Ti3C2Tx as A Promising Gas Sensor Material for CS2: A Theoretical Study

SF 6 is colorless and non-toxic, with good insulation properties, and is therefore widely used in the electrical industry. However, in the possess of the transportation, installation and use of electrical equipment, some conductive impurities, electrode defects and etc. inevitably appear, resulting in uneven electric field and partial discharge. Under the action of electric field and high energy current, SF 6 decomposes and reacts with $\mathrm{H}_{2}\mathrm{O},\mathrm{O}_{2}$ and organic substances to produce a variety of characteristic gases. This study is based on the density functional theory (DFT), CS 2 is used as the detection gas, and the two-dimensional material $\mathrm{Ti}_{3}\mathrm{C}_{2}\mathrm{~T}_{x}(\mathrm{~T}=\mathrm{O},\mathrm{F},\mathrm{OH})$ is selected as the sensing material, and the adsorption model of $\mathrm{Ti}_{3}\mathrm{C}_{2}\mathrm{~T}_{\times}$and CS 2 is established, and the adsorption energy, distance between gas and substrate, structural changes of the adsorption system, electron transfer and density of states(DOS) of the system were further analyzed. The results indicate that the adsorptions of CS 2 on the surface of $\mathrm{Ti}_{3}\mathrm{C}_{2}\mathrm{~F}_{2}$ and Ti 3 C 2 O 2 were weak and both were physical adsorptions, while the adsorption on the surface of Ti 3 C 2 OH 2 was chemical adsorption with a greater adsorption energy and significant charge transfer, and the Figure of the DOS changes showed that CS 2 improved the DOS near 0eV (Fermi level) and the electrical conductivity of the material was improved. These results suggest that $\mathrm{Ti}_{3}\mathrm{C}_{2}\mathrm{~T}_{x}$ has the potential as a sensing material.