Polysulfone/N,Pd co-doped TiO2 composite membranes for photocatalytic dye degradation

Abstract

Hybrid multifunctional membranes capable of simultaneously performing photocatalysis and filtration can lead to improved water treatment processes. Transparent polymeric membranes exhibiting two surfaces that can come directly into contact with the polluted water can be desirable candidates for photocatalyst deposition. Different proportions of N,Pd co-doped TiO2 were embedded in a PSf polymeric membrane through the phase inversion method and the membrane evaluated for the degradation of a dye (eosin yellow) under visible light irradiation. The synthesised hybrid membranes were characterised by FTIR, Raman Spectroscopy, DRUV-Vis, SEM, EDS, XRD, AFM, SAXSpace and Contact angle measurements. Anatase type N,Pd co-doped TiO2 nanoparticles were successfully entrapped in the PSf membrane through a simple phase inversion method. Addition of TiO2 to the PSf membrane led to improved membrane porosity, wettability and visible light activity while membrane integrity was maintained. Higher TiO2 loadings resulted in increased membrane roughness and particle aggregation of the embedded TiO2. Up to 92% dye degradation was realised with the 7% N,Pd TiO2/PSf nanocomposite membrane after 180 min of visible light irradiation. Degradation kinetics followed a pseudo first order model, evidence of possible changes in the membrane properties upon irradiation with simulated solar radiation. Solar active photocatalytic membranes fabricated through embedding doped TiO2 nanoparticles are promising candidates for low energy water purification in marginalised rural communities.