【作者】 宋娟；

【导师】 杨亲正；

【作者基本信息】 山东轻工业学院 ， 生物化工， 2010， 硕士

【摘要】 生物燃料电池(BFC)分为微生物燃料电池和酶生物燃料电池。由于媒生物燃料电池比微生物燃料电池产电量更高,已作为一类新型能源,成为各国科学家的研究热点。一直以来,功率问题是影响酶生物燃料电池发展的瓶颈。通过阳极修饰促进电子转移,进而提高酶生物燃料电池产电性能,成为当前酶生物燃料电池的研究重点。本论文利用层状金属双氢氧化物(LDH)和多壁碳纳米管(MWNT)在固定化辣根过氧化物酶(HRP)的同时,制备出电极阳极,并测定了对酶生物燃料电池产电性能的影响。主要研究包括:1.采用共沉淀法合成镍铝比为3:1的硝酸型镍铝层状双氢氧化物(Ni-Al-NO3型LDH),并以其为载体将HRP固定化后修饰玻碳(GC)电极,制得HRP/LDH/GC电极。以该电极为阳极构建单室酶生物燃料电池,对酶中心与阳极表面之间的直接电子传递及电池的输出功率进行了研究。X-射线衍射(XRD)和场发射扫描电镜(FESEM)分析表明HRP成功插层到LDH层间,且HRP/LDH具有有序的、均匀多孔结构。采用傅里叶红外光谱(FTIR)和圆二色光谱(CD)研究了LDH固定化HRP的构象变化,结果显示,HRP保持了原有的活性,α-螺旋含量略有减少,而β-折叠含量增加,结合循环伏安法(CV)、电化学交流阻抗技术(EIS)和极化曲线分析结果表明,正是这种构象变化促进了HRP与电极间的直接电子传递。2.采用层层自组装技术(LBL)将功能化MWNT修饰到碳纸(TP)电极表面,并制得HRP/MWNT/TP电极。以该电极作为阳极构建了单室酶生物燃料电池。X射线光电子能谱(XPS)和扫描电镜(SEM)显示MWNT通过层层自组装技术成功修饰了碳纸电极,且HRP吸附在了修饰电极表面。通过傅里叶红外光谱(FTIR)和圆二色光谱(CD)分析,表明与MWNT作用后的HRP仍保持活性,且伴随着α-螺旋含量降低。根据循环伏安法(CV)、电化学交流阻抗技术(EIS)和极化曲线分析结果可知,修饰阳极酶生物燃料电池功率密度高于未修饰的TP电极,进而证明MWNT有利于酶生物燃料电池系统中的直接电子传递。更多还原

【Abstract】 As a new energy source, biofuel cell (BFC) is classified into two types: microbial fuel cell (MFC) and enzymatic biofuel cell (EFC). EFC has become the investigating hotspot in recent two years because of its higher production. For a long time, small output of EFC is a bottleneck for its development. Modifying anode electrode can prompte electron transfer from enzyme to anode and thus improve the electricity production of EFC. It has become keystone of research in EFC. In this paper, the preparation and application in the enzymatic biofuel cell of horseradish peroxidase (HRP) immobilized on layered double hydroxides (LDH) and multiwall carbon nanotubes (MWNT) were investigated. The main research work is as follows:1. Ni-Al-NO3 LDHs with a Ni/Al molar ratio of 3.0 were synthesized by the coprecipitation method and used as carrier for HRP immobilization in order to modify glassy carbon (GC) electrodes. Then the enzymatic biofuel cell was constructed with HRP/LDH/GC electrode as anode for the purpose of studying the power output and direct electron transfer between the redox centers of HRP and the anode surface. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) showed that HRP was successfully intercalated into LDH, and the HRP/LDH film had an ordered structure with a uniform, porous morphology. The conformational changes of HRP when interacting with LDH were investigated utilizing both Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) characterization. The results demonstrated that HRP retained the basic enzymatic activity with the ratio of alpha-helix reduced a little and ratio of beta-sheet increased. This conformational change is highly likely account for the DET between HRP and anode, which is demonstrated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and polarization curve measurement.2. Carbon paper (TP) electrode was modified utilizing a layer-by-layer (LBL) assemble technique and the performance of the modified electrode (HRP/MWNT/TP) as an anode in enzymatic biofuel cell was investigated. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) showed that LBL-assembled MWNT composite films has formed on TP surface and also clearly demonstrated the successful immobilization of HRP onto the modified electrode. FTIR and CD characterization revealed that HRP/MWNT retained its basic enzymaticactivity with the ratio of alpha-helix reduced a little. According to CV, EIS and polarization curve measurements, with the modified anode, the enzymatic biofuel cell produced a higher power density comparing to the bare TP anode, which confirmed that MWNT facilitate electron transfer in the enzymatic biofuel cell system.更多还原