Functionalisation of electrospun polymer nanofibre membranes with TiO2 nanoparticles in view of dissolved organic matter photodegradation

In this study, polyamide-6 (PA-6) nanofibre membranes containing TiO2 nanoparticles were successfully prepared by electrospinning. Different types of TiO2 functionalisation methods (inline functionalisation and post-functionalisation) were tested with two types of TiO2 nanoparticles. A colloidal solution consisting of TiO2 nanoparticles with average dimensions of 6 nm was prepared and the performance of these nanoparticles was compared with commercially available Degussa P25 nanoparticles. The photocatalytic activity of the nanofibre membranes functionalised with TiO2 was demonstrated with the degradation of the dye methylene blue. The results of photodegradation with methylene blue in aqueous solution demonstrated excellent photocatalytic activity of TiO2 nanoparticles immobilised in and on the nanofibrous structure. After 2 h of UV irradiation, a degradation up to 84% methylene blue was observed. This degradation further increased and resulted in a degradation up to 99% methylene blue after 6 h of illumination. A stability test of the functional materials confirmed that the TiO2 nanoparticles were successfully incorporated in and onto the electrospun PA-6 fibres. Clean water flux was measured to find out the filter efficiency of the different membranes. The functionalised membranes have a clean water-flux varying from 1.0 × 104 to 2.1 × 104 l/m2 h bar. As such, the electrospun nanofibre membranes functionalised with TiO2 nanoparticles show a great potential as a water filter medium with an immobilised photocatalyst in view of dissolved organic matter degradation.