Unveiling the potential of polyaniline/Fe-MIL-88B–NH2 MOF composite as an anode for efficient bioelectricity generation

In response to pressing global energy and environmental challenges, microbial fuel cells (MFCs) have surfaced as potential bioelectrochemical technology capable of concurrently treating organic waste and generating electricity through the metabolic activity of exoelectrogenic microbes. However, the effectiveness and scalability of MFCs are considerably constrained by the anode's limited electrochemical activity and inadequate microbial adhesion. This research focuses on the modification of graphite felt (GF) anode with Fe-MIL-88B-NH 2 , an amine-functioned metal organic framework and its composite with polyaniline to support the formation of dense electroactive biofilm and enhance electron transfer kinetics. Both modified anodes exhibited improved performance compared to the uncoated GF anode. Notably, the polyaniline/Fe-MIL-88B-NH 2 @GF anode exhibited remarkably improved power output, with a power density value of 274 ± 5.7 mW/m 2 , which is approximately 6.2 times higher than that of the uncoated GF anode (44 ± 0.4 mW/m 2 ). This pronounced improvement in power output is attributed to multiple synergistic effects like lowered charge transfer resistance, accelerated extracellular electron transfer kinetics and enhanced microbial colonization derived from the protonated surface of PANI and the optimized electron transfer pathways provided by Fe-MIL-88B-NH 2 . These outcomes highlight that the polyaniline/Fe-MIL-88B-NH 2 composite effectively addresses a primary performance barrier, enabling more efficient MFCs and advancing sustainable bioelectrochemical systems for renewable energy and environmental applications. • Fe-MIL-88B-NH 2 and PANI were used to modify graphite felt anode for better MFC output. • Modified anode produced 274 ± 5.7 mW/m 2 , a 6.2-fold increase over bare GF anode. • PANI enhanced microbial colonization and accelerated extracellular electron transfer. • Composite anode reduced charge transfer resistance and enhanced conductivity. • This work proposes a scalable MFC anode design to advance sustainable energy systems.