Synthesis of highly stable UiO-66-NH₂ membranes with high ions rejection for seawater desalination

Compact and phase-pure UiO-66-NH₂ membranes were synthesized on the 3-aminopropy-ltriethoxysilane (APTES) modified macroporous Al₂O₃ tubes through a repeated synthesis strategy. APTES acts as a molecular linker for anchoring the metal ions onto the support surface to promote the nucleation and the crystallization of UiO-66-NH₂ membrane. Therefore, well-intergrown UiO-66-NH₂ membranes could be prepared through a repeated synthesis method on the APTES-modified macroporous Al₂O₃ tubes. The developed UiO-66-NH₂ membranes were evaluated for seawater desalination by pervaporation. It is found that the UiO-66-NH₂ membranes show high desalination performances attributing to the narrow pore size which is exactly in between the size of water molecules and hydrated ions. With increasing the feed temperature from 318 to 363 K, the water fluxes increase from 1.5 to 12.1 kg m⁻² h⁻¹, with ions rejections of above 99.7%. Further, the UiO-66-NH₂ membranes display high stability for a long time in seawater desalination, which is very promising for seawater desalination.