Robust production of 2D quantum sheets from bulk layered materials

Abstract

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

Controlled Production of MoS2 Full‐Scale Nanosheets and Their Strong Size Effects

“…We have recently realized the scalable production of a range of 2D QSs by combination of silica‐assisted ball‐milling and sonication‐assisted solvent exfoliation. [ 28 ] The extreme size‐reduction of bulk layered materials into 2D QSs of 2–3 nm brings bright prospect toward full‐scale NS production. Herein, we demonstrate the successful production of molybdenum disulfide (MoS 2 ) NSs with full‐scale controlled sizes.…”

“…Silica‐assisted ball‐milling promised the unprecedented pulverization of the pristine MoS 2 bulk materials (Figure S1, Supporting Information). [ 28 ] Ball‐milling control with time enabled the facile production of multiscale NSs with varying distributions. The following sonication‐assisted solvent exfoliation transformed the pulverized materials into few‐layer (<10 layers) NSs, which could be well dispersed in the solvent (i.e., N ‐methyl‐2‐pyrrolidone (NMP)).…”

“…Fortunately, the QSs could be rapidly and efficiently collected using our recently developed method (i.e., by combination of solvent precipitation and centrifugation separation). [ 28 ] For clarity, the MoS 2 NS (excluding QS) powders were denoted as sample “a‐b krpm,” where a and b represented the previous and current centrifugation rate, respectively. However, the QS powders were named as sample “12 krpm–,” indicating that the supernatants after centrifugation at 12 krpm were completely collected.…”

“…From Figure 3a, wide‐range (161–10 nm) controlled sizes of the MoS 2 NSs were obtained. Considering the recently achieved MoS 2 QSs with sizes of ≈2 nm, [ 28 ] full‐scale NSs were, for the first time, produced. The success of full‐scale MoS 2 NSs would greatly prompt the production of other 2D NSs with all sizes.…”

“…Such transformation of the characteristic peaks was driven by the quantum confinement and prominent edge effects. [ 16,28,31 ] Figure 3e presented the Raman spectra of MoS 2 bulk materials and NSs with varying sizes. For bulk MoS 2 , both peaks of E 1 2g mode at 380.9 cm −1 and A 1g mode at 406.6 cm −1 were observed.…”