Ga-doped phagraphene as a superior media for sensing of carbon monoxide: A detailed theoretical investigation

Abstract

Abstract The adsorption of highly toxic carbon monoxide molecule (CO) on pristine, Al, Si, and Ga-doped phagraphene are studied using Density Functional Theory (DFT) calculations at M06-2X level of theory with 6-311G++ (d,p) basis set, to explore the potential abilities of phagraphene as an effective CO detection sensor. The full relaxed geometries of CO molecule, pristine and doped phagraphenes and related CO/pristine and doped-phagraphene complexes are specified and the variety parameters such as energy of Highest Occupied Molecular Orbital (E HOMO), energy of Lowest Unoccupied Molecular Orbital (ELUMO), gap energy (Eg), energy of adsorption (Ead), basis set superposition error (BSSE), gap energy alterations percent (%ΔEg), Global Electron Density Transfer (GEDT), energy of Fermi level (EF), work function (Φ), work function alterations percent (%ΔΦ), Density of States (DOS) patterns and Molecular Electrostatic Potential (MEP) profiles were calculated and analyzed. The results demonstrate that the CO molecule has a very poor physical adsorption on the pristine phagraphene. The calculated Ead value of CO/Si-doped phagraphene complex (−4.2043 kcal/mol) is moderate, however, the calculated %Eg value (+2.3498%) shows that Si-doped phagraphene has a low sensibility to CO molecule. The Ead calculations also indicate that the adsorption of CO molecule on Ga-doped phagraphene (Ead = −6.9653 kcal/mol) has the shorter recovery time compared with Al-doped phagraphene (Ead = −8.1450 kcal/mol). Therefore, Ga-doped phagraphene can be considered as an promising gas sensing platform for detecting CO molecule.