A Room Temperature Trimethylamine Gas Sensor Based on Electrospinned Molybdenum Oxide Nanofibers/Ti 3 C 2 T x MXene Heterojunction.

The combination of two-dimensional material MXene and one-dimensional metal oxide semiconductor can improve the carrier transmission rate, which can effectively improve sensing performance. We prepared a trimethylamine gas sensor based on MoO 3 nanofibers and layered Ti 3 C 2 T x MXene. Using electrospinning and chemical etching methods, one-dimensional MoO 3 nanofibers and two-dimensional Ti 3 C 2 T x MXene nanosheets were prepared, respectively, and the composites were characterized via XPS, SEM, and TEM. The Ti 3 C 2 T x MXene-MoO 3 composite material exhibits excellent room-temperature response characteristics to trimethylamine gas, showing high response (up to four for 2 ppm trimethylamine gas) and rapid response-recovery time (10 s/7 s). Further, we have studied the possible sensitivity mechanism of the sensor. The Ti 3 C 2 T x MXene-MoO 3 composite material has a larger specific surface area and more abundant active sites, combined with p-n heterojunction, which effectively improves the sensitivity of the sensor. Because of its low detection limit and high stability, it has the potential to be applied in the detection system of trimethylamine as a biomarker in exhaled air.