海底沉积物燃料电池阴极聚四氟乙烯改性研究

Modified cathode by polytetrafluoroethylene in marine benthic microbial fuel cells

海洋生物污损严重影响电极性能。研究了聚四氟乙烯(PTFE)改性后粘胶基碳纤维阴极的疏水性、防污能力以及所构建电池的电化学性能。研究表明:聚四氟乙烯改性后阴极的接触角提高,并与聚四氟乙烯的含量成正比。质量浓度为60%的乳液改性后接触角提高到127.2°,比未处理阴极提高37°,接触角增大表明阴极疏水性提高,能防止微生物附着;改性阴极置于海水中3个月后表面藻类附着明显少于未改性阴极。电化学测试60%PTFE改性后的碳纤维阴极能使电池输出功率密度提高到38.92 mW/m2,这可能是由于聚四氟乙烯在碳纤维阴极表面形成了质子交换膜。该研究结果为海底沉积物燃料电池实海应用奠定了基础。

Marine biofouling seriously affects the electrode performance. The performance of the rayon-based carbon fiber cathode modified by PTFE, such as hydrophobicity, antifouling ability and electrochemical performance of cells was studied. Research shows that the contact angle of modified cathode increases, proportional to its PTFE content. The contact angle of the cathode modified by 60% PTFE emulsion increases to 127.2° , 37° more than untreated. The increased contact angle demonstrates the increases of the hydrophobicity, so it is beneficial to prevent microorganism attachment to the cathode; the surface adhesion of algae on modified cathode is obviously less than the unmodified cathode after three months. The electrochemical tests show that cathode modified by 60% PTFE can increase cell output power density to 38.92 mW/m2, preliminary analysis of the reason is PTFE form the proton exchange membrane on carbon fiber cathode surface. The study results lay the foundation for the real sea application of marine benthic microbial fuel cell.