Pt-embedded Janus WSTe monolayer for adsorption and detection of XO2 (X = C, N and S) gases: a first-principles study

Abstract

For sensing XO2 (X = C, N and S) gas species, this work purposes Pt-embedded WSTe monolayer, and using first-principles theory uncovers related gas adsorption properties and sensing mechanism. Results indicate that Pt-embedding is more energy favourable by replacing Te atom of the Janus WSTe monolayer with the formation energy of −1.78 eV, narrowing the bandgap to 0.926 eV. Besides, the Pt-WSTe monolayer performs weak physisorption upon CO2 with adsorption energy (E ad) of −0.17 eV, while strong chemisorption upon NO2 and SO2 with E ad of −1.43 and −1.17 eV, respectively. The analysis of electronic property uncovers the sensing potential of Pt-WSTe monolayer as a resistance-type NO2 or SO2 gas sensor with higher sensing response upon SO2, and the analysis of work function (WF) uncovers the sensing potential of Pt-WSTe monolayer as a WF-type NO2 or SO2 gas sensor with higher sensing response upon NO2. We are hopeful that the findings in this work can help to explore the possible application of Pt-WSTe monolayer in the gas sensing field and also to make some other explorations on Janus WSTe-based material for gas detections.