Enhancing microbial fuel cell performance using anode modified with Fe3O4 nanoparticles.

Low electricity generation efficiency is one of the key issues that must be addressed for the practical application of microbial fuel cells (MFCs). Modification of microbial electrode materials is an effective method to enhance electron transfer. In this study, magnetite (Fe3O4) nanoparticles synthesized by co-precipitation were added to anode chambers in different doses to explore its effect on the performance of MFCs. The maximum power density of the MFCs doped with 4.5 g/L Fe3O4 (391.11 ± 9.4 mW/m2) was significantly increased compared to that of the undoped MFCs (255.15 ± 24.8 mW/m2). The COD removal efficiency of the MFCs increased from 85.8 ± 2.8% to 95.0 ± 2.1%. Electrochemical impedance spectroscopy and cyclic voltammetry tests revealed that the addition of Fe3O4 nanoparticles enhanced the biocatalytic activity of the anode. High-throughput sequencing results indicated that 4.5 g/L Fe3O4 modified anodes enriched the exoelectrogen Geobacter (31.5%), while control MFCs had less Geobacter (17.4%). Magnetite is widely distributed worldwide, which provides an inexpensive means to improve the electrochemical performance of MFCs.