Ferreira, Camila R. [UNESP]Pulcinelli, Sandra H. [UNESP]Scolfaro, LuisaBorges, Pablo D.2020-12-122020-12-122019-01-01ACS Omega.2470-1343http://hdl.handle.net/11449/201192First-principles calculations done via density functional theory were used to study the structural and electronic properties of sodium montmorillonite clay (Mt-Na+) of general formula MxAl3Si8O24H4Na·nH2O (Mx: Mg or Fe). The final position of the interlamellar sodium atom is found to be close to the oxygen atoms located on the upper surface of silica. Following Fe-Mt-Na+ system relaxation, with subsequent analysis of magnetic moment and magnetic states, the electroneutrality of the system established that both Fe2+ and Fe3+ oxidation states are possible to occur. The Mg2+-Mt-Na+ material shows a band gap energy greater than that of Fe2+-Mt-Na+ when iron is in the octahedral site. It is found that the valence-band maximum and the conduction-band minimum of iron-doped montmorillonite are both at the G-point, while it is at V → G for magnesium-doped montmorillonite. The calculated band gap from hybrid functional (HSE06) of Fe2+-Mt-Na+ is equal to 4.3 eV, exhibiting good agreement with experimental results obtained from ultraviolet-visible spectroscopy of the natural Mt-Na+ (Cloisite-Na+). ©engArtigo10.1021/acsomega.9b006852-s2.0-85072560276