Title: Rational Design and Synthesis of Single Crystal Graphene towards Application
Time:14:30. Wednesday May 22, 2019
Location: Conference Room 4022 Gezhi Building
We demonstrate a library of synthetic methodologies for preparation of graphene-based materials. we observed an edge-epitaxial growth that is fundamentally different from conventional vdWs growth, in which the strong binding between the graphene edge and a metal step determines the final orientation. For example, we observe that graphene grains form with two possible orientations that are rotated by ~30° on the Cu (100) surface, and grains with three preferred orientations are observed on Cu (110). Density function theory calculations further prove the enhanced edge-metal step interaction and thus validate the experimental observations of these specific graphene crystal orientations on Cu (100) and Cu (110). Observation of this new type of edge-epitaxial growth helps to clarify many contradictory graphene growth phenomena that have been observed previously and provide insights on the growth of other materials using the chemical vapor deposition method. In addition, we will also cover our recent progress on the engineering of nonprecious transition metals as single atom catalysts (SACs) for hydrogen evolution reaction (HER). We found that only few of the transition metals (e.g., Co, Cr, Fe, Rh, and V) as SACs show good catalytic activity toward HER as their Gibbs free energies are varied between the range of –0.20 to 0.30 eV but among which Co‐SAC exhibits the highest electrochemical activity at 0.13 eV.
