CHAPTER 5: Liquid Phase Synthesis of Two-dimensional Crystals: from Top-down to Bottom-up

Recently, great effort has been devoted to the exploration of two-dimensional (2D) materials with atomic thickness, for their extraordinary electronic structures with respect to corresponding bulk counterparts, giving promising applications in various fields such as electronics, optoelectronics, catalysis, and energy storage. Nevertheless, relatively limited synthetic methods for preparing these 2D nanosheets undoubtedly restrict further progress, especially for materials with non-layered structures or quasi-layered structures containing relatively strong bonds and van der Waals forces between layers. Therefore, developing novel synthetic methods for 2D nanosheet preparation will not only enrich the family of 2D crystals with atomic thickness, but also bring us unprecedented surprises. Liquid-phase synthetic methods show great potential for preparing 2D crystals with atomic thickness when compared with traditional methods, especially for non-layered and quasi-layered materials. In this chapter, we focus on advances in liquid-phase synthetic strategies for preparing atomically-thick 2D crystals using top-down and bottom-up strategies.