2D confinement freestanding graphene oxide composite membranes with enriched oxygen vacancies for enhanced organic...

Introducing membrane filtration into advanced oxidation processes to decrease energy and cost consumption has been considered as a promising direction in environmental remediation. In this work, we firstly developed a kind of novel lawn-like Fe₂O₃@Co_0.08Fe_1.92@nitrogen-doped reduced graphene oxide@carbon nanotube composites (FeCo@GCTs) through in-situ pyrolysis of self-assembly of Prussian blue analogues and GO, followed through a vacuum-assisted filtration strategy to fabricate 2D confinement freestanding GO composite membrane. Electrochemical analysis and H₂-TPR revealed the superiority of FeCo@GCTs as ideal electron acceptor, and this unique lawn-like structure concentrated active sites with a confined space and enriched oxygen vacancies that realized 98.5% (0.128 min^-1) sulfamethoxazole degradation via peroxymonosulfate activation, and accelerated the reduction of Cr(VI). Owing to the increasing interlayer spacing of GO nanosheets, the permeation flux of FeCo@GCTs/GO membrane has not only been attained to 487.3 L·m^-2·h^-1·bar^-1, which was more than 7.5-fold of GO membrane (64.6 L·m^-2·h^-1·bar^-1), but also achieved the synergistic membrane filtration and catalytic degradation of pollutants. Furthermore, scavenger experiments and EPR tests were conducted to confirm the active radicals, of which SO₄·^- and ¹O₂ were responsible for SMX degradation. Therefore, these features demonstrated great potential for the fabricated 2D confinement catalytic membrane with enriched oxygen vacancies in wastewater purification.