Facile synthesis of vertically aligned hexagonal boron nitride nanosheets hybridized with graphitic domains

Motivated by the recent quest for producing novel two dimensional nanomaterials, we developed a facile synthetic method for growing boron nitride-carbon (BN-C) phase-separated composite nanosheet coatings on silicon/silicon dioxide (Si/SiO2) substrates. The coatings were composed of compact partially vertically aligned nanosheets with a nanoscale roughness. The majority of the obtained BN-C nanosheets were less than 5 nm in thickness, mostly consisting of 2-15 atomic layers. Electron energy loss spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed the natural sp(2) hybridization of the product, and cathodoluminescence spectroscopy measurements showed strong luminescence emission in the ultraviolet region at room temperature. Ultraviolet-visible spectroscopy demonstrated that the composite structure of alternating BN and C domains has different optical band gap features compared to pure h-BN nanosheets and graphenes, making it a promising material for further fundamental physical studies and potential applications in optoelectronics. Moreover, due to the rough morphology and nanoscale features of the BN-C coatings, they exhibited excellent water repellency (superhydrophobicity).