First principles study on toxic gas adsorption of PtSe2/GaN heterostructure modified by Cu-group elements

Monitoring and identifying toxic gases is essential due to their detrimental effects on human health and the environment. Consequently, developing high-efficiency sensors for the detection of these harmful gases is of paramount importance. Herein, we present a theoretical study on the adsorption and sensing properties of toxic gases CO, NO and NO2 on intrinsic and Cu, Ag and Au atom-decorated PtSe2/GaN van der Waals (vdW) heterostructures, based on first principles calculation investigations. The adsorption energy, charge transfer, band structures, density of states, charge density difference, electron localization functions and recovery time are analyzed. The findings reveal that the intrinsic system demonstrates weak adsorption capabilities. However, when the surface is modified with elements from the Cu-group, there is a significant improvement in the behavior related to gas adsorption. Particularly, the Ag-decorated system demonstrates optimal gas adsorption performance. Incorporating Ag atoms notably enhances the adsorption energy and the quantity of charge transfer for CO, NO and NO2, thereby promoting a shift from physical to chemical adsorption. This alteration significantly boosts the efficiency of adsorption processes for these gases. As for the recovery time, the decorated systems indicate potential application in gas detection devices and gas adsorbers at various temperatures.