新型rGO-CNTs复合材料和三元骨架CuAlZn材料的制备及在能源方面的应用研究

发布时间：2018-03-10 09:04

本文选题：能源材料　切入点：线型电极　出处：《广西大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着人类对不可再生能源消耗逐年增加,我们面临能源短缺和环境恶化的问题愈来愈突出。寻找清洁和可再生的能源已经成为世界各国共同关心的问题。研发新型的能源材料已经成为世界关注的前沿性课题。石墨烯具有显著的特点包括高比表面积、高导电性、良好化学稳定性和机械稳定性,因此,已经广泛作为高性能超级电容材料的电极材料。钙钛矿太阳电池的电极一般为金属材料,金属材料价格昂贵、对实验设备要求和实验条件要求太高。利用石墨烯-碳纳米复合制备薄膜型电极材料,组装到钙钛矿电池上作为对电极材料有很大的发展前景。制备高性能的碳材料电极,可以省去空穴传输层材料,又可作为对电极,成本降低且毒性相对降低。CO_2过度排放所引起的气候变化以及由此带来的危害,已成为21世纪人类所面临的最大环境问题。CO_2本身是丰富、廉价、清洁、安全的碳资源,通过催化加氢制备含氧化合物的研究近年来为人们所关注,不仅可以减少自然界中CO_2的含量,也可用来生产得到增值化学品。然而,CO_2是相当稳定的化合物,目前其利用转化的效率较低,因此,开发高效的催化材料实现CO_2资源化转化是研究的关键。本文制备了石墨烯-碳纳米管复合材料及讨论其性能,并应用于制备柔性线型超级电容器电极和钙钛矿太阳电池。另外,制备一种新型三元骨架催化材料,应用于CO_2催化氢化转化制备甲酸,以及提出其催化机理。研究的主要内容及结论如下:在第二章,使用维生素C作为还原剂,低温化学还原自组装方法制备了新的石墨烯和碳纳米管(rGO-CNT)复合纤维。机械性能测试表明,极限伸长率为150%的混合纤维具有比单一 rGO纤维更好的机械性能,其极限伸长率为105%。循环伏安法(CV)结果表明,rGO/CNT杂化纤维表现出比rGO纤维更好的电化学性能,因为前者的CV曲线面积更大。复合电极的体积比电容为559.9 F cm-3,其高电流密度为1Ag-1时的定性比电容为59.76 F g-1。rGO/CNT混合纤维的体积电容和质量电容都高于单个rGO纤维,特别是在低扫描速度下。rGO-CNT复合纤维的扫描电子显微镜和透射电子显微镜图像清楚地显示了 rGO和CNT共组装和互连的多孔结构形成。在混合纳米结构中,CNT起到骨架作用,并且rGO和CNT之间的协同作用导致混合纤维具有增强的机械和电化学性能。其次,研究了rGO-CNTs其它比例的复合纤维电化学性能。通过比较循环伏安曲线状况,分析了 rGO的比例对复合纤维电学性能的影响。结果表明,rGO比CNTs的比值越大,其复合纤维的循环伏安曲线矩形性越差,快速充放电能力越差。在第三章中,用rGO-CNTs复合薄膜材料作为正极材料同时充当空穴传输层,二氧化钛为电子传输层,钙钛矿晶体作为光吸收层,组装制备了钙钛矿太阳电池,经测试,其电池效率为0.3%,最大电流0.358 mA,最大电压0.231 V,开路电压0.7609 V,电流密度1.193 mAcm-2。在第四章,制备一种新型三元骨架催化材料CuAlZn用于CO_2资源化利用。并研究各反应条件对催化剂的影响,研究其催化机理。结果显示CuAlZn-2.5 h表现出较高的活性,在6 MPa H2和200 0C下4小时得到甲酸为86.1%。骨架CuAlZn-2.5 h催化剂中金属的组成和比表面积均为甲酸生产的非常重要的影响因素。结果发现,骨架CuAlZn催化剂的回收试验可重复使用三次,仍保持良好的活性。本研究为碳氢化合物或二氧化碳氢化为甲酸合成提供了一种温和有效的方法。
[Abstract]:With the consumption of non renewable energy increased year by year, we are facing energy shortages and environmental degradation issues become increasingly prominent. Looking for clean and renewable energy has become a common concern of all countries in the world. The development of new energy materials has become the world's attention the topic. Graphene has remarkable characteristics including high surface area, high conductivity, good chemical stability and mechanical stability, therefore, has been widely used as electrode material for high performance supercapacitors electrode materials. The perovskite solar cell is generally made of metal materials, metal materials are expensive, too high requirement for experimental equipment requirements and test conditions. The graphene / carbon nano composite films were prepared by using electrode materials as to the perovskite cell assembly, have great prospects for development of the electrode materials. The preparation of carbon electrode material with high performance, can save the empty hole The transport layer material, and can be used as the electrode, reduced cost and lower toxicity of excessive emissions of.CO_2 caused by climate change and the resulting harm,.CO_2 has become the largest environmental problems facing humanity in the twenty-first Century itself is abundant, cheap, clean, safe carbon source, through the study on the catalytic hydrogenation of oxygen in recent years, the compounds of concern for people, not only can reduce the content of CO_2 in nature, can also be used for the production of value-added chemicals. However, CO_2 is a compound of fairly stable, the conversion efficiency is low, because of this, the development of efficient catalytic materials to achieve the transformation is the key of the study of graphene CO_2 resources. Carbon nanotube composite material was prepared in this paper and discuss its performance and application in the preparation of flexible linear super capacitor electrode and perovskite solar cell. In addition, the preparation of a new type of three membered skeleton catalyst Materials used in CO_2 catalytic hydrogenation conversion and preparation of formic acid, and the catalytic mechanism. The main contents and conclusions are as follows: in chapter second, the use of vitamin C as a reducing agent, graphene and carbon nanotubes prepared by new self-assembly method for low temperature chemical reduction (rGO-CNT) composite fiber. Mechanical property test shows that for the 150% mixed fiber elongation limit has better mechanical properties of a single rGO fiber, the ultimate elongation of 105%. cyclic voltammetry (CV) results show that rGO/CNT hybrid fibers exhibit better electrochemical performance of rGO fiber was better, because the CV curve area of the former is greater. The volume ratio of the composite electrode capacitance is 559.9 F cm-3 the current density is high, the volume and quality of capacitor capacitance qualitative 1Ag-1 the specific capacitance of 59.76 F g-1.rGO/CNT hybrid fibers were higher than that of rGO fiber, especially at low scanning speed of.RGO-CNT composite Scanning electron microscopy and transmission electron microscopy image fiber clearly showed the formation of porous structure of rGO and CNT co assembly and interconnection. In hybrid nanostructures, CNT plays a role in skeleton, and the synergistic effect between rGO and CNT in hybrid fiber has enhanced mechanical and electrochemical properties. Secondly, the electrochemical properties of rGO-CNTs composite fiber the proportion of the other. By comparing the voltammograms of circulating, analyzed the influence of rGO ratio on the electrical properties of the composite fibers. The results show that the rGO is bigger than the ratio of CNTs, the cycle volt composite fiber safety curve of rectangular the difference, fast charging and discharging capacity is poor. In the third chapter, by rGO-CNTs composite films as cathode materials at the same time as the hole transport layer, titanium dioxide as the electron transport layer, perovskite crystal as the light absorption layer of solar cell prepared perovskite assembly system, the The test, the battery efficiency is 0.3%, the maximum current is 0.358 mA, the maximum voltage of 0.231 V, the open circuit voltage of 0.7609 V, current density of 1.193 mAcm-2. in the fourth chapter, a preparation for utilization of CO_2 CuAlZn model three yuan skeleton catalytic material. And the effects of various reaction conditions on the catalyst and its catalytic mechanism. The results of study CuAlZn-2.5 h showed higher activity in the 6 MPa H2 and 200 0C for 4 hours to get formic acid as the composition of the metal skeleton CuAlZn-2.5 86.1%. h in the catalyst for formic acid production and are the specific surface area of very important influencing factors. The results showed that the recovery test framework CuAlZn catalyst can be used repeatedly for three times, still keep the good activity. This study provides a method for mild and effective hydrocarbon or carbon dioxide hydrogenation to formic acid synthesis.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;O643.36

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