Dodecagonal Zinc Oxide ( d - ZnO ) Monolayer for Water Desalination and Detection of Toxic Gases

Nanoporous materials have attracted great interest because of their variety of applications in nanodevices, such as gas storage, low-density magnetic storage, energy storage, supercapacitors, catalysis, membranes, etc. The most common purpose of using nanoporous materials is to make a material much lighter while preserving or improving the high structural stability of these compounds. In this work, we propose a two-dimensional dodecagonal zinc oxide ($d$-$\mathrm{Zn}\mathrm{O}$) monolayer via first-principles calculations based on density-functional theory (DFT). Our extensive analysis shows that this semiconducting porous $d$-$\mathrm{Zn}\mathrm{O}$ material is mechanically, dynamically, and thermally stable and suitable for various applications, such as water membrane and gas detection at room temperature and above. We study the water permeability and ${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{\ensuremath{-}}$ ions' rejection of $d$-$\mathrm{Zn}\mathrm{O}$ material via conducting DFT and molecular dynamics (MD) simulations. Our simulations show that the energy barrier of the water molecule and ${\mathrm{Na}}^{+}/{\mathrm{Cl}}^{\ensuremath{-}}$ ions passing through the porous $d$-$\mathrm{Zn}\mathrm{O}$ structure is low and high, respectively. In addition, MD calculations show that the water permeability performance of $d$-$\mathrm{Zn}\mathrm{O}$ material is high enough to use this material for water desalination applications. For further investigations, the detection of some selected gases ($\mathrm{CO}$, $\mathrm{SO}$, $\mathrm{NO}$, ${\mathrm{CO}}_{2}$, ${\mathrm{SO}}_{2}$, and ${\mathrm{NO}}_{2}$) are investigated on $d$-$\mathrm{Zn}\mathrm{O}$ and find that ${\mathrm{NO}}_{2}$, and ${\mathrm{SO}}_{2}$ would preferentially be detected on the $d$-$\mathrm{Zn}\mathrm{O}$ substrate due to their high adsorption energy values as compared to physisorption of $\mathrm{CO}$, $\mathrm{NO}$, $\mathrm{SO}$, and ${\mathrm{CO}}_{2}$ molecules on the $d$-$\mathrm{Zn}\mathrm{O}$ surface.