Control of graphene nanoribbon vacancies by Fe and N dopants: Implications for catalysis

Theoretical calculations were performed to determine the edge effects governing structural and thermodynamic properties of vacancies, N-terminated (pyridinic) vacancies, and Fe/defect complexes in graphene nanoribbons. Fe and N coordinate with vacancies, changing their structure and preferentially stabilizing edge states and thereby facilitating the enhanced accessibility of reactants to potential catalytically active sites. Doping with either N or Fe also has the thermodynamic effect of lowering vacancy formation energies, thus, providing for an enhanced equilibrium concentration of reactive defect states in the graphene nanoribbons. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4742890]