First principles study of two-dimensional early transition metal carbides

Recently, we reported on the facile synthesis of a number of two-dimensional early transition metal carbides and nitrides, derived from the MAX phases, that we labeled MXenes. Herein, we report on the electronic and elastic properties-investigated by first principles calculations utilizing the generalized gradient approximation within the density functional theory-of the following two-dimensional transition metal carbides: Ti2C, Ti3C2, Ti4C3, V2C, Cr2C, Zr2C, Hf2C, and Ta2C, Ta3C2, and Ta4C3. Similar to the MAX phases, the MXenes are found to be metallic and possess high elastic moduli when stretched along the basal planes.