TY - JOUR
T1 - Regulating the respiration of microbe
T2 - A bio-inspired high performance microbial supercapacitor with graphene based electrodes and its kinetic features
AU - Ren, Hao
AU - Tian, He
AU - Lee, Hyung Sool
AU - Park, Taejin
AU - Leung, Frederick C.
AU - Ren, Tian Ling
AU - Chae, Junseok
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China ( 61025021 , and 61020106006 ), the National Key Project of Science and Technology ( 2011ZX02403-002 ) of China, the Special Fund for Agro-Scientific Research in the Public Interest ( 201303107 ) of China, and NSERC Discovery Grant ( 402045-2011 ). The authors acknowledge Cameron L. Gardner from Arizona State University for help in illustrations.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Toward a carbon neutral renewable energy conversion and storage device, we present a novel bio-inspired microbial supercapacitor, utilizing unique pseudocapacitance formed by exoelectrogen, a specific species of bacteria named Geobacter spp. grown on single-layer graphene film and 3D graphene-scaffold electrodes. Charging and discharging the microbial supercapacitor were performed by regulating the respiration of the exoelectrogen. Substantially high maximum current and power densities, 531.2A/m2 (1,060,000A/m3) and 197.5W/m2 (395,000W/m3), respectively, are marked. The microbial supercapacitor demonstrates high cycle stability of over 1 million. A specific capacitance of 17.85±0.91mF/cm2 is demonstrated, which is 4.4 fold to 2 orders of magnitude higher than previously reported supercapacitors having graphene-based electrodes, suggesting a promising alternative energy storage device. Furthermore, the microbial supercapacitor was used to deduce quantitative kinetic parameters of extracellular electron transfer (EET) by fitting discharging curves of the supercapacitor, which is critical to fully understand the EET of Geobacter spp. and determining the rate-limiting mechanism. At the initial-stage biofilm, the acetate turnover is the slowest among individual EET steps, whereas for fully-grown stage biofilm, kinetics of both acetate turnover and electron transfer from inside exoelectrogen to extracellular redox cofactors are rate-limiting. Our results also suggest cytochrome c may not be the main electron storage units of a microbial supercapacitor, regardless of initial- or fully-grown stage biofilms.
AB - Toward a carbon neutral renewable energy conversion and storage device, we present a novel bio-inspired microbial supercapacitor, utilizing unique pseudocapacitance formed by exoelectrogen, a specific species of bacteria named Geobacter spp. grown on single-layer graphene film and 3D graphene-scaffold electrodes. Charging and discharging the microbial supercapacitor were performed by regulating the respiration of the exoelectrogen. Substantially high maximum current and power densities, 531.2A/m2 (1,060,000A/m3) and 197.5W/m2 (395,000W/m3), respectively, are marked. The microbial supercapacitor demonstrates high cycle stability of over 1 million. A specific capacitance of 17.85±0.91mF/cm2 is demonstrated, which is 4.4 fold to 2 orders of magnitude higher than previously reported supercapacitors having graphene-based electrodes, suggesting a promising alternative energy storage device. Furthermore, the microbial supercapacitor was used to deduce quantitative kinetic parameters of extracellular electron transfer (EET) by fitting discharging curves of the supercapacitor, which is critical to fully understand the EET of Geobacter spp. and determining the rate-limiting mechanism. At the initial-stage biofilm, the acetate turnover is the slowest among individual EET steps, whereas for fully-grown stage biofilm, kinetics of both acetate turnover and electron transfer from inside exoelectrogen to extracellular redox cofactors are rate-limiting. Our results also suggest cytochrome c may not be the main electron storage units of a microbial supercapacitor, regardless of initial- or fully-grown stage biofilms.
KW - 3D graphene scaffold
KW - Bio-inspired materials
KW - Microbial supercapacitor
KW - Pseudocapacitance
KW - Renewable energy conversion and storage device
KW - Single-layer graphene film
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U2 - 10.1016/j.nanoen.2015.05.030
DO - 10.1016/j.nanoen.2015.05.030
M3 - Article
AN - SCOPUS:84931267052
SN - 2211-2855
VL - 15
SP - 697
EP - 708
JO - Nano Energy
JF - Nano Energy
ER -