The present disclosure relates to 2-dimensional MXenes surface-modified with catechol derivatives, a method for preparing the same, MXene organic ink including the same, and use thereof (e.g. flexible electrodes, conducive cohesive/adhesive materials, electromagnetic wave-shielding materials, flexible heaters, sensors, energy storage devices). Particularly, the simple, fast, and scalable surface-functionalization process of MXenes using catechol derivatives (e.g. ADOPA) organic ligands significantly improves the dispersion stability in various organic solvents (including ethanol, isopropyl alcohol, acetone and acetonitrile) and produces highly concentrated organic liquid crystals of various MXenes (including Ti2CTx, Nb2CTx, V2CTx, Mo2CTx, Ti3C2Tx, Ti3CNTx, Mo2TiC2Tx, and Mo2Ti2C3Tx). Such products offer excellent electrical conductivity, improved oxidation stability, excellent coating and adhesion abilities to various hydrophobic substrates, and composite processability with hydrophobic polymers. This finding will lead to further studies on the structures, properties, and physics of the organic MXene liquid crystals and their practical applications.