Adsorption and sensing properties of CO, H 2 S and SO 2 on Janus WSSe monolayer: a first-principles approach

In this work, the adsorption and sensing behaviours of the Janus WSSe monolayer for the hazardous gas molecules CO, H2S and SO2 are investigated through first-principles density functional theory calculations. The stability of the WSSe monolayer is confirmed through a negative value of formation energy. The electronic properties of interest for pristine and adsorbed WSSe monolayer include the work function (Wf), charge density analysis (CDD), band structure, total and partial density of states (TDOS, PDOS), relatively. The adsorption of gas molecules shifts the bandgap from semiconducting to metallic with a chemisorptive nature. As a chemoresistant sensor, the WSSe monolayer exhibits more sensitivity and a lower desorption time, indicating its potential for reusability. The study concludes with an analysis of the humidity's impact on the WSSe monolayer, specifically in relation to the adsorption of gas molecules.