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Trinity College Dublin

Isolation of 2-D Nanosheets

Science, Vol. 331, 2012

Many 3-D compounds exist as stacked layers of 2-D materials. If these 2-D layers could be isolated they could become a diverse source of 2-D crystals whose exotic electric properties and high specific surface areas will be important in a wide range of applications, from sensing to electronics to energy storage.

Graphene is the most well-known layered material; however, others do exist such as: transition metal dichalcogenides (TMDs), transition metal oxides (TMOs) and other 2-D compounds such as boron nitride (BN), molybdenum disulphide (MoS2) and bismuth telluride (Bi2Te3).

Work carried out in CRANN, by Prof. Coleman’s and Prof. Nicolosi's research groups, has resulted in a method of producing 2-D materials in a simple, large-scale and relatively high yield process, where 3-D materials are exfoliated down to very thin 2-D platelets using water and common solvents.

Applications for large yields of high quality 2-D flakes are many and varied; including gas barrier systems, composite materials, energy storage, sensing and electronics.

 

 

 

Figure: TEM of nanosheets. (A to C) Low resolution TEM images of flakes of BN, MoS2, and WS2, respectively. (D to F) High-resolution TEM images of BN, MoS2, and WS2 monolayers.

Fast Fourier transforms of the images. (G to I) Butterworth-filtered images of sections of the images in (D) to (F).