Chemical Oxidative Stability Research Articles

Nutraceutical Prospects of Pumpkin Seeds: A Study on the Lipid Fraction Composition and Oxidative Stability Across Eleven Varieties

The oxidative stability of nutritive and bioactive lipids is essential for their functionality. This study evaluated the potential of lipid fractions from pumpkin seeds obtained from eleven high-performing cultivars of Cucurbita maxima Duchesne, C. pepo L., and C. moschata Duchesne cultivated in Poland, aiming to evaluate their stability for nutraceutical applications. This study investigated the intrinsic relationship between chemical composition and oxidative stability to identify cultivars with promising functional potential and commercial value. The fatty acid, sterol, and lipid antioxidant profiles were characterized using gas chromatography (GC), GC–mass spectrometry (GC-MS), and ultra-high-performance liquid chromatography (UPLC), respectively. Antiradical activity was assessed via the DPPH assay, and oxidative stability was evaluated using differential scanning calorimetry (DSC). The oils exhibited high levels of polyunsaturated fatty acids (PUFAs) (59.5–68.6%), with n-6/n-3 fatty acid ratios ranging from 66.5 to 211.6. The lipid extracts contained up to 97.1% Δ7-sterols, while key antioxidants included squalene (616.6–3092.0 mg/kg) and γ-tocopherol (54.1–423.6 mg/kg). Notably, the C. pepo cultivar ‘Moonshine’ was the least abundant in these bioactive compounds. The carotenoid content ranged from 5.7 to 19.4 mg/kg across the extracts. Among the studied cultivars, ‘Show Winner’ and ‘Pink Jumbo Banana’ (C. maxima) stood out as promising candidates for nutraceutical applications due to their elevated levels of tocopherols, carotenoids, and squalene. A moderate n-6/n-3 fatty acid ratio (100–170), coupled with balanced levels of γ-tocopherol and squalene, was found to significantly enhance the oxidative stability of pumpkin seed lipids. These lipid fractions also show potential as stabilizing additives for oils rich in α-linolenic acid but deficient in natural antioxidants.

Chemical Properties and Oxidative Stability of Modified of Table Margarine from Buffalo Fat Fractions with Vegetable Oil Oleogels

Chemical Properties and Oxidative Stability of Modified of Table Margarine from Buffalo Fat Fractions with Vegetable Oil Oleogels

Sour Cream Analogue Supplemented with Red Grape Pomace and Tomato Pomace Extracts: Chemical Composition, Oxidative Stability, and Organoleptic Characteristics

Sour Cream Analogue Supplemented with Red Grape Pomace and Tomato Pomace Extracts: Chemical Composition, Oxidative Stability, and Organoleptic Characteristics

Cold Sintering Halide-in-Oxide Composite Solid-State Electrolytes with Enhanced Ionic Conductivity.

All-solid-state batteries (ASSBs) have attracted increasing attention for next-generation electrochemical energy storage due to their high energy density and enhanced safety, achieved through the use of nonflammable solid-state electrolytes (SSEs). Oxide-based SSEs, such as Li1.3Al0.3Ti1.7(PO4)3 (LATP), are notable for their high ionic conductivity and excellent chemical and electrochemical oxidation stability. Nevertheless, their brittle mechanical properties and poor interface contact with electrode materials necessitate high-temperature and long-duration sintering or postcalcination processes, limiting their processability for real-world applications. Additionally, the formation of secondary phases can detrimentally affect the ionic conductivity of LATP electrolytes. Emerging halide-based SSEs offer reliable deformation for practical processing while maintaining high ionic conductivity. In this work, we report a transient liquid-assisted cold sintering process to integrate oxide-based LATP as the matrix and halide-based Li3InCl6 as the conductive boundary phase into a halide-in-oxide ceramic composite electrolyte at a low processing temperature of 150 °C. This composite structure significantly reduces interface resistance, effectively addressing ion-transport depletion across the boundaries between LATP particles. Consequently, the cosintered LATP-Li3InCl6 composite SSE exhibits a high ionic conductivity of 1.4 × 10-4 S cm-1 at ambient temperature. Furthermore, the symmetric Li|LATP-Li3InCl6·nDMF|Li cell demonstrates stable stripping and plating processes for 1600 h at 55 °C (0.1 mA cm-2) and 1200 h at 100 °C (1 mA cm-2). This work represents the first demonstration of halide-oxide ceramic composite SSEs that combine the advantages of oxides and halides for high-performance SSBs.

Novel Nanocomposite of Carbonized Chitosan-Zinc Oxide-Magnetite for Adsorption of Toxic Elements from Aqueous Solutions.

Herein, a novel nanocomposite (carbonized chitosan-zinc oxide-magnetite, CCZF) was developed to effectively remove toxic elements in water remediation. Combining the high adsorption capacities of chitosan with the magnetic properties of magnetite and the chemical stability of zinc oxide, the combination of these unique properties makes it an efficient and versatile material that offers a sustainable solution for water purification. The (CCZF) nanocomposite was synthesized through the coprecipitation method and characterized using various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and zeta potential analysis. The results showed impressive maximum adsorption capacities of 891.34 mg/g for Ni2+, 1269.35 mg/g for Co2+, and 1502.67 mg/g for Cu2+, fitting well with a modified Langmuir isotherm model. The adsorption process was spontaneous and endothermic, characterized by low positive enthalpy (ΔH) values ranging from 10.95 to 34.9 kJ/mol, indicative of the physical adsorption mechanism. Additionally, the nanocomposite demonstrated good reusability over multiple adsorption and desorption cycles. This research highlights the potential of the (CCZF) nanocomposite as a highly efficient, reusable adsorbent for the removal of toxic elements from aqueous solutions, contributing significantly to environmental remediation efforts and pollution control.

FATTY ACID PROFILE OF COMMON CARP (CYPRINUS CARPIO) AFTER ADDITION OF ASTAXANTHIN TO THE FEED MIXTURE

Astaxanthin is a very strong antioxidant typically fed to rainbow trout mainly to alter the color of its’ meat to red. In our study, we incorporate a relatively low concentration of astaxanthin into the diet of common carp to enhance the chemical parameters and oxidation stability of carp meat without altering the typical coloration of meat. Also, we observed the fatty acid profile of reared fish. We observed an increase in protein content in animals with astaxanthin dietary addition. It was not statistically significant, but we observed a lowering of fat content in experimental groups. Regarding lipid oxidation, we did not observe any significant effect of astaxanthin on malondialdehyde production in samples. Fatty acid profiles were determined by gas chromatography and then compared. Only significant differences were observed in stearic and arachidonic acid and in the experimental group with lower astaxanthin addition. Our results conclude that dietary astaxanthin has no adverse effect on fatty acid profile or oxidation stability during storage (at -18 °C). On the other hand, astaxanthin has the potential to enhance the protein and lower the fat content, even in low concentrations.

2D Tantalum Disulfide Reduction Strategy Customized Ta2O5/rGO Heterointerface Aerogel Toward Boosting Electromagnetic Wave Absorption and Flame Retardancy.

The exceptional and substantial electron affinity, as well as the excellent chemical and thermal stability of transition metal oxides (TMOs), infuse infinite vitality into multifunctional applications, especially in the field of electromagnetic wave (EMW) absorption. Nonetheless, the suboptimal structural mechanical properties and absence of structural regulation continue to hinder the advancement of TMOs-based aerogels. Herein, a novel 2D tantalum disulfide (2H-TaS2) reduction strategy is demonstrated to synthesize Ta2O5/reduced graphene oxide (rGO) heterointerface aerogels with unique characters. As the prerequisite, the defects, interfaces, and configurations of aerogels are regulated by varying the concentration of 2H-TaS2 to ensure the Ta2O5/rGO heterointerface aerogels with appealing EMW absorption properties such as a minimum reflection loss (RLmin) of -61.93dB and an effective absorption bandwidth (EAB) of 8.54GHz (7.80-16.34GHz). This strategy provides valuable insights for designing advanced EMW absorbers. Meanwhile, the aerogel exhibits favorable thermal insulation performance with a value of 36mW m-1 K-1, outstanding fire resistance capability, and exceptional mechanical energy dissipation performance, making it promising for applications in the aerospace industry and consumer electronics devices.

Effect of Roasting on the Chemical Composition and Oxidative Stability of Tomato (Solanum lycopersicum L.) Seed Oil.

In this study, tomato seed (TS) samples were subjected to different roasting conditions (90-170 °C and 10-30 min) to compare their effects on the chemical composition and oxidative stability of tomato seed oil (TSO). Unroasted TS was considered as a control sample. Our results revealed that moderate roasting (130 °C/20 min) can significantly increase the content of linoleic acid (54.01-54.89%), linolenic acid (2.17-2.41%), phytosterols (2789.56-3037.31 mg/kg), squalene (5.06-13.10 mg/kg), total phenols (22.37-22.67 mg GAE/100 g), and other functional components (p < 0.05) in TSO, while the antioxidant activity (via DPPH, ABTS, and FRAP assays) also increased. In addition, the tocopherol content decreased significantly (758.53-729.50 mg/kg). Accelerated oxidation experiments showed that roasting (170 °C/30 min) increased the oxidative stability index (OSI) of TSO from 5.35 to 7.07 h (p < 0.05). Furthermore, roasting gradually increased the content of 5-hydroxymethylfurfural (HMF) (0-1.74 mg/kg), which indicates that the oxidative stability and the degree of the Maillard reaction increased upon roasting. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that moderate roasting (130 °C/20 min) improved the chemical composition, antioxidant activity, and oxidative stability of TSO. Furthermore, this work provides a useful theoretical basis for the processing and wide application of TSO in the pharmaceutical and food industries.

Influence of Cr2AlC on the thermal shock and corrosion resistance of low carbon Al2O3-C refractory

Incorporation of MAX phase to fabricate low-carbon refractories has been recently proposed. Among them, Cr2AlC was the undoubtedly one which was regarded as the most potential candidates for applications, due to the excellent chemical stability of chromium oxide. In this work, the influence of Cr2AlC on the thermal shock resistance and corrosion resistance of Al2O3-Cr2AlC-C refractories were investigated. The results indicated that the residual strength ratio still maintained stability when flake graphite content reduced from 9 wt% to 4 wt%. While the corrosion resistance of the sample with 4 wt% graphite and 5 wt% Cr2AlC increased approximately 40% compared with regular Al2O3-C refractories with 9 wt% graphite. The degradation mechanisms and interactions of Al2O3-Cr2AlC-C refractories in contact with MnO-rich slag were studied, and the role of Cr2AlC was elucidated.

Analysis fin field-effect transistor design with high-k insulators

In this article, we integrate a Fin Field Effect Transistor with high-k insulators to investigate the optimal design for chemical field effect transistors in order to give higher inductance (resulting in a higher transmission relationship), improved amplitude, and outcome-based substance. pH sensing was utilised to test the design. We investigated the responsiveness and linearity of silicon dioxide, oxide, and hafnium oxide as pH-sensing electromagnetic materials, as well as their chemical resistance in various acids. The device’s huge component ratio and fin shape allow for high currents and a more dependable planar conducting channel than conventional silicon nanowires. The hafnium oxide Fin Field Effect Transistor architecture delivered the greatest results, with the most linear features of generation and turnover and a broader dynamic range. The chemical stability of hafnium oxide was also the best. As a result, we believe the large component ratio Fin Field Effect Transistors/high-k dielectric combination can provide the optimal process fairness for Field-Effect Transistor-based sensors. The authors propose a novel seamless embedded induction approximation with a quaternary resonator. Only one deleterious modified divergent voltage current conveyor, one of the suggested quaternary synthesisers, uses a Z input, a rectifier, and two crossed capacitive. In the intended unidirectional isolated circuit emulator, just one customised split electrical output feeder with a sole Z electrode, two switches, and the first neutral capacitor are used. The suggested seamless rooted circuit simulation just requires a specific passive constituent compatibility criterion. In addition, the suggested lossless grounded inductor simulator yields a ring filter application. To illustrate the performance of all the circuits, a variety of models using the LTSPICE software, the cadence virtuoso 7nm parameter, and data analyses were performed.

Chitosan-photocatalyst nanocomposite on polyethylene films as antimicrobial coating for food packaging

Chitosan (CS), an edible and non-toxic natural biopolymer, has been widely used in food preservation attributed to its intrinsic antimicrobial, biodegradable, and excellent film-forming properties. In this work, we report photocatalyst-loaded chitosan coating on commercial polyethylene (PE) film with enhanced antimicrobial properties for food packaging application. To improve the chemical stability of zinc oxide (ZnO) photocatalyst in acidic chitosan matrix, a thin layer (1–5 nm) of amorphous tin oxide (SnOx) was coated on ZnO nanoparticles. Consequently, the charge transfer efficiency of ZnO is improved and most of the surface defects are retained according to the studies of UV–Vis and fluorescence spectroscopy. The thin SnOx coating on ZnO was observed by high-resolution transmission electron microscopy (HRTEM) and its effects on crystallinity and particle size of ZnO were examined using X-ray diffraction (XRD) and particle sizer, respectively. The addition of ZnO@SnOx particles in chitosan coating increases water contact angle (WCA) and enhances thermal stability of chitosan coating. The antimicrobial activity of chitosan, ZnO-SnOx nanoparticles, and CS-ZnO@SnOx coated PE films were examined against both Gram-negative (E. coli, A. faecalis) and Gram-positive (S. aureus, B. subtilis) bacteria. Compared to the limited antimicrobial effects of chitosan, ZnO-SnOx demonstrates an improved inhibition effect on bacterial growth over 48 h period under light. For the CS-ZnO@SnOx nanocomposite coated PE films, no inhibition zone was observed due to the limitation of disc diffusion method. Meanwhile, there were no bacterial colonies found to develop on the film, rendering this CS nanocomposite coating a good candidate for food packaging applications.

Effects of heat stress on the chemical composition, oxidative stability, muscle metabolism, and meat quality of Nile tilapia (Oreochromis niloticus).

The present study investigated the effects of chronic heat stress (HS) on the chemical composition, oxidative stability, muscle metabolism, and meat quality of Nile tilapia (Oreochromis niloticus). Compared with the control (26°C), chronic HS (32°C) lowered growth performance, the contents of whole-body lipid, muscle protein, and muscle lipid. Also, HS significantly increased the contents of reactive oxygen species (ROS) and decreased antioxidative status, causing a decline in meat quality, including increased lipid and protein oxidation, the centrifugal water loss, and cooking loss as well as decreased the fragmentation index and pH at 24h, which may be attributed to induced apoptosis by excessive ROS in Nile tilapia meat. Moreover, metabolomic analysis showed HS lowered flavor and nutritional value by affecting amino acid, lipid, and nucleotide metabolism. These results reveal that HS adversely affects oxidative stability, meat quality, flavor, and nutrition, warranting its recognition and prevention.

Preparation and characterization of zwitterion-substituted lignin/Nafion composite membranes

In this study, a novel zwitterion-substituted lignin (ZL) containing amino and sulfonic acid groups was synthesized, and ZL/Nafion composite membranes were fabricated as proton exchange membranes. Kraft lignin was modified using an aminosilane and 1,3-propanesultone via a continuous grafting reaction to provide zwitterionic moieties. Chemical structural analyses confirmed the successful introduction of the zwitterion moiety into lignin. In particular, the surface charge of ZL is positive in an acidic medium and negative in a basic medium, suggesting that ZL is a zwitterionic material. ZL was incorporated into a Nafion membrane to enhance its ion exchange capacity, thermal stability, and hydrophilicity. The proton conductivity of ZL/Nafion 0.5 %, 151.0 mS/cm, was 55.3 % higher than that of unmodified ML (methanol-soluble lignin)/Nafion 0.5 % (97.2 mS/cm), indicating that the zwitterion moiety of ZL enhances the proton transport ability. In addition, oxidative stability evaluation confirmed that ZL/Nafion 2 % was chemically more durable than pure Nafion. This confirmed that using lignin as a membrane additive yielded positive results in terms of chemical durability and oxidation stability in Nafion. Therefore, ZL is expected to be utilized as a multifunctional additive and exhibits the potential for fuel cell applications.

Highly conductive and dimensionally stable anion exchange membranes enabled by rigid poly(arylene alkylene) backbones

Dimensionally and chemically stable anion exchange membranes with excellent ion conductivity are highly desired in electrochemical energy conversion technologies. Herein, we present a design using rigid arylene units, i.e., p-tetraphenylene and p-terphenylene, to suppress the water sorption of quaternized poly(arylene alkylene) membranes with high ion contents. Of note, side chain double-quaternary ammonium (QA) functionalized poly(q-tetraphenylene-co-p-terphenylene alkylene) membrane P(4PA-co-3PA)-D100 with the IEC value as high as 2.93 mmol g−1 showed very limited water uptake and swelling at 80 °C of 75 wt% and 14 %, respectively. Meanwhile, the immiscibility of hydrophilic double-cation side chain and the hydrophobic poly(arylene alkylene) backbone drives the formation of phase-separated morphology. As a result, P(4PA-co-3PA)-D100 showed an exceptional conductivity of 227.8 mS cm−1 at 80 °C with activation energy of 10.5 kJ mol−1. Despite the rigid poly(arylene alkylene) backbone with highly chemical durability and oxidative stability, the tandem tethered double cation in the side chain showed a 11 % QA moiety loss after a 1000-h treatment in 2 M NaOH at 80 °C. Moreover, a good peak power density of 550 mW cm−2 at the current density of 1.06 A cm−2 was achieved for P(4PA-co-3PA)-D100 with the gases flow of 200 mL min−1. This work demonstrates that, in addition to the approach of cross-linking, the highly conductive AEMs with excellent dimensional stability can be achieved by improving the rigidity of polymer backbones.

Augmenting broiler diets with essential oils affects growth, intestinal microbiota and morphology, and meat quality

The health and productivity of broiler chickens are related to their intestinal microbiota, which may be influenced by supplemented feed components. This trial intended to evaluate the effects of a dietary mixture of essential oils from oregano (Origanum vulgare ssp. hirtum), sage (Salvia triloba L.), and lavender (Lavandula angustifolia L.) on broiler chicken growth performance, intestinal microbiota, intestinal morphology, and meat chemical composition and oxidative stability. A total of 288 one-day-old male Ross-308 chicks were randomly assigned to four treatments with six replicate pens (12 chicks per pen). The chicks of the control treatment were fed typical commercial maize and soybean meal rations in mash form. The rations of the other three treatments were supplemented with a mixture of essential oils at 100, 200, and 400 mg/kg, respectively. At the end of the trial (day 42), tissue samples were collected for analysis. Major bioactive components of the three essential oils were identified by gas chromatography-mass spectrometry. Essential oil supplementation increased the radical scavenging capacity and the total phenolic content of the feeds. Performance parameters (weight gain, feed intake, feed conversion ratio, European production efficiency factor) were not affected significantly by the supplementation. Intestinal microflora populations (determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry) were modified significantly in both the cecum and the jejunum. Breast and thigh meat oxidative stability under refrigerated storage was improved significantly. Additional research is required to elucidate the potential synergistic effects of dietary mixtures of essential oils.

Chemical stability of porous anodic aluminum oxide in both acidic and alkaline solutions

A porous anodic aluminum oxide (AAO) possessing higher chemical resistance in both acidic and alkaline solutions was fabricated by anodizing Al in an alkaline sodium tetraborate solution. The 5 N Al plates were anodized in five types of major acidic solutions (sulfuric, oxalic, phosphoric, chromic, and etidronic acids) and in alkaline sodium tetraborate solution to form AAOs. The anodized specimens were then immersed in a 0.52 M phosphoric acid solution (pH = 1.3) and a 2.5 M sodium hydroxide solution (pH = 13.8). Subsequently, the electrochemical impedance measurements and morphological characterizations of the AAOs before and after immersion were investigated. The time required for the complete dissolution of the AAOs formed in typical acidic electrolytes, including sulfuric, oxalic, phosphoric, and etidronic acids, increased linearly with the anodizing voltage. The AAO formed in chromic acid exhibited a higher chemical resistance than this linear relationship owing to the formation of high-purity alumina without incorporated anions. Moreover, the AAO formed in sodium tetraborate exhibited the highest chemical resistance in both acidic and alkaline solutions – approximately two times higher than that formed in etidronic and chromic acids. This can be attributed to their higher anodizing ratio and the formation of a high-purity alumina layer.

Fabrication of Nanoparticle‐Doped Polyvinyl Alcohol‐Cellulose Acetate Membrane and Characterization of the Surface Enhancement

AbstractIn the present study, nanocomposite polymeric membranes are fabricated using polyvinyl alcohol (PVA), cellulose acetate (CA) as polymers, and dimethyl sulfoxide (DMSO) as the solvent. To enhance the performance of the membrane, nanoparticles like TiO2, CaO, CdO, and ZrO are added to the polymeric solution and the doped polymeric solution is cast on a glass plate. Nine combinations of membranes are fabricated with two different concentrations (0.1% and 0.2%) of nanoparticles. The basic properties of the membranes such as density, porosity, viscosity, permeability, pure water flux, and water content are studied for the samples. Membrane pore structure and surface properties are identified and it is found that doping nanoparticles on the surface of membranes improve mechanical strength, stability, pore size, etc., allowing the membranes to perform better in extreme industrial‐level effluent treatment applications. High‐resolution scanning electron microscopy (SEM) shows the homogeneous dispersion of ZrO, TiO2, CaO, and CdO nanoparticles on the surface of the PVA‐CA membrane. The doping of nanoparticles on the PVA‐CA membrane results in improved mechanical strength and good chemical oxidation stability. In comparison, the PCD‐TiO2 sample shows high thermal stability and oxidation stability at high temperatures until 200°C, which has a high potential for treating industrial effluents.

The Liquid-Mediated Synthesis and Performance Evaluation of Li-Zr-F Composite for Ion-Conduction

Crystalline lithium fluoride (LiF) has been intensively pursued as potential alternative solid electrolytes (SEs) owing to its excellent chemical and electrochemical oxidation stability, and good deformability. However, due to its low ion conductivity, LiF is still challenging for practical SE applications. Herein, Li-Zr-F composite-based SE by liquid-mediated synthesis is proposed to be studied. methanol (CH&lt;sub&gt;3&lt;/sub&gt;OH) was mainly evaluated as a liquid-mediated precursor for synthesizing Li-Zr-F composites under the stoichiometric proportion of LiF and ZrF4 (2:1 and 2:0.8) and a subsequent annealing process at 25°C/150°C, 50°C/150°C, and 70°C/150°C, respectively. X-ray diffraction results revealed that the Li-Zr-F composites could be crystallized in the three main types of phase formations, including Li&lt;sub&gt;2&lt;/sub&gt;ZrF&lt;sub&gt;6&lt;/sub&gt; ( ), Li&lt;sub&gt;2&lt;/sub&gt;ZrF&lt;sub&gt;6&lt;/sub&gt; ( ), and Li&lt;sub&gt;4&lt;/sub&gt;ZrF&lt;sub&gt;8&lt;/sub&gt; ( ) octahedron structures. In addition, the effect of cation stack sublattice synthesized by methanol mediator on the ion conduction of Li-Zr-F composites was investigated by using electrochemical impedance spectroscopy (EIS). Through the Zr&lt;sup&gt;4+&lt;/sup&gt;-substitution, Li&lt;sub&gt;2&lt;/sub&gt;ZrF&lt;sub&gt;6&lt;/sub&gt; ( )-based SE exhibited the highest ion conduction which was increased to 2.40 × 10&lt;sup&gt;-8&lt;/sup&gt; S/cm and 3.89 × 10&lt;sup&gt;-8&lt;/sup&gt; S/cm under the stoichiometric proportion of LiF and ZrF&lt;sub&gt;4&lt;/sub&gt; 2:0.8 at a dried temperature of 50°C/150°C with, respectively. A 0.21 eV activation energy ( ) was achieved for a battery with Li&lt;sub&gt;2&lt;/sub&gt;ZrF&lt;sub&gt;6&lt;/sub&gt; ( )-based SE. Meanwhile, LiF exhibited up to 0.78 eV leading to a low kinetic rate for ion diffusion. These results implied that Li&lt;sub&gt;2&lt;/sub&gt;ZrF&lt;sub&gt;6 &lt;/sub&gt;( )-based SE was successfully synthesized under the optimal condition of CH&lt;sub&gt;3&lt;/sub&gt;OH-50°C/150°C which could improve the ion-conductivity of LiF.

Eu3+-doped Y7O6F9 ceramic powder phosphor for optical thermometry based on fluorescence spectral techniques

In recent years, optical thermometry performance of europium (Eu3+) doped phosphors has been studied by probing the temporal and spectral change of the fluorescence with temperature. In this scenario, the choice of the host material is important to maximize the temperature sensitivity. Yttrium oxyfluoride is an interesting host candidate because it combines low phonon energy of fluorides with high chemical and thermal stability of oxides. In this work, the combustion synthesis approach was used to produce Eu3+-doped Y7O6F9 powder phosphors. The Judd-Ofelt intensity parameters of the samples were calculated by the analysis of the fluorescence. When exposed to an externally-controlled change of the temperature, the fluorescence spectral profile of the sample changed. We observed that the relative temperature sensitivity estimated by the full-width at half-maximum and the valley-to-peak ratio methods were 0.08 and 0.35% K−1, respectively, at a temperature of 318 K, validating the phosphor for temperature sensing application.

Metal-oxide nanocomposite catalyst simultaneously boosts the oxygen reduction reactivity and chemical stability of solid oxide fuel cell cathode

Conductive perovskite oxides have received much attention as promising candidates for solid oxide fuel cell (SOFC) cathodes. However, they show chemical instability due to the segregation of A-site cations on the surface at high temperatures, which causes their performance to degrade. Moreover, the high activation barrier to oxygen reduction reactions makes these materials more difficult to use as electrodes at lower temperatures (less than 700 °C). Herein, by combining two general techniques: nanoparticle infiltration and atomic layer deposition (ALD), we significantly improve both the durability and reactivity of a state-of-the-art perovskite oxide, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF). Ag nanocatalysts are dispersed onto an LSCF cathode via wet infiltration, after which they are covered with a thin ZrO2 layer via ALD to prevent the agglomeration of nanocatalysts and the segregation of Sr ions. Accordingly, the Ag/ZrO2 nanocomposite-deposited LSCF cathode shows the electrode resistance of 0.085 Ωcm2 at 650 °C over 200 h, which is, to the best of our knowledge, the near-record level among all nanocatalyst-infiltrated LSCF cathode to date. Our result suggests a new research direction to fully utilize nanocatalysts and perovskite oxides in SOFCs, which can be a shortcut to their commercialization.