Self-supporting degradable Zn-MOF/SA/CNF multifunctional photoactive membrane for water treatment

Self-supporting and degradable (Zn-MOF/SA/CNF) acts as multifunctional photoactive membrane. • Zn-MOF acts as a porous skeleton to enhance flux, SA as a binder, and CNF as a photo-Fenton catalyst. • Membrane shows 96–98% rejection of dye, 80% rejection of tetracycline and a flux of 50–60 L‧m −2 ‧h −1 ‧bar −1 . • Membrane shows antibacterial property, photo-Fenton induced flux recovery and acid-triggered regeneration. In this study, self-supporting multifunctional photoactive membranes with a sandwich structure were prepared via a green route using eco-friendly materials for water treatment. The Zn-BDC synthesized at 25 °C was employed to construct a strippable skeleton with high flux. Sodium alginate (SA) acted as both a binder and cavity filler to repair defects and enhance tensile properties. Meanwhile, C₃N₄-Fe₂O₃ (CNF) was synthesized and applied as a photo-Fenton catalyst. The results showed that both the membrane with SA on the top (MCS) and the membrane with SA in the middle (MSC) achieved over 98% rejection toward Congo red, Alcian blue, and nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt, with a flux ranging from 50 to 70 L·m −2 ·h −1 ·bar −1 . While the MSC membrane displayed better photocleaning performance and mechanical flexibility than the MCS membrane. Its flux could be restored via the photo-Fenton reaction. Moreover, the MSC membrane also attained over 80% rejection of tetracycline with the assistance of the photo-Fenton reaction. Furthermore, the membrane showed over 95% dye rejection in ethanol and exhibited favorable antibacterial performance. In addition, the membrane could be dissolved in a citric acid solution, which offers a convenient strategy for membrane disposal or recycling. Collectively, this work provides a green and sustainable membrane candidate for water treatment applications. Download: Download high-res image (129KB) Download: Download full-size image