Emerging Role of Nb₂CT_x MXene in Sensors: The Roadmap from Synthesis to Health and Environmental Monitoring

The rise of two-dimensional (2D) materials has transformed gas sensing, with Nb₂CT_x MXene drawing significant interest due to its distinct physicochemical behaviors. As part of the MXene family, Nb₂CT_x MXene demonstrates a remarkable combination of high electrical conductivity, adjustable surface chemistry, and exceptional mechanical flexibility, positioning it as a promising candidate for next-generation gas sensors. This review explores the synthesis techniques for Nb₂CT_x MXene, highlighting etching methods and post-synthesis adjustments to achieve the tailored surface terminations and structural qualities essential for gas detection. A comprehensive examination of the crystal structure, morphology, and electronic characteristics of Nb₂CT_x MXene is presented to clarify its outstanding sensing capabilities. The application of Nb₂CT_x MXene for detecting gases, including NH₃, humidity, NO₂, and volatile organic compounds (VOCs), is assessed, showcasing its sensitivity, selectivity, and low detection limits across various environmental settings. Furthermore, the integration of Nb₂CT_x MXene with other nanostructures in sensor platforms is reviewed. Lastly, challenges related to scalability, stability, and long-term performance are addressed, along with future prospects for Nb₂CT_x MXene-based gas sensors. This review offers significant insights into the potential of Nb₂CT_x MXene as a pioneering material for enhancing gas sensing technologies.