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This work demonstrates that the packaging material commonly called "bubble wraps" (Aeroplast) can be leveraged to serve as a probe to visible sunlight exposure. This probe relies on a newly developed layered metal selenide photocatalyst with the general formula (DMAH)2xMnxSn3–xSe6 (DMSe‐1) (x = 1.3–1.7; DMAH+ = dimethylammonium), featuring a narrow bandgap of 0.76 eV, in addition to an indicator dye and a reducing agent. The photochemically sensitive probe is introduced into the air‐filled compartments of bubble wraps and undergoes photocatalytic degradation, resulting in a chromatic response to sunlight exposure. The probe's sensitivity to variable irradiation doses can be adjusted by varying the amount of the photocatalyst. The color intensity correlates with the absorbed irradiation dose, allowing for qualitative assessment by the naked eye or quantitative measurement using the RGB color system. The results obtained from the new probe agree with those obtained from standard sunlight pyranometers (r = 0.98), with an average error of <15%. This suggests that beyond their use as protective coatings, bubble wraps can be successfully repurposed as visible light sensors. Furthermore, this study describes the initial use of metal chalcogenides as visible light probes, potentially paving the way for the development of innovative light‐sensitive materials. [ABSTRACT FROM AUTHOR]

Photocatalysis is a prominent alternative wastewater treatment technique that has the potential to completely degrade pesticides as well as other persistent organic pollutants, leading to detoxification of wastewater and thus paving the way for its efficient reuse. In addition to the more conventional photocatalysts (e.g., TiO2, ZnO, etc.) that utilize only UV light for activation, the interest of the scientific community has recently focused on the development and application of visible light-activated photocatalysts like g-C3N4. However, some disadvantages of g-C3N4, such as the high recombination rate of photogenerated charges, limit its utility. In this light, the present study focuses on the synthesis of WO3 fibers/g-C3N4 Z-scheme heterojunctions to improve the efficiency of g-C3N4 towards the photocatalytic removal of the widely used insecticide clothianidin. The effect of two different g-C3N4 precursors (urea and thiourea) and of WO3 fiber content on the properties of the synthesized composite materials was also investigated. All aforementioned materials were characterized by a number of techniques (XRD, SEM-EDS, ATR-FTIR, Raman spectroscopy, DRS, etc.). According to the results, mixing 6.5% W/W WO3 fibers with either urea or thiourea derived g-C3N4 significantly increased the photocatalytic activity of the resulting composites compared to the precursor materials. In order to further elucidate the effect of the most efficient composite photocatalyst in the degradation of clothianidin, the generated transformation products were tentatively identified through UHPLC tandem high-resolution mass spectroscopy. Finally, the detoxification effect of the most efficient process was also assessed by combining the results of an in-vitro methodology and the predictions of two in-silico tools. [ABSTRACT FROM AUTHOR]

In the present study, the photocatalytic oxidation and detoxification of aqueous matrices contaminated with boscalid using g-C3N4 catalyst and UV-A light was investigated. The UV-A/g-C3N4 process was found to achieve higher than 83% removal of boscalid in both matrices, with h+ and O 2 • − being the main species. UHPLC-HRMS analysis allowed the identification of five TPs, while the main degradation pathways involved hydroxylation, cyclization, and dechlorination. Scenedesmus rubescens microalgae species was exposed to boscalid solutions and lake water spiked with the fungicide before the photocatalytic treatment and inhibition in the growth rate was observed. An increase in the toxicity was also observed during the first stages of the treatment. The results from the in silico study correlate with the observed evolution of ecotoxicity during the application of the process, as some of the identified TPs were found to be toxic or very toxic for aquatic organisms. However, prolonged application of the process can lead to detoxification. It was also observed that the g-C3N4 catalyst can retain its photochemical stability and activity after at least three cycles. However, a slight decrease in the activity was observed when repeated another two times. This study demonstrated that the suggested photocatalytic process can both decrease the harmful effects of boscalid as well as effectively lower its concentration in water. [ABSTRACT FROM AUTHOR]

The valorization of food industry byproducts has become a significant issue worldwide because of the drive towards a circular economy. The "zero waste target" in human activities seems to be a dominant objective in the design of future products by enterprises. In this work, food waste from the crayfish processing industry was converted into useful products (quantum dots), as nowadays, biowaste-derived materials tend to be more attractive than conventionally produced materials with a similar structure due to their lower production costs and environmentally friendly development processes. More specifically, shell waste from the crayfish industry was treated hydrothermally and, after a freeze-drying process, was transformed to useful quantum dots. Instrumental and chemical techniques, such as XRD, SEM-EDS, AFM, XPS, elemental analysis, fluorescence spectroscopy, TG, Microtox bioassay, and DPPH antioxidant activity, were employed to characterize the final product. The results indicated the existence of thermally stable spherical particles, with a diameter of 5–8 nm, which were mainly composed of carbon, oxygen, nitrogen, calcium, and sulfur. Their external surface was rough and rich with various functional groups that further contributed to their overall optical properties. The final product presented low ecotoxicity, as studied by the Microtox assay. The superior antioxidant activity of this product compared to other similar materials reported elsewhere renders it a potential material for, e.g., food packaging applications. In addition, for the first time, N/S-Carbon QDs were applied as an antioxidant/antibacterial agent for strawberry preservation, showing promising results as the coated strawberries maintained their color and weight for three consecutive days with no mold growth observed on their surface. [ABSTRACT FROM AUTHOR]

The presence of pharmaceuticals in water is a problem of utmost importance due to the various adverse effects that these compounds may have on aquatic organisms and also humans. Since conventional wastewater treatment plants fail to efficiently remove many of these compounds, new techniques such as heterogeneous photocatalysis have been developed that are capable of degrading them. In this study, graphitic carbon nitride (g-C3N4) was used as photocatalyst to remove metronidazole (MTZ), which is a widely prescribed antibiotic that has been reported as a potential carcinogen. The experiments were performed under lab and pilot scale conditions. During the lab scale experiments, 90.6% of the initial pharmaceutical concentration was removed after 360 min of irradiation and its removal followed a pseudo first order kinetic model with a degradation rate constant of k = 0.00618 min−1. Moreover, scavenging studies indicated that the indirectly produced hydroxy radicals contribute very little to the degradation mechanism. Through high precision mass spectrometry techniques, eight transformation products (TPs) were identified, and possible transformation pathways were suggested. Similarly, in the case of pilot scale experiments, 100 and 200 mg L−1 of g-C3N4 were used and the antibiotic's removal also followed pseudo first order kinetics with k = 0.00827 min−1 and k = 0.00942 min−1, respectively. However, starting from low level inherent concentrations, only two TPs were identified. By using in silico tools (ECOSAR and T.E.S.T.), various ecotoxicological values were predicted for the TPs, which were generally found to be less toxic than the parent compound and with lower mutagenic and bioaccumulative potential. Moreover, the monitoring of the ecotoxicity with the in vitro Microtox bioassay showed that at the end of all the photocatalytic processes, the toxicity was reduced. In conclusion, this technique could have the potential to remove MTZ and other similar pharmaceuticals in full-scale applications. However, for this to happen with the highest possible efficiency, further studies must be conducted, focusing on improving the catalyst's performance and reusability, improving the separation of catalyst as well as finding the optimum conditions for this process. [ABSTRACT FROM AUTHOR]

BACKGROUND: During the last few years, perovskite materials have been widely investigated as catalysts for peroxymonosulfate (PMS) and persulfate (PS) activation in advanced oxidation processes (AOPs) for the degradation of various pollutants. In the present work, a sequence of LaCoxNi1‐xO3 (x = 0, 0.25, 0.50, 0.75, 1) perovskite materials was synthesized by sol–gel method using glycolic acid ethoxylate lauryl ether anionic surfactant as soft template. RESULTS: The physicochemical properties of the prepared materials were studied by several techniques, such as N2 porosimetry, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT‐IR), X‐Ray Diffraction (XRD), X‐Ray Fluorescence (XRF), X‐Ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). The catalytic activity towards phenolic degradation by persulfate (PS) activation was studied and, based on the reaction rate constant values, the order of increasing catalytic performance was LaCoO3 < LaCo0.75Ni0.25O3 < LaCo0.5Ni0.5O3 < LaCo0.25Ni0.75O3 < LaNiO3. The perovskites that exhibited optimal catalytic activity (i.e., LaCo0.25Ni0.75O3 and LaNiO3) were further evaluated for their stability, reusability, and catalytic mechanism. Finally, according to scavenging experiments, 1O2, SO4•‐, and •OH generated with 1O2 played the dominant role in phenolic degradation. CONCLUSION: The substitution of Co by Ni in LaCoO3 materials showed an increase in their catalytic activity towards phenolic oxidation through persulfate activation. The results provide insights into the characterization and mechanisms of novel perovskite catalysts and their applications for the removal of organic pollutants by advanced oxidation processes (AOPs). Further studies improving the stability and reusability of the catalysts should be conducted. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]