Adsorption Features of Tetrahalomethanes (CX(4); X = F, Cl, and Br) on β(12) Borophene and Pristine Graphene Nanosheets: A Comparative DFT Study

The potentiality of the β(12) borophene (β(12)) and pristine graphene (GN) nanosheets to adsorb tetrahalomethanes (CX(4); 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(3)∙∙∙β(12)/GN)- and halogen (X(3)C-X∙∙∙β(12)/GN)-oriented configurations were characterized at various adsorption sites. According to the energetic manifestations, the adsorption process of the CX(4)∙∙∙β(12)/GN complexes within the tetrel-oriented configuration led to more desirable negative adsorption energy (E(ads)) values than that within the halogen-oriented analogs. Numerically, E(ads) values of the CBr(4)∙∙∙Br1@β(12) 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 E(HOMO), E(LUMO), and E(gap) values of the pure β(12) and GN nanosheets following the adsorption of CX(4) molecules. Bader charge transfer findings outlined the electron-donating property for the CX(4) molecules after adsorbing on the β(12) and GN nanosheets within the two modeled configurations, except the adsorbed CBr(4) 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(4)∙∙∙β(12)/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 β(12) and GN nanosheets toward small toxic molecules.