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  • Magnetite nanoparticle anchored graphene cathode enhances microbial electrosynthesis of polyhydroxybutyrate by Rhodopseudomonas palustris TIE-1
Title: Magnetite nanoparticle anchored graphene cathode enhances microbial electrosynthesis of polyhydroxybutyrate by Rhodopseudomonas palustris TIE-1
Microbial electrosynthesis (MES) is an emerging technology that can convert carbon dioxide (CO2) into value-added organic carbon compounds using electrons supplied from a cathode. However, MES is affected by low product formation due to limited extracellular electron uptake by microbes. Herein, a novel cathode was developed from chemically synthesized magnetite nanoparticles and reduced graphene oxide nanocomposite (rGO-MNPs). This nanocomposite was electrochemically deposited on carbon felt (CF/rGO-MNPs), and the modified material was used as a cathode for MES production. The bioplastic, polyhydroxybutyrate (PHB) produced by Rhodopseudomonas palustris TIE-1 (TIE-1), was measured from reactors with modified and unmodified cathodes. Results demonstrate that the magnetite nanoparticle anchored graphene cathode (CF/rGO-MNPs) exhibited higher PHB production (91.31±0.9 mg l−1). This is ∼4.2 times higher than unmodified carbon felt (CF), and 20 times higher than previously reported using graphite. This modified cathode enhanced electron uptake to −11.7±0.1 μA cm−2, ∼5 times higher than CF cathode (−2.3±0.08 μA cm−2). The faradaic efficiency of the modified cathode was ∼2 times higher than the unmodified cathode. Electrochemical analysis and scanning electron microscopy suggest that rGO-MNPs facilitated electron uptake and improved PHB production by TIE-1. Overall, the nanocomposite (rGO-MNPs) cathode modification enhances MES efficiency.  more » « less
Award ID(s):
2021822
PAR ID:
10222074
Author(s) / Creator(s):
Date Published:
Journal Name:
Nanotechnology
Volume:
32
Issue:
3
ISSN:
0957-4484
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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