We’ve all heard of graphene – the two-dimensional carbon allotrope with exceptional strength, flexibility, and conductance – but what about borophene?
Borophene is the next generation graphene. It has recently been successfully synthesized using molecular beam epitaxy, and now, researchers from Rice University, USA, and Nanjing University of Aeronautics and Astronautics, China, report in Advanced Functional Materials their complete first-principles analyses of the mechanical properties of borophene.
Although similar to graphene in its lightweight nature and strength, borophene has two distinguishing features that contribute to its novel desirable properties. First, borophene is composed of a highly variable boron atom network of hollow hexagons (HHs) in a reference triangular lattice, where tuning the HH concentration can tailor its mechanical properties. Secondly, borophene is metallic in nature owing to is delocalized multi-centered bonding, which the researchers say could “anticipate qualitatively new phenomena”.
In this study, the researchers have shown that borophene has “record high” flexibility, a higher stiffness to weight ratio than graphene, and a higher ideal strength than the best known polymer materials. In fact, rather than fracturing under strain like many materials, borophene experiences strain-induced structural phase transitions that strengthen the material further. Furthermore, its material strength is heightened by introducing more HHs into the network, providing us with the ability to tailor and fine tune the material properties.
With low mass density, high strength, and high levels of flexibility, borophenes are promising for reinforcing elements for designing composites and for flexible nanodevices, such as flexible electrodes and contacts for nanoelectronics.