Controllable Epitaxial-like Growth of Bi2S3/MoS2 Hybrid Aerogel Nanostructures for Sensitive NO2 Detection at Room Temperature

Constructing heterogeneous interfaces on a nanoscale that can prominently improve the gas-sensing properties has been comprehensively reported. However, the effect of parallel heterostructures formed by unique synthetic means on nitrogen dioxide room-temperature sensing properties still needs to be clarified, which hinders the development of heterostructured hybrid materials in the field of gas sensing. In this study, large-sized MoS2 was parallel-wrapped on the surface of nanoscale Bi2S3 rods, and then, the Bi2S3/MoS2 nanocomposite aerogels were formed by freeze drying and calcination. The NO2 sensing performance of the hybrids and possible surface processes at room temperature have been investigated and deduced. The as-prepared nanocomposite aerogels (Bi2S3/MoS2-2) exhibited a larger specific surface area, a mass of active defect sites, and a higher charge density, thus possessing 15- and 20-times higher response than that of pristine MoS2 nanosheets and Bi2S3 nanorods, respectively. This study provides an efficient way to synthesize large-area parallel heterostructures between two bis-sulfides (Bi2S3 and MoS2), leading to excellent NO2 gas sensing performance.