原位生长碳纳米管及其改性复合材料的微生物燃料电池产电性能研究

发布时间：2018-06-28 20:08

  本文选题：微生物燃料电池 + 碳纳米管　； 参考：《扬州大学》2014年硕士论文

【摘要】：本文首先选取碳毡(CF)作为制备复合阳极材料的基体,利用化学气相沉积法(CVD)在碳纤维表面原位生长碳纳米管(CNTs),并以此作为主体材料,之后均在此基础之上进一步改性。实验所制备改性复合材料的表征分析包括扫描电子显微镜(SEM)、X射线衍射(XRD)、能量色散X射线(EDX)和傅里叶变换红外光谱(FTIR),运用循环伏安法(CV)和电化学阻抗法(EIS)对其电化学性能进行测试和分析,并研究改性材料应用于微生物燃料电池(MFC)阳极的产电特性。MFC外电路连接2500Ω电阻,数据采集器的采集频率设置为1000 Hz,阳极室有效容积约120 mL,阳极和阴极电极的有效表面积分别为25 cm2和45 cm2,阴极液为50mmol·L-1 K3[Fe(CN)6] (pH=7)磷酸盐缓冲体系。通过对不同温度和浓度下的COD去除率分析,确定装置最佳运行条件为：pH=7、温度38℃和阳极初始COD浓度约1500 mg·L-1。另外,由于MFC连续运行一星期后其产电水平和基质浓度会大幅下降,并且稳定在一个很低的值。因此,为了恢复微生物活性和产电能力,设定7天更换一次营养液,研究在一个微生物间歇周期内的MFC产电性能。本实验针对主体材料总共制备了5种改性电极,其中涉及的方法包括聚乙烯醇(PVA)开口修饰处理、配制纳米级ZnO和纳米级Sn02溶胶分别进行负载以及原位聚合聚苯胺(PANI)添加与不添加石墨烯(G)。在产电特性和电化学性能上,改性电极相比主体材料均有不同程度的提高,其中石墨烯/聚苯胺复合电极的产电功率密度最高,可达165.89mW·m-2,表观内阻最小仅206Ω,最高电压0.687 V,平均电压0.4 V, COD去除率近81%,库伦效率约5.7%。其循环伏安测试也表现出良好的导电性和一定的氧化还原性能,根据电化学阻抗测试得到的奈奎斯特曲线选择相应的等效电路进行拟合分析,其欧姆内阻仅2.5Ω,电荷转移电阻18.9Ω,同时石墨烯能增强复合电极的电容性,此外,其它复合电极也体现出较好的综合特性。总体分析得出,改性之后的电极具有较大的比表面积、界面面积和导电性,可提供较多微生物附着生长所需要的空间位点,较低的内阻使得电子转移效率得到提高,除此之外,改性电极与微生物之间具有良好的相容性,有利于增加阳极表面产电微生物数量,释放出更多的电子,从而进一步提高MFC产电性能。
[Abstract]:Carbon felt (CF) was first selected as the matrix for preparing composite anode materials. Carbon nanotubes (CNTs) were grown on carbon fiber surface by chemical vapor deposition (CVD). Carbon nanotubes (CNTs) were used as the main materials, which were further modified on the basis of chemical vapor deposition (CVD). The characterization and analysis of the modified composite materials prepared by the experiment include scanning electron microscope (SEM) X-ray diffraction (XRD), energy dispersive X-ray (edX) and Fourier transform infrared spectroscopy (FTIR). The electrochemical properties of the composites were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). To test and analyze their academic performance, The electrical characteristics of the anode used in the microbial fuel cell (MFC) were studied. The external circuit of MFC was connected with 2500 惟 resistor. The acquisition frequency of the data collector is 1000 Hz, the effective volume of anode chamber is about 120mL, the effective surface area of anode and cathode electrode is 25 cm2 and 45 cm ~ 2, respectively, and the cathode solution is 50mmol L-1 K _ 3 [Fe (CN) _ 6] (pH ~ (7) phosphate buffer system. Through the analysis of COD removal rate at different temperature and concentration, the optimum operating conditions were determined as follows: 1: pH7, 38 鈩，

本文编号：2079207