A first-principles study into Pt-embedded NiS2 monolayer as an outstanding gas sensor upon CO and HCHO dry-type reactors

Abstract

This work purposes Pt-embedded NiS2 (Pt-NiS2) monolayer as a promising gas sensor upon CO and HCHO in dry-type reactors on basis of first-principles theory. The Pt-NiS2 monolayer is modelled through the replacement of a S atom by a Pt atom, and the formation energy is −0.57 eV, implying the exothermicity for Pt-emending on the NiS2 surface. The CO and HCHO systems are respectively clarified as chemisorption and physisorption, given their adsorption energy of −1.98 and −0.77 eV. The analyses of band structure in line with density of state show the deformation of electronic properties in Pt-NiS2 monolayer in gas adsorptions, and the sensing responses in CO and HCHO systems are obtained as −99.6% and −99.2%, respectively. Moreover, the work function analysis exhibits the stronger sensitivity in the HCHO system. Our theoretical simulations put forward the strong potentials of Pt-NiS2 monolayer to be a gas sensing material for CO or HCHO detection, thus realizing the evaluation of the operation conditions of the dry-type reactors, and we hope further experimental investigations can further verity our hypothesis in the near future.