Luminescent monolayer MoS 2 quantum dots produced by multi-exfoliation based on lithium intercalation

•A new preparation, multi-exfoliation method based on lithium (Li) intercalation, has been demonstrated for preparing monolayer molybdenum disulfide (MoS2) quantum dots (QDs).•The advantage of this approach is that it is capable of producing monolayer MoS2 QDs in a large number, regardless of whether the raw material is bulk or nanoparticles.•The PL intensity excited at 300nm can be enhanced by five times after ultrasonicated heating treatment.