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. [ABSTRACT FROM AUTHOR]