Multifunctional porphyrinic Zr-MOF composite membrane for high-performance oil-in-water separation and organic dye adsorption/photocatalysis

A new and multifunctional porphyrinic Zr-MOF composite membrane (PCN-224/TA/PVDF) was fabricated via a facile in-situ deposition method under vacuum system. PCN-224 nanocrystals, a typical porphyrinic Zr-MOF built by Zr6 clusters and tetrakis(4-carboxyphenyl)porphyrin ligands, were immobilized on the surface of flexible PVDF base membrane by using hydrophilic tannic acid (TA) as the binder. The fabricated PCN-224/TA/PVDF membrane has a rough surface structure and a superwettability of superhydrophilicity and underwater superoleophobicity. Besides, the composite membrane has visible-light response ability ascribed to the photosensitive porphyrin ligands in PCN-224. The fabricated PCN-224/TA/PVDF membrane was able to effectively separate kinds of representative water-insoluble emulsified oils from water with excellent separation efficiency above 99% and relatively high flux (829–1542 Lm−2h−1bar−1). Additionally, the as-prepared porphyrinic Zr-MOF composite membrane also can be applied in the removal of water-soluble organic dyes by adsorption and photocatalysis mechanism, including active adsorption removal of organic dyes from dynamic water, and visible-light-driven photocatalytic degradation of organic dyes in static water. Moreover, PCN-224/TA/PVDF membrane exhibited good stability, renewability and reusability. This successful development of high-performance PCN-224/TA/PVDF composite membrane will provide a new candidate for both chemical separation and wastewater treatment, as well as promote the fully utilization of PCN series porphyrinic MOFs in the construction of multifunctional membrane for environmental purification.