石墨烯复合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：2018-05-18 03:27

本文选题：微生物燃料电池 + 氧还原反应　；参考：《哈尔滨工程大学》2014年硕士论文

【摘要】：微生物燃料电池(MFCs)是一种在处理废水的同时能够产生电能的新技术,这种技术利用微生物作为催化剂来实现对有机质或无机质进行分解并在这个过程中获得电流。微生物燃料电池的这种独特的产能方式为解决能源问题并同时达到治理废水的目的提供了一条全新的道路。目前,微生物燃料电池产电性能差以及成本较高的缺点成为了限制其规模化应用的主要障碍。众所周知,阴极催化剂的成本占据了微生物燃料电池成本的一大部分。Pt是微生物燃料电池中最常用的阴极催化剂,但其成本较高,且易中毒。针对这个问题本实验中制备了石墨烯二氧化锰复合材料、多孔氮掺杂碳纳米片以及氮掺杂石墨烯三种高效低成本的阴极催化剂并成功的将氮掺杂石墨烯空气阴极单室微生物燃料电池应用于处理对硝基苯酚废水。本论文具体的研究成果概括如下:在微波照射下由石墨烯直接原位还原高锰酸钾所制得的纳米结构的石墨烯/Mn02复合材料因具备的特殊结构以及石墨烯本身极好的导电性能导致其制备的电极表现出了极高的催化性能。该材料作为阴极催化剂被应用于微生物燃料电池时,显著提高了电池的产电性能。采用石墨烯/MnO2复合材料作为阴极氧还原催化剂的微生物燃料电池可以产生高达2083 mW/m2的最大功率密度,分别是单独的MnO2催化剂的1.42倍以及Pt/C催化剂的1.22倍。通过碳化GO-PANI并进一步采用碱活化处理而制备的多孔氮掺杂碳纳米片(PNCN)是一种简单可行的制备氮掺杂碳材料的方法。该方法制备的PNCN具有极高的比表面积,并且其制备的电极在中性磷酸盐缓冲溶液中表现出了极好的氧还原催化性能。采用PNCN作为微生物燃料电池的阴极催化剂时产生的最大功率密度为1159.34 mW/m2,比相同条件下的Pt/C催化剂(858.49mW/m2)高35%。采用后处理法以硝酸或水合肼作为氮源可以制备氮掺杂石墨烯。两种氮掺杂石墨烯制备的电极均表现出了极好的氧还原催化性能,其中硝酸制备的氮掺杂石墨烯的氧还原催化性能较高。以两种氮掺杂石墨烯作为微生物燃料电池阴极氧还原催化剂时产生的最大功率密度均比Pt/C催化剂要高。构建了以氮掺杂石墨烯为阴极催化剂的空气阴极单室微生物燃料电池系统用以降解对硝基苯酚废水。混合基质与单一基质运行微生物燃料电池的结果表明混合基质更有利于废水中对硝基苯酚的降解。混合基质运行时,对硝基苯酚的去除率随浓度的增大而减小,但最低去除率仍在70%以上,具有较好的去除效果。含50 mg/L的对硝基苯酚混合基质废水运行微生物燃料电池时,其最大输出功率为561.69 mW/m2,对硝基苯酚的去除率为77.35%,比普通厌氧生物法的去除率提高了 20.27%。
[Abstract]:Microbial fuel cell (MFCs) is a new technology which can produce electric energy while treating wastewater. This technology uses microorganism as catalyst to decompose organic matter or inorganic matter and obtain electric current in the process. This unique capacity of microbial fuel cell provides a new way to solve the energy problem and achieve the purpose of wastewater treatment. At present, the disadvantages of low electrical performance and high cost of microbial fuel cells have become a major obstacle to its application on a large scale. It is well known that the cost of cathode catalyst accounts for a large part of the cost of microbial fuel cell. Pt is the most commonly used cathode catalyst in microbial fuel cell, but its cost is high, and it is easy to be poisoned. In order to solve this problem, the graphene manganese dioxide composite was prepared in this experiment. Porous nitrogen-doped carbon nanochips and nitrogen-doped graphene were successfully used in the treatment of p-nitrophenol wastewater by using nitrogen-doped graphene air cathode single-chamber microbial fuel cell. The specific research results of this thesis are summarized as follows: the nanostructure graphene / Mn02 composites prepared by direct in situ reduction of potassium permanganate by graphene under microwave irradiation have special structure and excellent graphene itself. The electrode prepared by the electrode exhibits high catalytic performance due to its electrical conductivity. When the material is used as cathode catalyst in microbial fuel cells, the electrical performance of the cell is improved significantly. The maximum power density of the microbial fuel cell using graphene / MnO2 composite as cathode oxygen reduction catalyst is up to 2083 mW/m2, which is 1.42 times of that of the single MnO2 catalyst and 1.22 times of that of the Pt/C catalyst. It is a simple and feasible method to prepare nitrogen-doped carbon materials by carbonizing GO-PANI and further using alkali activation to prepare porous nitrogen-doped carbon nanoflakes. The PNCN prepared by this method has a very high specific surface area and the electrode prepared by this method exhibits excellent catalytic performance for oxygen reduction in neutral phosphate buffer solution. The maximum power density produced by using PNCN as cathode catalyst for microbial fuel cell is 1159.34 MW / m ~ (2), which is 35% higher than that of Pt/C catalyst (858.49 MW / m ~ (2) under the same conditions. Nitrogen-doped graphene can be prepared by post-treatment with nitric acid or hydrazine hydrate as nitrogen source. The two kinds of nitrogen-doped graphene electrodes showed excellent catalytic performance for oxygen reduction, and nitrogen-doped graphene prepared by nitric acid had higher catalytic performance for oxygen reduction. The maximum power density of two nitrogen-doped graphene catalysts for cathode oxygen reduction of microbial fuel cells is higher than that of Pt/C catalysts. An air cathode single-chamber microbial fuel cell system with nitrogen-doped graphene as cathode catalyst was constructed for the degradation of p-nitrophenol wastewater. The results showed that the mixed matrix was more favorable to the degradation of p-nitrophenol in wastewater. The removal rate of p-nitrophenol decreased with the increase of concentration, but the lowest removal rate was still more than 70%. The maximum output power of microbial fuel cell was 561.69 MW / m ~ (2) and the removal rate of p-nitrophenol was 77.35 when the mixed substrate wastewater containing 50 mg/L was operated with microbial fuel cell. The removal rate of p-nitrophenol was 20.27% higher than that of ordinary anaerobic biological method.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.45

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