Reduction Kinetics of Graphene Oxide Determined by Electrical Transport Measurements and Temperature Programmed Desorption

Abstract

The thermal stability and reduction kinetics, of graphene oxide were studied by measuring the electrical resistivity of single-layer. graphene films at various stages of reduction in high vacuum and by performing temperature programmed desorption (TPD) measurements of multilayer films in ultrahigh vacuum. The graphene oxide was exfoliated from the graphite oxide source material by slow-stirring in aqueous solution, which produces single-layer platelets with an average lateral size of similar to 10 mu m. From the TPD measurements, it was determined that the primary desorption products of the graphene oxide films for temperatures up to 300 degrees C are H2O, CO2, and CO, with only trace amounts of O-2 being detected. Resistivity measurements on individual single-layer graphene oxide platelets resulted in an activation energy of 37 +/- 1 kcal/mol. The TPD measurements of multilayer films of grapbene oxide platelets give an activation energy of 32 +/- 4 kcal/mol.