Molecular dynamics simulations of the removal of lead(II) from water using the UiO-66 metal-organic framework

In this work, we use molecular dynamics simulations to investigate the viability of using the UiO-66 MOF for the removal of lead ions, Pb2+, from water. We study the concentration of Pb(II) in water in the presence of this MOF under varying conditions of number density of particles in the system (500, 300, 74 and 20 particles), metal cation concentration (1.5 M, 3.7 M, 6 M and 55.6 M) and presence of NO3− ions. Pb(II) ions are observed to adsorb onto the UiO-66 framework under favorable conditions, corresponding to: low number density of particles, high metal cation concentration and absence of NO3− ions in the vicinity of the MOF. According to the radial distribution functions, preferential adsorption sites for the Pb2+ in UiO-66 correspond to the oxygen atoms forming the Zr–O–Zr bridge. This study indicates that UiO-66 could be a successful candidate for the removal of Pb(II) from water.