Efficient dispersant-free liquid exfoliation down to the graphene-like state of solvent-free mechanochemically delaminated bulk hexagonal boron nitride

It is shown that during mechanochemical treatment of the bulk hexagonal boron nitride (hBN) in the presence of an inert delamination agent the nanostructuring of hBN occurs: its partial delamination, shift of the layers relative to one another, reduction of the particle size. It is established that the reactive paramagnetic defects are formed in the structure of the nanostructured hBN, and their number is significantly reduced under the effect of water. The formation of oxygen-containing functional groups at the outer edge of the nanoparticles, and ability of such nanoparticles to effectively exfoliate in various organic solvents and in water under the effect of ultrasound are shown. The data of electron diffraction, XPS and UV-vis indicated the preservation of the hBN structure in the plane of the nanoparticles. The predominately monolayer morphology of the particles in the dispersions is confirmed by AFM microscopy and Raman spectroscopy.