A first-principles study of Cl2, PH3, AsH3, BBr3 and SF4 gas adsorption on MoS2 monolayer with S and Mo vacancy

Abstract The intrinsic influence of gas sensing nature of S vacancy (V S ) and Mo vacancy (V Mo ) MoS 2 monolayer plays an important vital role for sensing highly toxic gases. A systematic study was carried out to act its ability to be a gas sensor, which can be benefited from its high surface to volume ratio similar to graphene. The highly toxic gas molecules such as Cl 2 , PH 3 , AsH 3 , BBr 3 and SF 4 was selected to examine the affinity with V S and V Mo MoS 2 monolayer based on first principle calculations. To explore the sensing capacity and electronic property of V S and V Mo MoS 2 monolayer the geometrical structures, adsorption energy, adsorption distance, charge transfer and density of states were analyzed and discussed. The results indicate that all the gas molecules are allowed to adsorb on V S and V Mo MoS 2 monolayer through Van Der Waals interaction. Among all these gases, PH 3 adsorption on V Mo MoS 2 monolayer exhibits relatively high adsorption energy of −1.8082 eV and charge transfer of −0.56 e, followed by the SF 4 on V S and V Mo MoS 2 monolayer showing enhanced adsorption energy of 0.9366 eV and −0.8052 eV and charge transfer of 0.029 e and 0.064 e respectively. PH 3 and BBr 3 adsorption on V Mo MoS 2 monolayer shows more change in the conductivity when compared to other gas molecules. Thus, V S and V MO MoS 2 monolayer are producing beneficial results for sensing PH 3 , BBr 3 and SF 4 gas molecules than Cl 2 and AsH 3 .