Effect of surface roughness, porosity and roughened micro-pillar structures on the early formation of microbial anodes.

Autor: Champigneux P; Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France., Renault-Sentenac C; Laboratoire d'Analyse et d'Architecture des Systèmes CNRS, Université de Toulouse, 7 avenue du colonel Roche, 31031 Toulouse, France., Bourrier D; Laboratoire d'Analyse et d'Architecture des Systèmes CNRS, Université de Toulouse, 7 avenue du colonel Roche, 31031 Toulouse, France., Rossi C; Laboratoire d'Analyse et d'Architecture des Systèmes CNRS, Université de Toulouse, 7 avenue du colonel Roche, 31031 Toulouse, France., Delia ML; Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France., Bergel A; Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France. Electronic address: alain.bergel@ensiacet.fr.
Jazyk: angličtina
Zdroj: Bioelectrochemistry (Amsterdam, Netherlands) [Bioelectrochemistry] 2019 Aug; Vol. 128, pp. 17-29. Date of Electronic Publication: 2019 Mar 06.
DOI: 10.1016/j.bioelechem.2019.03.002
Abstrakt: The early formation of electroactive biofilms was investigated with gold electrodes inoculated with Geobacter sulfurreducens. Biofilms were formed under an applied potential of 0.1 V/SCE, with a single batch of acetate 10 mM, on flat gold electrodes with different random surface roughness. Roughness with arithmetical mean height (S a ) ranging from 0.5 to 6.7 μm decreased the initial latency time, and increased the current density by a factor of 2.7 to 6.7 with respect to nano-rough electrodes (S a  = 4.5 nm). The current density increased linearly with S a up to 14.0 A·m -2 for S a of 6.7 μm. This linear relationship remained valid for porous gold. In this case, the biofilm rapidly formed a uniform layer over the pores, so porosity impacted the current only by modifying the roughness of the upper surface. The current density thus reached 14.8 ± 1.1 A·m -2 with S a of 7.6 μm (7 times higher than the nano-rough electrodes). Arrays of 500-μm-high micro-pillars were roughened following the same protocol. In this case, roughening resulted in a modest gain around 1.3-fold. A numerical model showed that the modest enhancement was due to ion transport not being sufficient to mitigate the local acidification of the structure bottom.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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