Preparation and Characterization of UiO-66 Onto Modified Alumina Hollow Membrane With Sol-Gel Pechini of Zirconia Oxide Nanoparticles.

Well-continuous zirconia (Zr)-based metal-organic framework (UiO-66) grown onto alumina hollow fiber (AHF) remains challenging. By introducing Zr oxide (ZrO₂) nanoparticles as coat-seeded particles, the hydrogen bond between UiO-66 and ZrO₂ nanoparticles can be enhanced. This study aims to modify AHF by coat-seeding ZrO₂ nanoparticles using the sol-gel Pechini method prior to in situ solvothermal deposition of UiO-66. The prepared samples were characterized using scanning electron microscopy (SEM), field emission SEM (FESEM), atomic force microscopy (AFM), and contact angle measurement. The residual UiO-66 samples were examined using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. The study of humic acid (HA) removal revealed that the AHF/ZrO₂/Zr-B24 sample showed excellent performance in HA removal with 99.8% rejection and 42.4 ± 1.7 L·m⁻²·h⁻¹ of solute permeation. This result was attributed to charge repulsion between the negative charge of carboxyl groups belonging to UiO-66 and HA.