Fluoromethane and chloromethane adsorption studies on hydrogenated C8 nanosheets – A first-principles study

Abstract

We studied the structural stability of hydrogenated C8 (H-C8) sheets which exhibit body-centered tetragonal (BCT) structure and found to be stable in its structure. The energy gap of H-C8 sheets is observed to be 3.517 eV. The structural firmness of H-C8 is verified with formation energy, which is recorded as −5.947 eV/atom. Besides, fluoromethane and chloromethane, two predominant halomethanes are adsorbed on H-C8 nanosheets. The effectiveness of the H-C8 sheets for the detection of fluoromethane and chloromethane is explored in the current work with the help of density functional theory (DFT) calculations. In addition, the electronic properties and adsorption attributes of fluoromethane and chloromethane on H-C8 sheets were investigated through the band structure, DOS spectrum, and electron density difference diagrams. Moreover, the charge transfer and adsorption energy calculations were also determined to ascertain halomethane adsorption. The results show that halomethanes are physisorbed (-0.429 eV to −0.823 eV) as well as chemisorbed (-1.574 eV) on H-C8 sheets. Thus, H-C8 nanosheets can be used as a sensing element towards fluoromethane and chloromethane molecules.