石墨烯/聚苯胺修饰阴极对反硝化MFC性能影响

反硝化生物阴极微生物燃料电池（MFC）以电极为电子供体，在自养条件下完成硝酸盐去除过程.本研究以碳布（CC）为基底材料，分别制备获得还原氧化石墨烯修饰（rGO-CC），聚苯胺修饰（PANI-CC）及二者复合修饰的CC电极（rGO/PANI-CC），并考察其作为阴极材料对反硝化生物阴极MFC产电脱氮性能的影响.扫描电镜结果显示，rGO-CC和PANI-CC的碳纤维分别被片层状rGO和网状PANI覆盖，而rGO/PANI-CC表面呈现PANI在附着rGO的碳纤维上团聚的形貌，均增大了碳布的比表面积.循环伏安测试显示，rGO/PANI-CC具有最高的电化学活性.以rGO-CC，PANI-CC和rGO/PANI-CC为阴极构建MFC的产电能力分别提高了82%，24%和41%，其阴极对NO₃^--N的去除能力增强了23%，9%和13%.16S rDNA测序结果揭示修饰后电极表面微生物的多样性下降，Stappia和Pacacoccus属微生物的丰度增加.

Effect of graphene/polyaniline composite modified cathode on performance of MFC with denitrification biocathode

In denitrifying microbial fuel cells (MFCs), the biocathode is the electron donor and nitrate is removed in autotrophic conditions. Reduced graphene oxide modified carbon cloth (rGO-CC), polyaniline modified CC (PANI-CC), and rGO/PANI composite modified CC (rGO/PANI-CC) were prepared, and the electricity and the denitrification performances of MFCs with modified CC as cathodes were evaluated. Scanning electron microscopy analysis revealed that the carbon fibers of rGO-CC and PANI-CC were covered by lamellar rGO and reticular PANI, respectively, while PANI agglomerated on the rGO-covered carbon fibers for rGO/PANI-CC; both of which increased the specific surface area of CC. Cyclic voltammetry tests showed the rGO/PANI-CC had the highest electrochemical activity. The electricity performances of MFCs with rGO-CC, PANI-CC and rGO/PANI-CC as cathodes were improved by 82%, 24% and 41%, and the cathodic denitrification rates were enhanced by 23%, 9% and 13%, respectively. The 16S rDNA sequencing results demonstrated the α-diversity index of electrode-attached microorganisms on modified CC decreased, and the relative abundances of Stappia and Pacacoccus increased.