Fig. 1. Schematic illustration of MOF-303 membranes synthesized by a DS method.

The alumina HF is placed vertically in an autoclave filled with a ligand solution containing NaOH and an inadequate stoichiometric amount of aluminium chloride hexahydrate (AlCl₃·6H₂O). The ligand reacts with the OH groups both on the surface of the alumina HF support and in the synthesis solution to form the seed layer (seeding step), followed by a secondary growth for the final MOF-303 membranes named as DS membrane.