The electronic properties and adsorption mechanism of Agn, Aun (n = 1–4) modified GeSe monolayer towards hazardous gases (H2S, NH3, NO2 and SOF2): A first-principles study

In this study, the first-principles were adopted to investigate adsorption behaviour and electrical properties of Agn, Aun (n = 1–4) modified GeSe monolayer towards hazardous gases (H2S, NH3, NO2, SOF2). The contributions of transition metal nanoparticles to the surface modification and gas adsorption behaviour of the two-dimensional material GeSe were analysed. We have studied the adsorption and sensing properties between the target gas molecules and GeSe substrate through the analysis of the adsorption energy, charge transfer, differential charge density, and density of states. In order to better simulate the mixture under the pragmatic doping situation, the number of gold and silver nanoparticles doped in this study ranged from 1 to 4, meanwhile the most stable computational structures were selected based on the binding energy. The results show that Agn, Aun cluster modifications can improve the electrical conductivity of GeSe monolayer, and the vibrant sites provided by the dopants significantly enhance the gas-sensitive response of the pristine GeSe to these hazardous gases. The adsorption type changes from initial non-spontaneous reactions to physico chemical adsorption, and the ideal adsorption energy make the doped system possess good adsorption and desorption properties. In addition, compared with peaceable interreaction of SOF2 adsorption system, Agn, Aun-GeSe has strong capturing ability for NO2. The results provide a theoretical basis for further manufacture of industrial toxic gas sensors and online monitoring of SF6 insulated equipment.