Au doped MXene for sulphurous gases sensing: a DFT study

Sulfur-containing gas reflects the internal operation of SF6 gas-insulated switchgear and is of great importance for the insulation fault diagnosis of equipment. Based on density functional theory (DFT), several sulfur-containing gases are selected as the target detection gases, and Au-doped Ti3C2Tx MXene is used as the sensing material to carry out adsorption simulation in this paper. These results suggest that the O and OH terminated Au@Ti3C2Tx have larger adsorption energies as well as charge transfer for SO2 and SOF2, and furthermore, combined with density of states analysis and molecular frontier orbital analysis, it's found that gas adsorption can lead to changes in the density of states near the 0 eV and changes in the frontier orbital band gap, which can be used as SO2 and SOF2 gas sensor. These provide initial insights into the application of Au@Ti3C2Tx in the monitoring of electrical equipment, evaluating the working condition of the SF6 gas-insulated electrical equipment by detecting SO2 and SOF2.