Intriguing of two-dimensional Janus surface-functionalized MXenes: An ab initio calculation

MXenes, two-dimensional (2D) transition metal carbides and nitrides displaying astonishing properties are emerged as a new class of two-dimensional (2D) layered materials. Motivated by the recent successful synthesis of Janus monolayers of transition metal dichalcogenides, we investigated the structural, electronic, magnetic and vibrational properties of Janus structure of pristine M′MC and functionalized M′MCT2 (where T = F, O, OH) MXene by means of first-principles calculations. Here M′MC as a representative Janus MXene material is designed. The ground state structures of Janus pristine M′MC and functionalized M′MCT2 are found in four different configurations. Our calculated electronic band structures indicate that the Janus M′MC MXenes are metallic and their functionalized M′MCT2s display half-metallic, metallic and semiconductor behaviors upon surface functionalized type. Our results reveal that (i) phonon band dispersion diagram of Janus pristine M′MC MXenes are dynamically stable (ii) ab initio molecular dynamic simulations (AIMD) clearly proved that they kept thermal stabilities at high temperature (900 K) and (iii) Raman-active vibrational modes are predicted. Janus surface-functionalized MXenes suggest that they are promising candidates for spintronic applications, which should stimulate interest in their synthesis.