Chapter 1 - Two-Dimensional Nanomaterials: Crystal Structure and Synthesis

Abstract

Since the discovery of graphene in 2004, research on two-dimensional (2-D) nanomaterials has grown exponentially in the fields of material science, condense matter physics, chemistry, and nanotechnology. The 2-D nanomaterials such as graphene, transition metal dichalcogenides, silicate clays, and hexagonal boron nitride provide enhanced physical, chemical, and biological functionality owing to their uniform shapes, high surface-to-volume ratios, and surface charge. However, research on 2-D nanomaterials is still its infancy, with majority of research focusing on elucidating unique material characteristics. To characterize the layer-dependent changes in properties and to provide pathways for their integration into a multitude of applications, it is essential to explore the reliable synthesis of single- and few-layer 2-D nanomaterials. Therefore, many synthetic strategies such as micromechanical exfoliation, liquid-phase exfoliation, and chemical vapor deposition have been developed to synthesize high-quality and ultrathin nanosheets showing their own merits and demerits in preparing 2-D nanomaterials. In this chapter, we summarize the state-of-the-art progress of this dynamically developed material family with a particular focus on their crystal structure and synthetic methods. Eventually, the potential trends and future direction for synthesizing technology for 2-D nanomaterials are proposed.