Interfacial Engineering Facilitates Real-Time Detection of Dual Hazardous Gases at ppb Levels via Single-Step Hydrothermal Nanoarchitectonics of Self-Assembled PbSnS/SnO Heterostructures.

Next-generation real-time gas sensors are crucial for detecting multiple gases simultaneously with high sensitivity and selectivity. In this study, ternary metal sulfide (PbSnS)-incorporated metal oxide (SnO) heterostructures were synthesized via a one-step hydrothermal method. Characterizations such as X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy confirmed the successful formation of PbSnS/SnO heterostructures. Subsequently, thin films based on PbSnS/SnO heterostructures were fabricated and employed for the detection of real-time dual hazardous oxidizing gases at room temperature. The sensor response for NO gas was found to be 1.04 at 25 parts per billion (ppb) with a limit of detection (LOD) of 18.17 ppb, while for O gas, the sensor response was 1.03 at 15 ppb with an LOD of 7.34 ppb. Moreover, high selectivity for detecting two oxidizing gases in real time by using differential analysis of the gas sensing curve has been reported. Furthermore, density functional theory calculations corroborated the sensing mechanism, elucidating that the Pb atom in PbSnS/SnO is primarily responsible for the adsorption of NO gas, whereas SnO in PbSnS/SnO is responsible for the adsorption of O gas. These findings demonstrate the potential of PbSnS/SnO heterostructures for advanced gas sensing applications, offering insights into their fundamental sensing mechanisms.