Metal organic framework-loaded polyethersulfone/polyacrylonitrile photocatalytic nanofibrous membranes under visible light irradiation for the removal of Cr(vi) and phenol from water

Abstract

In this work, various amounts of the UiO-66-NH₂ and UiO-66-NH₂/TiO₂ MOFs have been loaded into polyacrylonitrile (PAN) nanofibers supported on polyethersulfone (PES). The visible light irradiation was used to investigate the influence of pH (2–10), initial concentration (10–500 mg L⁻¹), and time (5–240 min) on the removal efficiency of phenol and Cr(VI) in the presence of MOFs. The reaction time: 120 min, catalyst dosage: 0.5 g L⁻¹, pH: 2 for Cr(VI) ions and pH: 3 for phenol molecules were optimum to degrade phenol and to reduce Cr(VI) ions. The characterization of the produced samples was performed using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller analysis. The capability of synthesized photocatalytic membranes was investigated for the removal of phenol and Cr(VI) ions from water. The water flux, Cr(VI) and phenol solutions fluxes and their rejection percentages were evaluated under pressure of 2 bar in the presence of visible light irradiation and in the dark. The best performance of the synthesized nanofibers was obtained for UiO-66-NH₂/TiO₂ MOF 5 wt% loaded-PES/PAN nanofibrous membranes at temperature of 25 °C and pH of 3. Results demonstrated the high capability of MOFs-loaded nanofibrous membranes for the removal of various contaminants such as Cr(VI) ions and phenol molecules from water.