Formation, electronic, gas sensing and catalytic characteristics of graphene-like materials: A first-principles study

The formation geometry, electronic property, gas sensing and reactive activity of single-atom Fe anchored on different nanoporous carbon materials (graphenylene-Fe and gamma-graphyne-Fe) are comparably analyzed by using first-principles calculations. Firstly, the graphenylene structure is more stable than that of gamma-graphyne sheet. The varied strains (from -10% to +10%) can regulate the metal and semiconducting properties of graphenylene sheet. Compared with the gamma-graphyne-Fe, the single or two reactive gases have larger adsorption energies on graphenylene-Fe sheet. Meanwhile, the electronic structures and magnetic properties of graphenylene-Fe can be modified by these adsorbed species. Secondly, the coadsorbed configurations of different gas reactants on two kinds of gamma-graphyne-Fe and graphenylene-Fe sheets are further analyzed for the catalytic oxidation of NO and CO. By the Langmuir-Hinshelwood (LH) mechanism, the coadsorption of CO and O-2 on graphenylene-Fe has lower reaction barriers than the same mechanism for NO oxidation. Furthermore, the adsorbed 2NO molecules can promote the oxidation reactions of 2CO (2NO + 2CO -> 2CO(2) + N-2) through Eley - Rideal (ER) mechanism ( < 0.6 eV), which provides a theoretical reference on exploring new nanoporous graphene-like catalyst for toxic gases removal.