Adsorption of acetone onto the pristine and Al-doped ZnO nanotubes: A dispersion corrected DFT study

Abstract

Over the recent decades, the elimination of organic solvents from various media, particularly by utilizing nanostructured materials has played an essential role in extensive industries such as devising new versatile nano adsorbents. Since computational methods are known as one of the most potent tools for the atomic level exploration of molecular systems and investigating the nature of the interactions, in this research, dispersion corrected DFT method was used to represent a meticulous understanding of adsorption behavior of acetone molecule onto the pristine, and Al-doped armchair and zigzag ZnO nanotubes (ZnONTs). In order to do this, active sites and optimized geometrical criteria of the interacting systems were thoroughly surveyed. To evaluate the adsorption capability of pristine ZnONT and Al-ZnONT for acetone, the binding features of interacting species were evaluated through the interaction energy, the electronic properties, the charge transfer, and the AIM analysis. To investigate the adsorption of the water molecule as competing entity, the interaction between ZnONTs/Al-ZnONTs and water molecule was examined, too. Our theoretical endeavors revealed that acetone bound stronger to the both ZnONTs and Al-ZnONTs in comparison with the H2O molecule. Furthermore, Al-doping can enhance significantly the adsorption strength of ZnONTs having superior ability in acetone remediation from contaminated water. The adsorption ability of ZnONT/Al-ZnONT was explored by DFT, and DFT-MD simulations at environmental conditions. The appropriate adsorption strength of acetone by considered adsorbents, leads to virtual worry of these suitable nanotubes as superior adsorbents for acetone adsorption. Our findings can be considered to establish the basis for the design of novel energy-efficient nano adsorbents as an economical means for the removal of solvent contaminants from wastewater.