Abstract:Two-dimensional (2D) functional materials, which can be usually achieved by a) mechanically exfoliating or liquid exfoliating layered structural materials featuring weak intra-plane bonding and strong inplane covalent bonding to produce single- and/or few-layer nanosheets; b) chemical synthesis approaches; c) Langmuir-Blodgett method; d) layer-by-layer self-assembly; e) chemical vapor deposition; f) molecular beam epitaxy and g) atomic layer deposition technology as well, has found many potential applications in the fields of e.g., field-effect transistors, optical modulators, mode-locked and Q-switched lasers, optical limiters, information and energy storages, radio-frequency devices, chemical sensing, and others due to their unique structural characteristics and superior properties. Besides well-known 2D graphene, the other 2D materials, including inorganic layered materials (e.g. hexagonal boron nitride, transition metal halides, graphitic carbon nitride, layered metal oxide and so on), 2D polymers, metal organic framework, perovskite, and black phosphorus have also been widely explored in recent years. Design and preparation of novel 2D