Membrane adsorber with hierarchically porous HKUST-1 immobilized in membrane pores by flowing synthesis

A membrane adsorber with hierarchically porous HKUST-1 (HP-HKUST-1) immobilized in membrane pores has been fabricated by flowing synthesis. The X-ray diffraction (XRD) characteristics indicate that the structural integrity of the HP-HKUST-1 immobilized in the membrane pores can be kept after template agents are removed. Other characteristics prove the effective immobilization of HP-HKUST-1 in membrane pores. As a concept-of-proof, the adsorption for Congo red (CR) and Methylene blue (MB) is carried out to evaluate the adsorption performance of the membrane adsorber. The adsorption capacity for CR with 458 mg g -1 and MB with 241 mg g -1 can be obtained by HP-HKUST-1 powder, which is 2–3 times higher than those by HKUST-1 powder, owing to the mesopores with rich active adsorption sites. When the solution flows through the membrane adsorber, the adsorption rate for these adsorbates in the range of 0.049 g mg -1  h -1 and 0.129 g mg -1  h -1 can be obtained, which is 4–5 times higher than that by HP-HKUST-1 powder, owing to the enhanced mass transfer in the confined space of the membrane pores with micro or nano scale. After going through seven adsorption-desorption experiments, the membrane adsorber with HP-HKUST-1 immobilized shows remarkable repeatability.