DFT simulations and fine-tuned theoretical linear solvation energy relationship (TLSER) models for predicting organic compound adsorption onto diverse boron nitride nanotubes (BNNTs)

Abstract

Exploring the adsorption of organic compounds onto boron nitride nanotubes (BNNTs) is essential for designing advanced BNNT-based absorbents to remove emerging organic pollutants from the environment. Herein, density functional theory (DFT) computations were carried out for exploring the adsorption of 30 organic compounds onto 14 BNNTs with varying diameters and types of chirality. Furthermore, 14 predictive models based on the fine-tuned theoretical linear solvation energy relationship (TLSER) were established for estimating the adsorption energy (E_ad) values onto BNNTs. These prediction models are applicable to aliphatic and aromatic hydrocarbons featuring diverse substituents, i.e., –CH₃, –NH₂, –NO₂, –OH, –F, –CN, –C(O)CH₃, –CH₂CH₂OH, –CH₂OH, –CH₂CH₃ and –CH₂CH₂CH₃. Besides, the results imply that the adsorption energies can be enhanced by increasing the diameter of BNNTs. The functional groups of the organic compounds can further promote the adsorption onto BNNTs. The more functional groups, the more effective the adsorption. The dispersion interactions were identified as the primary driving forces in the adsorption, while the hydrogen-donating ability had minimal effects on the adsorption. These results provide molecular-level insights into diverse organic compound adsorption onto BNNTs with different diameters and types of chirality, and also offer efficient tools for predicting the adsorption behavior onto BNNTs so as to rationally design high-performance BNNT-based absorbents.