Adsorption Features of Tetrahalomethanes (CX; X = F, Cl, and Br) on Borophene and Pristine Graphene Nanosheets: A Comparative DFT Study.

The potentiality of the borophene () and pristine graphene (GN) nanosheets to adsorb tetrahalomethanes (CX; X = F, Cl, and Br) were investigated using density functional theory (DFT) methods. To provide a thorough understanding of the adsorption process, tetrel (XC-X∙∙∙/GN)- and halogen (XC-X∙∙∙/GN)-oriented configurations were characterized at various adsorption sites. According to the energetic manifestations, the adsorption process of the CX∙∙∙/GN complexes within the tetrel-oriented configuration led to more desirable negative adsorption energy () values than that within the halogen-oriented analogs. Numerically, values of the CBr∙∙∙Br1@ and T@GN complexes within tetrel-/halogen-oriented configurations were -12.33/-8.91 and -10.03/-6.00 kcal/mol, respectively. Frontier molecular orbital (FMO) results exhibited changes in the , , and values of the pure and GN nanosheets following the adsorption of CX molecules. Bader charge transfer findings outlined the electron-donating property for the CX molecules after adsorbing on the and GN nanosheets within the two modeled configurations, except the adsorbed CBr molecule on the GN sheet within the tetrel-oriented configuration. Following the adsorption process, new bands and peaks were observed in the band structure and density of state (DOS) plots, respectively, with a larger number in the case of the tetrel-oriented configuration than in the halogen-oriented one. According to the solvent effect affirmations, adsorption energies of the CX∙∙∙/GN complexes increased in the presence of a water medium. The results of this study will serve as a focal point for experimentalists to better comprehend the adsorption behavior of and GN nanosheets toward small toxic molecules.