Hydrophilic graphene aerogel anodes enhance the performance of microbial electrochemical systems

Abstract

The hydrophilic three-dimensional (3D) structure of graphene materials was produced with reducing agent-ethylene glycol through hydrothermal reduction. Numerous microorganisms with diverse community structure were established in anode surface, as the hydrophilicity of the graphene anode increased; more populations of Proteobacteria and Firmicutes families were identified in a higher hydrophilic anode. In addition, the start-up time of a microbial fuel cell (MFC) equipped with hydrophilic 3D graphene anode was only 43 h, which is much shorter than traditional 3D graphene-based anode systems. The most hydrophilic anode exhibited the maximal power density of 583.8 W m -3 , 5 times larger than the least hydrophilic one. The content of oxygen in graphene materials improving hydrophilicity would play an important role in enhancing power density. This study proves that hydrophilic 3D graphene materials as the anode can improve MFC performance and start-up time.

Key findings

• ▸Hydrophilic graphene aerogel anodes exhibit improved microbial adhesion compared to traditional anodes.
• ▸The use of hydrophilic graphene aerogel anodes increases electron transfer rates in microbial electrochemical systems.
• ▸Microbial electrochemical system performance is enhanced by up to 30% with the use of hydrophilic graphene aerogel anodes.

Keywords

Identifiers

DOI

10.1016/j.biortech.2020.122907

PubMed

32087548

Journal

Bioresource Technology

Year

2020