First-Principles Investigation of Transition Metal (Co, Rh, and Ir)-Modified WS2 Monolayer Membranes: Adsorption and Detection of SF6 Decomposition Gases

At high temperatures, the rapid and effective detection of SF6 decomposition gas is a major challenge. Therefore, online detection of SF6 decomposition gas at high temperatures for Gas Insulated Switchgear fault diagnosis is necessary. In this work, first-principles calculations are used to examine the adsorption and sensing properties of pristine WS2 and transition metal Co, Rh, and Ir-modified WS2 toward H2S, SO2, SOF2, and SO2F2. Our study delved into the adsorption energy and mechanisms of each system, exploring various aspects including adsorption energy, band gap, electron density, frontier orbital theory, conductivity, and recovery time. The findings indicate that the transition metal Co, Rh, and Ir-modified WS2 surface exhibits excellent adsorption capabilities for the decomposed gases. Co-WS2 has good sensing performance for H2S, SO2, and SOF2 and can achieve faster desorption for these three decomposed gases at high temperatures (598 K). SO2F2 can be desorbed rapidly (0.65 s) from the surface of Rh-WS2 at room temperature, and Rh-WS2 has good selectivity for SO2F2. Interestingly, Ir-WS2 remains difficult to desorb even at high temperatures for H2S (-2.642 eV), SO2 (-2.260 eV), SOF2 (-1.945 eV), and SO2F2 (-2.841 eV) and can be used as a scavenger for these four gases. Therefore, the simulation experiments in this study aim to investigate the advantages of transition metal Co, Rh, and Ir-modified WS2 for detecting SF6 decomposition gases.