Non-metallic copolymer material-based universal bio-abiotic hybrid platform for boosting the efficient electronic collection of microbial fuel cells

Abstract

Microbial fuel cells (MFCs) collect the electrons derived from bacterial metabolism, which are beginning to show potential uses in aerospace and other fields. The major limitation of MFC research lies in the interaction between the electrode materials and bacteria cells, including the adsorption, capacity of cell loading and electron transmission between these components. Herein, we designed and constructed bio-abiotic hybrid biofilms on the surface of electrodes primarily through a one-step copolymerization synthesis and modification of porous graphite felt, which greatly facilitated the interaction and the electron transduction between these elements. Specifically, the copolymerized supramolecular structures were evenly distributed on the poly-1-vinyl-3-ethylimidazolium tetrafluoroborate films. The cationic polymer coating of electrodes sometimes reduces their electrical conductivity; however, the proposed materials significantly enhanced not only the electropositivity, affinity and load capability of the bacterial cells but also the efficiency of electron migration. By using these Shewanella oneidensis MR-1 containing bio-abiotic hybrid biofilms, the power density of the microbial fuel cell reached 7.02 ± 0.35 W m⁻², which was the highest recorded for an S. oneidensis MR-1 based MFC so far. Interestingly, this type of MFCs could simultaneously light up 5 LED miniature lamps with an active working time of more than 108 hours. In addition to bacteria, this system can be extended to eukaryotic fungi, such as the yeast Saccharomyces cerevisiae, the power density of which reached 13.82 ± 2.91 W m⁻², approximately 7.3 times compared to the control group, indicating a generality of this synthetic biological platform for microbial fuel cell utilization.