High-Yield and Damage-free Exfoliation of Layered Graphdiyne in Aqueous Phase

The two-dimensional carbon material graphdiyne (GDY) holds great promise as a semiconductor and porous material, however, exfoliation of bulk GDY into single- or few-layered GDY in the aqueous phase remains a challenge. We report an efficient method for the damage-free exfoliation of bulk GDY into single- or few-layered GDY with high yield in an aqueous solution of inorganic salts (e.g., Li2SiF6). This was confirmed by spherical-aberration-corrected scanning transmission electron microscopy, scanning/transmission electron microscopy, atomic force microscopy, Fourier transform infrared/Raman spectroscopy, X-ray photoelectron spectroscopy. The method gives high exfoliation efficiency (75 wt %) without creating additional structural defects or oxides in the exfoliated GDY. Theoretical calculations suggest that non-covalent adsorption of the anion, diffusion of the cation, and subsequent repulsive forces between adjacent flakes are the main driving force for the efficient exfoliation.