Design and mechanism study of fast response MoS2/SnS2 heterojunction ammonia sensor for gas detection in chicken coops

Abstract

In this paper, a ppb-level MoS₂/SnS₂ heterojunction ammonia (NH₃) sensor with rapid response at room temperature was prepared by a simple hydrothermal method. The construction of heterojunction greatly increased the specific surface area of the material, enhanced the electron transfer ability of the material, and provided more active sites and wider transmission channels for NH₃ adsorption. Enables NH₃ to enter the material faster and more fully, thereby improving sensor response and reducing response/recovery time. The MoS₂/SnS₂ sensor has good selectivity for NH₃, fast response/recovery time (0.8/1 s) at 500 ppb NH₃, and good repeatability and long-term stability. The first principles calculation shows that the construction of MoS₂/SnS₂ heterojunction increases the absorption energy of NH₃, and the increase of sulfur vacancy also significantly improves the electron transport capacity. In addition, MoS₂/SnS₂ can be used as a stable, fast response sensor for coops NH₃ monitoring. This study promotes the development of low concentration fast response RT NH₃ sensor and provides a new way for NH₃ monitoring in chicken coops.