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.