Layered Ti3C2Tx MXene heterostructured with V2O5 nanoparticles for enhanced room temperature ammonia sensing

To enhance ammonia sensing at room temperature (25 degrees C), Two-dimensional transition metal carbonyl nitride (Ti3C2Tx MXene) modified by vanadium pentoxide nanoparticle (V2O5) is synthesized by hydrothermal method. The effects of weight ratio on the microstructure and ammonia sensing performance at room temperature are studied. The results indicate that when the weight percentage of V2O5 is 25 %, V2O5 nanoparticles with an average size of 90.33 nm are produced on the surface and between the layers of the two-dimensional MXene. The prepared MXene/V2O5 composites sensor has a good response (12.12) to 10 ppm NH3. The enhanced sensing performance can be attributed to the modification of V2O5 nanoparticles as well as the catalytic effect and the formation of heterojunction. The doped V2O5 nanoparticles open up the unstratified portion of MXene and catalyze the chemisorption of oxygen and oxidation of NH3. The difference in Fermi level between twodimensional MXene and V2O5 drives the charge transfer at the heterojunction interface, enriching the electrons on the surface of V2O5, thus improving the sensitivity. Density functional theory suggests that the composite adsorption system is more stable and has lower NH3 adsorption energy. This work provides a feasible route to develop high-performance gas sensors with MXene-based composites.