Adsorption of TNT on the surface of pristine and N-doped carbon nanocone: A theoretical study

Abstract

In this research, the performance of the carbon nanocone as an adsorbent and a sensing material for the removal and detection of trinitrotoluene (TNT) was investigated using the density functional theory. The atomic structures of TNT and its complexes with carbon nanocone were optimized geometrically. Infra-red (IR) and frontier molecular orbital computations were employed to evaluate the interaction of TNT with the carbon nanocone. The obtained negative values of adsorption energies, Gibbs free energy changes, adsorption enthalpy variations and great values of thermodynamic equilibrium constants revealed that the interaction of the TNT with carbon nanocone was exothermic, spontaneous and experimentally feasible. The effect of the nitrogen doping and temperature on the adsorption process was also evaluated and the results indicated that TNT interaction with N-doped carbon nanocone was stronger than that of pristine one. In addition, 298 K was the optimum temperature for the adsorption process. The specific heat capacity values revealed that the heat sensitivity was declined tangibly after the TNT adsorption on the surface of carbon nanocone. Besides, the frontier molecular orbital parameters such as bandgap, electrophilicity, maximum transferred charge proved that the carbon nanocone could be utilized as an excellent sensing material for the construction of new electrochemical sensors for TNT determination. Some structural and energetic features were also discussed in details.