Effect of hydrogenation on graphene thermal transport

We studied thermal conductivity of the three most stable hydrogenated graphene (graphane) conformers by means of non-equilibrium molecular dynamics. We estimated thermal conductivity for pristine graphene with sample length 2.1 (2.4) μm as large as κ = 745.4 ± 0.3 and 819.1 ± 0.3 W m−1 K−1 in the armchair and zigzag directions, respectively, in very good agreement with previous theoretical results based on the Boltzmann transport equation. In the case of the three graphane isomers we observed a dramatic κ reduction by at least one order of magnitude with respect to pristine graphene. We elucidated this reduction in terms of different phonon density of states and mean-free path distribution between graphene and graphane. The deterioration of thermal transport upon hydrogenation in graphene, could be proposed as a way to tune thermal transport in graphene for phononic applications such as thermal diodes.