Adsorption and sensing performances of transition metal (Ag, Pd, Pt, Rh, and Ru) modified WSe2 monolayer upon SF6 decomposition gases (SOF2 and SO2F2)

In this study, we explored the adsorption of SF6 decomposition products (SOF2 and SO2F2) on transition metal (Ag, Pd, Pt, Rh, and Ru) modified WSe2 (with adatom and TM-substitution) using DFT calculations. The adsorption energy, charge transfer, electrostatic potential, and density of states of the adsorption structures between the target gas molecules and TM-WSe2 were studied. The calculation results show that the conductivity of the WSe2 monolayer modified with metal atoms is improved. And the adsorption energy of these gases on Ag-WSe2 (with adatom), and SO2F2 on Pd, Pt modified WSe2 (with TM-substitution) is very small. The density of states analysis indicates that Ag-WSe2 (with TM-substitution) shows weak sensing property to SO2F2 molecule. Therefore, these five modified systems are not suitable for gas-sensing equipment. For other modified systems, the conductivity decreases to different degrees after the adsorption of gas. Therefore, the gases can be detected according to the different change rule of conductivity after adsorption. In addition, these adsorption structures have a reasonable recovery time. The results not only have important significance for explaining the sensing mechanism of TM modified WSe2 adsorption to SF6 decomposition products, also provide a potential material for the further development of gas-sensing sensors.