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

Constructing heterogeneous interfaceson a nanoscalethat can prominentlyimprove the gas-sensing properties has been comprehensively reported.However, the effect of parallel heterostructures formed by uniquesynthetic means on nitrogen dioxide room-temperature sensing propertiesstill needs to be clarified, which hinders the development of heterostructuredhybrid materials in the field of gas sensing. In this study, large-sizedMoS(2) was parallel-wrapped on the surface of nanoscale Bi2S3 rods, and then, the Bi2S3/MoS2 nanocomposite aerogels were formed by freeze dryingand calcination. The NO2 sensing performance of the hybridsand possible surface processes at room temperature have been investigatedand deduced. The as-prepared nanocomposite aerogels (Bi2S3/MoS2-2) exhibited a larger specific surfacearea, a mass of active defect sites, and a higher charge density,thus possessing 15- and 20-times higher response than that of pristineMoS(2) nanosheets and Bi2S3 nanorods,respectively. This study provides an efficient way to synthesize large-areaparallel heterostructures between two bis-sulfides (Bi2S3 and MoS2), leading to excellent NO2 gas sensing performance.