Effects of Vacancy-Defected, Dopant and the Adsorption of Water upon $Mn_{2}O_{3}$ and $Mn_{3}O_{4}$ (001) Surfaces: A First-Principles Study

In this study, a first-principles study using the spin-polarized density functional theory approach within corrected functional was carried out to investigate the electronic features of manganese oxide surfaces under three situations of (a) cation vacancy, (b) intercalation of multi- and univalent ions, and (c) adsorption of a water molecule upon the surface as catalytic performance. The possibility of obtaining the significant absolute magnetic momentum phases from native defects in orthorhombic structures of $Mn_{2}O_{3}$ and $Mn_{3}O_{4}$ (001) surface is explored, whereas Mn vacancy provides a transition from the insulating phase into a metal-like nature and modifies the electronic transport. Moreover, bandgap engineering via impurity intercalation has been explored. $Ca^{+2}$ and $Al^{+3}$ intercalations have manifested substantial attributes and explain the experimental results as efficient conducting system and catalytic activity. Furthermore, the adsorption of one water molecule and the most stable configuration, adsorption energies and electronic properties were thoroughly discussed. Accordingly, it was explored that $H_{2}O$: $Mn_{2}O_{3}$ and $Mn_{3}O_{4}$ exhibit suitable parameters as efficient catalytic synthesis.