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Fluorine possesses remarkable properties that ensure its enduring and indispensable role in both academic and industrial development across diverse domains of our daily lives. Nevertheless, fluorine has become a growing environmental concern, leading to the consideration of molecular fluorine (F2) as an alternative fluorinating agent due to its low environmental impact compared to hydrofluorocarbons (HFCs) or perfluorinated compounds (PFCs). However, its pronounced toxicity, corrosiveness, and hazardous nature are problematic when handling F2 gas cylinders. Solid storage through chemisorption via the CeF4/CeF3 transformation appears to be a promising approach to overcome its intrinsic problems. This article introduces a fundamental study exploring the impact of the chemical composition of precursor materials, CeF3 or CeO2, and the nanostructuration in the form of nanoparticles or macroporous structures on fluorination/defluorination temperatures, redox process reversibility, and the nature of the released gas, a parameter not systematically examined in previous studies. Through a deep investigation via X-ray diffraction (XRD) and electron microscopies (SEM, TEM), we demonstrate the benefit of both the pristine phase (CeO2) and the nanostructuration into a macroporous structure (OPIF) on the limitation of crystalline growth during the fluorination process. The defluorination process, monitored by TGA and gas-phase IR spectroscopy, revealed that when CeO2-OPIF undergoes fluorination to form CeF4 followed by consecutive vacuum defluorination without exposure to ambient air, incomplete decomposition of CeF4 into CeF3 results in the partial release of F2. Conversely, exposure of the fluorinated material to air results in partial formation of a hydrate, CeF4·0.33H2O, confirmed by solid-state NMR, and promotes the defluorination (enhanced yield and release kinetics) through the formation of CeF3 with both HF and F2 release, increasing the cyclability performance from 1 cycle to at least 8 cycles. [ABSTRACT FROM AUTHOR]

To date, there is still a lack of definite knowledge regarding the toxicity of Cu(OH)2 nanoparticles towards bacteria. This study was aimed at shedding light on the role played by released cupric ions in the toxicity of nanoparticles. To address this issue, the bactericidal activity of Cu(OH)2 was at first evaluated in sterile water, a medium in which particles are not soluble. In parallel, an isovalent substitution of cupric ions by Mg2+ was attempted in the crystal structure of Cu(OH)2 nanoparticles to increase their solubility and determine the impact on the bactericidal activity. For the first time, mixed Cu1−xMgx(OH)2 nanorods (x ≤ 0.1) of about 15 nm in diameter and a few hundred nanometers in length were successfully prepared by a simple co-precipitation at room temperature in mixed alkaline (NaOH/Na2CO3) medium. For E. coli, 100% reduction of one million CFU per mL (6 log10) occurs after only 180 min on contact with both Cu(OH)2 and Cu0.9Mg0.1(OH)2 nanorods. The entire initial inoculum of S. aureus is also killed by Cu(OH)2 after 180 min (100% or 6 log10 reduction), while 0.01% of these bacteria stay alive on contact with Cu0.9Mg0.1(OH)2 (99.99% or 4 log10 reduction). The bactericidal performances of Cu(OH)2 and the magnesium-substituted counterparts (i.e. Cu1−xMgx(OH)2) are not linked to cupric ions they release in water since their mass concentrations after 180 min are much lower than minimal concentrations inhibiting the growth of E. coli and S. aureus. Finally, an EPR spin trapping study reveals how these nanorods kill bacteria in water: only the presence of hydrogen peroxide, a by-product of the normal metabolism of oxygen in aerobic bacteria, allows the Cu(OH)2 and its magnesium-substituted counterparts to produce a lethal amount of free radicals, the majority of which are the highly toxic HO˙. [ABSTRACT FROM AUTHOR]

The successful preparation of organized porous inorganic fluorides (OPIFs) with a high specific surface area is demonstrated for MgF2. For the first time, macroporous MgF2 OPIFs with a surface area of above 200 m2 g–1 and mesoporous MgF2 powder were prepared through the assembly of preformed MgF2 nanoparticles and homemade polymer templates with a tunable size. These OPIF materials have been fully examined at different synthesis stages by means of powder X-ray diffraction, N2 sorption, scanning electron microscopy, and transmission electron microscopy analyses and 19F and 1H solid-state nuclear magnetic resonance. The relation between the nature, the size, and the amount of polymer template on the porous structure was deeply investigated. The MgF2 OPIFs present a higher thermal stability under air and F2 calcination than MgF2 nanoparticles as the structuration of the OPIF composite considerably slows down the crystallite growth during thermal treatment under air. OPIF materials were evaluated as heterogeneous catalysts for the fluorination of 2-chloropyridine under HF gas as a fluorinating agent at 350 °C. This study evidences catalytic sites with two Lewis acidity strengths (medium and low). [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO2 (CO2RR) driven by renewable energy has gained increasing attention for sustainable production of chemicals and fuels. Catalyst design to overcome large overpotentials and poor product selectivity remains however challenging. Sn/SnOx and In/InOx composites have been reported active for CO2RR with high selectivity toward formate formation. In this work, the CO2RR activity and selectivity of metal/metal oxide composite nanoparticles formed by in situ reduction of bimetallic amorphous SnInOx thin films are investigated. It is shown that during CO2RR the amorphous SnInOx pre‐catalyst thin films are reduced in situ into Sn1–XInX@In1–YSnYOz core@shell nanoparticles composed of Sn‐rich SnIn alloy nanocores (with x < 0.2) surrounded by InOx‐rich bimetallic InSnOx shells (with 0.3 < y < 0.4 and z ≈ 1). The in situ formed particles catalyze the CO2RR to formate with high faradaic efficiency (80%) and outstanding formate mass activity (437 A gIn+Sn−1 @ −1.0 V vs RHE in 0.1 m KHCO3). While extensive structural investigation during CO2RR reveals pronounced dynamics in terms of particle size, the core@shell structure is observed for the different electrolysis conditions essayed, with high surface oxide contents favoring formate over hydrogen selectivity. [ABSTRACT FROM AUTHOR]

Water-soluble polymers with the ability to complex metal ions through complexing ligands have attracted significant interest in diverse domains, such as optical or catalyst applications. In this paper, we successfully synthesized, through a one-pot process combining polymerization-induced self-assembly and reversible addition-fragmentation chain transfer polymerization, aqueous dispersions of terpyridine-decorated poly[poly(ethylene glycol)methyl ether methacrylate]- b -poly(methyl methacrylate) (tpy-PPEGMA- b -PMMA) amphiphilic block copolymers. The in-situ formation of well-defined amphiphilic block copolymers and their self-assembly led to nanosphere latex with the hydrodynamic diameters increasing from 17 to 52 nm and the length of the copolymers increasing from 21,000 to 51,000 g·mol -1 . These aqueous dispersed tpy-PPEGMA- b -PMMA nanospheres effectively complex metal ions, such as Cu 2+ , in a stoichiometric ratio of 2:1. Subsequently, these metal-complexed nanospheres were employed as soft template nanocarriers to control, on the nanometer scale, the dispersion of metal on a nanostructured support. This is exemplified by the synthesis of copper supported on cerium oxide hollow spheres (Cu-CeO 2 ) using Cu 2+ -tpy-PPEGMA- b -PMMA as template nanocarriers and CeO 2 nanoparticles. This novel assembly engineering strategy for the preparation of atomically dispersed metal on a nanostructured support was highlighted through the utilization of Cu-CeO 2 hollow spheres as an electrocatalyst for the nitrate reduction reaction (NO 3 RR) to NH 3 . These encouraging outcomes emphasize the potential of metal-metal oxide-nanostructured materials to treat contaminated water sources with nitrate while allowing the green production of ammonia.

To date, there is still a lack of definite knowledge regarding the toxicity of Cu(OH) 2 nanoparticles towards bacteria. This study was aimed at shedding light on the role played by released cupric ions in the toxicity of nanoparticles. To address this issue, the bactericidal activity of Cu(OH) 2 was at first evaluated in sterile water, a medium in which particles are not soluble. In parallel, an isovalent substitution of cupric ions by Mg 2+ was attempted in the crystal structure of Cu(OH) 2 nanoparticles to increase their solubility and determine the impact on the bactericidal activity. For the first time, mixed Cu 1- x Mg x (OH) 2 nanorods ( x ≤ 0.1) of about 15 nm in diameter and a few hundred nanometers in length were successfully prepared by a simple co-precipitation at room temperature in mixed alkaline (NaOH/Na 2 CO 3 ) medium. For E. coli , 100% reduction of one million CFU per mL (6 log 10 ) occurs after only 180 min on contact with both Cu(OH) 2 and Cu 0.9 Mg 0.1 (OH) 2 nanorods. The entire initial inoculum of S. aureus is also killed by Cu(OH) 2 after 180 min (100% or 6 log 10 reduction), while 0.01% of these bacteria stay alive on contact with Cu 0.9 Mg 0.1 (OH) 2 (99.99% or 4 log 10 reduction). The bactericidal performances of Cu(OH) 2 and the magnesium-substituted counterparts ( i.e. Cu 1- x Mg x (OH) 2 ) are not linked to cupric ions they release in water since their mass concentrations after 180 min are much lower than minimal concentrations inhibiting the growth of E. coli and S. aureus . Finally, an EPR spin trapping study reveals how these nanorods kill bacteria in water: only the presence of hydrogen peroxide, a by-product of the normal metabolism of oxygen in aerobic bacteria, allows the Cu(OH) 2 and its magnesium-substituted counterparts to produce a lethal amount of free radicals, the majority of which are the highly toxic HO˙.

High-specific-surface-area MgF 2 was prepared by microwave-assisted solvothermal synthesis. The influences of the solvent and the magnesium precursors, and the calcination atmospheres, on the nanoparticle sizes and specific surface areas, estimated by X-Ray Powder Diffraction, N 2 sorption and TEM analyses, were investigated. Nanocrystallized (~7 nm) magnesium partially hydroxylated fluorides (MgF 2-x (OH) x ) with significant specific surface areas between 290 and 330 m 2 ∙g -1 were obtained. After activation under gaseous HF, MgF 2-x (OH) x catalysts underwent a large decrease of both their surface area and their hydroxide, rates as shown by their 19 F and 1 H solid-state NMR spectra. Expect for MgF 2 prepared from the acetate precursor, an activity of 30-32 mmol/h∙g was obtained which was about 40% higher compared with that of MgF 2 prepared using Trifluoroacetate method (21.6 mmol/h∙g).