Favorable and strain-tunable sensing property of chalcogenide-defected Janus SnSSe monolayer towards thermal runaway fault gases in a lithium-ion battery

This paper based on the first-principles simulations sheds light on the chalcogenide-defected behavior of the Janus SnSSe monolayer and the sensing property of the defected-SnSSe monolayer upon three typical thermal runaway fault gases, namely H2, CO and C2H2. Results indicate that the Se-vacancy is more likely to be formed in a SnSSe monolayer, and the Se–SnSSe monolayer performs physisorption, with adsorption energies of −0.14, −0.61 and −0.37 eV for three systems, and electron-donating property, contributing 0.047, 0.087 and 0.070 e to such three gases. The band structure and work function analyses reveal the desirable potential of Se–SnSSe monolayer as a resistance-type or WF-based sensor for CO detection. Also, the recovery property is analyzed to consider the reusability of such sensing material. Besides, the applied biaxial strains reveal that Se–SnSSe monolayer performs high and tunable sensitivity for these gas species, especially for H2 and C2H2 detections. This work paves the way to explore SnSSe-based material for gas sensing application in many typical fields involving H2, CO and C2H2 detection, which is also guidable to explore the sensing potential of many other Janus 2D materials.