Two-Dimensional NbS₂ Gas Sensors for Selective and Reversible NO₂ Detection at Room Temperature

Transition metal dichalcogenides (TMDs) have attracted enormous attention in diverse research fields. Especially, gas sensors are considered in a promising application exploiting TMDs. However, the studies are confined to only major TMDs such as MoS₂ and WS₂. Particularly, the chemoresistive sensing properties of two-dimensional (2D) NbS₂ have never been explored. For the first time, we report room temperature NO₂ sensing characteristics of 2D NbS₂ nanosheets and the sensing mechanisms using first-principles calculations based on density functional theory. The results demonstrate that the NbS₂ edges possessing different configurations depending on synthetic conditions differ in the sensing ability of the TMD nanosheets. This study not only broadens the potential of 2D NbS₂ for gas sensing applications, but also presents the important role of edge configuration of TMDs depending on synthetic conditions for further studies.