Improvement of sensing performance of SO2, SOF2, and SO2F2 gases on monolayer and bilayer HfSe2 under electric field

Abstract

In this contribution, we use DFT simulations to gain a systematic understanding of how an external vertical electric field (E-field) affects the improvement of the sensing performance of SF6 gases on monolayer and bilayer HfSe2. The individual layered HfSe2 nanosheets' predicted band gaps and lattice constants agree with previously published results, demonstrating the validity of our theoretical framework and computational details. In the current study, it is examined the viability of stacked HfSe2 nanosheets as a candidate for detection SO2, SOF2, and SO2F2. An external E-field can facilitate the adsorption and the stability of SF6 products onto monolayer and bilayer HfSe2 nanosheets. The highest adsorption energies of SO2, SOF2, and SO2F2 on bilayer HfSe2 occurred at an E-field intensity of roughly −0.41 V/A0, with values −1.46, −1.39, and −1.16 eV, respectively. The electronic structures of the layered HfSe2 systems were seen to change as a result of the adsorption of gas molecules, where all the monolayer HfSe2 systems containing adsorbed molecules exhibited semiconductor properties with various band gaps, barring the monolayer HfSe2/SO2 system. Also, all bilayer HfSe2 systems exhibit metallic behavior in all values of E-field. Overall, these study's findings demonstrated that monolayer and bilayer HfSe2 might be utilized in techniques for the adsorption and detection of SF6 products. That bilayer HfSe2 also works to remove these gases.