Facile and mass production of intrinsic and defect-free 2D QSs from bulk layered materials is achieved via a unified top-down method.

Mass production of two-dimensional quantum sheets (2D QSs) is highly desired to fully exploit their properties. Herein, we present a general strategy for the high-yield production of molybdenum disulfide (MoS) and tungsten disulfide (WS) QSs by a sequential combination of salt-assisted ball-milling and sonication-assisted solvent exfoliation of their bulk materials. Such a strategy enables reproducible production of intrinsic and defect-free MoS and WS QSs with exceedingly high yields of 25.5 and 20.1 wt %, respectively. By precipitation-redispersion treatment, the QSs can be redispersed in a wide range of solvents with redispersion concentration up to 20 mg/mL or even higher. Remarkable nonlinear absorption saturation is demonstrated in the QSs-poly(methyl methacrylate) (PMMA) hybrid thin film with loading content of merely 0.1 wt %. Our method provides an avenue toward mass production and full exploration of 2D QSs.