Immobilization of TiO2 and TiO2-GO hybrids onto the surface of acrylic acid-grafted polymeric membranes for pollutant removal: Analysis of photocatalytic activity

Abstract

The nanocomposite titania@graphene oxide (TiO2-GO) hybrids were prepared to achieve the photocatalysis synergy after they were immobilized onto the surface of hydrophobic microporous poly(vinylidene fluoride) (PVDF) membranes. The immobilization of TiO2 and TiO2-GO hybrids was followed after the membrane was plasma-activated and was grafted with acrylic acid (AA). The crystal structure, morphology, chemical composition, and hydrophilicity of such photocatalytic membranes were analyzed. The rate of the recombination of electron-hole pairs generated by the composite membranes under UV irradiation was also determined from electrochemical impedance spectra and photocurrent measurements. The photocatalytic activity of TiO2 and TiO2-GO hybrids on the membranes was examined under UV illumination, particularly at different AA concentrations in the grafting solution (20, 30, and 40 vol% in isopropanol) and different compositions of the TiO2-GO hybrids (0, 25, 50, and 75 wt.% of GO. It was shown that the AA concentration played a crucial role in the attachment of the nanoparticles, and the prepared TiO2-GO nanocomposite membranes presented a largely enhanced photocatalytic activity than the freely suspended catalyst particles.