Exfoliation of Quasi-Two-Dimensional Nanosheets of Metal Diborides

Metal diborides are a class of ceramic materials with crystal structures consisting hexagonal sheets boron atoms alternating planes metal held together mixed character ionic/covalent bonds. Many the ultrahigh-temperature ceramics such as HfB2, TaB2, and ZrB2, which have melting points above 3000 °C, high mechanical hardness strength at temperatures, chemical resistance, while MgB2 is superconductor transition temperature 39 K. Here, we demonstrate that this diverse family non-van der Waals (vdW) can be processed into stable dispersions quasi-two-dimensional (2D) nanosheets using ultrasonication-assisted exfoliation. We generate quasi-2D AlB2, CrB2, MgB2, NbB2, TiB2, ZrB2 use electron scanning probe microscopy techniques to characterize their structures, morphologies, compositions. The exfoliated layers distribution lateral dimensions from tens nanometers up several micrometers thicknesses low 2–3 nm nanometers, all retaining atomic structure composition. exploit convenient solution-phase CrB2 incorporate them directly polymer composites. In contrast hard brittle bulk find nanocomposites remain very flexible simultaneously provide increases in elastic modulus ultimate tensile polymer. successful liquid-phase production enables processing scalable low-temperature methods, extending previously unexplored applications, reveals new non-vdW efficiently forms.