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Electronic structure modulation of active sites is critical important in Fenton catalysis as it offers a promising strategy for boosting H 2 O 2 activation. However, efficient generation of hydroxyl radicals (•OH) is often limited to the unoptimized coordination environment of active sites. Herein, we report the rational design and synthesis of iron oxyfluoride (FeOF), whose iron sites strongly coordinate with the most electronegative fluorine atoms in a characteristic moiety of F-(Fe(III)O 3 )-F, for effective H 2 O 2 activation with potent •OH generation. Results demonstrate that the fluorine coordination plays a pivotal role in lowering the local electron density and optimizing the electronic structures of iron sites, thus facilitating the rate-limiting H 2 O 2 adsorption and subsequent peroxyl bond cleavage reactions. Consequently, FeOF exhibits a significant and pH-adaptive •OH yield (~450 µM) with high selectivity, which is 1 ~ 3 orders of magnitude higher than the state-of-the-art iron-based catalysts, leading to excellent degradation activities against various organic pollutants at neutral condition. This work provides fundamental insights into the function of fluorine coordination in boosting Fenton catalysis at atomic level, which may inspire the design of efficient active sites for sustainable environmental remediation. Electronic structure modulation of active sites is critical important in Fenton catalysis. Herein, the authors report that the iron oxyfluoride involving fluorine coordination to iron sites, can effectively activate H 2 O 2 into •OH for water treatment.

The rapid market growth of rechargeable batteries requires electrode materials that combine high power and energy and are made from earth-abundant elements. Here we show that combining a partial spinel-like cation order and substantial lithium excess enables both dense and fast energy storage. Cation overstoichiometry and the resulting partial order is used to eliminate the phase transitions typical of ordered spinels and enable a larger practical capacity, while lithium excess is synergistically used with fluorine substitution to create a high lithium mobility. With this strategy, we achieved specific energies greater than 1,100 Wh kg –1 and discharge rates up to 20 A g –1 . Remarkably, the cathode materials thus obtained from inexpensive manganese present a rare case wherein an excellent rate capability coexists with a reversible oxygen redox activity. Our work shows the potential for designing cathode materials in the vast space between fully ordered and disordered compounds. There is an intensive search for high-performance cathode materials for rechargeable batteries. Here the authors report that oxyfluorides with partial spinel-like cation order, made from earth-abundant elements, display both exceptionally high energy and power.

Chlorine-based plasma is widely used in key etching applications. However, while etching the wafer materials, chlorine plasma can cause damage to the internal components of the etching chamber, which adversely affects the equipment’s lifespan. As a result, selecting appropriate coating materials for the chamber’s internal components is essential for mitigating corrosion. The etch resistance of these coatings directly impacts not only the quality of wafer production but also the operational safety and maintenance cycle of the etching equipment. In this study, three yttrium oxyfluoride coatings with different oxygen contents (3%, 6%, and 9%) were prepared using atmospheric plasma spraying technology. The etch resistance of these YOF coatings, as well as yttrium oxide coating, was systematically investigated under a Cl2/O2 plasma environment. Transmission electron microscopy analysis revealed that at the initial stage, Cl− formed a protective layer on the surface of the YOF coatings, effectively slowing down further etching by Cl−. Among the samples, the YOF 6% coating exhibited the best etching resistance, which is primarily attributed to its higher capacity for Cl− adsorption. Overall, YOF coatings demonstrated excellent resistance in chlorine-based plasma environments, with YOF 6% in particular showing great potential as an ideal protective material for etching chamber components.

Current catalytic materials and processes designed for water treatment face a significant challenge in balancing reactivity and stability. Catalysts with initially high reactivity often lack long-term stability under environmentally relevant conditions, limiting their advancement toward practical application. In this study, we demonstrate that spatial confinement of catalysts at angstrom scale can significantly enhance the stability of iron oxyfluoride (FeOF), a highly efficient catalyst for advanced oxidation. We fabricate a catalytic membrane by intercalating FeOF catalysts between layers of graphene oxides. In flow-through operation, the catalytic membrane maintains near-complete removal of model pollutants, neonicotinoids, for over two weeks by effectively activating H 2 O 2 to generate • OH. Catalyst deactivation is significantly mitigated by spatially confining fluoride ions leached from the catalyst, which is identified as the primary cause of catalytic activity loss. The angstrom-scale membrane channels effectively reject the majority of natural organic matter via size exclusion, thereby preserving radical availability and sustaining pollutant degradation under practical conditions. This innovative strategy for enhancing catalyst stability can be potentially applied to other existing catalysts developed for water treatment applications. By intercalating FeOF between layers of graphene oxide, the researchers demonstrate near-complete removal of neonicotinoid pollutants over two weeks by leveraging spatial confinement to stabilize the catalysts during oxidation reactions.

The ErF3-doped oxyfluoride phospho-tellurite glasses in the (40-x) TeO2-10P2O5-45 (BaF2-ZnF2) -5Na2O-xErF3 system (where x = 0.25, 0.50, 0.75, 1.00, and 1.25 mol%) have been prepared by the conventional melt-quenching method. The effect of erbium trifluoride addition on thermal, structure, and spectroscopic properties of oxyfluoride phospho-tellurite precursor glass was studied by differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and Raman spectroscopy as well as emission measurements, respectively. The DSC curves were used to investigate characteristic temperatures and thermal stability of the precursor glass doped with varying content of ErF3. FTIR and Raman spectra were introduced to characterize the evolution of structure and phonon energy of the glasses. It was found that the addition of ErF3 up to 1.25 mol% into the chemical composition of phospho-tellurite precursor glass enhanced 2.7 µm emission and upconversion. By controlled heat-treatment process of the host glass doped with the highest content of erbium trifluoride (1.25 mol%), transparent erbium-doped phospho-tellurite glass-ceramic (GC) was obtained. X-ray diffraction analysis confirmed the presence of BaF2 nanocrystals with the average 16 nm diameter in a glass matrix. Moreover, MIR, NIR, and UC emissions of the glass-ceramic were discussed in detail and compared to the spectroscopic properties of the glass doped with 1.25 mol% of ErF3 (the base glass).

Oxyfluoride glass-ceramics (OxGC) present attractive optical properties suitable for many applications. The incorporation of fluoride crystals into silicate matrices improves the luminescence properties, producing materials appropriate for photonic applications. Many papers focus on the preparation of oxyfluoride glass ceramics by melting quenching (MQ), the most widely utilized process. However, in the last decades, the sol-gel process has gained increasing interest as an alternative method for avoiding the MQ drawbacks. The first sol-gel route for producing glass-ceramics with rare earth (RE) doped fluoride nanocrystals were based on the preparation and further mixing of two separate sols. The crystallization of the fluoride nanoparticles occurs during the controlled thermal treatment. More recently, a new sol-gel strategy was proposed, based on the previous synthesis of aqueous fluoride nanoparticles suspensions that are subsequently dispersed in a silica sol-gel matrix. This paper summarizes the most relevant results as well as the advantages and disadvantages of each route and their limitations for future industrial scale up. The synthesis routes are compared considering the structural and morphological characterization, elucidating the crystallization mechanisms, and evaluating the optical properties of the resulting materials. Particular attention is paid to the possibility of producing transparent oxyfluoride glass ceramics films with improved luminescence and enhanced optical properties. Graphical abstract

The present study reports on the synthesis and investigation of a series of oxyfluoride phosphate glasses having a composition of (50-x)P2O5-50KF-xAl2O3 (PKAl), with x = 8 mol.%, 12 mol.%, 16 mol.%, and 20 mol.%, by the melt-quenching method. The introduction of Al2O3 in the composition promotes a stabilizing effect, producing stable glasses in air and water ambient conditions. X-ray diffraction (XRD) showed the amorphous characteristics of the materials. The glasses presented high transparency in the UV-Vis-NIR regions (340–2000 nm). Differential scanning calorimetry (DSC) results showed that PKAl glasses have low glass transition temperature values (398–456°C). Fourier-transform infrared spectroscopy (FTIR) spectra showed structural changes caused by variations in P2O5-Al2O3 ratios. The density values of PKAl glasses increased with Al2O3 concentration from 2.45 g/cm3 to 2.50 g/cm3. The molar volume decreases from 39.97 cm3/mol to 36.81 cm3/mol. The prepared new oxyfluoride phosphate glasses can be useful for photonic device applications such as lasers and light-emitting diodes (LEDs).

Disordered rock-salt oxides and oxyfluorides are promising positive electrode materials for high-performance lithium-ion batteries free of nickel and cobalt. However, conventional synthesis methods rely on post-synthesis pulverization to achieve cycling-appropriate particle sizes, offering limited control over particle microstructure and crystallinity. This accelerates degradation and complicates secondary particle processing. Here we present a synthesis strategy that enhances nucleation while suppressing particle growth and agglomeration across various disordered rock-salt compositions, including lithium–manganese–titanium oxide, lithium–manganese–niobium oxide, and lithium–nickel–titanium oxide systems. Applied to Li 1.2 Mn 0.4 Ti 0.4 O 2 , this method yields highly crystalline, well-dispersed sub-200 nm particles that form homogeneous electrode films with stable cycling behavior. Tested in cells with lithium metal as the counter electrode, these electrodes deliver ~200 mAh/g with 85% capacity retention relative to the first cycle after 100 cycles (20 mA/g, 1.5–4.8 V), and an average discharge voltage loss of 4.8 mV per cycle, compared to 38.6% retention and 7.5 mV loss per cycle for electrodes derived from pulverized solid-state particles. This approach suggests a route to enhance the performance and durability of disordered rock-salt electrodes for sustainable lithium-ion batteries. Disordered rock-salt positive electrodes are promising for nickel- and cobalt-free lithium-ion batteries. Here, the authors demonstrate a synthesis method that yields highly crystalline, sub-200 nm dispersed single particles, enabling improved electrochemical cycling stability.

Yttrium oxyfluoride (YOF) protective materials were fabricated on sputter-deposited yttrium oxide (Y2O3) by high-density (sulfur fluoride) SF6 plasma irradiation. The structures, compositions, and fluorocarbon-plasma etching behaviors of these films were systematically characterized by various techniques. After exposure to SF6 plasma, the Y2O3 film surface was fluorinated significantly to form a YOF film with an approximate average thickness of 30 nm. X-ray photoelectron spectroscopy revealed few changes in the elemental and chemical compositions of the surface layer after fluorination, confirming the chemical stability of the YOF/Y2O3 sample. Transmission electron microscopy confirmed a complete lattice pattern on the YOF/Y2O3 structure after fluorocarbon plasma exposure. These results indicate that the SF6 plasma-treated Y2O3 film is more erosion resistant than the commercial Y2O3 coating, and thus accumulates fewer contamination particles.

Novel ternary fluoro-germano-tellurite (GTS) glasses doped with Er[sup.3+] ions with 0.5 mol% and 1.0 mol% were fabricated by a conventional melt and quenching method and investigated using methods of optical spectroscopy. The room-temperature absorption spectrum was recorded and analyzed to determine radiative transition rates, radiative lifetimes, and branching ratios of Er[sup.3+] luminescence. Decay curves of Er[sup.3+] luminesccence were recorded and analyzed. Temperature dependences of emission spectra and absorption spectra in the region from RT (room-temperature) up to 675 K were studied in detail. The contribution of competing radiative and nonradiative processes to the relaxation of luminescent levels of Er[sup.3+] was assessed. Absolute and relative sensitivity were established utilizing the comprehensive model based on thermally coupled [sup.2]H[sub.11/2]/[sup.4]S[sub.3/2] excited states of erbium. The high quantum efficiency of the first erbium-excited state and value of gain coefficient indicate that GTS:Er glass system can be considered as conceivable NIR (near infrared) laser material as well.