Vibrational properties of TiVC-based Mxenes by first-principles calculation and experiments

As a new member of Mxene, TiVC showed promising application prospects in SERS and lithium-ion battery materials. However, the stable structures of the TiVC with different functional groups are still elusive. In this paper, possible models of TiVC and TiVCT2(where T = F, O, OH) are investigated using density functional theory. The structure of TiVC-based MXenes is optimized, the kinetic stability is analyzed, and the phonon vibrational modes with Raman activity (A1, E) and IR activity (A1, E) are calculated. At the same time, the in-fluence of the terminal group T (where T = F, O, OH) on the vibrational modes and the peak positions of the Raman spectra was studied by combining experimental Raman spectra. The results show that the TiVCT2 model is consistent with the experimental Raman spectra. This work provides detailed insights into identifying and characterization TiVC-based samples using Raman spectroscopy.