Study of H₂S, CO, and SO₂-based Nano-Gas Sensors using Pristine and Pt-Doped WS₂ Monolayer

This study reports the electronic, sensing, and transport properties of Pt-doped WS 2 monolayer for CO, H 2 S, and SO 2 gas molecules using DFT (Density Functional Theory). We have calculated the formation energy and binding energy for the pristine and Pt-doped WS2 monolayer to predict the structural stability. The computed values align with the reported works and are observed to be stable. The electronic properties, such as bandstructure, total density of states (TDOS), partial density of states (PDOS), charge density, work function, and electrostatic potential, are studied for pristine and Pt-doped WS2 monolayer. The impact of these properties on the adsorption of CO, H 2 S, and SO 2 gas molecules is investigated. Pristine WS 2 monolayer has limited adsorption capacity for the target gas molecules. Moreover, Pt-doping significantly enhances the sensing of these gas molecules. Further, the sensing properties, such as adsorption energy and recovery time, were reported. The recovery time was calculated at three different temperatures (300K, 473K, 673K) to show the desorption ability. The transport properties of pristine and Pt-doped WS 2 monolayer were extracted by designing a 4x4 scattering region with Au left and right electrodes. The transport properties show significant changes upon adsorption of gas molecules (CO, H 2 S, SO 2 ) in the scattering region. The adsorbed gases show a relative change of 34.11% from the Pt-doped WS2 monolayer. Thus, the WS 2 monolayer is suitable for detecting hazardous gases and minimizing industrial pollution.