Photocatalytic PVDF ultrafiltration membrane blended with visible-light responsive Fe(III)-TiO2 catalyst: Degradation kinetics, catalytic performance and reusability

A novel Fe(III)-TiO2/polyvinylidene fluoride (PVDF) composite ultrafiltration (UF) membrane was prepared by using phase inversion method. The structural characteristics, as well as the photocatalytic, antifouling and reusability properties, of composite membranes were investigated. Our results showed that the reaction of bisphenol-A (BPA) degradation fitted the pseudo-second-order kinetics models. The Fe-TiO2/PVDF-0.10 composite membrane achieved a higher BPA degradation efficiency (69.9%) within reaction time of 180 min than pristine PVDF membrane 45.1%. The quenching tests and ESR results confirmed the dominant role of hole (h(+)) and O-center dot(2)- as active species responsible for BPA degradation in the photocatalytic system. Combing pathway of photocatalytic degradation of BPA and quantitative structure activity relationship (QSAR) analysis indicated decline in toxicity of most intermediates compared with BPA. Additionally, the composite membrane also exhibited a higher permeation flux (585 L.m(-2).h(-1)) and water flux recovery rate (>70%) under simulated visible-light irradiation, indicating better antifouling property of the membrane. Moreover, excellent durability and reusability were demonstrated by a insignificant loss of photocatalytic efficiency losses (4%) after 9-cycle operation. The incorporation of Fe(III)-TiO2 could improve physical and chemical properties of UF membrane in terms of hydrophilicity, mechanical properties and thus photocatalytic anti-fouling performance, which broadens the application field of membrane filtration technology.

Automated summary

The Fe(III)-TiO2/PVDF composite ultrafiltration membrane demonstrates high efficiency in BPA degradation and antifouling performance, with hole (h(+)) and O-center dot(2)- identified as the active species in the photocatalytic system. The membrane also shows high permeation flux and water flux recovery rate, excellent durability, and reusability, making it a promising option for membrane filtration technology.