Fracture-induced nanoscrolls from CVD-grown monolayer molybdenum disulfide

We report a simple and effective way of fabricating molybdenum disulfide (MoS 2 ) nanoscrolls by self-rolling up fractured monolayer CVD-grown MoS 2 microflakes. Morphological results reveal that MoS 2 nanoscrolls are formed only at newly formed edges, owing to an orientation-specific fracture behavior. Using Raman spectroscopy, we show that the E 1 2g Raman peak (A 1g peak) for MoS 2 nanoscrolls significantly red-shifts (blue-shifts), indicating structural change. The proposed mechanism is that the newly formed edges induced by fracture behavior self-roll up to nanoscrolls to minimize the surface free energy, meanwhile, the serious lattice contradiction of upper sulfur plane controls the rolling directions. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)