Abstract:
Effective removal of toxic inorganic and organic pollutants is one of the current leading
challenges of wastewater treatment. In this study, the decomposition of methylene blue (MB) under UV light irradiation was investigated in the presence of copper nanoclusters (NCs)-deposited
polyethylene terephthalate (PET) track-etched hybrid membranes. PET track-etched membranes
(TeMs) with an average pore size of ~400 nm were grafted by functional acrylic acid (AA) monomer
under electron beam irradiation after oxidation with H2O2/UV system. The radiation dose varied between 46 and 200 kGy. For the deposition of copper NCs, poly(acrylic acid) (PAA)-grafted membranes
saturated with Cu(II) ions were irradiated either by electron beam or γ-rays to obtain copper-based
NCs for the catalytic degradation of MB. Irradiation to 100 kGy with accelerated electrons resulted
in the formation of small and uniform copper hydroxide (Cu(OH)2
) nanoparticles homogeneously
distributed over the entire volume of the template. On the other hand, irradiation under γ-rays
yielded composites with copper NCs with a high degree of crystallinity. However, the size of the
deposited NCs obtained by γ-irradiation was not uniform. Nanoparticles with the highest uniformity
were obtained at 150 kGy dose. Detailed analysis by X-ray diffraction (XRD) and scanning electron
microscopy (SEM) confirmed the loading of copper nanoparticles with an average size of 100 nm
on the inner walls of nanochannels and on the surface of PET TeMs. Under UV light irradiation,
composite membranes loaded with NCs exhibited high photocatalytic activity. It was determined
that the highest catalytic activity was observed in the presence of Cu(OH)2@PET-g-PAA membrane
obtained at 250 kGy. More than 91.9% of the initial dye was degraded when this hybrid membrane
was employed for 180 min, while only 83.9% of MB was degraded under UV light using Cu@PETg-PAA membrane. Cu(OH)2@PET-g-PAA membranes obtained under electron beam irradiation
demonstrated a higher photocatalytic activity compared to Cu@PET-g-PAA membranes attained by
γ-rays.
