Fabrication of α-MnO ₂ /GO/PVDF Catalytic Membranes via a Phase Inversion Method for Universal Separation and Degradation of Dye Wastewater

In this study, a manganese dioxide/graphene oxide/poly-(vinylidene fluoride) catalytic membrane (α-MnO₂/GO/PVDF) was fabricated via a solution phase inversion method for efficient dye wastewater treatment. The membrane integrated α-MnO₂ nanowires as heterogeneous Fenton-like catalysts and GO to enhance its own separation and catalytic properties. Characterizations revealed that the introduction of GO and α-MnO₂ optimized the membrane's surface roughness, hydrophilicity, pore structure, and mechanical properties. The optimized membrane (M-4) exhibited exceptional universal separation performance, achieving rejection rates exceeding 96% for both anionic dyes (Congo red, methyl blue) and cationic dyes (rhodamine B (Rh B), methylene blue), overcoming the target-specific limitation of previous membranes. The synergistic effect of physical interception and the heterogeneous Fenton-like reaction, driven by H₂O₂, generated HO^• and HOO^• radicals for dye degradation. The membrane also showed excellent operational stability, maintaining a rejection rate of 91.59% after five cycles. This work provided a novel strategy for constructing versatile catalytic membranes, highlighting their potential as a sustainable solution for efficient and universal dye wastewater treatment.