Synthesis methods and surface chemistry/functionalization of MXene

In 2011, a new family of two-dimensional (2D) inorganic compounds (MXenes), consisting of several atomic layers of transition metal carbides/nitrides/carbonitrides was discovered. Since then, numerous experimental and theoretical investigations have been conducted to elucidate the variable and tailorable physicochemical properties of MXenes, such as good electrical conductivity, large elastic moduli, outstanding optical properties, compatibility with water and organic solvents, to name a few. Notably, the application of MXenes is based on the premise that they can be synthesized and can stably exist with tunable properties under certain environments. In this chapter, we firstly summarize the comprehensive and state-of-the-art methods for fabricating MXenes, which are mainly divided into the top-down and bottom-up synthesis routes. Thereafter, the surface chemistry/functionalization of MXenes is outlined with respect to adjusting and obtaining specific properties. Finally, the key opportunities, challenges, and prospects for future research on MXene-based materials are presented from both experimental and theoretical aspects.