Probing the Synthesis of Two-Dimensional Boron
The synthesis of novel two-dimensional (2D) materials has attracted considerable interest because of their various unique properties. While the production of 2D boron (2DB) sheets remains a challenge, it is important to theoretically investigate the possible fabrication methods. In a Communication, just published in Angew. Chem. Int. Ed., we explore the formation of B sheets on metal (Cu, Ag, Au) and metal boride (MgB2, TiB2) substrates using first-principles calculations. Our results suggest that B sheets can be grown on the Ag(111) or Au(111) surfaces by deposition. B atoms decomposed from a precursor, and driven by the gradient of the chemical potential, will assemble into 2D clusters and further grow into a larger sheet, while formation of three-dimensional boron (3DB) structures could be impeded owing to a high nucleation barrier. In addition, saturation of a boron-terminated MgB2 surface in a boron-rich environment can also lead to the formation of B sheets. These sheets are weakly bound to the substrates, suggesting a feasible post-synthetic separation into the free-standing forms. Our work proposes feasible approaches to synthesize 2DB, and could possibly pave the way towards its application in nanoelectronics.