Room-Temperature NO2 Detection by MoS2-Nanoflake-Decorated AuPt/SnO2 Nanotubes

Although SnO2 nanomaterials have been leading components of semiconductor gas sensors, their long-standing challenges of high working temperatures limit their practical application for ultralow- power-consumption room-temperature sensing. In this study, Au and Pt bimetallic nanoparticles were used to fabricate a MoS2/AuPt/SnO2 nanocomposite device by interfacially engineering a MoS2/SnO2 nanostructure. Owing to the unique structure and electrical properties, the as-fabricated MoS2/AuPt/SnO2 device exhibits a remarkable sensing response (2.22), short response time (20 s), and excellent baseline recovery (8 s) to 10 ppm NO2 gas at 23 +/- 2 degrees C. Meanwhile, the MoS2/ AuPt/SnO2 device possesses high sensitivity, a low detection limit (20 ppb), commendable reversibility, appreciable stability, and excellent selectivity against ammonia, carbon monoxide, ethanol, isopropanol, and acetone gases. The superior sensing characteristics of the MoS2/AuPt/SnO2 nanocomposite device are attributed to the modulation effect of the Schottky junction and p-n heterojunction on the potential barrier, highly efficient interfacial electron transport, and edge-enriched structure, which provide abundant active adsorption sites. This work will advance the evolution of room-temperature gas-sensitive nanomaterials and render them promising for applications in ultralow power-integrated sensors.

Automated summary

In this study, a MoS2/AuPt/SnO2 nanocomposite device was fabricated by interfacially engineering a MoS2/SnO2 nanostructure using Au and Pt bimetallic nanoparticles. The device exhibited remarkable sensing response, short response time, and excellent baseline recovery to NO2 gas at room temperature, as well as high sensitivity, low detection limit, commendable reversibility, stability, and selectivity against various gases. This work advances the development of room-temperature gas-sensitive nanomaterials and shows promise for applications in ultralow power-integrated sensors.