GeP3 monolayer as a promising 2D sensing materials in detecting SO2, H2S, SOF2 and SO2F2

Abstract The detection of SF 6 decomposition components using gas-sensitive sensors is significantly important for characterizing internal insulation failures and assessing the operational status of SF 6 gas-insulated equipment. In this paper, the adsorption properties of GeP 3 monolayers for SO 2 , H 2 S, SOF 2 and SO 2 F 2 gases were investigated based on density functional theory. Four gas adsorption systems were constructed, and the adsorption mechanisms and sensing characteristics of GeP 3 monolayers on target gases were investigated by calculating parameters such as adsorption energy, charge transfer, density of states, and recovery time, along with their potential application as resistive gas sensors and field-effect transistor sensors. It is demonstrated that GeP 3 monolayers were suitable for the detection of SO 2 , H 2 S, SOF 2 and SO 2 F 2 gases, all of which exhibited good chemisorption with adsorption energies of −1.36 eV, −0.78 eV, −1.82 eV and −2.91 eV, respectively. The adsorption of SO 2 and H 2 S is found to cause a significant change in the conductivity of the GeP 3 monolayers, and desorption is achieved at the optimal operating temperature in only 54.428 s and 10.686 s, respectively. Also the adsorption of SOF 2 and SO 2 F 2 can make the work function of the GeP 3 monolayers significantly larger. Consequently, the GeP 3 monolayers have the potential to be used as a resistive gas sensor for SO 2 and H 2 S gases, or as a field effect transistor sensor for SOF 2 and SO 2 F 2 gases. This study provides theoretical guidance for the development of GeP 3 -based sensors for monitoring the insulation status and operational conditions of SF 6 gas-insulated equipment.