Ni-doped HfSe2 monolayer as a gas scavenger toward SO2 and SOF2: a DFT study

Abstract

In this work, the adsorption behavior of a monolayer of HfSe2 (Ni-HfSe2) decorated with a Ni catalyst toward the SF6 decomposed gases SO2 and SOF2 is examined using the first-principles theory. On the pure HfSe2 surface, Ni atom as the catalyst substitutes the Se atom. This theoretical work investigates the geometry configurations of Ni-HfSe2 monolayers both before and after gas adsorption, as well as the electronic properties and sensitivities. The greater performance of the Ni-HfSe2 monolayer on the SO2 molecule is implied by the simulation's calculation of the of SO2 and SOF2 gas adsorption systems as −2.21 eV and −0.68 eV, respectively. This is further verified by the DOS, BS and WF analyses. The formula predicts that the Ni-HfSe2 monolayer can detect SO2 and SOF2 with sensitivity up to −80.89% and 105.59%, respectively, at room temperature (298 K), which demonstrates the sensor's advantageous sensitivity to both gases as a chemical resistance-type sensor. It is hopeful that a Ni-HfSe2 monolayer-based gas sensor will be able to distinguish between SO2 and SOF2 in a single gas atmosphere. In conclusion, this study may promote the steady operation of the power system and provide some guidance for cutting-edge electrical engineering resistance-type sensing materials.