Favorable sensing property of Pt-doped Janus HfSSe monolayer upon H2S and SO2: a first-principles theory

Abstract

In this paper, we investigate the adsorption performances of the pristine and Pt-doped HfSSe (Pt-HfSSe) monolayer upon H2S and SO2 molecules based on the first-principles theory. Results indicate that the Pt dopant preferred to be doped on the Se-surface of the HfSSe monolayer with the formation energy (Ef) of −1.06 eV. The Pt-HfSSe monolayer has remarkably improved adsorption energy (Ead) upon H2S and SO2, calculated as −0.614 and −0.918 eV respectively which are about 2.6 and 2.9 times than those in the counterpart systems. The BS and DOS analysis reveal the sensing mechanism of Pt-HfSSe monolayer for detection of H2S and SO2 and manifest its strong potential as a resistance-type gas sensor with sensing response of 26.3% and −70.1%, respectively, and the desirable recovery property in the Pt-HfSSe/gas systems offers it good reusability at 298 K. Our theoretical findings suggest that the Pt-HfSSe monolayer is a promising room-temperature gas sensor for detection of such two toxic gases with admirable sensitivity. This work is beneficial to propose novel 2D sensing materials for toxic gas detection, and paves the way for further experimental researches to realize their application in some typical fields.