Fabrication of Delaminated 2D Metal Carbide MXenes (Nb2CTx) by CTAB‐based NO2 Gas Sensor with Enhanced Stability

Abstract Sensitivity is the prime factor in solid‐state gas sensors in terms of explicit noting of the change in signal. For achieving this, two vital prerequisites to be satisfied simultaneously: (i) electrical noise should be null and (ii) significant signal which is not met by the existing sensing materials. This study demonstrates that 2D metal carbide MXenes (Nb 2 CT x ) have strong metal conductivity for noise reduction and abundant functional groups for detecting the signal toward higher sensitivity. This work shows successful exfoliation of Nb 2 CT x in the presence of cationic surfactants like cetyltrimethylammonium bromide (CTAB), which is significantly stable. The confirmation about the successful stabilization of Nb 2 CT x in DI water is obtained from material characterization and gas sensing observations. The experiments show that the dynamic sensing response of the Nb 2 CT x ‐CTAB sensor increases by ≈3 times for NO 2 gas detection. The sensitivity of the Nb 2 CT x and Nb 2 CT x ‐CTAB found 0.543 and 1.686 ppm –1 , respectively, toward NO 2 gas. Over time (up to 30 d), CTAB functionalized Nb 2 CT x MXene noticed trace‐level detection capability with better environmental stability than pristine MXene. Herein, the obtained results show the gas sensing characteristics of Nb 2 CT x ‐CTAB and witness a selective and ultra‐sensitive response toward NO 2 gas detection.