(745b) Synthesis of Solvent Dispersed Ultrathin Sheets of Boron Nitride

In this talk, we demonstrate a chemical method that enables high-throughput synthesis of solvent dispersible ultrathin hexagonal Boron Nitride Nanosheets (UTBNSs) with highest yields reported so far. UTBNSs are the lesser explored structural isomorphs of graphene, and offer immense promise to complement graphene by virtue of their analogous electrical nature and profound chemical stability. We report a synthetic route which utilizes the strongly protonating ability of superacid to chemically functionalize the intermittent h-BN layers (by introducing –NH and –NH₂ functionalities), which not only enables their layer-by-layer exfoliation (1-5 layer thick sheets at a yield of ~23%), but is also shown to result in an efficient aqueous phase stabilization without the use of polymeric surfactants. The availability of surfactant-less high yield UTBNS dispersions will pave the path for using conventional solution processing techniques to facilely create new BN based materials and hence broaden the scope of their applications. We also show that the amine-functionalities on the UTBNSs can interface effectively with electron-rich gold nanoparticles and negatively charged dye molecules to form inorganic composites. The results presented here will evolve research on atomic-thick BN; and will open avenues for next-generation applications of insulating 2D planar nanocrystals including piezoelectric devices, UV-emitters, transistor gate barriers, polymeric composites with reinforced strength, luminescent nanomaterials, single-atom-tunneling-barrier devices, impermeable membranes, and graphene-UTBNS interfaced devices.