MoS2-doped spherical SnO2 for SO2 sensing under UV light at room temperature

MoS2, as a two-dimensional material, shows great potential for use in the gas sensor field because of its large specific surface area and remarkable electrical performance. However, previous studies have shown that gas sensors based on MoS2 materials have the drawbacks of low response and instability, which limit their development. In this paper, a suitable amount of MoS2 and metal oxide (SnO2) were used to form a composite material and the SnO2 were prepared by a hydrothermal method. Compared with that of original sensors, the response of this SnO2/MoS2 sensor is 4.68 at a low concentration of 1 ppm SO2. The crystal structures and morphologies of the composites were characterized, showing that they have high crystallinity and that SnO2 is spherical. Further experimental data indicate that the SnO2/MoS2 sensor has good selectivity, repeatability and stability. In addition, the enhanced sensing characteristics of the sensor were discussed on the basis of the depletion layer and SnO2/MoS2 heterojunction.