Sensing of Nitroaromatics Using Substituted Nitrene-Functionalized Boron Carbide Nanosurfaces

The search for new functional nanomaterials with tunable properties is an ongoing research field. This study presents a density functional theory of the functionalization of boron carbide (BC₃) nanosurfaces with nitrene intermediates, resulting in new nanosurfaces with 7-membered rings that can be used for the sensing of nitroaromatics, which are environmental pollutants or byproducts of explosive materials. First, we investigated the interaction between methylazide and methylnitrene to probe the nanosurface for the most favorable positions for physical (<i>E_i</i> = +0.09 to -0.05 eV) and chemical (<i>E</i> _r = -2.89 to -3.61 eV) adsorption, showing that the chemical reaction of nitrenes with BC₃ is favored over their physical adsorption. The density of states and band structures showed that the chemical reactions induced important effects on the electronic properties of BC₃. In the second step, the BC₃ surface modified with nitrenes with functional groups (4-PhOH (<b>1</b>), 4-PhNH₂ (<b>2</b>), 3,4-Ph-(NH₂)₂ (<b>3</b>), and 4-PhNH-NH₂ (<b>4</b>)) interact with nitroaromatics: 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), 4-mononitrotoluene (MNT), and 2,4,6-trinitrophenol (TNP) through hydrogen and pnictogen bonding with adsorption energies of -0.10 to -0.41 eV. The Bader partial charges and charge densities confirmed these interactions. These findings suggest that functionalized BC₃ nanosurfaces are promising candidates for the design of new nitroaromatic sensors.