Edge Functionalization of Bulk γ-Graphyne Facilitates Mechanical Exfoliation and Modulates the Mode of Sheet Stacking
Claire M. Bolding, Tejaswini Haraniya, Grace L. Parker, William Blake Martin, Victor G. Desyatkin, Logan Heck, Konstantin V. Bukhryakov, Valentin O. Rodionov
Abstract
We have successfully achieved selective and efficient functionalization of sheet edges in microcrystalline multilayer γ-graphyne through two methods: cross-coupling with residual bromide edge groups and copper-catalyzed azide–alkyne cycloaddition (CuAAC) with edge terminal alkyne groups. This modification significantly enhances the ease of mechanical exfoliation and dispersibility of the sheets of γ-graphyne. Specifically, C 18 -grafted γ-graphyne forms stable dispersions in compatible organic solvents, allowing for the imaging of atomically thin layers of γ-graphyne for the first time. Additionally, we have discovered that phenylacetylide edge groups alter the preferred stacking mode of γ-graphyne sheets. Few-layer flakes of Ph-edge γ-graphyne exhibit a preference for the R 3 m space group, contrasting with the aperiodic stacking of Br-edge γ-graphyne. These results open the door for scalable exfoliation of few-layer flakes of γ-graphyne with a high aspect ratio, enabling potential applications in carbon electronics.