In situ deposition of double Fe-based Fenton catalysts on the porous membrane for the development of multi-defense against various foulants toward highly efficient water purification.

This work designs and constructs a porous surface with multi-defense against various organic foulants in water purification, where hydrophilic, underwater superoleophobic, and anti-bacterial double Fe-based Fenton catalysts of β -FeOOH nanorods and CuFeO 2 nanoparticles were coated on PVDF membrane via a facile metal-ion-induced in situ deposition process. [Display omitted] • Multi-defense is designed and constructed on the porous membrane. • Double Fe-based Fenton nano-catalysts were in situ deposited on PVDF membrane. • M FeOOH/CF has ultra-stable underwater superoleophobicity and ultra-low oil adhesion. • M FeOOH/CF can degrade various foulants under the solar-driven photo-Fenton process. Membrane separation technology has been widely employed in wastewater separation, although, it is restricted by terrible membrane fouling. The acceptable "single defense" is insufficient to generate a desirable antifouling surface against various organic foulants in complex wastewater. Therefore, this work designs and constructs a porous surface with "multi-defense" by integrating hydrophilic, underwater superoleophobic, and anti-bacterial nano Fe-based Fenton catalysts of β -FeOOH nanorods and CuFeO 2 nanoparticles on the polyvinylidene difluoride membrane via metal-ion-induced deposition process. The obtained composite membrane (M FeOOH/CF) has ultra-stable underwater superoleophobicity and ultra-low oil adhesion, which prevent oils from adhering to the membrane and benefit to separate various surfactant-stabilized oil-in-water emulsions with high water flux and separation efficiency of 99%. M FeOOH/CF also exhibits nearly 100% bactericidal activity against Escherichia coli. Moreover, the various foulants (such as bovine serum albumin, methylene blue, and crude oil) adhered to the membrane after filtration can be successfully degraded by M FeOOH/CF under the solar-driven Fenton process, leading to ultrahigh flux recovery ratio (FRRV) of 98.2 ± 0.3% and a low irreversible fouling ratio (RirV) of 2.0 ± 0.1%. The apparent degradation rate constant (k) of M FeOOH/CF is 2.5 times the β -FeOOH coated membrane (M FeOOH) because the introduction of CuFeO 2 nanoparticles provides more reactive sites and lowers the Fe3+/Fe2+ redox potential. This study is working to bring about a highly efficient "multi-defense" on the porous membrane, which will realize membrane regeneration and boost wastewater purification. [ABSTRACT FROM AUTHOR]