Large-scale production of two-dimensional nanosheets

Abstract

Two-dimensional (2D) nanomaterials such as graphene, boron nitride (BN), and molybdenum disulfide (MoS 2 ) have been attracting increasing research interest in the past few years due to their unique material properties. However, the lack of a reliable large-scale production method is an inhibiting issue for their practical applications. Here we report a facile, efficient, and scalable method for the fabrication of monolayer and few-layer BN, MoS 2 , and graphene using combined low-energy ball milling and sonication. Ball milling generates two forces on layered materials, shear force and compression force, which can cleave layered materials into 2D nanosheets from the top/bottom surfaces, and the edge of layered materials. Subsequent sonication would further break larger crystallites into smaller crystallites. These fabricated 2D nanosheets can be well dispersed in aqueous solutions at high concentrations, 1.2 mg mL À1 for BN, 0.8 mg mL À1 for MoS 2 , and 0.9 mg mL À1 for graphene, which are highly advantageous over other methods. These advantages render great potential in the construction of high-performance 2D material-based devices at low cost. For example, a prototype gas sensor is demonstrated in our study using graphene and MoS 2 , respectively, which can detect several ppm of ammonia gas.

Facile and size-controllable preparation of graphene oxide nanosheets using high shear method and ultrasonic method

“…Typically, under the shear force, preferential cleavage happens mainly along the weak inter-plane bonds so that the thin GO nanosheets were able to be mechanically peeled off from the graphite oxide particles [60]. The shear force can cleave graphite oxide from their outer surface [61] (Figure 11(a)), while the impacting force peels off thin GO nanosheets from the edge of graphite oxide [62] (Figure 11(b)). Concurrently, the impacting force also can lead to the in-plane fracture of the GO [63] (Figure 11(b)), which will reduce the area of the GO nanosheets.…”

Two-dimensional inorganic analogues of graphene: transition metal dichalcogenides

“…A variety of layered crystals including TMDCs, transition metal oxides and BN have been successfully exfoliated in aqueous medium by ultrasonication with sodium cholate as a surfactant to prevent re-aggregation of the dispersed nanosheets. Yao et al [24] combined low-energy ball milling with ultrasonication for exfoliation of various inorganic layered materials into nanosheets. Ultrasonication has an undesired effect of breaking the nanosheets and reducing their lateral dimensions.…”

All-Inorganic Perovskite CsPb2Br5 Microsheets for Photodetector Application

“…Two dimensional (2D) nanostructures, such as BN [1], MoS 2 [2], and WS 2 [3] have attracted increasing attention due to the unique properties and are widely studied in many fields ranging from energy storage to environmental protection [4,5]. Compared with one dimensional (1D) and zero dimensional (0D) nanostructures, 2D nanostructures materials show great advantages in some special applications attributed to their extraordinary electrical, optical and magnetic properties [6][7][8].…”