Adsorption configuration, electronic structure and spectra of the harmful NH3, NO, and NO2 molecules on a bilayer boron cluster

Density functional theory (DFT) calculations were performed to investigate the adsorption configuration, electronic structure and spectra of a bilayer B48 cluster with NH3, NO, and NO2 adsorptions. The B48 shows a high affinity for NH3 and NO2 molecules and a medium adsorption ability for NO. The high binding strength of the B48 cluster for these gases originates from the direct B–N bonds corresponding to partially covalent characters. The energy gap changes are in the order of NO2 > NH3 > NO. The recovery time of the B48 for different gases can be adjusted to a reasonable range by increasing the temperature. Infrared (IR) and ultraviolet–visible (UV–vis) spectra were in detail analyzed before and after gas adsorptions for the identification of the adsorption structures in further experiments. Along with gas adsorption, the B48 cluster exhibits vastly different spectral characteristics. Our results indicate that the B48 shows promising sensor performance for studied gases, in particular for NO molecules, and can be considered as potential gas sensor candidates.