Determination of van der Waals C3 coefficients for titanium carbide MXenes with alkali atoms

Abstract

Ti3C2Tx MXene have emerged as propitious candidate in two dimensional (2D) family having almost similar properties as that of graphene. Presence of functional groups as surface terminations on MXene plays a crucial role in adsorption and sensing applications. In this work, we theoretically calculate the van der Waals (vdW) C3 coefficients to determine the interaction of pristine and functionalized titanium carbide MXene samples with alkali atoms by considering non retardation potentials, the basis of which lies on Lifshitz theory. The pristine and functionalized MXene samples act as a wall and the atom-wall interactions between the alkali atom and MXene wall can be predicted by corresponding C3 coefficients. In order to do so, first we fetch the frequency dependent optical constant values of titanium carbide MXene from optical data already calculated using first principle calculations from literature [6]. Thereby, the dielectric permittivity of titanium carbide MXene wall is evaluated by Kramers-Kronig relation. For alkali atoms, we use the dynamic electric dipole polarizabilities evaluated accurately using relativistic coupled cluster (RCC) method. The calculation of C3 coefficients is performed for pristine Ti3C2 MXene without surface termination and for surface functionalized MXene Ti3C2T2 with T as oxygen (-O), fluorine (-F) and hydroxyl group (-OH) surface terminations. This study predicts the interaction of different surface functionalized titanium carbide MXene with alkali atoms.