Revealing a Highly Sensitive Sub-ppb-Level NO 2 Gas-Sensing Capability of Novel Architecture 2D/0D MoS 2 /SnS Heterostructures with DFT Interpretation.

In this work, we use a chemical method to design novel 2D-material/0D-quantum dot (MoS 2 /SnS) heterostructures. Furthermore, the unique 2D/0D heterostructure enhanced the NO 2 gas-sensing capability 3 times and increased the sensing recoverability by more than 90%. Advanced characterization tools such as SEM, TEM, XRD, and AFM confirm the formation of MoS 2 /SnS heterojunction nanomaterials. Using AFM data, the average thickness of the MoS 2 layer was found to be 5 nm. The highest sensor response of 0.33 with good repeatability was observed at 250 ppb of NO 2 . Sensing characterization reveals the ultra-fast response time, that is, 74 s, at 50 ppb of NO 2 . The limit of detection for detecting NO 2 was also found to be very low, that is, 0.54 ppb, by using MoS 2 /SnS heterostructures. The theoretical calculations based on density functional theory well corroborated and quantified the intermolecular interaction and gas adsorption on the surface of MoS 2 /SnS.