Selective functionalization of halogens on zigzag graphene nanoribbons: A route to the separation of zigzag graphene nanoribbons

Using the ab initio pseudopotential density functional method, we investigate the functionalization of halogen molecules into graphene-based nanostructures with zigzag and armchair edges. We find that halogen molecules adsorb through chemisorption on the zigzag edge carbon atoms with a binding energy of similar to 1-5 eV, in sharp contrast to physisorption on the armchair edge and elsewhere where they adsorb with a binding energy of similar to 0.07 eV. Our findings would be utilized for an approach to the separation of zigzag graphene nanoribbons with regular edges with the change of the solubility of the functionalized nanoribbons. (C) 2010 American Institute of Physics. [doi:10.1063/1.3523252]