TiO2-Doped HfSe2 Monolayer for Efficient SF6 Decomposition Gas Detection

Monitoring sulfur hexafluoride (SF 6 ) is vital in the electrical insulation sector, where it serves as a key insulator. SF 6 decomposition, caused by operational wear or aging, releases hazardous gases such as SO 2 , SOF 2 , SO 2 F 2 , and H 2 S, raising safety concerns. However, the effectiveness of current nanoscale gas sensors is compromised by SF 6 's protective nature, struggling with multi-gas detection. This study utilizes density functional theory (DFT) calculations to assess the performance of a novel 2D TiO 2 -doped HfSe 2 (TiO 2 -HfSe 2 ) monolayer. We found that TiO 2 doping not only broadens the bandgap and enhances the structural stability ( E b = -2.934 eV) of the HfSe 2 monolayer but also increases its gas adsorption ability (197.142-573.104%). The sensors can effectively distinguish SF 6 gas and its by-products in the sequence: SO 2 F 2 > SOF 2 > SO 2 > H 2 S >> SF 6 . The sensor effectively spots SF 6 gas at 298 K, ensuring smooth gas-insulated system operations. Further analysis indicates that solvents with higher dielectric constants significantly boost adsorption strength (16.907-71.996%), improving gas differentiation. Finally, a literature comparison confirms the exceptional performance of the TiO 2 -HfSe 2 monolayer, endorsing its application as a reliable sensor for SF 6 decomposition gases.