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In this work, two novel acridone-based photoinitiators were designed and synthesized for the free radical polymerization of acrylates with a light-emitting diode emitting at 405 nm. These acridone derivatives were employed as mono-component Type II photoinitiators and as multicomponent photoinitiating systems in the presence of an iodonium salt or an amine synergist (EDB) in which they achieved excellent polymerization initiating abilities and high final conversions of the acrylate group. Photoinitiation mechanisms through which reactive species are produced were investigated employing different complementary techniques including steady-state photolysis, steady-state fluorescence, cyclic voltammetry, UV–visible absorption spectroscopy, and electron spin resonance spectroscopy. Finally, these molecules were also used in the direct laser writing process for the fabrication of 3D objects. [ABSTRACT FROM AUTHOR]

Industrial wastewater discharge, tainted with hazardous substances, including dyes like methylene blue (MB) from the textile sector, further emphasizes the need for water treatment to produce safe drinking water. This study explores the potential of olive mill solid waste, an abundant and cost-effective agricultural waste in Mediterranean regions, to yield high-quality activated carbon (AC) with zinc chloride activation for MB adsorption. The activation process, carried out at a modest temperature of 500 °C without the need for an inert atmosphere, resulted in AC with remarkable characteristics, boasting a substantial surface area of 1184 cm2·g−1 and a total pore volume of 0.824 cm3·g−1. Extensive characterization of the AC was carried out through a large range of surface techniques. The pH of the solution had minimal influence on MB adsorption, the maximum removal was 95%, which was under slightly acidic pH conditions (5.8), and the adsorbent dose was 0.4 g·L−1 for a 50 mg·L−1 MB concentration. Equilibrium data pertaining to MB adsorption were subjected to fitting with different models, namely Langmuir, Freundlich, and Temkin. Notably, the Langmuir model exhibited the best fit, revealing a maximum monolayer adsorption capacity of 500 mg·g−1 at 25 °C, and the adsorption kinetics closely followed a pseudo-second-order model. [ABSTRACT FROM AUTHOR]

In this study, ultrasound treatment was used to exfoliate commercially available graphite flakes into reduced graphene oxide (rGO) dispersed in ethanol. After centrifugation, solid copper chloride trihydrate was added, resulting in a green liquor containing Cu(II), Cu(I), and rGO. These liquors exhibited good and rapid photocatalytic activity in the degradation of eosin and bromophenol blue dyes (elimination in a few seconds) under visible-light irradiation. UV–visible spectroscopy confirmed the presence of rGO and Cu species. The size and morphology of the rGO sheets were investigated by several methods (SAXS, wide-angle XRD, SEM, and TEM). Negative UV peaks indicated light emission, which was independently verified by fluorescence. Intense plasmon peaks, with absorbances greater than 10, were observed after adding copper chloride salt. These plasmons were eliminated by a high dilution before the described catalytic tests were performed. [ABSTRACT FROM AUTHOR]

In this study, the effective removal of three major micropollutants (e.g., propranolol hydrochloride, 1-naphthylamine, and 2-naphthol) from water is investigated using defected UiO-66 and functionalized derivatives as adsorbents. The defects in UiO-66 are induced using two distinct strategies. The first one involves a process of selectively thermolyzing labile linkers, leading to the creation of a hierarchical mesoporous framework (HP-UiO-66). The second technique employs monocarboxylic acid modulator, such as acetic acid (AA) or trifluoroacetic acid (TFA), which is coordinated with the Zr-clusters during synthesis and removed upon activation, resulting in the creation of defective UiO-66 structures. The influence they have on structural features of metal–organic framework (MOF) nanocrystals is compared to the ideal nonmodulated UiO-66 MOF. The samples are fully characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller surface area analyzer (BET), and thermogravimetric analysis (TGA). Their effectiveness as adsorbents for the elimination of 1-naphthylamine, propranolol hydrochloride, and 2-naphthol from water is examined. The thermodynamic and kinetic parameters of the adsorption process are determined. Interestingly, among the UiO-66 samples examined, HP-UiO-66 exhibits remarkable adsorption capacities of approximately 743, 602, and 409 mg g–1 for 1-naphthylamine, propranolol hydrochloride, and 2-naphthol, respectively. These values surpass all of the reported adsorbents in the literature. The surface interactions between HP-UiO-66 and the three micropollutants were demonstrated by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. This enhancement in adsorption performance is linked to the preferential adsorption mechanism, primarily by binding to coordinatively unsaturated zirconium atoms within the MOF structure. Through this study, an effective method for improving the adsorption capability of MOF-based adsorbents is presented through defects engineering in Zr-based MOFs. These findings open the path for the creation of effective MOF adsorbents for water treatment applications. [ABSTRACT FROM AUTHOR]

Catalysts enriched in Zinc ferrite (ZFO) were synthesized using coprecipitation and hydrothermal methods. Mixtures of crystalline nanoparticles (ZFO and α-Fe2O3, several allotropic varieties of FeO) were characterized by various techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM, SEM), N2 sorption, UV-visible spectrophotometry (UV-Vis) and X-ray photoelectron spectroscopy (XPS). After detailed characterizations, the catalytic performance of the solids (1 g/L) in the degradation of amoxicillin (AMX) (10 mg/L) as an antibiotic pollutant in water was evaluated. In addition, we used air as the oxygen source and adjusted the pH to 5.0. Consequently, the catalysts obtained via the hydrothermal method HT-ZFO had a high activity (100% of AMX removal in less than 100 min when an LED (75 W) light was used) compared to a similar mixture of oxides with graphene HT-ZFO-GO (a longer time of 150 min) that was necessary for the complete degradation of AMX. Impregnation with an aqueous solution containing 80 mg of GO obtained using Hummer's method, reduced into RGO by an ultrasound treatment, enhances the initial reaction rate but is associated with a prolonged time for complete AMX removal (10 ppm in water) that we attribute to its spontaneous corrosion. [ABSTRACT FROM AUTHOR]

Semiconductor oxides such as titanium dioxide (TiO2) have been used as photocatalysts for removing contaminants. In addition, TiO2 nanoparticles in suspension form are difficult to recover and recycle, and they are expensive. In our work, titanium dioxide has been immobilized on a commercially available, thermally stable, chemically stable, and cheap polymer. The nanocomposite is synthesized with varying percentages of TiO2, 0.25, 0.5, and 1 weight percent. The obtained nanocomposites were characterized, and the effect of the process parameter (i. e., initial concentration of MB, amount of catalyst, light wavelength, and power of light) was investigated. Also, the results show good photodegradation of MB by the TiO2‐epoxy nanocomposite. The decomposition of 10 ppm methylene blue (MB) during 200 min under 25 W visible LED irradiation can reach 95 %. This value is higher than that obtained with pristine TiO2, which does not have photocatalytic activity under LED light. The antibacterial activity of nanocomposites concerning Escherichia coli and Stephalocous aureus was studied, and an inhibition zone of 2 cm and 3.5 cm was obtained, respectively. Therefore, the TiO2‐epoxy nanocomposite was applied to a glass jar and tested after four months for the degradation of methylene blue (5 ppm) and methyl orange (8 ppm) under sunlight. The paint demonstrated good photocatalytic efficiency of 41 % and 72 % within 310 min, respectively. [ABSTRACT FROM AUTHOR]

Herein, visible light‐driven gas‐phase photocatalytic CO2 reduction into CH4 is tuned by designing optimized three‐component Au/doped C3N4/TiO2 composite photocatalysts. The key point strategy consists in the formation of high‐quality C3N4/TiO2 heterojunction by associating low containing doped graphitic carbon nitride to commercially available TiO2 UV‐100. Those heterojunctions result in both visible light sensitization and increased charge‐carrier separation. Further deposition of small Au nanoparticles (≈3 nm), quite exclusively onto TiO2 surfaces, mainly acts as electron trapping/cocatalytic functions without excluding surface plasmonic effects. The resulting doped g‐C3N4 material exhibits enhanced visible light harvesting properties, especially in the case of C‐doping. In addition, it is assumed that B– and C–C3N4 doping, leading to a more or less lower conduction band position, is the impacting factor toward total CH4 selectivity achievement. The (0.77 wt%)Au/(0.59 wt%)C–C3N4/TiO2 composite photocatalyst, exhibiting the best compromise between the various impacting factors, leads to a continuous productivity rate of CH4 of 8.5 μmol h−1 g−1 under visible light irradiation over at least 10 h. To the best of knowledge, this level of performance is unprecedented under continuous gas‐phase flowing CO2 in the presence of water as reducing agent, without addition of any sacrificial agent. [ABSTRACT FROM AUTHOR]