Readily Available “Stock Solid” of MoS2 and WS2 Nanosheets through Solid‐Phase Exfoliation for Highly Concentrated Dispersions in Water

We report a facile method for large-scale exfoliation of bulk molybdenum disulfide (MoS2) and tungsten disulfide (WS2) in the presence of sodium cholate through ball milling. The exfoliated sample can be stored as a “stock solid” and is readily dispersed in water just by shaking by hand, giving a highly concentrated dispersion (up to 4.2 and 2.6 mg mL−1) of MoS2 and WS2 nanosheets with up to 93 % and 57 % yields, respectively, after centrifugation.