石墨烯复合气凝胶的结构控制合成及性能研究

发布时间：2018-04-11 14:12

本文选题：气凝胶 + 石墨烯　；参考：《江南大学》2015年硕士论文

【摘要】：气凝胶是具有超低密度、大孔隙率和高比表面积的高度多孔型固体材料。石墨烯气凝胶不仅具有传统气凝胶材料的高比表面积、低密度等特点,还表现出石墨烯特有的高导电等特性,在能量存储与转换、催化、环境清洁及传感器等领域具有广泛的应用前景。本文研究了石墨烯复合气凝胶的可控合成及性能。以Hummers方法制备得到的氧化石墨烯为原料,通过自发组装、相转移及有机-无机氮源共掺杂调控石墨烯复合水/气凝胶的三维结构及组成,并对这些复合气凝胶材料的微观结构及性能进行了深入研究。具体内容包括:通过氧化石墨烯与吡咯单体之间的自发组装,无需添加其他氧化剂和还原剂、室温下成功制备出石墨烯-聚吡咯(r GO-PPy)复合水凝胶,并进一步超临界二氧化碳干燥得到r GO-PPy复合气凝胶。利用FT-IR、Raman、XPS以及XRD等测试手段对凝胶形成的机理进行了深入研究。结果表明该自发组装是基于氧化石墨烯与吡咯单体之间的氧化还原反应。SEM、TEM等微观测试及氮气吸脱附测试表明r GO-PPy复合气凝胶中的PPy以纳米颗粒的形式粘附于石墨烯片层上,因而复合气凝胶具有较高的比表面积。另外,PPy在r GO-PPy气凝胶中也充当着“交联剂”,从而导致r GO-PPy复合气凝胶具有良好的机械性能,储能模量高达12 MPa。该石墨烯-聚吡咯气凝胶用作超级电容器电极材料时,表现出较高的比电容(0.5 A/g电流密度下比电容为304 F/g)。以氧化石墨烯作为表面活性剂,得到了一系列氧化石墨烯稳定的低维纳米材料水性分散液,再经过还原、超临界二氧化碳干燥等步骤获得一系列石墨烯与低维纳米材料的复合水凝胶/气凝胶。其中,低维纳米材料包括零维的聚吡咯纳米颗粒、一维的银纳米线、一维的氧化钨纳米线以及二维的二硫化钼纳米片。通过UV-Vis、Micro-IR以及Zeta电位等测试手段证明了相转移过程;利用SEM、TEM及氮气吸脱附测试研究了复合气凝胶的微观形貌及孔洞结构;最后,通过石墨烯-银纳米线复合气凝胶的表面增强拉曼散射效应,实现了对罗丹明B探针分子的痕量检测,其检测极限可低至1.0×10-8 mol/L,并具有良好的重复性。以乙醇胺为有机氮源、氨气为无机氮源,采用有机-无机氮源共掺杂法制备出氮掺杂石墨烯气凝胶(N-G-NH3),考察了获得的N-G-NH3气凝胶的物理化学性能,并与以乙醇胺-石墨烯气凝胶在氮气条件下退火得到的N-G-N2气凝胶的相关性能作为对比。SEM和氮气吸脱附测试结果表明,N-G-NH3气凝胶具有更高的比表面积和孔体积等特点;利用EDX、XPS等测试技术对气凝胶中氮元素的含量及存在形式进行了详细的研究,结果表明该有机-无机氮源共掺杂法不仅显著提升了总氮含量,而且可对气凝胶中不同形式的氮进行调控。导电性能测试表明,N-G-NH3气凝胶具有良好的导电性(154.2S/m),高于N-G-N2导电率(143.1 S/m)。以N-G-NH3气凝胶修饰电极,电化学检测对苯二酚的检测极限为5.61×10-6 mol/L(S/N=3),线性范围在1.0×10-5 mol/L~8.5×10-4mol/L之间。
[Abstract]:Aerogel is with low density, highly porous solid materials with high porosity and high surface area. The graphene aerogel has not only the traditional aerogel materials with high surface area, low density and other characteristics, also exhibit high conductivity properties of graphene unique, catalysis in energy storage and conversion, and has application prospect wide field of clean environment and sensors. This paper studies the controllable synthesis and properties of graphene composite aerogels. The Hummers method for preparation of graphene oxide as raw material, through self assemble, phase transfer and organic - inorganic nitrogen doped graphene composite control water / aerogel three-dimensional structure and composition. And the composite aerogel material microstructure and properties were studied. The specific contents include: the spontaneous between graphene oxide and pyrrole monomer assembly, without addition of oxygen and other agents Reducing agent at room temperature successfully prepared graphene / polypyrrole (R GO-PPy) composite hydrogel, and further supercritical carbon dioxide drying R GO-PPy composite aerogel. By using FT-IR, Raman, XPS and the mechanism of XRD and other testing methods on the gel forming were studied. The results show that the spontaneous assembly is oxidation oxidation graphene and pyrrole monomer reaction based on.SEM, TEM and other microscopic test and nitrogen adsorption desorption test showed that R GO-PPy composite aerogels in PPy in the form of nano particles adhered to the graphene layers, and composite aerogels with high specific surface area. In addition, PPy in R GO-PPy aerogels also act as a crosslinking agent, which can lead to R GO-PPy composite aerogel has good mechanical properties, the storage modulus of up to 12 MPa. of the polypyrrole graphene aerogel as electrode material of super capacitor, the more High specific capacitance (0.5 A/g current density under the specific capacitance of 304 F/g). Using graphene oxide as surfactant, obtained a series of graphene oxide stable low dimensional nano material aqueous dispersion, and then after reduction step, supercritical carbon dioxide drying to obtain the composite hydrogel / graphene and a series of low dimensional nano material aerogel. The polypyrrole nano particles of low dimensional nano materials including zero dimensional, one-dimensional silver nanowires, one dimensional tungsten oxide nanowires and molybdenum disulfide two-dimensional. Through UV-Vis, Micro-IR and Zeta potential test means that the phase transfer process by using SEM, TEM and nitrogen; the morphology and structure of suction holes of the composite aerogel desorption test; finally, by surface enhanced Raman scattering of graphene silver nanowires composite aerogels, the trace examination on Luo Danming B probe Test, the detection limit can be as low as 1 x 10-8 mol/L, and has good repeatability. With ethanolamine as organic nitrogen source, ammonia as inorganic nitrogen, using organic inorganic nitrogen sources were prepared by doping nitrogen doped graphene aerogel (N-G-NH3), physical and chemical properties of N-G-NH3 aerogels obtained. The investigation, related properties and N-G-N2 aerogel with ethanolamine - graphene aerogel by annealing in nitrogen conditions as compared with.SEM and nitrogen adsorption desorption test results show that the N-G-NH3 aerogel has higher specific surface area and pore volume; the use of EDX, XPS and other testing techniques are discussed in detail study on the nitrogen content in the aerogel and form. The results show that the organic inorganic nitrogen co doping method not only significantly enhance the total nitrogen content, but also on the different forms of nitrogen in the aerogel regulation. Conductivity tests show that N-G-NH3 Aerogels had good conductivity (154.2S/m), higher than N-G-N2 conductivity (143.1 S/m). The detection limit of electrochemical detection of hydroquinone was 5.61 * 10-6 mol/L (S/N=3), and the linear range was 1 * 10-5 mol/L~8.5 * 10-4mol/L based on N-G-NH3 aerogel modified electrode.

【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O613.71

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