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Nanocapsule composites of C/Ce-co-doped ZnO supported on graphene synthesized by a one-pot hydrothermal method with a band gap of 2.72 eV were used to enhance the photodegradation of methylene blue under various conditions.

This study examined 16 sampling sites and detected a total of 16,122 marine litter items, which were identified and classified into 39 different types. Foam fragments ranging from 0.5 cm to 50 cm in size accounted for the majority of the litter at 68.4%. Plastic waste was found to be the most common type of litters, making up 95.86% of the total while paper, glass, and metal were present in smaller amounts. The sources of marine litter in the study area were attributed to three main sources: aquaculture and fishing activities (73%), municipal waste (13%), and unidentified sources (14%). Through field observations, it was found that the use of small boats with foam sheets as buoyancy materials, foam containers for storing and transporting seafood, and the use of foam materials in aquaculture are the primary contributors to plastic waste found on beaches.

In this study, the three-dimensional Delft3D-PART model was applied to study micro-plastics transport in the Bach Dang estuary. Micro-plastics as data input for the model in this study were assessed by taking water samples by 80 μm mesh size plankton net, and sediment samples by Petersen grab. The determination of input parameters for the micro-plastic transport model through averaging the particle characteristics of micro-plastics has been applied. Microplastics results appear in 10 water samples and 10 sediment samples surveyed. The results of micro-plastics in the water body of Bach Dang estuary presented that the regional tidal regime was closely related to the number of micro-plastics according to the season. In the wet season, the number of micro-plastics was around 2–3 nr/m3, spreading stronger than in the dry season.

Nanosized zinc oxide is an intriguing material that can be applied in various fields. In this study, Ce doped ZnO nano-catalysts (Ce-ZnO) were synthesized by two different methods (i.e., hydrothermal (Ce-ZnO-HT) and polymer gel combustion (Ce-ZnO-CB) methods) to compare their photodegradation efficiency. The prepared material characteristics were investigated using XRD, SEM, TEM, FTIR, UV-Vis, PL, XPS, EDS, and BET. The bandgap of both nanoparticles (NPs) was 2.95 eV, despite the fact that the morphology of Ce-ZnO-HT NPs was 1D-rod-shaped and that of Ce-ZnO-CB NPs was 0D-spherical. However, the surface area and oxygen vacancy rate of Ce-ZnO-HT NPs were higher than those of Ce-ZnO-CB NPs. These differences are directly related to the photocatalytic activity of Ce-ZnO NPs. Accordingly, the results showed that photocatalytic efficiency was classified in the order Ce-ZnO-HT > Ce-ZnO-CB > pure ZnO, and the photocatalytic reaction rate constant of Ce-ZnO-HT used to decompose MB was 3.0 times higher than that of Ce-ZnO-CB. Interestingly, the photodegradation mechanism study revealed that hydroxyl radicals and holes were shown to be more important contributors to methyl blue degradation than photo-induced electrons and superoxide radical ions.

BiTaO4 nanoparticles were successfully synthesized by the gel-combustion method using polyvinyl alcohol and freshly prepared precursor Ta2O5.nH2O. Materials were characterized by x-ray diffraction and transmission electron microscopy (TEM). With an average grain size of 30 nm, the prepared particle was used to investigate the photocatalytic capacity under the visible light irradiation. The photodegradation process of methyl orange occurred following the pseudo-first order reaction mechanism on the surface of the materials. BiTaO4 nanoparticles which calcined at 750°C presented the best catalytic capacity with the highest rate constant to degrade methyl orange about 5.43 × 10−2 mg l−1 min−1. Besides, the intermediates coming from the photocatalytic degradation of methyl orange were evaluated by liquid chromatography coupled with electrospray ionization ion-trap mass spectrometry (LC/MS). The results showed that the intermediates of degradation reactions of methyl orange were not more toxic than the initial methyl orange. BiTaO4 nanoparticles can mineralize the methyl orange after 60 min of illumination.

In this study, CeO2-Fe2O3 coated SiO2 nanoparticles were prepared by a sol–gel process. One of the prepared nanoparticles was applied in a formulation of polyurethane film for automotive applications. The loading of nanoparticle was varied between 0.1% and 2.0%. First, these films' properties were investigated by using FTIR and thermal gravimetric analysis. Next, these films were subjected to UV exposure testing. The structural changes were characterized by applying FTIR analysis and measuring water contact angle, gloss, and colour deviation. The results indicate that incorporating nanoparticles into the polymer matrix improves the UV-resistance properties of the polymer matrix. Additionally, the nanoparticles enhanced the polymer film's thermal stability until the temperature was 320 °C. Above this temperature, nanoparticles were catalytically active, which accelerated polymer's decomposition giving residue of lower weight percentage. Overall, polyurethane films with nanoparticle loading levels from 0.1 to 1.0 wt% gave the best UV-resistance performance.

Polyurethane (PU) coating degrades quickly under the irradiation of ultraviolet (UV). Thus, increasing the durability of the coating is necessary. In this study, porous CeO2-SiO2 nanocomposites (CS-NCs) were used to disperse into the PU matrix. The CS-NCs were prepared by a sol-gel combustion method using polyvinyl alcohol as precursors. Prepared nanocomposites were characterized by x-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) as well as Energy dispersive x-ray (EDX) mapping analysis. Next, the prepared nanocomposites were employed for the preparation of PU coatings. The loading of nanoparticles was varied between 0.1% and 2.0%. These coating properties were investigated by using FTIR and UV–vis spectroscopy. As also in this study, these coatings were subjected to UV exposure with accelerated weather testing. The structural changes were characterized by applying FTIR analysis and measuring gloss and color deviation. The results indicate that incorporating nanocomposites into the polymer matrix improves the UV-durable properties of the PU matrix.

The photocatalytic BiFeO3 perovskite nanoparticles were fabricated by gel combustion method using polyvinyl alcohol and corresponding metal nitrate precursors under the optimum mild conditions such as pH 2, gel formation temperature of 80 °C, metal/polyvinyl alcohol molar ratio of 1/3, metal molar ratio Bi/Fe of 1/1 and calcination temperature at 500 °C for 2 h. The prepared sample was characterized by x-ray diffraction, field scanning electron microscopy, transmission electron microscopy, Brunauer–Emmetl–Teller nitrogen adsorption method at 77 K, energy dispersive x-ray spectroscopy, ultraviolet-visible light spectrophotometry, and thermal analysis. The effects of molar ratios of starting material and calcination temperature on phase formation and morphology were investigated. The degradation of methylene blue, methylene orange and some toxic organic compounds such as phenol and diazinon under visible light irradiation by photocatalytic BiFeO3 nanoparticles were evaluated at different parameters and conditions such as the light intensity determined from the light source to the measured sample, the addition H2O2, reaction time and the regeneration performance. Obtained results showed that the synthesized perovskite BiFeO3 nanoparticles for the optimized sample have a size smaller than 50 nm and the high mean surface area of 50 m2 g−1. Degradation efficiency was almost 90.0% for methylene blue and 80.0% for methylene orange with added H2O2 after 30 min of reaction. After the 3rd time of regeneration, the BiFeO3 nanoparticles still have 92.8% of the degradation performance for removing methylene blue. Phenol and diazinon toxic compound were degraded with the performance of 92.42% and 85.7%, respectively, for 150 min