Separation of nitrate ion from water using silicon carbide nanotubes as a membrane: Insights from molecular dynamics simulation

Molecular dynamics (MD) simulations were performed to investigate the separation of nitrate ion as contaminant from aqueous solution by means of armchair silicon carbide (SiC) nanotubes. The (7,7) and (8,8) SiC nanotubes embedded in a silicon nitride (SiN) membrane as a membrane immersed in an aqueous solution of NaNO₃. An external electric field was applied to the system along the z axis of the simulation cell. In order to investigate these systems, we calculated the ion current, the radial distribution function of water-nanotube and ion-water, the retention time of ions, water density, the hydrogen bond of water, and the autocorrelation function of the hydrogen bond. The results showed that the considered armchair SiC nanotubes can be used for separating nitrate ion from water. The results revealed that nitrate ions were separated successfully using the (8,8) SiC nanotube, though these ions did not pass through the (7,7) SiC nanotube.