A comparative DFT Investigation of industry affiliated gases on Molybdenum Diboride and Molybdenum Tetraboride for gas sensing application

Abstract

Our research has generated considerable interest in MBenes because of their promising applications in chemistry, physics, and materials science. We specifically investigated the MoB₄ and MoB₂ MBene family materials for gas sensing applications through density functional theory (DFT). These calculations indicate that the MoB₄ structure exhibits a higher adsorption affinity for gases CO, CO₂, NO, NO₂, NH₃, SO, SO₂, and SO₃, while MoB₂ shows limited gas adsorption capacity. The metallic nature of the MoB₄ monolayer, its stable characteristics, and its negative adsorption energy lead to the emergence of novel states in the density of states (DOS). The metallic behavior of the MoB₄ material remains unchanged after the adsorption of gases. The CO₂, CO, NO, NO₂, and SO₃ exhibit chemisorption while NH₃, SO, and SO₂ display physisorption behavior. The gases transferred the charge to the substrate. We analyzed parameters like structural, electronic, adsorption properties, and electron localization function (ELF) concerning adsorbed gases on MoB₄. Significant charge transfers determine the material’s sensitivity to detect and adsorb various gases. ELF diagrams illustrate that all gases showed chemisorption behavior, with computed adsorption energies ranging from − 1.63 to -5.70 eV, and interaction distances observed on the MoB₄ monolayer. MoB₄ excels in detecting NO₂ gas molecules due to its exceptional sensitivity, appropriate recovery time, and remarkable stability. These insights into MoB₄ are expected to drive the discovery of new, highly conductive materials for future gas-sensing applications.