Laser‐Induced‐Structural Transformation in Ti ₃ CNT _x MXene Monitored by Raman Spectroscopy with DFT Insight

ABSTRACT MXenes are emerging 2D nanomaterials that have attracted growing attention for their highly tunable atomic structure, composition, and surface terminations. Raman analysis is widely used to study the structural and functional properties of nanomaterials, including MXenes (such as Ti ₃ C ₂ T _x and Ti ₃ CNT _x ). Current literature on Ti ₃ CNT _x MXene shows inconsistent spectral interpretations and unclear guidance on optimal laser excitation conditions, and remains largely unexplored. To address these gaps, a comprehensive Raman spectroscopic study has been conducted for the microwave‐assisted hydrothermally synthesized Ti ₃ CNT _x MXene using multiple excitation wavelengths (457, 514.5, 532, and 660 nm) and different laser powers. Our analysis identified threshold laser power levels for each wavelength, below which intrinsic MXene features are preserved and above which photothermal effects lead to the formation of amorphous carbon, TiO ₂ phases, and N‐doping. To support experimental observations and guide vibrational mode assignments, density functional theory calculations were performed on monolayer Ti ₃ CNT _x MXene functionalized with ─OH, ─F, and ─Cl groups. Additionally, we evaluated the environmental stability of Ti ₃ CNT _x MXene thin film under ambient conditions. The material exhibited excellent structural integrity with no significant spectral changes over more than a month. These findings pave the way for their integration into advanced solid‐state laser‐processed technologies such as sensors, electrodes and electronics.