Preferential functionalization on zigzag graphene nanoribbons: first-principles calculations

We investigate the functionalization of functional groups to graphene nanoribbons with zigzag and armchair edges using first-principles calculations. We find that the formation energy for the configuration of the functional groups functionalized to the zigzag edge is ∼ 0.2 eV per functional group lower than that to the armchair edge. The formation energy difference arises from a structural deformation on the armchair edge by the functionalization whereas there is no structural deformation on the zigzag edge. Selective functionalization on the zigzag edge takes place at a condition of the temperature and the pressure of ∼ 25 0C and 10-5 atm. Our findings show that selective functionalization can offer the opportunity for an approach to the separation of zigzag graphene nanoribbons with their solubility change. (fast track communication)