光电催化降解有机污染物并产电的研究

发布时间：2018-06-03 18:01

本文选题：光催化燃料电池 + 有机污染物　；参考：《南京大学》2015年硕士论文

【摘要】：随着人口的增长及工业的发展,大量的生活污水和工业废水排放入水体,其中不乏难降解的有机污染物,造成了严重的环境污染和生态破坏,对人类的生存与健康构成了极大的威胁,同时也不可避免的加剧了能源危机的爆发。而传统的污水处理技术已经不能满足现代对于污染物处理的需求,因此发展更经济有效的环境污染治理技术已是迫在眉睫。半导体光催化氧化技术作为高级氧化技术最具前途的污染物处理技术之一,与传统的污染物处理技术相比具有绿色、节能、高效、无二次污染等优点,其能够在常温下将有机污染物完全氧化分解。在半导体光催化氧化技术基础上根据原电池原理设计的光催化燃料电池是近年来发展的新型水处理技术,能够同步实现有机污染物的氧化分解和化学能的资源化利用,被认为是未来水处理技术的重要发展方向之一。其中,单光子型光催化燃料电池凭借其较高的开路电压和放电电流,更具备未来实用意义。但是目前传统的单光子型光催化燃料电池(Single-Photon Photocatalytic Fuel-cell)尚还存在着使用成本高及操作过程复杂等缺陷。因此,通过优化单光子光催化燃料电池的结构体系及电极材料来减小其使用成本,简化操作步骤,并且进一步提升单光子型光催化燃料电池的污染物处理能力及电池放电性能,将对未来的环境治理及能源问题产生深远影响。论文基于原电池原理,设计了两种结构体系的单光子光催化燃料电池来研究有机污染物降解过程中释放的化学能。论文首先以纳米二氧化钛薄膜电极为光阳极,Nafion质子交换膜/Pt-碳黑催化剂层/空气扩散层的复合结构电极为阴极,并通过缩短阴阳极间距来优化单光子PFC的结构体系。以多种模型有机化合物和模型染料为有机源,考察了 Pt/C型单光子光催化燃料电池的放电性能。结果表明,经过结构优化的Pt/C型单光子光催化燃料电池在简化操作步骤,降低使用成本的前提下,电池放电性能也得到明显提升,在以1mol L~(-1)甲醇为有机源时,电池的开路电压1.02V,短路电流3.75mAcm~(-2),最大输出功率密度1.40mWcm~(-2)。除此之外,研究发现初始有机物浓度、阴阳极间距、溶液pH、有机物种类均对PFC性能有重要影响。利用该电池体系进行了甲基橙的循环光降解,实验结果充分验证了光催化燃料电池体系完全能够同步实现难降解有机污染物的氧化分解与化学能的高效利用,并且有着优异的稳定性和重复使用性。为了优化Pt/C型光催化燃料电池的结构,减小其使用成本,我们重新设计了 PFC电池的阴极结构,以MnO_2/金属集流网/气体扩散层滚压成型的空气电极为光催化燃料电池的阴极,以甲醇为有机源考察了 Mn02型PFC体系的放电性能,及初始有机物浓度、电解质浓度、溶液pH、有机物种类对PFC性能的影响。结果表明,经过结构优化的MnO_2型PFC在减小使用成本的前提下,有效的提高了电池的放电性能,对比Pt/C型PFC,前者的开路电压和短路电流是后者的1.12和1.19倍。此外,为了克服纳米TiO_2薄膜电极自身存在的电荷复合严重、光吸收率低等不足,我们制备了高电导率的Ti02纳米管阵列材料及具有可见光响应的CdS/Ti02复合材料作为PFC光电极材料来研究电池光电性能。结果表明,改性了的光电极材料可以有效提高PFC电池的放电性能。
[Abstract]:With the growth of the population and the development of industry, a large number of domestic sewage and industrial waste water are placed into the water body. There are no lack of organic pollutants which are difficult to degrade, causing serious environmental pollution and ecological destruction. It poses a great threat to the survival and health of human beings. At the same time, the energy crisis is aggravated. Sewage treatment technology has been unable to meet the needs of modern pollution treatment, so it is imminent to develop more economical and effective environmental pollution control technology. As one of the most promising treatment technologies for advanced oxidation technology, semiconductor photocatalytic oxidation technology is green compared with the traditional pollutant treatment technology. It has the advantages of high efficiency, no two pollution and so on. It can completely oxidize organic pollutants at normal temperature. On the basis of semiconductor photocatalytic oxidation technology, photocatalytic fuel cell designed based on the principle of primary battery is a new water treatment technology developed in recent years. It can synchronize the oxidation decomposition and chemical energy resources of existing machine pollutants. It is considered to be one of the important development directions of future water treatment technology. One photon catalytic fuel cell with high open circuit voltage and discharge current has more practical significance in the future. However, the traditional Dan Guangzi Photocatalytic Fuel-cell (Single-Photon) fuel cell is still still in existence. Therefore, by optimizing the structure and electrode materials of the single photon photocatalytic fuel cell to reduce the cost of its use, simplify the operation steps, and further improve the capacity of the single photon photocatalytic fuel cell and the discharge performance of the battery, the future environmental treatment and energy will be improved. The source problem has a profound influence. Based on the principle of the original battery, the paper designs a single photon photocatalytic fuel cell of two structural systems to study the chemical energy released in the degradation process of organic pollutants. Firstly, the nano titanium dioxide film electrode is used as the photoanode, and the Nafion proton exchange membrane /Pt- carbon black catalyst layer / air diffusion layer is complex. The structural system of single photon PFC is optimized by combining the structure electrode and shortening the distance between the anode and the anode. The discharge performance of the Pt/C single photon photocatalytic fuel cell is investigated with a variety of model organic compounds and model dyes as organic sources. The results show that the simplified operation of the Pt/ C single photon photocatalytic fuel cell with structural optimization is simplified. On the premise of reducing the cost, the battery discharge performance is obviously improved. When 1mol L~ (-1) methanol is used as organic source, the open circuit voltage of the battery is 1.02V, the short-circuit current 3.75mAcm~ (-2) and the maximum output power density 1.40mWcm~ (-2). Besides, the initial organic matter concentration, the anode and anode space, the solution pH, and the organic matter are found. It has an important influence on the performance of PFC. The cyclic photodegradation of methyl orange is carried out by using the battery system. The experimental results fully verify that the photocatalytic fuel cell system can fully synchronize the oxidation decomposition of the refractory organic pollutants and the efficient use of chemical energy, and has excellent stability and reusability. In order to optimize the Pt/C type The structure of the photocatalytic fuel cell is reduced. The cathode structure of the PFC battery is redesigned. The cathode of the MnO_2/ metal collector / gas diffusion layer rolling air electrode is used as the cathode of the photocatalytic fuel cell. The discharge performance of the Mn02 type PFC system is investigated with methanol as the organic source, and the initial organic concentration and electrolyte are investigated. The effect of concentration, solution pH and organic substance on the performance of PFC shows that the MnO_2 type PFC which has been optimized by structure can effectively improve the discharge performance of the battery, compared with Pt/C PFC, the open circuit voltage and the short circuit current of the former are 1.12 and 1.19 times of the latter. In addition, in order to overcome the nanometer TiO_2 film electrode self. The charge compound of the body is serious and the light absorption rate is low. We have prepared the high conductivity Ti02 nanotube array material and the CdS/Ti02 composite with visible light response as the PFC photoelectrode material to study the photoelectric performance of the battery. The results show that the modified optoelectronic material can effectively improve the discharge performance of the PFC battery.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.3;TM911.4

【相似文献】