Revealing the Role of <i>X</i>₁₂<i>Y</i>₁₂ Nanocages (<i>X</i> = B, In; <i>Y</i> = N, Sb) in NH₃ Gas Adsorption: toward Gas Sensor Application

The dangers of ammonia gas (NH₃) to human health must be considered. Exposure to NH₃ gas can have several adverse effects, including harm to the skin; irritation of the eyes, nose, and throat; and damage to the respiratory system. New materials are being developed for use in gas sensors to mitigate the hazards associated with ammonia exposure. This study investigated the <i>X</i> ₁₂ <i>Y</i> ₁₂ nanocages (<i>X</i> = B, In; <i>Y</i> = N, Sb), B₁₂Sb₁₂, In₁₂N₁₂, and In₁₂Sb₁₂, specifically for their potential as NH₃ gas sensors for the first time, alongside B₁₂N₁₂. Utilizing density functional theory (DFT) at the theoretical level of B3LYP-D4/LANL2DZ, all adsorption processes and their properties were analyzed. All theoretical adsorption systems occurred via chemisorption and changed the electronic state after the adsorption process because of band gap/reactivity changes, as observed in the DOS graph and UV-vis spectrum. NBO analysis revealed strong interactions for all <i>X</i> ₁₂ <i>Y</i> ₁₂ nanocages. In QTAIM analysis, the interactions that occur are partial covalent interactions marked by positive ∇²ρ and negative <i>H</i> _BCP values. The interaction region indicator (IRI), independent gradient model based on Hirshfeld partition (IGMH), and electrostatic potential (ESP) of all nanocages are studied in depth. In ALMO-EDA2, the contribution of stability is dominated by electrostatic energy with a value of more than 55%. AIMD simulations show that, during adsorption, all nanocage adsorption systems with NH₃ gas remain bound up to 5000 fs of observation. B₁₂N₁₂ shows the best nanocages that are compared in this study with adsorption energy of -181.9472 kJ/mol.