Surface modification by β-cyclodextrin/polyquaternium-11 composite for enhanced biofilm formation in microbial fuel cells

The anode performance in microbial fuel cells (MFCs) is of great concern for affecting electricity generation. The relatively weak microbial adhesion remains the bottleneck for the further elevation of the electrocatalytic activity of anodes. In this paper, a novel biocompatible β-cyclodextrin (β-CD)/polyquaternium-11 (PQ-11) composite coupled with current collector carbon cloth (CC) is applied as an anode in MFCs. The CC-CD-PQ-11 anode delivers the maximum power density of 1754.1 ± 54.0 mW m⁻², which is 5.2 and 1.4 times greater than that of the CC (340.2 ± 15.0 mW m⁻²) and CC-CD (1269.8 ± 35.0 mW m⁻²), respectively. Besides, the CC-CD-PQ-11 shows the excellent capacitance behavior with the net capacitance charge of 6.537 ± 0.354C m⁻² during 5 min of interruption. The β-CD with PQ-11 co-modified the base electrode not only affects the surface roughness and wettability, but also increases the total biomass and promotes the high electrochemically active biofilm formation. In summary, the CC-CD-PQ-11 anode excelling among the studied anodes can be ascribed to the excellent biocompatibility and the dual physicochemical properties of β-CD/PQ-11 coating, making it a promising anode for high-performance MFCs applications.