Identification of biofilm formation and exoelectrogenic population structure and function with graphene/polyanliline...

Improving anode configuration with polymer or nanomaterial modification is promising for enhancing microbial fuel cell performance. However, how anode modification affects biofilm development and electrogenic function remains poorly understood. In this study, the carbon cloth anode modified with polyaniline and reduced graphene oxide was successfully fabricated which obtained the highest power output. Accelerated electrogenic biofilm formation and the better electrogenic bacterial colonization based on the superior material properties (preferable electrochemical characteristics, the film-like structure and the more activated sites) were observed with the in situ biofilm development monitoring. The acclimation time was 2.4 times shorter with graphene and polyaniline modified anode than the bare one when inoculated with wastewater. Biofilm structure and function analysis show that Geobacter is the most predominant with the abundance as high as 81.4%, and meanwhile, electrogenesis related outer-surface octaheme c-type cytochrome omcZ is highly expressed in the modified anode. The anode modified with graphene and polyaniline favors Geobacter colonization, accelerates electrogenic biofilm formation and improves omcZ expression level, eventually leading to the improved performance of microbial fuel cell. The study for the first time reveals the impacts on biofilm development and microbial function by anode modification, which will better guide the potential application of microbial fuel cell for wastewater recovery.