Flower-like MoS2 hierarchical architectures assembled by 2D nanosheets sensitized with SnO2 quantum dots for high-performance NH3 sensing at room temperature

Abstract

Flower-like MoS2 hierarchical architectures assembled by ultrathin 2D nanosheets decorated with SnO2 quantum dots (QDs) were successfully prepared through a solvothermal method and used for room-temperature NH3 sensing detection. The morphology and structure of as-prepared hierarchical architectures were fully characterized, showing that SnO2 QDs with uniform particle size of 2–4 nm were uniformly distributed on the ultrathin nanosheets of MoS2 hierarchical architectures. SnO2 QDs@MoS2 composites based gas sensor exhibited a high response of 8.6 and short response/recovery times of 6 s/121 s to 100 ppm NH3 with good selectivity, excellent repeatability, and outstanding long-term stability at room temperature of 25 °C. Such highly enhanced response toward NH3 was ascribed to the synergistic effect between active SnO2 QDs with abundant dangling bonds and MoS2 nanosheets with large specific surface area and high carrier mobility. This work presented a potential room-temperature sensing material and revealed the underlying sensitization mechanism of the quantum dots, offering new ideas for the development of low-temperature gas sensors.