Identifying the Active Sites on N-doped Graphene toward Oxygen Evolution Reaction

摘要

Identifying and generating more active sites with high activity on N-doped graphene for oxygen evolution reaction (OER) are challenging in the renewable energy conversion and storage technologies. However, the local electronic/chemical environment on graphene surface is significantly influenced and can be controlled by doping with foreign atoms, which will contribute to its improved catalytic performance. Henceforth, different N-doping formats, diverse N distributions and concentrations, as well as the edge effect are investigated on the basis of density functional theory, to discover the ideal N-doping condition for high OER behavior. By analyzing the free-energy-change diagrams, adsorbed interactions of reactant intermediates, electrostatic potential surfaces, and other obtained data, it is suggested that graphitic N with low doping concentration and N atoms distributed near edge sites is the ideal candidate for high OER activity, which is efficient as a carbon-based electrocatalyst for water splitting and metal-air batteries applications.