Enhancing self-cleaning performance of graphene oxide membranes via IRMOF-3 integration for efficient naphthol blue black dye filtration.

Abstract

Wastewater containing dye pollutants presents a serious environmental challenge in industrial activities. Membrane filtration is a promising treatment method due to its high selectivity and environmental friendliness. Graphene oxide (GO), rich in oxygen-containing functional groups, is commonly incorporated into polyvinyl alcohol (PVA) matrices to improve permeability; however, membrane fouling remains a major limitation. To overcome this issue, Isoreticular Metal-Organic Framework-3 (IRMOF-3), a photocatalytically active material, was incorporated as a self-cleaning additive into PVA/GO membranes. GO was synthesized using a modified Hummer's method, while IRMOF-3 was prepared via precipitation. Composite membranes were fabricated by vacuum filtration on nylon supports and characterized by UV-Vis, FTIR, XRD, SEM-EDX, and UV-Vis DRS. Porosity and pore size were evaluated using the gravimetric method and the Guerout-Elford-Ferry equation. Results confirmed the successful integration of IRMOF-3, producing multifunctional membranes with diverse active sites. IRMOF-3 exhibited an indirect band gap of 2.83 eV. Compared to GO and PVA/GO membranes, PVA/GO/IRMOF-3 membranes showed higher porosity, smaller pore radii, and enhanced rejection stability. Membranes containing 10 mg and 30 mg IRMOF-3 achieved dye rejection rates of 87.75% and 83.72% after five cycles, demonstrating improved performance during repeated UV-assisted filtration-cleaning cycles while maintaining high dye rejection efficiency.