title: Rapid electron transfer by the carbon matrix in natural pyrogenic carbon.
abstract: Surface functional groups constitute major electroactive components in pyrogenic carbon. However, the electrochemical properties of pyrogenic carbon matrices and the kinetic preference of functional groups or carbon matrices for electron transfer remain unknown. Here we show that environmentally relevant pyrogenic carbon with average H/C and O/C ratios of less than 0.35 and 0.09 can directly transfer electrons more than three times faster than the charging and discharging cycles of surface functional groups and have a 1.5 V potential range for biogeochemical reactions that invoke electron transfer processes. Surface functional groups contribute to the overall electron flux of pyrogenic carbon to a lesser extent with greater pyrolysis temperature due to lower charging and discharging capacities, although the charging and discharging kinetics remain unchanged. This study could spur the development of a new generation of biogeochemical electron flux models that focus on the bacteria-carbon-mineral conductive network.
authors.affiliation: Department of Soil and Crop Sciences, School of Integrated Plant Sciences, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Tianran
authors.initials: T
authors.lastname: Sun
authors.affiliation: School of Applied and Engineering Physics, College of Engineering, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Barnaby D A
authors.initials: BD
authors.lastname: Levin
authors.affiliation: Department of Biological and Environmental Engineering, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Juan J L
authors.initials: JJ
authors.lastname: Guzman
authors.affiliation: Department of Soil and Crop Sciences, School of Integrated Plant Sciences, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Akio
authors.initials: A
authors.lastname: Enders
authors.affiliation: School of Applied and Engineering Physics, College of Engineering, Cornell University, Ithaca, New York 14853, USA.|Kavli Institute for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA.
authors.forename: David A
authors.identifier: 0000-0003-4129-0473
authors.initials: DA
authors.lastname: Muller
authors.affiliation: Department of Biological and Environmental Engineering, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, USA.|Atkinson Center for a Sustainable Future, Cornell University, Ithaca, New York 14583, USA.|Center for Applied Geosciences, University of Tübingen, Tübingen, 72074, Germany.
authors.forename: Largus T
authors.initials: LT
authors.lastname: Angenent
authors.affiliation: Department of Soil and Crop Sciences, School of Integrated Plant Sciences, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, USA.|Atkinson Center for a Sustainable Future, Cornell University, Ithaca, New York 14583, USA.
authors.forename: Johannes
authors.initials: J
authors.lastname: Lehmann