Ab-initio Study Based Understanding of Pnictogen Trihydrides Adsorption on WS2 Monolayer

The work in this paper mainly focuses on the adsorption possibility of some pnictogen trihydride based highly toxic gas molecules such as NH 3 , PH 3 , AsH 3, and SbH 3 towards 2D layered transition metal dichalcogenides (TMDs) based pristine WS 2 monolayer using density functional theory incorporated with QuantumATK atomistic toolkit. To explore the sensing performance and electronic properties of pristine WS 2 monolayer towards above mentioned gas molecules, geometrical parameters, adsorption energy, charge transfer mechanism, adsorption distance, and projected density of states were studied and discussed. The outcome of the study suggested that the WS 2 monolayer allowed all gases to be adsorbed and the comparative adsorption probability was found to be maximum for NH 3 gas molecule with highest adsorption magnitude of -0.308 eV. The maximum charge transfer was found in NH 3 -WS 2 interaction. The second most adsorbed gas molecule on WS 2 monolayer was PH 3 . The lowest gas adsorption possibility was found for SbH 3 molecule with the adsorption magnitude of -0.185 eV which was around 66% lesser than the adsorption possibility of NH 3 molecule on WS 2 monolayer. SbH 3 gas molecule was adsorbed with highest adsorption distance among other pnictogenic gas molecules. No covalent bonds were formed after adsorption of gas molecules on WS 2 monolayer where the adsorptions mainly occurred due to the association of weak van der Waals forces.