Research on the application of Ti-MoTe2 in cable condition assessment as gas sensor: A First-principles study

XLPE cables inevitably have defects that can cause them to deteriorate. The operational condition of cables can be assessed by detecting gases from overheating and discharge. Ti doped MoTe2 has excellent adsorption properties for gas molecules which leads to the application potential in gas sensors. In this paper, the doping process of Ti on MoTe2 is simulated, and the doping properties of Ti are analyzed. The adsorption properties of Ti-MoTe2 on four pyrolytic components (CO, CH4, C2H4 and C2H6) are investigated based on adsorption configuration, electron localization function (ELF), independent gradient model based on Hirshfeld partition (IGMH), and density of states (DOS) analyses. Finally, the potential application of Ti-MoTe2 as a sensing material is comprehensively evaluated in conjunction with the sensing properties. The results showed that the adsorption energy and transfer charge of Ti-MoTe2 to CO are -0.891 eV and -0.239 e, respectively The ELF between CO and Ti-MoTe2 is as high as 0.6 with a significant electronic localization. The IGMH results also show a significant chemical bonding force between CO and Ti. Meanwhile, the sensitivity and recovery time of Ti-MoTe2 for CO are ideal, and it can be used as a gas sensor for CO, which in turn can be used for cable condition assessment. However, the adsorption properties of Ti-MoTe2 for CH4, C2H4 and C2H6 are poor, which makes it unsuitable for the detection of these gases. The research results in this paper can provide theoretical basis and data support for the application of Ti-MoTe2 sensors.