Aerographite vs Graphite: Investigating the role of electrode architecture in H2-mediated electroautotrophic biofilms
Citation Link: https://doi.org/10.15480/882.18002
Publikationstyp
Journal Article
Date Issued
2026-08-07
Sprache
English
Author(s)
TORE-DOI
Volume
65
Issue
32
Start Page
17018
End Page
17029
Citation
Industrial & Engineering Chemistry Research 65 (32): 17018−17029 (2026)
Publisher DOI
Scopus ID
Publisher
American Chemical Society (ACS)
Oxic microbial electrosynthesis using aerobic hydrogenotrophic bacteria requires productive cathodic biofilm formation, yet reactive oxygen species (ROS) generated at the electrode surface present a critical barrier to initial colonization. This study investigates biofilm development by Cupriavidus necator H16 on Aerographite, an ultralow-density carbon foam (3–12 mg cm–3, porosity > 99%) with a hierarchical tetrapodal pore network, as a cathode material in microfluidic bioelectrochemical systems and compares it to graphite (a composite material consisting of graphite and polypropylene (PPG86)). A biphasic cultivation strategy, in which heterotrophic biofilm establishment preceded a switch to electroautotrophic conditions at −45.45 μA cm–2, successfully overcame the ROS barrier on both electrode materials. Noninvasive optical coherence tomography revealed a final biovolume of 0.086 mm3 mm–2 on graphite after 14 days, representing the first continuous kinetic characterization of C. necator cathode biofilm formation under defined flow conditions. Despite lower absolute biovolume per projected area, Aerographite supported higher biomass per unit electrode mass, reflecting its 585-fold higher mass-specific electroactive surface area relative to graphite. Scanning electron microscopy confirmed C. necator colonization of internal pore regions up to 500 μm below the electrode surface under laminar flow-over conditions. The macropore dimensions substantially exceed documented self-limiting biofilm thicknesses, indicating that pore occlusion is unlikely even at full biofilm development, and positioning Aerographite as a structurally enabling electrode material for smart, scalable, flow-through CO2 valorization systems.
DDC Class
660: Chemistry; Chemical Engineering
628: Sanitary; Municipal
Publication version
publishedVersion