MXene and Their Surface Functionalization for the Development of Functional MXene Organic Inks

Due to their unique metallic conductivity, transparency, and outstanding solution processability in water, MXenes have been attracted to many potential applications such as EMI shielding, energy storage, and electronic applications. However, oxidation instability of aqueous MXene dispersions and poor dispersion stability in organic solvents prevent the utility of MXenes in potential applications. Surface functionalization of MXene is critical for controlling the dispersion system, surface chemistry, processing, physicochemical properties, and applications. Herein, we designed and conceptualized various organic ligands that can improve oxidation stability and organic dispersibility of the functionalized MXene. The recently developed surface functionalization methods demonstrate a range of processes for synthesizing MXene organic inks into composites with different polymer and metal nanoparticles without chemical oxidation issues. Moreover, utilizing these functional inks as highly efficient electrodes, it is also possible to achieve fine patterning and direct writing on hydrophilic or hydrophobic substrates with excellent conductivity.