Exploring the Potential of Defective UiO-66 as Reverse Osmosis Membranes for Desalination

Defects in metal-organic frameworks (MOFs) can play an important role in the development of MOFs as promising reverse osmosis (RO) membranes for water desalination. By employing molecular dynamics techniques, we explore the effects of experimentally relevant defects in UiO-66 on their desalination performance. Different defect types with varying densities and chemical compensations are studied. Our results show that defective membranes can possess substantially improved water permeability and an enhanced water intrusion rate by orders of magnitude compared to the defect-free one while still maintaining an excellent ability to reject salts. Further, the relationship between adsorption energetics and transport kinetics of water is established to shed light on the permeation behaviors of MOF membranes at an atomic scale. The outcomes of this work suggest that controlling structural defects provides opportunities toward the optimization of MOFs as RO membranes for reduced energy and cost requirements in desalination.