TNT interaction with BN Nanocone: A comprehensive computational study

Abstract

In this study, trinitrotoluene (TNT) adsorption on the surface of the boron nitride nanocone was investigated using the infra-red (IR), natural bond orbital (NBO), and frontier molecular orbital (FMO) computations. The calculated negative adsorption energies, Gibbs free energy changes (ΔGad) and great thermodynamic constants (Kth) showed that the TNT adsorption was spontaneous, irreversible, and experimentally possible. The effect of temperature on the thermodynamic parameters was also studied and the findings indicated that, at 298.15 K the TNT adsorption process had the highest efficiency. The values of the enthalpy changes (ΔHad) and specific heat capacity (CV) revealed that, BN nanocone can reduce the heat sensitivity of the TNT and this nanostructure can be used for making new thermal sensors for detecting the TNT. The NBO results revealed that, TNT interaction with BN nanocone was a chemisorption as monovalent chemical bonds with Sp 3 hybridization were formed between TNT and the adsorbent in all of the evaluated configurations. The computed DOS spectrums showed that, the BN nanocone was an ideal recognition element for developing novel TNT electrochemical sensors as the bandgap experienced a sharp increase in all of the studied configuration when TNT was adsorbed on the surface of the nanostructure. The frontiers molecular orbital parameters including the energies of HOMO and LUMO orbitals, electrophilicity, chemical hardness, chemical potential and maximum transferred charge was also evaluated and the results demonstrated that, the TNT reactivity and softness improved when it was adsorbed on the BN nanocone. All of the computations were conducted using the density functional theory method in the B3LYP/6-31 G(d) level of theory.