  Recently two-dimensional (2D) transition metal carbides and nitrides (MXenes)
have gained significant attention in electronics and electrochemical energy
conversion and storage devices where the heat production significantly affects
the safety and performance of these devices. In this paper, we have studied the
thermal transport in monolayer Ti3C2Tz, the first and most studied MXene, using
density functional theory (DFT) and phonon Boltzmann transport equation and
quantified the effect of surface termination (bare, fluorine and oxygen) on its
lattice thermal conductivity. We found that thermal conductivity of
fluorine-terminated Ti3C2Tz (108 W/m.K) is approximately one order of magnitude
higher than its oxygen-terminated counterpart (10 W/m.K). Our calculations
reveal that the increased thermal conductivity for the fluorine-terminated
structure is due to its enhanced specific heat and group velocity and
diminished scattering rate of phonons.
