Simultaneous enhancement of flux and selectivity of UiO-66 membranes for pervaporation via post-synthetic defect healing

Abstract

Zirconium-based metal-organic framework (Zr-MOF) UiO-66 is widely recognized as an exceptional candidate for fabricating high-performance membranes owing to its rich porosity, customizable chemistry and remarkable stability. However, exploration of accessible zirconium sources for UiO-66 membrane fabrication is not enough and eliminating the undesired defects occurring during synthesis is also imperative. In this work, 1.3 μm thick UiO-66 polycrystalline membranes were successfully fabricated using ZrOCl₂·8H₂O as the sole metal source. The undesired lattice defects were controlled at a low concentration level through utilizing post-synthetic defect healing method, leading to simultaneous enhancement of flux and separation factor of UiO-66 membranes for pervaporation test as the competitive permeation between different penetrants was reduced to a large extent. The finally obtained UiO-66 membranes exhibited exceptional performance, with the separation factor of around 10,000 for alcohol/ether separation, showing good potential for applying in industrial production processes.