Adsorption of Phosgene Gas on Pristine and Copper-Decorated B₁₂N₁₂ Nanocages: A Comparative DFT Study

Abstract

Nanostructured gas sensors find diverse applications in environmental and agricultural monitoring. Herein, adsorption of phosgene (COCl₂) on pure and copper-decorated B₁₂N₁₂ (Cu-BN) is analyzed through density functional theory (DFT) calculations. Adsorption of copper on B₁₂N₁₂ results in two optimized geometries, named Cu@b₆₆ and Cu@b₆₄, with adsorption energies of -193.81 and -198.45 kJ/mol, respectively. The adsorption/interaction energies of COCl₂ on pure BN nanocages are -9.30, -6.90, and -3.70 kJ/mol in <b>G1</b>, <b>G2</b>, and <b>G3</b> geometries, respectively, whereas the interaction energies of COCl₂ on copper-decorated BN are -1.66 and -16.95 kJ/mol for <b>B1</b> and <b>B2</b>, respectively. To examine the changes in the properties of pure and Cu-BN nanocages, geometric parameters, dipole moment, <i>Q</i> _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 COCl₂ binds more strongly onto copper-doped BN nanocages. Moreover, a higher charge separation is observed in COCl₂-Cu-BN geometries as compared to copper-decorated BN geometries. Therefore, these nanocages may be considered as potential candidates for application in phosgene sensors.