Synergistic IL grafting and NH2-ZIF-8 doping enable PVDF composite membranes with enhanced separation, antifouling, and piezo-photocatalytic degradation functions

The inherent hydrophobicity of polyvinylidene fluoride (PVDF) separation membranes severely limits their flux and anti-fouling performance, and traditional membrane materials struggle to simultaneously achieve efficient separation and degradation of pollutants. This study innovatively proposes a synergistic modification strategy combining Chlorinated 1-butyl-3-vinylimidazole (IL) grafting with amino-functionalized zeolitic imidazolate framework-8 (NH 2 -ZIF-8) doping. This approach constructs a multifunctional composite membrane integrating efficient separation, adsorption, and piezo-photocatalytic degradation. The prepared PVDF-g-IL/NH 2 -ZIF-8 membrane demonstrates outstanding overall performance. Under combined ultrasound and ultraviolet excitation, it achieves a methylene blue degradation efficiency of 80.5 %, showcasing its capability for in-situ pollutant degradation during the separation process. Furthermore, the membrane exhibits a pure water flux as high as 685.6 L m −2 h −1 , which is approximately seven times that of the pristine PVDF membrane. It also maintains dye rejection rates exceeding 93 % for various dyes, and possesses a high adsorption capacity (>7.0 mg/g) along with excellent cycling stability due to the flux recovery rate above 80 %. This study provides new insights for developing water treatment membranes combined efficient separation with in situ degradation functionality.