Adsorption of small gas molecules of transition metal (Pt and Au) modified HfSe2 monolayer

We have carried out a first-principles study of the adsorption of three types of hazardous gases onto pristine and Pt, Au atom modified HfSe2 monolayer. The adsorption structure, adsorption energy, electron transfer and applied strain of the HfSe2 monolayer were discussed, and their sensing performance was evaluated. The results show that the adsorption energies of the pristine HfSe2 for gas molecules were all small. In contrast, the adsorption energies and charge transfer were improved by the adsorbed of different metal atoms. The best adsorption effect on H2S gas molecules was observed, especially after adsorbing with Au atoms, which showed strong sensing properties for H2S. The effect of applied strain on the Au-HfSe2/H2S adsorption system was also investigated, with the adsorption energy decreased with increased strain. The results indicate that the Au-HfSe2 monolayer was an ideal material sensor for developing highly efficient H2S gas.