Thermal conductivity of oxidized gamma-graphyne

Abstract

Graphyne is an allotrope of graphene containing both sp and sp² hybridized carbon atoms. In this paper, we perform non-equilibrium molecular dynamics simulations to explore the thermal conductivity of oxidized gamma-graphyne based on the advanced reactive force field. The effects of the oxygen adsorption, its coverage and external tensile strain are thoroughly studied. Owing to the oxygen adsorption, the thermal transport property of gamma-graphyne is greatly deteriorated with lower thermal conductivity. The thermal conductivity is controlled by altering the oxygen coverage as well as external tensile strain. The underlying mechanisms for the thermal conductivity change are elaborated by the corresponding vibrational density of states. Our simulation results imply that graphynes are more attractive than graphene in the thermoelectric applications where lower thermal conductivity is essential to achieve a higher figure of merit. Oxygenation and strain engineering are promising methods to modulate graphyne to achieve designated thermal properties.