Raman Spectroscopy and Laser-Induced Surface Modification of Nb₂CT_x MXene

Abstract

The Nb 2 CT x MXene has garnered interest for its potential applications in energy storage, catalysis, and sensors. Recent reports of Raman spectra of Nb 2 CT x 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 Nb 2 CT x 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 Nb 2 CT x that are consistent with our density functional theory calculations. Additionally, we investigated laser-induced surface modification of Nb 2 CT x 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 Nb 2 CT x and a tool for creating a stable, tunable, and localized surface modification.