Transition-metal-doped Si/C nanosurfaces for CO, CO 2 , NO, and NO 2 sensing: showcasing a first-principles study of adsorption and electronic modulation

Abstract This article investigates the physical and chemical properties of a type of graphene-like silicon carbide, called Si 14 XC 16 (where X is titanium, chromium, or manganese), when it is doped with these elements. The study uses first-principles calculations based on density functional theory (DFT) to explore how well this material can capture gas molecules like CO, CO 2 , NO, and NO 2 . The findings show that the Mn-doped Si 14 XC 16 monolayer sheet has a stronger attraction for these gas molecules compared to the undoped version. The gas molecules attach to the Ti/Cr/Mn site by forming covalent bonds. In fact, studies have shown how titanium, chromium, or manganese doping in Si 14 XC 16 nanosheets affects the interaction between C, N, and O atoms in gas molecules like CO/CO 2 /NO/NO 2 . These methods suggest the (Ti, Cr, Mn)-doped Si 15 C 16 surface as the gas sensors in air pollution monitoring. It was found that the priority for selecting the binding of the N-atom from NO and the O-atom from NO 2 /CO/CO 2 on the surface of Si 14 XC 16 (X = Ti, Cr, Mn) depends on the presence of nearby atoms on the surface. Non-covalent bonds form from the interactions between gas molecules and the surface, while covalent bonds occur from the interactions between the Ti, Cr, or Mn atom in the transition metal and Si 14 XC 16 . Silicon carbide is a type of semiconductor that has a wide bandgap, and it holds great promise for improving optoelectronic and electronic devices.