用于微型微生物燃料电池阳极的聚吡咯/石墨烯复合纳米线的可控生长机理研究

Miniature microbial fuel cell (MFC) has wide potentially applications in new miniature power, bioscreening and other areas. As a carrier for electrogenisis microbes adhered to the anode material, the performance of the anode material is a key factor to affect the efficiency of miniature MFC. From the view of the anode surface with 3D structure and environment friendly, a new kind of polypyrrole/graphene nanocomposite with promising properties is proposed as the anode material to significantly improve the efficiency of miniature MFC. The project will investigate the controlled growth mechanisms of polypyrrole/graphene nanocomposite based on the analysis of chemical dynamics and the influence of key factors on the structure and properties of nanocomposite. It will also explore electron transfer mechanisms between biofilm and nanocomposite based on the interface study of biofilm and nanocomposite. In this project it will solve some key scientific problems, such as the nucleation and growth modes during the growth process of nanocomposite, the interface study between biofilm and nanocomposite. This kind of nanocomposite by electrochemical method exhibits several promising characteristics, such as high conductivity, 3D space with open porous structure, large area as anode material, good biocompatibility, and easier compatibility with MEMS technology, which is fundamental to obtain miniature MFC with high performance. The project research will be useful for the research and development of electrode materials in other miniature devices as well as miniature powers.

微型微生物燃料电池（简称MFC）在新型微电源和生物检测等方面具有广泛的应用前景。阳极材料作为产电微生物附着的载体, 其性能是影响MFC 运行效率的重要因素。本项目从表面三维结构和生物友好性的角度考虑，提出了一种能明显提高微型MFC效率的高性能聚吡咯/石墨烯复合纳米线的阳极新材料。结合动力学与复合纳米线结构和性能的关键因素分析，研究该复合纳米线的可控生长机理；在复合纳米线与生物膜界面分析的基础上，探讨生物膜与复合纳米线之间的电子传递机制。该项目的研究解决了复合纳米线的成核与生长方式、生物膜与复合纳米线的界面特性分析等关键科学问题。基于电化学技术合成的该复合纳米线具有高导电性、微尺度的开放式三维空间、较大的阳极面积、良好的生物相容性及易于同MEMS技术兼容等特点，为研制出高性能的微型MFC器件提供坚实的基础。该项目的研究为其它微型器件电极材料的研发提供了直接参考，对微电源的研发具有借鉴意义。

本项目研究了可用于微生物燃料电池的聚吡咯/石墨烯复合纳米线的可控生长研究。该项目主要从三个方面进行了研究：石墨烯的优化研究；聚吡咯/石墨烯复合纳米线的可控生长机理和以聚吡咯/石墨烯复合纳米线为阳极的微型微生物燃料电池的性能评估。研究表明采用高分子（PSS）修饰石墨烯氧化物，可使功能化石墨烯亲水性很好，形成的稳定的黑色悬浮液；这一优化的措施使石墨烯与聚吡咯的复合成为了可能。在石墨烯与聚吡咯纳米线的复合方面，研究表明不同的聚合电势、聚合时间、聚合的反应物浓度以及电解液的浓度对复合纳米线的性能都有极大影响，获得了镍片电极上生长聚吡咯/石墨烯复合纳米线的优化条件。同以聚吡咯纳米线为阳极的微型微生物燃料电池相比，以聚吡咯/石墨烯复合纳米线为阳极的微型微生物燃料电池，其开路电压为710mV，电池内阻减少了三分之一，电池的输出功率密度为22.3 mW/m¬2，增加了40%。电池的库伦效率也有明显的提高。