Adsorption of Phosgene Gas on Pristine and Copper-Decorated B ₁₂N ₁₂ Nanocages: A Comparative DFT Study

Abstract

Nanostructured gas sensors find diverse applications in environmental and agricultural monitoring. Herein, adsorption of phosgene (COCl ₂) on pure and copper-decorated B ₁₂N ₁₂ (Cu–BN) is analyzed through density functional theory (DFT) calculations. Adsorption of copper on B ₁₂N ₁₂ results in two optimized geometries, named Cu@b ₆₆ and Cu@b ₆₄, with adsorption energies of −193.81 and −198.45 kJ/mol, respectively. The adsorption/interaction energies of COCl ₂ on pure BN nanocages are −9.30, −6.90, and −3.70 kJ/mol in G1, G2, and G3 geometries, respectively, whereas the interaction energies of COCl ₂ on copper-decorated BN are −1.66 and −16.95 kJ/mol for B1 and B2, respectively. To examine the changes in the properties of pure and Cu–BN nanocages, geometric parameters, dipole moment, Q _NBO, frontier molecular orbitals, and partial density of states (PDOS) are analyzed to comprehensively illustrate the interaction mechanism. The results of these parameters reveal that COCl ₂ binds more strongly onto copper-doped BN nanocages. Moreover, a higher charge separation is observed in COCl ₂–Cu–BN geometries as compared to copper-decorated BN geometries. Therefore, these nanocages may be considered as potential candidates for application in phosgene sensors.