SnO–Sn3O4 heterostructural gas sensor with high response and selectivity to parts-per-billion-level NO2 at low operating temperature

摘要

Considering the harmfulness of nitrogen dioxide (NO _(2) ), it is important to develop NO _(2) sensors with high responses and low limits of detection. In this study, we synthesize a novel SnO–Sn _(3) O _(4) heterostructure through a one-step solvothermal method, which is used for the first time as an NO _(2) sensor. The material exhibits three-dimensional flower-like microparticles assembled by two-dimensional nanosheets, in situ -formed SnO–Sn _(3) O _(4) heterostructures, and large specific surface area. Gas sensing measurements show that the responses of the SnO–Sn _(3) O _(4) heterostructure to 500 ppb NO _(2) are as high as 657.4 and 63.4 while its limits of detection are as low as 2.5 and 10 parts per billion at 75 °C and ambient temperature, respectively. In addition, the SnO–Sn _(3) O _(4) heterostructure has an excellent selectivity to NO _(2) , even if exposed to mixture gases containing interferential part with high concentration. The superior sensing properties can be attributed to the in situ formation of SnO–Sn _(3) O _(4) p–n heterojunctions and large specific surface area. Therefore, the SnO–Sn _(3) O _(4) heterostructure having excellent NO _(2) sensing performances is very promising for applications as an NO _(2) sensor or alarm operated at a low operating temperature.