Indoor white light activated NO2 sensor based on Au@MoS2/SnS nanocomposites with enhanced responsiveness at room temperature

The exploitation of visible-light-activated gas sensors based on molybdenum disulfide (MoS 2 ) has been extensively investigated and is expected to hold tremendous potential in emerging fields of indoor gas sensing applications activated by daylight lamp. Enlightened by the localized surface plasmon resonance (LSPR) effect of Au nanoparticles in visible light spectrum and the abundant active sites of SnS quantum dots, an indoor white light activated gas sensor based on Au@MoS 2 /SnS nanocomposites is rationally developed for the high sensitive detection of nitrogen dioxide (NO 2 ). Under the white light irradiation, the as-proposed gas sensor demonstrates an enhanced response exceeding 25-folds toward 1 ppm of NO 2 compared with the pristine MoS 2 gas sensor. Moreover, the white light-activated Au@MoS 2 /SnS gas sensor manifests excellent repeatability, rapid response/recovery speed (7/8 s), ppb-level detection limit, favorable long-term stability, and remarkable selectivity toward NO 2 . These enhanced gas sensitive performances principally stem from the interfacial charge transfer effect within the Au@MoS 2 /SnS composite material and the multiplied gas-sensitive pathways facilitated by the LSPR effect originating from the Au nanoparticle cores. This work paves an efficacious avenue for the development of high-performance gas sensitive devices operable at room temperature, thereby facilitating innovative advancements of gas sensing technology in various Internet of Things (IoTs) applications.