Liquid-Phase Exfoliation of Rhenium Disulfide by Solubility Parameter Matching.

In this work, we provide a detailed account of the liquid-phase exfoliation (LPE) of rhenium disulfide (ReS), a promising new-generation two-dimensional material. By screening LPE in a wide range of solvents, we show that the most optimal solvents are characterized by similar Hildebrand or dispersive Hansen solubility parameters of 25 and 18 MPa, respectively. Such values are attained by solvents such as -methyl-2-pyrrolidone, ,-dimethylformamide, and 1-butanol. In line with solution thermodynamics, we interpret the conditions for high-yield exfoliation as a matching of the solvent and ReS solubility parameters. Using -methyl-2-pyrrolidone as an exemplary exfoliation solvent, we undertook a detailed analysis of the exfoliated ReS. In-depth morphological, structural, and elemental characterization outlined that the LPE procedure presented here produces few-layer, anisotropically stacked, and chemically pure ReS platelets with long-term stability against oxidation. These results underscore the suitability of LPE to batch-produce few-layer and pristine ReS in solvents that have a solubility parameter close to 25 MPa.