2D boron nitride nanosheets (BNNS) prepared by high-pressure homogenisation: structure and morphology

2D Boron Nitride Nano-sheets (BNNS) were prepared using a high-pressure homogenisation process to exfoliate bulk hexagonal boron nitride (h-BN). The effectiveness of this process was studied by characterising bulk h-BN and BNNS post-processing using numerous techniques. The BNNS produced was composed of a mixture of sheets having lengths on the nanometre (nm) scale, but lateral thicknesses on the micron (m) length scale. The product was a macro-porous material containing slit-like pores with a surface area of 170 m(2) g(-1). It had a polycrystalline structure with d(002) = 0.335 nm and L-002 = 2 nm. From the sharp E-2g peak in the Raman spectrum at 1360 cm(-1) (FWHM = 12.5 cm(-1)), the sheets had a low defect density and were highly exfoliated. X-Ray photoelectron spectroscopy (XPS) studies detected B-OH and N-H groups on the BNNS surface and the presence of residual surfactant. Contact angle measurements (60 degrees +/- 3 degrees (0 s); 40 degrees +/- 2 degrees (10 s)) confirmed a hydrophilic surface. The BNNS was thermally stable under oxidative conditions up to 323 degrees C.