面向高性能微生物燃料电池的产电微生物功能化

Microbial fuel cell (MFC) is a type of energy-related bioelectrical device that harness the metabolism of exoelectrogenic bacteria to harvest electricity from organic substrates, and have attracted continuous attention due to their great potential for simultaneously satisfying the need of sustainable energy production and wastewater treatment. However, MFC is still far from reaching the level of practical applications due to their relatively low power density. Bacterial cell-surface modification can introduce more functionality to living bacterial cells for extending their applications. By employing conducting nanomaterials as surface coatings, the conductivity of individual bacterial cell can be improved, which provide the opportunity to build novel bioanode with high electrical transfer efficiency from the “bottom up” for improving the performance of MFC. Based on this, we here focus on the development of surface multi-functionalized exoelectrogenic bacteria and their application in MFC. By taking advantage of suitable nanomaterials and surface modification strategies, we aim to achieve two goals: 1) Developing exoelectrogenic bacteria surface-coated with conducting nanomaterials and photoelectric nanomaterials, so that the solar energy and chemical energy can be converted into electrical energy in the anode except for the high electrical transfer efficiency from conducting nanomaterials coating; 2) Fabricating exoelectrogenic bacteria surface-coated with conducting nanomaterials and magnetic nanomaterials, so that high bacteria-loading amount, intimate contact between bacterial cells and simplified anode fabrication process can be realized with the help of external magnetic field, as well as high electrical transfer efficiency from conducting nanomaterials coating.

微生物燃料电池（MFC）是一类以微生物为催化剂，将燃料中的化学能转化为电能的装置。作为一种绿色清洁的能源技术，MFC已经成为当前研究热点之一，但MFC的实际应用仍受限于其较低的输出性能。借助于导电聚合物纳米材料在产电微生物表面功能化，我们证明了它能够有效地提高产电微生物的导电性及生物阳极的电子传递效率，进而提高MFC输出性能。在此工作基础上，本项目以设计新颖的产电微生物表面多功能化策略为着眼点，聚焦于： 1）开发导电纳米材料和光电转换功能纳米材料同时修饰产电微生物，实现微生物既能提高电子传递效率和把化学能转变为电能，又能将光能转化为电能的双功能化策略；2）开拓产电微生物表面同时修饰导电纳米材料和磁性纳米材料的新途径，实现微生物在高效电子传递效率的基础上又能够通过外界磁场帮助提高其阳极产电微生物的负载量，从而组建高性能微生物燃料电池。

产电菌表面功能化因其能够最大化的提高电极材料与细菌的接触面积来提高微生物燃料电池的性能，已成为微生物燃料电池领域的热点研究。然而，该技术在微生物燃料电池中的应用还局限于单功能化。本项目拟对产电菌进行多功能化，进一步提高微生物燃料电池的性能以及加深产电菌表面功能化技术在微生物燃料电池中的应用。具体研究中，首先从提高功能化修饰细菌与基底电极的结合方式入手，发展了一种导电纳米材料和磁性纳米材料共同修饰的产电菌，在确保了高电子传递效率的同时，在外界磁场的辅助下修饰过后的产电菌能快速的结合到基底电极上，实现了微生物燃料电池启动时间到整体性能的全面提升；构建了导电材料和光电材料共同修饰的产电菌，探究了细菌表面修饰层数以及两种材料位置对光促型微生物燃料电池的影响，为表面功能化细菌在光促型微生物燃料电池中的应用奠定了基础；以电容性的导电纳米材料为产电细菌表面修饰层，开创性的将表面功能化细菌运用到超级电容器和纸基微生物燃料电池集成体中，实现了产电性能和充放电性能的双提升；总结了产电菌表面修饰技术在微生物燃料电池中的应用前景，并探讨了微生物燃料电池与二氧化碳还原技术的结合趋势。本项目为基础研究层面的生物电化学过程，微生物燃料电池的性能提升及其未来的应用出口都提供了重要的技术及理论支撑。