Synergistic effect between poly(diallyldimethylammonium chloride) and reduced graphene oxide for high electrochemically active biofilm in microbial fuel cell

Abstract Microbial Fuel Cell (MFC) can recover electrical energy from wastewater as a potential technology. Rational design of electrode materials can significantly improve the MFC performance. Herein, a novel poly(diallyldimethylammonium chloride) (PDDA) synergizing reduced graphene oxide (rGO) modified carbon cloth (CC-PDDA-rGO) not only increased the anode biocompatibility, but also affected the colony structure. The CC-PDDA-rGO anode was demonstrated to significantly improve the anode performance and achieved a power density of 2039.3 ± 57.5 mW m−2, which was 6.0, 2.2, and 1.6 times than those of the CC, CC-PDDA, and CC-rGO, respectively. Additionally, it had the maximum net capacitance charge of 11.25 ± 2.00 C m−2, which was 5.1 and 5.9 times greater than those of the CC-PDDA and CC-rGO. The PDDA/rGO composite modified electrode provided a large surface area for bacterial adhesion and reduced the charge transfer resistance significantly. The EET related to the interaction of flavin with outer-membrane c-type cytochromes was enhanced. Besides, the synergy of PDDA and rGO screened the strains and enriched electroactive bacteria, forming a stable and high electrochemically active biofilm. In summary, the PDDA/rGO binary composite inherited the advantages of raw materials and created the synergistic effect, which improved the power generation performance and enhanced the anodic capacitive behavior, possessing potential application in microbial fuel cells.