The extremely high levels of water pollution caused by various industrial activities represent one of the most important environmental problems. Efficient techniques and advanced materials have been extensively developed for the removal of highly toxic organic pollutants, including pesticides. This study investigated the photocatalytic degradation of the fungicide carbendazim (Czm) using composite track-etched membranes (TeMs) in an aqueous solution. Copper(I) oxide (Cu₂O) and zinc oxide (ZnO) microtubes (MTs) were prepared using an electroless template deposition technique in porous poly(ethylene terephthalate) (PET) TeMs with nanochannels with a density of 4 × 10⁷ pores/cm⁻² and diameter of 385 ± 9 nm to yield Cu₂O@PET and ZnO@PET composite membranes, respectively. A mixed Cu₂O/ZnO@PET composite was prepared via a two-step deposition process, containing ZnO (87%) and CuZ (13%) as crystalline phases. The structure and composition of all composite membranes were elucidated using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. Under UV–visible light irradiation, the Cu₂O/ZnO@PET composite displayed enhanced photocatalytic activity, reaching 98% Czm degradation, higher than Cu₂O@PET and ZnO@PET composites. The maximum Czm degradation efficiency from aqueous solution was obtained at an optimal pH of 6 and contact time of 140 min. The effects of various parameters such as temperature, catalyst dosage and sample exposure time on the photocatalytic degradation process were studied. The degradation reaction of Czm was found to follow the Langmuir–Hinshelwood mechanism and a pseudo-first order kinetic model. The degradation kinetics of Czm accelerated with increasing temperature, and the activation energy (E_a) levels were calculated as 11.9 kJ/mol, 14.22 kJ/mol and 15.82 kJ/mol for Cu₂O/ZnO@PET, ZnO@PET and Cu₂O@PET composite membranes, respectively. The reusability of the Cu₂O/ZnO@PET catalyst was also investigated at different temperatures for 10 consecutive runs, without any activation or regeneration processes. The Cu₂O/ZnO@PET composite exhibited degradation efficiency levels of over 50% at 14 °C and over 30% at 52 °C after 5 consecutive uses.

Nanoporous track-etched membranes (TeM) are promising materials as adsorbents to remove toxic pollutants, but control over the pore diameter and density in addition to precise functionalization of nanochannels is crucial for controlling the surface area and efficiency of TeMs. This study reported the synthesis of functionalized PET TeMs as high-capacity sorbents for the removal of trivalent arsenic, As(III), which is more mobile and about 60 times more toxic than As(V). Nanochannels of PET-TeMs were functionalized by UV-initiated reversible addition fragmentation chain transfer (RAFT)-mediated grafting of 2-(dimethyamino)ethyl methacrylate (DMAEMA), allowing precise control of the degree of grafting and graft lengths within the nanochannels. Ag NPs were then loaded onto PDMAEMA-g-PET to provide a hybrid sorbent for As(III) removal. The As(III) removal efficiency of Ag@PDMAEMA-g-PET, PDMAEMA-g-PET, and pristine PET TeM was compared by adsorption kinetics studies at various pH and sorption times. The adsorption of As(III) by Ag@DMAEMA-g-PET and DMAEMA-g-PET TeMs was found to follow the Freundlich mechanism and a pseudo-second-order kinetic model. After 10 h, As(III) removal efficiencies were 85.6% and 56% for Ag@PDMAEMA-g-PET and PDMAEMA-g-PET, respectively, while PET template had a very low arsenic sorption capacity of 17.5% at optimal pH of 4.0, indicating that both PDMAEMA grafting and Ag-NPs loading significantly increased the As(III) removal capacity of PET-TeMs.

In this study, the use of composite track-etched membranes (TeMs) based on polyethylene terephthalate (PET) and electrolessly deposited silver microtubes (MTs) for the decomposition of toxic phenothiazine cationic dye, methylene blue (MB), under visible light was investigated. The structure and composition of the composite membranes were elucidated by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction technique. Under visible light irradiation, composite membrane with embedded silver MTs (Ag/PET) displayed high photocatalytic efficiency. The effects of various parameters such as initial dye concentration, temperature, and sample exposure time on the photocatalytic degradation process were studied. The decomposition reaction of MB was found to follow the Langmuir–Hinshelwood mechanism and a pseudo-first-order kinetic model. The degradation kinetics of MB accelerated with increasing temperature and activation energy, E_a, was calculated to be 20.6 kJ/mol. The reusability of the catalyst was also investigated for 11 consecutive runs without any activation and regeneration procedures. The Ag/PET composite performed at high degradation efficiency of over 68% after 11 consecutive uses.

In this study, the potential of biogenic zinc oxide nanoparticles (ZnO NPs) in the removal of alizarin yellow R (AY) from aqueous solutions by photocatalytic degradation, as well as adsorption, was investigated. The synthesized ZnO NPs were prepared by the simple wet-combustion method using the plant extract of Serratula coronata L. as a reducing and stabilizing agent and characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy. Photocatalytic degradation of AY was monitored by UV–visible spectroscopy and the effects of parameters, such as light source type (UV-, visible- and sunlight), incubation time, pH, catalyst dosage and temperature on degradation were investigated. It was demonstrated that the source of light plays an important role in the efficiency of the reaction and the UV-assisted degradation of AY was the most effective, compared to the others. The degradation reaction of AY was found to follow the Langmuir-Hinshelwood mechanism and a pseudo-first-order kinetic model. The degradation kinetics of AY accelerated with increasing temperature, and the lowest activation energy (E_a) was calculated as 3.4 kJ/mol for the UV-light irradiation system, while the E_a values were 4.18 and 7.37 kJ/mol for visible light and sunlight, respectively. The dye removal by the adsorption process was also affected by several parameters, such as pH, sorbent amount and contact time. The data obtained in the kinetics study fit the pseudo-second-order equation best model and the rate constant was calculated as 0.001 g/mg·min. The isotherm analysis indicated that the equilibrium data fit well with the Freundlich isotherm model. The maximum adsorption capacity of AY on biogenic ZnO NPs was 5.34 mg/g.

This paper reports the synthesis of composite track-etched membranes (TeMs) modified with electrolessly deposited copper microtubules using copper deposition baths based on environmentally friendly and non-toxic reducing agents (ascorbic acid (Asc), glyoxylic acid (Gly), and dimethylamine borane (DMAB)), and comparative testing of their lead(II) ion removal capacity via batch adsorption experiments. The structure and composition of the composites were investigated by X-ray diffraction technique and scanning electron and atomic force microscopies. The optimal conditions for copper electroless plating were determined. The adsorption kinetics followed a pseudo-second-order kinetic model, which indicates that adsorption is controlled by the chemisorption process. A comparative study was conducted on the applicability of the Langmuir, Freundlich, and Dubinin–Radushkevich adsorption models to define the equilibrium isotherms and the isotherm constants for the prepared composite TeMs. Based on the regression coefficients R², it has been shown that the Freundlich model better describes the experimental data of the composite TeMs on the adsorption of lead(II) ions.

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@PET-g-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.