Au nanoparticles decorated flower-like SnS2/Ti3C2 MXene microcomposite for high performance NO2 sensing at room temperature

The continuous discharging of nitrogen dioxide (NO 2 ) significantly damaged global environment and human health. In this study, SnS 2 microflowers/Ti 3 C 2 MXene heterostructure was modified by Au nanoparticles (AuNPs) for the detection of NO 2 at room temperature. The microcomposite decorated with 6 wt% AuNPs exhibited excellent sensing properties including response value of 5.34 to 1 ppm NO 2 , which was almost 5 times higher than that of undecorated one. The limit of detection lowered from 500 ppb to 5 ppb with the addition of AuNPs. Besides, the AuNPs decorated SnS 2 /MXene microcomposite revealed good selectivity, fatigue resistance, as well as potential application towards flexible sensing. The NO 2 gas sensing mechanism of AuNPs decorated with SnS 2 /Ti 3 C 2 MXene microcomposite was discussed through density functional theory calculation on adsorption behavior and transferred charges in detail. This work may provide an important pathway for the future development of NO 2 sensors at room temperature.