Raman Spectroscopy and Laser-Induced Surface Modification of Nb₂CT_<i>x</i> MXene

The Nb2CTx MXene has garnered interest for its potential applications in energy storage, catalysis, and sensors. Recent reports of Raman spectra of Nb2CTx reveal stark differences of the MXene incorporated into devices, which may affect the devices’ performance and reproducibility. These differences illuminate a need for fundamental characterization of the Nb2CTx Raman modes to better understand the material-specific properties of the MXene integrated into devices. We conducted a comprehensive multiexcitation Raman study and observed nine Raman-active modes in Nb2CTx that are consistent with our density functional theory calculations. Additionally, we investigated laser-induced surface modification of Nb2CTx through changes in the peak intensities and frequencies, along with the generation of amorphous carbon with increasing incident laser power. This fundamental study provides a framework to spectroscopically assess the integrity of Nb2CTx and a tool for creating a stable, tunable, and localized surface modification.