Metal-organic framework-derived iron oxide modified carbon cloth as a high-power density microbial fuel cell anode

Abstract

Microbial fuel cells have become a research topic of considerable interest in bioelectrochemistry, considering their potential to replace fossil energy sources. However, the main factor limiting their commercial application is poor anode performance, which leads to a lower power density. Herein, based on the interaction between iron minerals and electroactive microorganisms in geological systems, metal-organic framework-derived iron oxide-modified carbon cloth was prepared using a simple hydrothermal roasting method to enhance the extracellular electron transfer function of electricity-producing microorganisms, and was evaluated in two-chamber microbial fuel cells. Electrochemical tests showed that MIL-Fe2O3 and MIL-Fe3O4 nanoparticles effectively enhanced the electrochemical performance and biocompatibility of the anode. The microbial fuel cell equipped with MIL-Fe3O4/CC achieved an output power density of 4305 mW/m2. This excellent performance can be attributed to the fact that MIL-88(Fe)-derived iron oxide facilitates the adhesion of electricity-producing microorganisms to the anode and the secretion of proteins related to extracellular electron transfer, realizing the synergistic promotion of c-type cytochrome and flavin. This study provides a strategy for preparing high-performance microbial fuel cell anode materials, thus sustaining the promise for the eventual commercialization of microbial fuel cells.