Preparation Of Mesoporous Nanowires Electrode Via AAO-Lyotropic Liquid Crystalline Conjunct Templates And Its Performance

In recent years, much attention is paid to the ordered nanostructure materials in fuel cell, sensor, electrochemical capacitor and so on because of their large specific surface area and ordered organization. With the development of self-assemble nanotechniques, a new kind of fabrication methods of ordered nanomaterials-template synthesis attracts people's attention. The template method involves using the correlated template as a nanoscopic beaker for the synthesis of nanoarrays of the desired materials by chemical or physical method, such as metal, nonmetal, semiconductor and so on. Therefore, people can control the structure of mesoporous ordered nanomaterials truly and effectively by template synthesis.Porous anodic aluminum oxide (AAO) template is most widely used to prepare ordered nanostructure materials among the templates to fabricate nanoatructure materials. Meanwhile, the lyotropic liquid crystalline phases of surfactants are also widely used as templates to prepare mesoporous materials due to the rich polymorphism and long-range periodicities of porous structures. The repeat distances of mesostructure range from 2 to 10 nanometers. In this thesis, we introduced the AAO-lyotropic liquid crystalline conjunct templates to the obtaining of the periodic nanostructure materials. By electrodepositing at constant electric potential, we got ordered mesoporous nanomaterials, whose application in direct methanol fuel cell (DMFC) is analysed in depth. The main research works are as follows:1. Al/Ti/Si substrates were fabricated by radio frequency sputtering. Then the ordered AAO templates were successfully transfered to silicon substrates by a two-step electrochemical anodization. AAO/Ti/Si substrates with different diameters were obtained by optimizing the experimental conditions. Compared with the single AAO templates, the AAO/Ti/Si substrates have the properties of good mechanical strength and durability against heat treatment at higher temperature. In addition, the AAO/Ti/Si substrates have also unique electrodeposited properties and could bond well with the deposited materials.2. Using electrochemical workingstation, based on the surfactant Brij56:MnAc2 liquid crystalline template, mesoporous manganese oxides nanowires electrode was synthesized by dual template electrodeposition method. The average pore diameter of the mesoporous materials is about 3-5 nm. The ordered solid and mesoporous Pt nanowires arrays had been directly fabricated via aqueous and Brij56 liquid crystal. The structure and the composition of the electrodes were characterized by SEM, TEM and XRD.3. The nanoarrays/Ti/Si as working electrode, the electchemical performance of the mesoporous Pt nanowires electrode was systematically measured. The measure result showed the higher current density and stability of the mesoporous Pt nanowires than the solid nanowires, which had prospect in the application of DMFC.