Modeling of Inert Gas Sensors Using First Principles Methods

The detection of inert gases is difficult due to their inactive nature, which makes the preparation of the applicable gas sensor a challenging task. This work reports comprehensive first-principles investigations to design inert gas sensors. Graphene (Gr) sheets decorated with palladium (Pd) clusters Pdn ( ${n}$ = 2–6) were optimized after which adsorption of inert gases He, Ne, Ar, Kr, Xe, and Rn was carried out using the density functional theory (DFT)-based formalism. The reactivity of the sensors comprising Pd cluster-decorated-defected graphene is significantly higher than that of the sensor with a bare and defect-free graphene sheet. The adsorption caused redistribution of the electronic structure which provides the basis for sensing the adsorbate. The gas sensor Pd2–Gr exhibited good sensitivity toward neon and xenon while Pd3–Gr appeared more effective in the detection of krypton gas. Helium is appropriately detected by the Pd4–Gr sensor and the Pd5–Gr sensor is found capable of sensing radon and argon gases. The Pd6–Gr sensor is not a favorable sensor for sensing inert gases. The findings of this work are beneficial for the fabrication of inert gas sensors for small and industrial-scale applications.