Membranes with Nanoparticles of Tungsten Oxide–Iron Oxide for CO ₂ Selective Permeation and Degradation of Azo Phenols

Catalytic membranes have emerged as a promising approach for environmental remediation, offering efficient solutions for both gas separation and the treatment of organic pollutants. In this study, an amine-functionalized polyglycidyl methacrylate-based tungsten oxide–iron oxide (AWFeO) nanocomposite was synthesized and characterized using various spectroscopic techniques. The synthesized nanocomposite was incorporated into a Pebax polymer solution at different loadings (1, 5, and 10 wt %) and subsequently cast into catalytic membranes (Peb/AWFeO). Membranes containing 1 and 5 wt % AWFeO demonstrated uniform dispersion of nanocomposites within the Pebax matrix. In contrast, a higher loading of 10 wt % resulted in structural distortion attributable to particle agglomeration. These membranes are utilized for gas separation, and permeability results indicate that the modified membrane achieved a CO2 permeability of 102.84 Barrer, which is markedly higher than that of the pristine Pebax at 87.19 Barrer. Additionally, the selectivity remained comparable, thus overcoming the conventional permeability–selectivity trade-off. Modified membranes were tested for photo-Fenton degradation of toxic azo phenol compounds in water treatment. A 5 wt % catalyst loading demonstrated the highest degradation efficiency (97.9%), outperforming both 1 wt % (96.3%) and 10 wt % (93.8%). The reduced efficiency at 10 wt % was attributed to excess reactive oxygen species (ROS), which can hinder the degradation process. Furthermore, real wastewater analysis using textile dye pollutants confirmed the membrane’s practical applicability, achieving a degradation efficiency of 86%. Overall, this work highlights the multifunctionality of Peb/AWFeO catalytic membranes, demonstrating their effectiveness in both CO2-selective separation and organic pollutant degradation.