High Specific Surface\nArea 2D/1D Hybrid Materials\nof Nb<sub>2</sub>CT<sub><i>x</i></sub>/CNT for Efficient\nVOCs Detection at Room Temperature

Monitoring of volatile organic compounds (VOCs) is important\nin\nmany fields. MXene, a class of two-dimensional materials, exhibits\nsignificant potential for high-sensitivity VOCs detection owing to\nits high specific surface area and abundant functional groups. However,\nMXene layers tend to restack or aggregate in practical applications\ndue to van der Waals forces and hydrogen bonding, which leads to a\ndecrease of surface area compared to theoretical performance. One-dimensional\n(1D) carbon nanotube (CNT)/two-dimensional (2D) MXene mixed-dimensional\nheterostructures have been proven to be effective in improving catalytic\nefficiency or battery performance. Therefore, in this study, CNT and\nMXene (Nb<sub>2</sub>CT<sub><i>x</i></sub>) are constructed\nas hybrids, which effectively reduced the restack of MXene layers,\nthereby increasing the surface area available for VOCs binding. The\nsensitivity of the hybrids to ethanol and acetone is 3.9 and 5.6 times\nhigher than that of pristine Nb<sub>2</sub>CT<sub><i>x</i></sub>, respectively. In addition, the sensor based on Nb<sub>2</sub>CT<sub><i>x</i></sub>/CNT hybrids shows a higher response\nto a variety of VOCs and exhibits good stability. It is an effective\nmethod for VOCs detection to take advantage of the high specific surface\narea of low-dimensional materials by constructing mixed-dimensional\nheterostructures.