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

Abstract

The detection of SF6 decomposition components using gas-sensitive sensors is significantly important for characterizing internal insulation failures and assessing the operational status of SF6 gas-insulated equipment. In this paper, the adsorption properties of GeP3 monolayers for SO2, H2S, SOF2 and SO2F2 gases were investigated based on density functional theory. Four gas adsorption systems were constructed, and the adsorption mechanisms and sensing characteristics of GeP3 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 GeP3 monolayers were suitable for the detection of SO2, H2S, SOF2 and SO2F2 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 SO2 and H2S is found to cause a significant change in the conductivity of the GeP3 monolayers, and desorption is achieved at the optimal operating temperature in only 54.428 s and 10.686 s, respectively. Also the adsorption of SOF2 and SO2F2 can make the work function of the GeP3 monolayers significantly larger. Consequently, the GeP3 monolayers have the potential to be used as a resistive gas sensor for SO2 and H2S gases, or as a field effect transistor sensor for SOF2 and SO2F2 gases. This study provides theoretical guidance for the development of GeP3-based sensors for monitoring the insulation status and operational conditions of SF6 gas-insulated equipment.