碳基阴极材料的制备及其在微生物燃料电池中的应用

发布时间：2018-04-22 07:29

本文选题：氧还原反应 + 微生物燃料电池　；参考：《广州大学》2017年硕士论文

【摘要】：随着人类社会的发展,能源短缺和不断加剧的环境污染促进了对新型能源技术的需求。微生物燃料电池(Microbial Fuel Cells,MFCs)作为一种新型能源转换设备,它有别于传统的燃料电池,能以微生物作为阳极催化剂,消耗可降解有机物并释放出电子,从而具有产电和降解有机污染物的双重功能。近年来,微生物燃料电池以其独特的优势得到了迅速的发展。然而,目前仍然存在一些技术上的缺陷,尤其是阴极催化剂材料的高成本,低催化效率和弱稳定性。传统的阴极催化材料通常使用贵金属及其合金,但是此类催化剂不仅成本高,而且不稳定,极大地限制了微生物燃料电池的实际应用。因此,有必要设计开发一种高效稳定,低成本的阴极催化剂来替代贵金属。本论文通过采用水热法、化学浴沉积法、Hummer`s法、模板法和热还原法等方法设计合成了一系列新型碳基纳米复合材料,并系统研究了其氧还原性能以及其在微生物燃料电池阴极上的应用。具体研究内容如下:(1)通过简单的水热法成功制备了CuSe@CNTs纳米复合材料。该复合材料显示出优越的氧还原性能和阴极催化能力,其微生物燃料电池的最大输出功率密度可以达到425.9±5 mW m-2。这主要归因于碳纳米管的存在弥补了硒化铜的半导体缺陷,同时较小的硒化铜纳米颗粒有效地增加了催化剂的活性位点。(2)通过Hummer’s法和水热法自组装合成了CuSe@rGO-CNTs三维层状结构的纳米复合材料。相比于CuSe@rGO和CuSe@CNTs,CuSe@rGO-CNTs显示出了更好的氧还原性能和微生物燃料电池阴极催化活性,电池的最大输出功率密度可达到504±5 mW m-2。这主要是因为复合材料的三维层状结构为质子和电子的传递提供了有效空间,同时碳纳米管的引入有效地缓解了石墨烯的团聚现象,保持了石墨烯原有的高比表面积,从而极大地提高了复合材料的氧还原催化性能。(3)通过酚醛树脂的碳化,化学浴沉积法和热解的方法成功制备了空心球结构的氮掺杂碳负载四氧化三钴。这种氮掺杂碳与钴氧化物的结合有效地提高了复合材料的催化性能,应用于电池后其最大输出功率密度可达到553±10 m W m-2。一方面,氮掺杂碳能够有效增加催化活性位点;另一方面,碳的高导电性弥补了四氧化三钴半导体的导电缺陷。此外,空心球结构极大地增大了催化物质的比表面,从而增加了氧气与电子的接触机会。(4)通过Hummer’s法,模板法,热还原法和化学浴沉积法成功制备了四氧化三钴均匀包裹的多孔氮掺杂石墨烯材料。这种多孔结构有效地防止了石墨烯的团聚现象,氮的掺杂为四氧化三钴的均匀负载提供了锚定点,同时也增强了四氧化三钴与石墨烯的有效结合,显著提高了复合材料的氧还原催化性能,应用于电池后,其最大输出功率密度可达到578±10 mW m-2。
[Abstract]:With the development of human society, energy shortage and increasing environmental pollution promote the demand for new energy technology. Microbial Fuel cells (MFCs), as a new type of energy conversion equipment, are different from conventional fuel cells in that they can use microorganisms as anode catalysts, consume degradable organic compounds and release electrons. The utility model has the dual function of producing electricity and degrading organic pollutants. In recent years, microbial fuel cells have been developed rapidly because of their unique advantages. However, there are still some technical defects, especially the high cost, low catalytic efficiency and weak stability of cathode catalyst materials. The traditional cathodic catalytic materials usually use precious metals and their alloys, but these catalysts are not only expensive, but also unstable, which greatly limits the practical application of microbial fuel cells. Therefore, it is necessary to design and develop a high efficient, stable, low-cost cathode catalyst to replace precious metals. In this paper, a series of new carbon nanocomposites were designed and synthesized by hydrothermal method, chemical bath deposition method, Hummer's method, template method and thermal reduction method. The oxygen reduction performance and its application in microbial fuel cell cathodes were systematically studied. The main contents are as follows: (1) CuSe@CNTs nanocomposites were successfully prepared by hydrothermal method. The composite shows excellent oxygen reduction performance and cathodic catalytic ability. The maximum output power density of the microbial fuel cell can reach 425.9 卤5 MW m-2. This is mainly due to the existence of carbon nanotubes that make up for the semiconductor defects of copper selenide. At the same time, the smaller copper selenide nanoparticles effectively increased the active site of the catalyst. (2) the CuSe@rGO-CNTs three-dimensional layered nanocomposites were synthesized by Hummer's and hydrothermal self-assembly. Compared with CuSe@rGO and CUSE @ CNTsN, CuSer r GO-CNTs showed better oxygen reduction performance and catalytic activity of microbial fuel cell cathode. The maximum output power density of the cell was 504 卤5 MW m ~ (-2). This is mainly because the three-dimensional laminated structure of the composite provides an effective space for proton and electron transfer, and the introduction of carbon nanotubes effectively alleviates the agglomeration of graphene and maintains the original high specific surface area of graphene. Therefore, the catalytic performance of oxygen reduction of the composite was greatly improved. (3) through carbonization of phenolic resin, chemical bath deposition and pyrolysis method, the hollow spheres were successfully prepared with nitrogen-doped carbon supported cobalt tetroxide. The combination of nitrogen-doped carbon and cobalt oxide can effectively improve the catalytic performance of the composite, and the maximum output power density of the composite can reach 553 卤10 m W m -2 after being applied to the battery. On the one hand, nitrogen-doped carbon can effectively increase the catalytic activity sites; on the other hand, the high conductivity of carbon makes up for the conductive defects of cobalt trioxide semiconductors. In addition, the hollow sphere structure greatly increases the specific surface of the catalytic material, thus increasing the contact between oxygen and electrons. Porous nitrogen-doped graphene materials were successfully prepared by thermal reduction and chemical bath deposition. This porous structure effectively prevents the agglomeration of graphene, and nitrogen doping provides the anchoring point for the uniform loading of cobalt tetroxide, and also enhances the effective combination of cobalt tetroxide and graphene. The catalytic performance of oxygen reduction of the composite is improved significantly. The maximum output power density of the composite is 578 卤10mW m ~ (-2) after being applied to the battery.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.45

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