Easily recyclable photocatalyst Bi2WO6/MOF/PVDF composite film for efficient degradation of aqueous refractory organic pollutants under visible-light irradiation

A novel composite film, Bi2WO6/MIL-53(Al)/PVDF, was successfully fabricated through a hydrothermal process combined with immersion phase inversion method and characterized by XRD, SEM, XPS, FTIR and UV-vis DRS techniques. The photocatalytic activity of the as-synthesized composite film was investigated through the degradation of dyes Rhodamine B (RhB), Methylene Blue and Malachite Green in water under visible-light irradiation. And the composite film prepared at the ratio of 6wt% of 1.25-BWO/MIL (with optimal ratio of Bi2WO6 to MIL-53(Al)) to poly(vinylidene fluoride) (PVDF) casting solution showed the highest photocatalytic activity. A 95.3% photocatalytic degradation of RhB was achieved at 1.6dm(2)/L of 6-BWO/MIL/PVDF dosage and 10mg/L of initial RhB concentration. The increased photocatalyst dosage, optimal initial RhB concentration and weak acidity should be responsible for the increased photocatalytic activity. The photocatalytic degradation mechanism was investigated by quenching tests, revealing that the predominant reactive species in the BWO/MIL/PVDF-RhBaq-visible light system were h(+), O sub arrange=stack 2