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 °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.