Vapor Phase η⁶ Surface Functionalization of Hexagonal Boron Nitride nanosheets

Hexagonal boron nitride (h-BN) exhibits high tensile strength (~100 GPa), wide bandgap (~6 eV), high thermal conductivity (227-280 W.m^-1.K^-1), excellent insulation and chemical stability. Functionalizing these nanostructures for expanding their application in electronics (such as depositing conductive film atop hBN flakes can provide a unique metal/single-atom-layer junctions), catalysis, and biomedical sensors require further investigation. Here, we show a novel organometallic covalent functionalization of h-BN with chromium carbonyl without distorting its lattice planarity or cleaving the B-N bonds. A chemical vapor deposition technique was employed for the vapor phase η⁶ functionalization of h-BN for a clean and efficient process. Spectroscopic evidence shows that this unique functionalization route retains the lattice connectivity between the B- and N- centers, while the metal binds to each member of the hBN ring. The computational analysis demonstrates that the surface reaction occurs spontaneously with ?G = -35.50 kcal/mol. Further, we also show that the carbonyl group on the metal center can be employed to attach silver nanoparticles forming a conductive layer atop hBN. This non-destructive and chemically active functionalization of hBN can enable the incorporation of hBN's structural and thermal properties into several applications.