【作者】 杨洋；

【导师】 Alan G. MacDiarmid； 王策；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2010， 博士

【摘要】 一维纳米结构材料由于其自身的结构特点所赋予的大比表面积以及长径比使其在电学、光学、热学、力学、磁学等方面都具有优异的性能,在纳电子器件、生物及化学传感、电池和电极材料、过滤器、环境清洁、药物释放、生物敷料、组织工程以及催化等领域都展现了其独特的魅力。在众多制备一维纳米结构材料的方法中,静电纺丝技术以其操作简单、成本低廉等优势成为制备一维纳米结构材料的通用方法。本论文通过将静电纺丝技术与溶胶-凝胶、气固反应、高温碳化、共沉淀等方法相结合,制备了一系列的一维纳米复合材料,并将其应用于光催化、电催化以及化学催化等方面的研究,围绕着催化这一主题开展了以下三方面的工作:第一,通过将静电纺丝技术与溶胶-凝胶技术相结合,采用离子掺杂的方式,制备得到两种复合纤维-过渡金属钨离子掺杂介孔二氧化钛复合纳米纤维膜和稀土铒离子掺杂二氧化钛复合纳米纤维膜,并研究了复合纳米纤维膜在可见光区范围内对亚甲基蓝的光催化降解作用;第二,通过将静电纺丝技术和高温碳化方法相结合,分别采用两种还原方式(高温原位还原和化学还原)制备得到碳纳米纤维负载铂粒子,然后将制备的两种材料修饰于玻碳电极,并研究了修饰电极的电化学行为以及对过氧化氢的电催化作用;第三,通过将静电纺丝法和共沉淀法相结合制备了负载四氧化三铁纳米粒子的聚丙烯腈复合纳米纤维膜,并将其作为类Fenton试剂对染料废水进行脱色降解的实验研究,分别讨论了各项参数对反应动力学的影响。更多还原

【Abstract】 In the past few years, one-dimensional （1D） nanostructures have attracted a lot of attention due to their novel properties including the high surface-to-volume ratio, high aspect ratio and intriguing applications in many areas such as nanoelectronic devices, biological and chemical sensors, battery and electrode materials, filter, environmental, biomedical and catalysis applications. A large number of advanced techniques have been developed to fabricate 1D nanostructures with well-controlled morphology and chemical composition. Among these methods, electrospinning seems to be the simplest and most versatile technique capable of generating 1D nanostructures from a variety of polymers. One of the most important advantages of the electrospinning technique is that it is relatively easy and not expensive to produce different kinds of nanofibers. Other advantages of the electrospinning technique are the ability to control the fiber diameters, the high surface-to-volume ratio, high aspect ratio, and pore size as non-woven fabrics. The advantage of the facile formation of 1D composite nanomaterials via electrospinning affords the materials multifunctional properties for various applications.In this thesis, the 1D composite nanofibers were prepared via electrospinning combined with sol-gel, gas-solid, carbonization and co-deposition. The 1D composite nanofibers were used as photocatalysis, electrocatalysis and chemicatalysis. The thesis was devided into three parts based on the three kinds of catalysis.Firstly, the trasition metal ions （tungsten ions） and rare earth ions （erbium ions） were doped into the titanium dioxides nanofibers based on the electrospinning technique combined with sol-gel. The composite nanofibers were characterized by SEM, TEM, XRD as well as N2 adsorption/desorption isotherm. The photocatalysis activity of the two kinds of composite nanofibers was investigated by employing the methylene blue as probe. A series of experiment were done to investigate the optimal experimental conditions including the doping content and calcination temperature. The UV-Vis analysis proved that ions doping can narrow the band gap of the titanium dioxides to absorb more visible light. The photodegradation mechanisms for the methylene blue were proposed based on our experiments.Secondly, two kinds of platinum nanoparticles-loaded on carbon nanofibers （CNFs） were synthesized by electrospinning and reduction （thermal in situ reduction and chemical reduction）. These composite materials possess high electrochemically active surface area and good conductivity, and are ideal candidate for electrode materials. A high density of metal nanoparticles （catalytic sites） could be obtained by using the electrospinning technique. The interesting three-dimensional （3D） structure of platinum nanoparticles-loaded on CNFs may result in a large effective platinum surface area and good electrocatalytic properties. Through the SEM characterization, the platinum nanoparticles-loaded on CNFs films were 3D networklike structure and the porous structure could significantly increase the effective electrode surface and facilitate the diffusion of analytes into the films. This nanocomposite materials exhibited high electric conductivity and accelerated the electron transfer, as verified by the cyclic voltammetry. The platinum nanoparticles-loaded on CNFs-modified glassy carbon electrode domenstrated direct and mediatorless responses to H2O2. The analytical performances of the platinum nanoparticles-loaded on CNFs-modified glassy carbon electrode towards reduction of H2O2 were evaluated. The high sensitivity, wide linear range, good reproducibility and selectivity make the platinum nanoparticles-loaded on CNFs-modified glassy carbon electrode a promising candidate for amperometric H₂O₂.Thirdly, the novel Fe3O4-carrying composite PAN nanofibers were prepared via the electrospinning combined with co-deposition method and taken as an effective iron source for degradation of organic pollutants in Fenton-like system. In our present study, the Fe3O4-carrying composite PAN nanofibers-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B, in an aqueous solution. Through a number of experiments under various conditions, it was found that the reactivity of the system was influenced by catalysis dosage, temperature, the concentration of hydrogen peroxide, the pH, the initial dye concentration. The most important characteristic of heterogeneous Fenton-like processes is the formation of OH radicals, which are highly oxidative, nonselective, and able to decompose many organic compounds. Also, the advantages of the heterogeneous Fenton processes are complete mineralization of organic compounds at ambient temperature and easy separation of the heterogeneous catalysts from the treated wastewater. In our experiment, the catalysis can be used under moderate conditions （neutral and relatively low temperature） and recycled via magnetic adsorption. The Fenton-like catalysis could be repeatedly used many times still with high catalytic activity. In summary, the prepared Fe3O4-carrying composite PAN nanofibers exhibited excellent catalytic performance in the Fenton-like reaction towards degradation of the dye wastewater.更多还原