Adsorption and sensing performances of greenhouse gases (CO2, CH4, N2O, and SF6) on pristine and Pd-doped GeSe monolayer: A DFT study

Nowadays, the global greenhouse effect's influence has become more serious, and the reduction and recovery of greenhouse gases have become more urgent. Therefore, in this study, we use DFT calculations to explore the adsorbing and sensing properties of intrinsic and Pd-doped GeSe (Pd-GeSe) monolayer on four greenhouse gases (CO2, CH4, N2O, and SF6), and investigate the potential use of the material as a gas sensor. The relevant gas-sensitive mechanism was analyzed by adsorption energy, charge transfer amount, deformation charge density (DCD), density of states (DOS), work function, frontier molecular orbital, sensitivity, and recovery time. The research showed that the Pd dopant effectively improved the gas-sensing activity of the pristine GeSe monolayer. Compared with CO2 and CH4 molecules, the monolayer of Pd-GeSe has superior adsorption properties for N2O and SF6. The electrical response of N2O and SF6 detection is more sensitive and it can be used to purify N2O and SF6 gases. In addition, the excellent desorption performance of Pd-GeSe for N2O makes it suitable for recycling as a low-power resistive N2O gas sensor. Our research has important implications for theoretically proposing potential sensing materials for the detection of greenhouse gases.