Adsorption of TCDD molecule onto CNTs and BNNTs: Ab initio van der Waals density-functional study

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCCD) is one of the most dangerous compounds that infect the environment and hence its removal is crucial for safety in human life. In this work, we have investigated the interaction of TCDD with boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) by using the density functional theory (DFT) calculations. Our first-principles results have been validated by experiment and also other theoretical values for the similar system. The adsorption energies for TCDD molecule on the BNNTs and CNT are calculated. It was found that TCDD adsorption ability of BNNT is slightly stronger than that of CNT and TCDD molecule prefers to be adsorbed on BNNTs with molecular axis parallel to the tube axis. The results obtained indicate that TCDD is weakly bound to the outer surface of all the considered nanotubes and the obtained adsorption energy values and binding distance are typical for the physisorption. We also evaluated the influence of curvature and introduced defects on the TCDD adsorption ability of BNNTs. Furthermore, we have analyzed the electronic structure and charge population for the energetically most favorable complexes and the results indicate that no significant hybridization between the respective orbitals of the two entities was accomplished. (C) 2014 Elsevier B.V.. All rights reserved.