The nanostructure of microbially-reduced graphene oxide fosters thick and highly-performing electrochemically-active biofilms

Virdis, Bernardino and Dennis, Paul G. (2017) The nanostructure of microbially-reduced graphene oxide fosters thick and highly-performing electrochemically-active biofilms. Journal of Power Sources, . doi:10.1016/j.jpowsour.2017.02.086


Author Virdis, Bernardino
Dennis, Paul G.
Title The nanostructure of microbially-reduced graphene oxide fosters thick and highly-performing electrochemically-active biofilms
Journal name Journal of Power Sources   Check publisher's open access policy
ISSN 0378-7753
1873-2755
Publication date 2017-03-06
Sub-type Article (original research)
DOI 10.1016/j.jpowsour.2017.02.086
Open Access Status Not yet assessed
Total pages 10
Place of publication Amsterdam, Netherlands
Publisher Elsevier BV
Collection year 2018
Language eng
Abstract Biofilms of electrochemically-active organisms are used in microbial electrochemical technologies (METs) to catalyze bioreactions otherwise not possible at bare electrodes. At present, however, achievable current outputs are still below levels considered sufficient for economic viability of large-scale METs implementations. Here, we report three-dimensional, self-aggregating biofilm composites comprising of microbial cells embedded with microbially-reduced graphene oxide (rGO) nanoparticles to form a thick macro-porous network with superior electrochemical properties. In the presence of metabolic substrate, these hybrid biofilms are capable of producing up to five times more catalytic current than the control biofilms. Cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy, show that in spite of the increased thickness, the biofilms amended with GO display lower polarization/charge transfer resistance compared to the controls, which we ascribe to the incorporation of rGO into the biofilms, which (1) promotes fast electron transfer, yet conserving a macroporous structure that allows free diffusion of reactants and products, and (2) enhances the interfacial dynamics by allowing a higher load of microbial cells per electrode surface area. These results suggest an easy-to-apply and cost-effective method to produce high-performing electrochemically-active biofilms in situ.
Keyword Bioelectrochemical systems
Electrochemically-active biofilms
Electrode modification
Graphene oxide
Improved current production
Mixed-community biofilms
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Agriculture and Food Sciences
Advanced Water Management Centre Publications
 
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