calculation study of conversion nitrate ions to n2 and o2 by zinc oxide nano-cage (zn12o12-nc)

The aim of this study is to investigate the performance of zinc oxide nano-cages (zn12o12-nc) to detect and reduce nitrate (no^3-) ions from aqueous media and convert them to oxygen and nitrogen gases by the density functional theory (dft) method on a b3lyp level with basis set of 6-31+g*. due to the structure of the nano-cage (zn12o12-nc), there are some location positions with different potential on it. the results showed that the first n atom of nitrate ion strongly prefers to be adsorbed on o atoms and o of nitrate ion is adsorbed on zn atoms of the 4-membered ring (4-mr). the electronic, structure and thermodynamic properties of these conversions are calculated and investigated. the energy gap (eg) of the zn12o12-nc is dramatically reduced from 3.88 to 1.22 ev upon the adsorption of no^3- ion, suggesting that it is transformed to n-type semiconductor ascribed to the large charge transfer from the ion to the nano-cage and ions convert into oxygen and nitrogen on it. the data show that zn12o12 nano-cage can be used to identify and reduce nitrate ions from the environment and may be helpful in several fields of study such as sensors, catalysts, and field emission investigations.