Revealing a Highly Sensitive Sub-ppb-Level NO2 Gas-Sensing Capability of Novel Architecture 2D/0D MoS2/SnS Heterostructures with DFT Interpretation

In this work, we use a chemical method to design novel 2D-material/0D-quantum dot (MoS2/SnS) heterostructures. Furthermore, the unique 2D/0D heterostructure enhanced the NO2 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 MoS2/SnS heterojunction nanomaterials. Using AFM data, the average thickness of the MoS2 layer was found to be 5 nm. The highest sensor response of 0.33 with good repeatability was observed at 250 ppb of NO2. Sensing characterization reveals the ultra-fast response time, that is, 74 s, at 50 ppb of NO2. The limit of detection for detecting NO2 was also found to be very low, that is, 0.54 ppb, by using MoSiSnS heterostructures. The theoretical calculations based on density functional theory well corroborated and quantified the intermolecular interaction and gas adsorption on the suthce of MoS2/SnS.

Automated summary

This work presents the design of novel 2D-material/0D-quantum dot heterostructures using a chemical method, and demonstrates their enhanced NO2 gas-sensing capability. Advanced characterization techniques were used to confirm the formation of MoS2/SnS heterojunction nanomaterials. The sensing characterization showed excellent response time and low limit of detection for NO2 using the MoSiSnS heterostructures.