title: Electrical conductivity of oxidized-graphenic nanoplatelets obtained from bamboo: effect of the oxygen content.
abstract: The large-scale production of graphene and reduced-graphene oxide (rGO) requires low-cost and eco-friendly synthesis methods. We employed a new, simple, cost-effective pyrolytic method to synthetize oxidized-graphenic nanoplatelets (OGNP) using bamboo pyroligneous acid (BPA) as a source. Thorough analyses via high-resolution transmission electron microscopy and electron energy-loss spectroscopy provides a complete structural and chemical description at the local scale of these samples. In particular, we found that at the highest carbonization temperature the OGNP-BPA are mainly in a sp(2) bonding configuration (sp(2) fraction of 87%). To determine the electrical properties of single nanoplatelets, these were contacted by Pt nanowires deposited through focused-ion-beam-induced deposition techniques. Increased conductivity by two orders of magnitude is observed as oxygen content decreases from 17% to 5%, reaching a value of 2.3 × 10(3) S m(-1) at the lowest oxygen content. Temperature-dependent conductivity reveals a semiconductor transport behavior, described by the Mott three-dimensional variable range hopping mechanism. From the localization length, we estimate a band-gap value of 0.22(2) eV for an oxygen content of 5%. This investigation demonstrates the great potential of the OGNP-BPA for technological applications, given that their structural and electrical behavior is similar to the highly reduced rGO sheets obtained by more sophisticated conventional synthesis methods.
authors.affiliation: Center of Excellence on Novel Materials, Universidad del Valle, PO Box 25157, Cali, Colombia.
authors.forename: K
authors.initials: K
authors.lastname: Gross
authors.forename: J J Prías
authors.initials: JJ
authors.lastname: Barragán
authors.forename: S
authors.initials: S
authors.lastname: Sangiao
authors.forename: J M
authors.initials: JM
authors.lastname: De Teresa
authors.forename: L
authors.initials: L
authors.lastname: Lajaunie
authors.forename: R
authors.initials: R
authors.lastname: Arenal
authors.forename: H Ariza
authors.initials: HA
authors.lastname: Calderón
authors.forename: P
authors.initials: P
authors.lastname: Prieto
mesh_terms: D004553:Electric Conductivity; D006108:Graphite; D010084:Oxidation-Reduction; D010087:Oxides; D010100:Oxygen
chemical_list: D010087:Oxides; D006108:Graphite; D010100:Oxygen