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

Abstract

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. The adsorption of dioxin molecule with BNNT and CNT was investigated by using first-principles calculations with the vdW-DF method. • The interaction of TCDD with CNTs/BNNTs was investigated using vdW-DF calculations. • Full structural optimization was performed for several possible active sites. • Electronic structure of the energetically favorable complexes was analyzed. • The TCDD adsorption ability of BNNTs is slightly stronger than the CNTs. • We evaluated the effect of BNNTs curvature and defects in TCDD adsorption.