包括形状、尺寸、组成及结构等。目前,科研人员己经开发很多制备技术。通过这些技术,可以设计和可控制备贵金属纳米结构以及性质,从而使他们能够在众多领域尤其是电化学催化、燃料电池、生化检测、医药及传感等方面得到应用。本论文基于伽伐尼取代和选择性刻蚀可控制备了不同形貌的中空、多孔贵金属纳米结构,探讨了其反应机理,并研究了其催化、自修复性质。主要内容分为以下三个部分:(1)Ag-Pt双金属中空纳米线的制备。通过Ag纳米颗粒和Pt(IV)之间的伽伐尼取代反应,制备了不同形貌的Ag-Pt纳米结构。系统的考察了AgN03、PDDA、TEG、NaO H对Ag-Pt纳米结构生长过程的影响,并且对合成的纳米结构进行了甲醇、乙醇电催化性能测试,结果表明:由于一维线状空心纳米结构比表面积大,活性位点多,因此具有很好的催化效果。(2)选择性刻蚀和生长制备不同形貌的Au-Pt纳米环。合成过程中溶液中的02对Au纳米颗粒具有刻蚀作用,发现其选择性的刻蚀Au纳米颗粒的外围晶棱,刻蚀导致这些部位出现了大量的高活性位点。同时,H2PtCl6被溶液中的抗坏血酸(AA)还原,生成的Pt选择性的生长在这些活性位点上,从而保护了该部位的Au不被刻蚀。因此,刻蚀转向没有P t的{111}面上。最终,大部分Au被刻蚀,形成环状纳米结构。此外,我们还考察了其它反应条件的影响,如反应时间和反应温度对最终结构的影响。(3)Au-Pt纳米环的自修复生长。以制备的Au-Pt纳米环为模板,加入不同的贵金属修复剂,例如,HAuCU、AgN03、H2PdCl4等,通过调节修复剂与还原剂(AA)的比例,实现纳米环的自修复生长。研究表明,HAuCU、AgN03作为修复剂时,原先的纳米结构可以很好的完成修复生长;H2PdCU作为修复剂,纳米结构不能完全修复。因此,要完成纳米结构的自修复生长,修复剂的选择,修复剂与还原剂比例的调控是两个关键因素。
[Abstract]:Noble metal nanostructures have a wide range of applications due to their unique physical, chemical properties and rich morphology. It is well known that the properties of noble metal nanostructures are determined by a series of physical parameters, including shape, size, composition and structure. At present, researchers have developed a lot of preparation technology. Through these technologies, noble metal nanostructures and properties can be designed and controlled, which will enable them to be applied in many fields, especially in electrochemical catalysis, fuel cell, biochemical detection, medicine and sensing. Based on the Gavani substitution and selective etching, hollow and porous noble metal nanostructures with different morphologies were prepared and their reaction mechanism was discussed. The catalytic and self-repairing properties of the nanostructures were also studied. The main contents are divided into the following three parts: the preparation of hollow nanowires of Ag-Pt. The Ag-Pt nanostructures with different morphologies were prepared by the Gavani substitution reaction between Ag nanoparticles and PTIV. The effect of AgN03PDDATTEGN NaH on the growth process of Ag-Pt nanostructures was systematically investigated, and the electrocatalytic properties of the synthesized nanostructures were tested by methanol and ethanol. The results showed that the one-dimensional linear hollow nanostructures had large specific surface area and many active sites. Therefore, the Au-Pt nanorings with different morphologies were prepared by selective etching and growth. The au nanoparticles were etched by 02 in the solution during the synthesis process. It was found that the selective etching of the peripheral edges of au nanoparticles resulted in a large number of highly active sites in these sites. At the same time, H2PtCl6 is reduced by ascorbic acid (AAA) in the solution, and the resulting Pt selectively grows on these active sites, thus protecting the au from etching. Therefore, the etching turns to the {111} surface without P t. Eventually, most au was etched to form annular nanostructures. In addition, the effects of other reaction conditions, such as reaction time and reaction temperature, on the final structure were investigated. The self-repair growth of Au-Pt nanorods was achieved by adjusting the ratio of repair agent to reductant, by adding different precious metal repair agents, such as HAuCUN AgN03H2PdCl _ 4, using the prepared Au-Pt nanospheres as template, and adding different precious metal repairable agents such as HAuCUN AgN03H _ 2PdCl _ 4 etc. The results showed that when HAuCUN AgN03 was used as the repair agent, the original nanostructures could be successfully repaired with H2PdCU as the repair agent, and the nanostructures could not be completely repaired. Therefore, in order to complete the self-repair growth of nanostructures, the selection of the repair agent and the control of the ratio of the repair agent to the reducing agent are two key factors.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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