Flexible Conductive Graphene Paper Obtained by Direct and Gentle Annealing of Graphene Oxide Paper

We report the fabrication of flexible conductive graphene paper through a direct and gentle annealing process of graphene oxide paper. Thermal treatments at 700 oC under argon or hydrogen atmosphere directly applied to parent graphene oxide paper lead to a significant removal of disruptive oxygen-containing functional groups, and to a considerable recovery of the sp network structure. Detailed comparison of chemical and combined chemical-thermal treatments by scanning electronic microscopy (SEM), Raman, X-photoelectron spectroscopy (XPS) and conductivity measurements underline the high efficiency of the direct annealing process. The resulting highly reduced graphene oxide paper exhibits electrical conductivities as high as 8100 S/m representing an increase of 5 orders of magnitude with respect to the parent graphene oxide paper, Corresponding author. Tel/Fax: +34 97673-3977/-3318. E-mail address: [email protected] (W.K. Maser)