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NaMgF 3 -based phosphors have been described frequently in the literature. Their synthesis faces difficulties typical of fluoride materials. A simple precipitation synthesis for NaMgF 3 -based phosphors is described in this paper. This consisted of mixing aq. NaF and MgCl 2 /MgSO 4 solutions. Various activators could be incorporated by adding the required salts during this process. Characteristic emission of the activators was observed in the prepared phosphors. As-prepared samples exhibited predominantly trivalent lanthanide emission. After thermal treatment in a reductive atmosphere, europium-doped samples showed the intense emission of Eu 2+ . By virtue of the intense nature of the emission, lifetime measurements could be made for this sample. Notably, intense thermoluminescence and optically stimulated luminescence were observed in NaMgF 3 :Eu. A simple, fast method for the synthesis of NaMgF 3 was therefore developed., (© 2021 John Wiley & Sons, Ltd.)

Sodium-rich iron hexacyanoferrates were prepared by coprecipitation, hydrothermal route, and under reflux, with or without dehydration. They were obtained with different structures described in cubic, orthorhombic, or rhombohedral symmetry, with variable compositions in sodium, water, and cationic vacancies and with a variety of morphologies. This series of sodium-rich Prussian blue analogues allowed addressing the relationship between synthesis conditions, composition, structure, morphology, and electrochemical properties in Na-ion batteries. A new orthorhombic phase with the Na 1.8 Fe 2 (CN) 6 ·0.7H 2 O composition synthesized by an hydrothermal route at 140 °C is reported for the first time, whereas a phase of Na 2 Fe 2 (CN) 6 ·2H 2 O composition obtained under reflux, previously described with a monoclinic structure, shows in fact a rhombohedral structure.

Hybrid magnetite/maghemite nanoparticles (MNP) coated with waste-sourced bio-based substances (BBS) were synthesized and studied for the degradation of phenol, chosen as a model pollutant, in water. A systematic study was undertaken in order to rationalize MNP-BBS behavior and optimize their performance. The effect of experimental parameters, such as light irradiation, addition of hydrogen peroxide, and the ratio between hydrogen peroxide and MNP-BBS concentrations, was studied. The generation of hydroxyl radicals was assessed, and the recovery and re-cycle of the material was investigated. Our results indicate that phenol degradation could be attained by both Fenton and photo-Fenton processes, with higher efficiency in dark condition and in the presence of a suitable amount of hydrogen peroxide. Evidence was obtained for the roles of iron ions leached from the materials as well as of organic matter released in the solution upon partial photodegradation of the organic coating. The reusability tests indicated a lower but still valid performance of the material. Optimization of the experimental conditions was performed to achieve the highest efficiency in substrate degradation, and fundamental insights into the mechanism of the MNP-BBS Fenton-like reaction were obtained.

Considerable efforts have been focused on the exploitation of macromolecule ligands for synthesis of magnetic Fe 3 O 4 nanoparticles as T 1 magnetic resonance imaging (MRI) contrast agents, but studies that concern macromolecule ligands with different charges and coordination groups are still limited. Herein, we used poly(acrylic acid) (PAA), poly(allylamine hydrochloride) (PAH), and polyvinyl alcohol (PVA), which possess negative, positive and neutral charges with carboxylic acid, amino and hydroxyl groups respectively, as templates and stabilizers to fabricate Fe 3 O 4 nanoparticles through coprecipitation reaction. The obtained Fe 3 O 4 -PAA, Fe 3 O 4 -PAH, and Fe 3 O 4 -PVA nanoparticles showed T 1 contrast performance with r 1 relaxivities of 23.4, 60.3, and 30.6 mM s -1 at 0.5 T (25 °C), and a r 2 / r 1 ratio of 2.62, 3.82, and 7.26, respectively. The cell viability assay revealed that Fe 3 O 4 -PAA and Fe 3 O 4 -PVA exhibited good biocompatibility, while Fe 3 O 4 -PAH displayed high cytotoxicity. In vivo T 1 -weighted (1 T) mice showed that both Fe 3 O 4 -PAA and Fe 3 O 4 -PVA were able to display remarkably brighten the contrast enhancement for the mice tumor and kidney sites, but Fe 3 O 4 -PAA had better contrast performance. This work highlights that the macromolecule ligands play an important role in the biocompatibility and T 1 contrast performance of magnetic Fe 3 O 4 nanoparticles.