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The outstanding catalytic property of cerium oxide (CeO2) strongly depends on the polaron formation due to the oxygen vacancy ( V ̈ O ) defect and Ce4+ to Ce3+ transformation. Temperature plays an important role in the case of polaron generation in CeO2 and highly influences its electrical transport properties. Therefore, a much needed attention is required for detailed understanding of the effect of temperature on polaron formation and oxygen vacancy migration to get an idea about the improvement in the redox property of ceria. In this work, we have probed the generation of polarons in CeO2 thin-film deposited on a silicon (Si) substrate using the resonance photoemission spectroscopy (RPES) study. The RPES data show an increase in polaron density at the substrate–film interface of the thermally annealed film, indicating the formation of an interfacial Ce2O3 layer, which is, indeed, a phase change from the cubic to hexagonal structure. This leads to a modified electronic band structure, which has an impact on the capacitance–voltage (C–V) characteristics. This result nicely correlates the microscopic property of polarons and the macroscopic transport property of ceria. [ABSTRACT FROM AUTHOR]

We report a theoretical investigation of temperature, size, and composition effects on the structural, energetic, and electronic properties of the (La4O6)n, (La2Ce2O7)n, and (Ce4O8)n nanoclusters (NCs) for n = 10, 18. Furthermore, we investigated the single O vacancy formation energy as a function of the geometric location within the NC. Our calculations are based on the combination of force-field molecular dynamics (MD) simulations and density functional theory calculations. We identified a phase transition from disordered to ordered structures for all NCs via MD simulations and structural analysis, e.g., radius changes, radial distribution function, common neighbor analysis, etc. The transition is sharp for La36Ce36O126, La20Ce20O70, and Ce72O144 due to the crystalline domains in the core and less abrupt for Ce40O80, La40O60, and La72O108. As expected, radius changes are abrupt at the transition temperature, as are morphological differences between NCs located below and above the transition temperature. We found a strong dependence on the O vacancy formation energy (Evac) and its location within the NCs. For example, for La40O60, Evac decreases almost linearly as the distance from the geometric center increases; however, the same trend was not observed for Ce40O80, while there are large deviations from the linear trend for La20Ce20O70. Evac has smaller values for Ce40O80 and higher values for La40O60, that is, almost three times, while Evac has intermediate values for mixed oxides, as expected from weighted averages. Therefore, the mixture of one formula unit of La2O3 with two formula units of CeO2 has the effect of increasing the stability of CeO2 (binding energy), which increases the magnitude of the formation energy of the O vacancy. [ABSTRACT FROM AUTHOR]

Ceria (CeO2) doped with Gd2O3 (Ce1−xGdxO2−x/2) is considered a surrogate of a burnable poison-doped nuclear fuel. Oxygen vacancies (VO) are induced in Ce1−xGdxO2−x/2 by the substitution of Gd3+ ions into the Ce4+ sites, and the oxygen deficiency is mainly controlled by the Gd2O3 concentration. Oxygen vacancies can also be generated by elastic collisions with high-energy electrons for recoil energies of oxygen atoms above the threshold displacement energy (Ed,O). Oxygen vacancy formation is a key factor to determine the radiation tolerance since it enhances the recombination of point defects. The behavior of point defects in ceramics is known to depend on their charge states, although there is only limited research on this topic. In this study, in situ cathodoluminescence (CL) spectroscopy is applied to studying the charge states of defects induced in the oxygen-deficient cerium dioxides, Ce1−xGdxO2−x/2, by using a high-voltage electron microscope for electron energies from 400 to 1250 keV. The CL emission bands of Ce3+ − VO, Ce3+, and F+ centers are obtained for Ce1−xGdxO2−x/2 as well as pure ceria. An energy shift and quenching of CL emission in Ce1−xGdxO2−x/2 are observed. Those effects are discussed as a consequence of the generation of extrinsic oxygen vacancies induced by Gd2O3 doping (VO,ext) and the influence of the respective electronic configurations of the Ce3+ ions and VO,ext. A schematic picture of energy levels of defects in the bandgap of Ce1−xGdxO2−x/2 is suggested. [ABSTRACT FROM AUTHOR]

In this work, the effects of cerium doping and oxygen defects of ferroelectric Hf0.5Zr0.5O2 (HZO) are systematically studied by first-principles calculations. According to the results, the combined effect of Ce atoms and oxygen vacancy has a significant effect on the improvement of the orthorhombic phase fraction in HZO, and the mechanism of this phenomenon is also studied. The optimal concentration of Ce doping is 9.375 formula unit%, and the optimal concentration of oxygen vacancy is 9.375 formula unit%. The interaction between Ce doping and oxygen defects is also discussed from the perspective of structural stability and electrical balance. These findings are helpful for the preparation of Ce-doped HZO ferroelectric thin films and provide experience for the study of other dopants. [ABSTRACT FROM AUTHOR]

This study investigates the structural stability of the CeO2-ZrO2 system when subjected to high doses of irradiation (a few hundred displacements per atom). The goal is to explore their potential use in safe immobilization of spent nuclear fuel and development of accident-tolerant fuels for next-generation nuclear reactors. Highly dense pellets were synthesized using a solid-state reaction and then irradiated with 1.75 MeV Xe5+ ions at ion fluences ranging from 1 × 1015 to 1 × 1017 ions/cm2. Structural and microstructural analyses were conducted using glancing angle x-ray diffraction, micro-Raman spectroscopy, and scanning electron microscopy. The results indicate that Ce0.8Zr0.2O2 has a high tolerance against irradiation-induced phase transformation or amorphization but does generate irradiation-induced point defects. Each energetic ion produced a deformed region with a voluminous swelling of ∼0.61 ± 0.09 nm and a damaged zone of ∼0.09 ± 0.02 nm, as calculated from the irradiation-caused peak broadening that is explained by a three-step damage accumulation model. The electron microscopy studies show that grain boundaries serve as a sink for defects, and an increase in grain size was observed due to defect accumulation inside the grain's volume. Overall, the study shows that polycrystalline fluorite-structured Ce0.8Zr0.2O2 is a promising nuclear material for advanced energy systems as it did not show significant structural damage such as amorphization and grain fragmentation, even on irradiation at a high dose of ∼428 dpa. [ABSTRACT FROM AUTHOR]

Rare earth sulfides are environmentally friendly and have excellent physical optoelectronic properties and coloring applications. In particular, red γ-Ce2S3 is an important and popular inorganic optical functional material. However, it has become crucial to improve the production efficiency of γ-Ce2S3 and its color performance and stability. By adding ammonium thiocyanate to the precursor, eco-friendly γ-Ce2S3 with excellent color performance was produced in this study. In addition, the effect of different amounts of Na+ doping on the final product's purity and the effect of chroma value were systematically investigated. Results show that an increase in Na+ can effectively lower the synthesis temperature of γ-Ce2S3, improve production efficiency, and optimize color performance prior to saturation. Finally, using density functional theory, the influence of the vacancy structure of γ-Ce2S3 and the change of energy band after the addition of Na+ were calculated, and a detailed experimental characterization in conjunction with density functional theory calculation thoroughly explained the significance of ion doping for reaction synthesis. [ABSTRACT FROM AUTHOR]

The facet-dependent adsorption of CO on oxidized and reduced CeO2 single crystal surfaces is reviewed, with emphasis on the effect of CO coverage and the ability of state-of-the-art quantum-mechanical methods to provide reliable energies and an accurate description of the IR vibrational frequency of CO. Comparison with detailed, high-resolution experimental infrared reflection absorption spectroscopy data obtained for single crystal samples allows the assignment of the different CO vibrational bands observed on all three low-index ceria surfaces. Good agreement is achieved with the hybrid density functional theory approach with the HSE06 functional and with saturation coverage. It is shown that CO is very sensitive to the structure of cerium oxide surfaces and to the presence of oxygen vacancies. The combined theoretical-experimental approach offers new opportunities for a better characterization of ceria nanoparticles and for unraveling changes occurring during reactions involving CO at higher pressures. [ABSTRACT FROM AUTHOR]

Supported metallic nanoparticles play a central role in catalysis. However, predictive modeling is particularly challenging due to the structural and dynamic complexity of the nanoparticle and its interface with the support, given that the sizes of interest are often well beyond those accessible via traditional ab initio methods. With recent advances in machine learning, it is now feasible to perform MD simulations with potentials retaining near-density-functional theory (DFT) accuracy, which can elucidate the growth and relaxation of supported metal nanoparticles, as well as reactions on those catalysts, at temperatures and time scales approaching those relevant to experiments. Furthermore, the surfaces of the support materials can also be modeled realistically through simulated annealing to include effects such as defects and amorphous structures. We study the adsorption of fluorine atoms on ceria and silica supported palladium nanoparticles using machine learning potential trained by DFT data using the DeePMD framework. We show defects on ceria and Pd/ceria interfaces are crucial for the initial adsorption of fluorine, while the interplay between Pd and ceria and the reverse oxygen migration from ceria to Pd control spillover of fluorine from Pd to ceria at later stages. In contrast, silica supports do not induce fluorine spillover from Pd particles. [ABSTRACT FROM AUTHOR]

The removal of pollutants from water bodies is crucial for the well-being of humanity and is a topic of global research. Researchers have turned their attention to green synthesized nanoparticles for wastewater treatment due to their eco-friendly nature, biocompatibility, and cost-effectiveness. This work demonstrates the efficient removal of organic dye and both gram-positive and gram-negative bacteria from water bodies using copper-doped cerium oxide nanoparticles synthesized with Murraya Koenigii extract. Characterized via various methods, the 15% copper doped cerium oxide nanoparticles (Cu 15% NPs) exhibited maximum Congo red dye adsorption (98% degradation in 35 min). Kinetic analysis favoured a pseudo-second-order model, indicating the chemical nature of adsorption. Equilibrium adsorption isotherms aligned with the Langmuir model, indicating homogenous monolayer dye adsorption on the doped adsorbent. The maximum uptake of adsorbate, Q m obtained from Langmuir model for Cu 15% NPs was 193 mg g−1. The study also showed enhanced antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa for Cu-doped ceria, attributed to generation of reactive oxygen species (ROS) induced by the redox cycling between Ce3+ and Ce4+. This substantiated that the green synthesized copper doped cerium oxide nanoparticles are potential candidates for adsorptive removal of Congo red dye and as antibacterial agents. [ABSTRACT FROM AUTHOR]

A series of mesoporous ceria-supported vanadium oxide catalysts were prepared and explored for aerobic oxidation of ethylbenzene to acetophenone without the involvement of any solvent or additive. Catalysts with varying contents of V2O5 (3, 6, and 10 wt%) on a mesoporous CeO2 support were prepared by the wet-impregnation method. Catalysts were characterized using techniques namely, XRD, Raman spectroscopy, BET surface area analysis, ICP-OES, FE-SEM, HR-TEM, XPS, and H2-TPR to establish a correlation between the physicochemical properties and catalytic performance. Among the investigated catalysts, the catalyst with 6 wt% of V2O5 on mesoporous ceria showed better activity with 69% ethylbenzene conversion and 88% acetophenone selectivity. The superior activity of this catalyst was ascribed to a strong synergetic interaction between ceria and vanadia as well as the formation of a CeVO4 phase, and a high specific surface area. The reaction parameters like temperature, pressure, and the amount of catalyst were optimized for possible commercial utilization. The stability of the catalyst was also investigated by the reusability test and was found to be stable and active up to five cycles. [ABSTRACT FROM AUTHOR]

Samarium praseodymium (Sm–Pr) co-doped ceria was synthesized by the co-precipitation technique as an electrolyte for low-temperature solid oxide fuel cell (LT-SOFC) applications. The structural, morphological, compositional, and electrical characterization of the synthesized samples were evaluated via x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and impedance spectroscopy. The generation of a single-phase fluorite structure of co-doped ceria without any secondary phases has been verified by XRD analysis, exhibiting the successful incorporation of Sm and Pr ions into the ceria lattice. Vegard's law is utilized for Pr redox behavior explaining the variation in lattice constant values. SEM pictures show that the co-doped ceria powder has a homogeneous and well-dispersed microstructure, and has enhanced particle size. The impedance spectroscopy results indicate that Sm–Pr co-doped ceria has much higher ionic conductivity than single-doped ceria. The highest amount of ionic conductivity (σ i o n i c ) for the composition Ce 0.80 Sm 0.10 Pr 0.10 O 2 − δ recorded as 2.12 × 10 − 2 S / c m at 500 ° C , and 6.19 × 10 − 2 S / c m at 750 ° C with the lowest activation energy E a = 0.48 e V , which has been not reported earlier. Sm and Pr are chosen as dopants because of their capacity to generate oxygen vacancies and improve ceria's ionic conductivity. This study contributes to the enhancement in the ionic conductivity of co-doped ceria by co-precipitation technique and the temperature-dependent frequency exponent factor "s" is also explored to comprehend the conduction mechanism of the prepared samples. [ABSTRACT FROM AUTHOR]

Glass ceramic dielectric materials with high power density and high energy density have important application value in the miniaturization and integration of lightweight pulse power devices. In this work, SrO 2 –BaO 2 –Nb 2 O 5 –SiO 2 –Al 2 O 3 –B 2 O 3 glass ceramics doped with various contents of CeO 2 were prepared via high-temperature melting combined with temperature-controlled crystallization process. Results showed that CeO 2 doping increased the content of Ba 0.27 Sr 0.75 Nb 2 O 5.78 tungsten bronze phase precipitate from the glass matrix in glass ceramics (from 55.7% to 82.2%), thereby increasing dielectric constant of SrO 2 –BaO 2 –Nb 2 O 5 –SiO 2 –Al 2 O 3 –B 2 O 3 glass ceramics (from 66.5 to 101.9). Besides that, CeO 2 -doped ceramics exhibited excellent temperature stability and low loss (below 0.015). The highest breakdown strength (1590 kV/cm) and energy density (12.88 J/cm3) were achieved in the ceramic with a CeO 2 doping concentration of 3.0 mol.%, being 3.03 times higher than those in undoped glass ceramic. The increase in energy density of the ceramics was attributed to moderate CeO 2 doping concentration that improved the crystallinity (from 83.8% to 89.8%) and reduced the interfacial activation energy of the glass ceramics. [ABSTRACT FROM AUTHOR]

This study focused on the fabrication of Ni, Ni–ZrO 2 and Ni–ZrO 2 –CeO 2 nanocoatings using ultrasonic pulse electrodeposition. The research delved into examining the surface morphology, microhardness, abrasion, and corrosion resistance of these coatings. The results indicated that the Ni coatings displayed coarse grains and an irregular structure. Among the three, the Ni–ZrO 2 –CeO 2 nanocoatings exhibited the most dense, flat and fine microstructure among all three coatings, and the average diameters of Ni grains, ZrO 2 and CeO 2 nanoparticles were 68.6 nm, 21.1 nm and 23.4 nm, respectively. The Ni, Ni–ZrO 2 , and Ni–ZrO 2 –CeO 2 nanocoatings displayed high micro-hardness values, measuring an average of 363.1 Hv, 421.6 Hv, and 543.8 Hv, respectively. Moreover, the friction coefficient of Ni–ZrO 2 –CeO 2 nanocoatings was approximately 0.31. When exposed to a 3.5 wt% NaCl solution at room temperature, the Ni–ZrO 2 –CeO 2 nanocoatings displayed minimal corrosion damage, exhibiting the lowest corrosion rate of 0.06 mm/year compared to the other coatings. The incorporation of ZrO 2 and CeO 2 nanoparticles in the Ni–ZrO 2 –CeO 2 coating led to grain size reduction and a more uniform, compact microstructure, contributing to enhanced corrosion resistance when compared to both Ni and Ni–ZrO 2 coatings. [ABSTRACT FROM AUTHOR]

Dissipative structures often appear as an unstable counterpart of ordered structures owing to fluctuations that do not form a homogeneous phase. Even a multiphase mixture may simultaneously undergo one chemical reaction near equilibrium and another one that is far from equilibrium. Here, we observed in real time crystal seed formation and simultaneous nanocrystal aggregation proceeding from CeIV complexes to CeO2 nanoparticles in an acidic aqueous solution, and investigated the resultant hierarchical nanoarchitecture. The formed particles exhibited two very different size ranges, resulting in further pattern formation with opalescence. The hierarchically assembled structures in solutions were CeO2 colloids, viz. primary core clusters (1–3 nm) of crystalline ceria and secondary clusters (20–30 nm) assembled through surface ions. Such self-assembly is widespread in multi-component complex fluids, paradoxically moderating hierarchical reactions. Stability and instability are not only critical but also complementary for co-optimisation around the nearby free energy landscape prior to bifurcation. For atomically precise nanoparticle synthesis, it is crucial to understand hierarchical interactions during nanostructure formation. Here, the authors observe the crystal seed formation and simultaneous nanocrystal aggregation of ceria from aqueous solution in real time to understand hierarchically different intra- and interparticle interactions governing the particle shapes. [ABSTRACT FROM AUTHOR]

Growing hydrogen demand and progress in fuel cell technology contributed to renewed interest in water-gas shift (WGS) reaction. Supported gold catalysts attracted a special attention during the last three decades. Given the undisputed role of support nature in catalyst activity the purpose of this work was exploration of the effect of ceria amount (1, 3, and 5 wt%) and preparation approach as sol-gel (SG) or mechanochemical mixing (MM) to WGS activity of Au/TiO 2 catalyst. Thorough studies using textural measurements, X-ray fluorescence spectrometry, powder X-ray diffraction, transmission electron microscopy, UV–Vis diffuse reflectance, UV-Raman and X-ray photoelectron spectroscopy, electron paramagnetic resonance, and temperature-programmed reduction were carried out to explain the relationship among structure, electronic properties, and WGS performance. The catalysts showed a notably better performance as compared to Ce-free Au/TiO 2 counterpart by reaching a 90−93 % CO conversion at 180 °C vs. 75 % with unmodified sample. Formation of defective Ti 4 O 7 and Ce 11 O 20 phases occurred during sample preparation by SG. In addition, a distinct ceria phase was found in MM-prepared carriers to assist preferential gold deposition. All these structures contributed to improved WGS activity of the supported gold catalysts. Activity enhancement was related to Ce–Ti interactions and modification of structural and electronic properties that favor water dissociation. New insights into structure-to-function relationships of Au/Ce–TiO 2 catalysts for WGS reaction are provided. [Display omitted] • Effect of Ce doping in Au/TiO 2 and preparation route on WGS activity was explored. • Au/Ce-doped TiO 2 outperformed Au/TiO 2 by reaching a 93 % CO conversion at 180 °C. • Defective Ti 4 O 7 and Ce 11 O 20 phases occurred during sample preparation. • Modification of structural and electronic properties favored H 2 O dissociation. • Tuning physicochemical properties of TiO 2 enable higher WGS activity of Au catalysts. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) is a life threatening disease in critically ill patients, and characterized by excessive reactive oxygen species (ROS) and inflammatory factors levels in the lung. Multiple evidences suggest that nanozyme with diversified catalytic capabilities plays a vital role in this fatal lung injury. At present, we developed a novel class of polydopamine (PDA) coated cerium dioxide (CeO2) nanozyme (Ce@P) that acts as the potent ROS scavenger for scavenging intracellular ROS and suppressing inflammatory responses against ALI. Herein, we aimed to identify that Ce@P combining with NIR irradiation could further strengthen its ROS scavenging capacity. Specifically, NIR triggered Ce@P exhibited the most potent antioxidant and anti-inflammatory behaviors in lipopolysaccharide (LPS) induced macrophages through decreasing the intracellular ROS levels, down-regulating the levels of TNF-α, IL-1β and IL-6, up-regulating the level of antioxidant cytokine (SOD-2), inducing M2 directional polarization (CD206 up-regulation), and increasing the expression level of HSP70. Besides, we performed intravenous (IV) injection of Ce@P in LPS induced ALI rat model, and found that it significantly accumulated in the lung tissue for 6 h after injection. It was also observed that Ce@P + NIR presented the superior behaviors of decreasing lung inflammation, alleviating diffuse alveolar damage, as well as promoting lung tissue repair. All in all, it has developed the strategy of using Ce@P combining with NIR irradiation for the synergistic enhanced treatment of ALI, which can serve as a promising therapeutic strategy for the clinical treatment of ROS derived diseases as well. [ABSTRACT FROM AUTHOR]

The development of advanced transition metal catalysts for efficient electrocatalytic oxygen evolution has been widely studied, and these catalysts have the potential to replace precious metals and achieve widespread commercial application. The rare earth element cerium with a flexible 4f state can strongly regulate the electronic structure and charge transfer rate of the transition metal catalysts and obviously improves the activity and stability of the catalysts. Herein, we fabricated advanced electrocatalysts consisting of CeO2 nanorods anchored on Co(OH)2 nanosheets based on a facile co-deposition protocol. The CeO2/Co(OH)2 nanocomposite exhibits obviously enhanced OER activity with an overpotential of only 322 mV at a current density of 10 mA cm-2 and a Tafel slope of 55 mV dec-1, which are greater than those of pristine CeO2 and Co(OH)2, respectively. These results were ascribed to the tight interfacial contact and the populations of surface oxygen vacancies, which efficiently increased the electrochemical specific surface area and promoted the transfer/separation of interfacial charge carriers. Overall, the successful synthesis and characterization of the CeO2/Co(OH)2 nanocomposite, along with its exceptional electrocatalytic performance, offer valuable insight into the development of advanced electrocatalysts with applications in green chemistry and environmental remediation. [ABSTRACT FROM AUTHOR]

In order to improve CeO 2 ultraviolet absorption performance and transparency, this paper puts forward that different proportions of calcium oxide are doped during the formation of CeO 2. Doping calcium ions with larger ion size and lower valence leads to the formation of oxygen defects by inhibiting the precipitation of oxygen from cerium oxide and keeps the fluorite structure of cerium oxide stable. The effects of CaO doping on the crystal structure, morphology, and optical characteristics of CeO 2 were analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis spectrophotometry. The pH of sunscreen, spread ability and some physical as well as chemical evaluations were carried out, while to study its UV protection performance the sunscreen SPF test was performed. The UV–vis results revealed that CeO 2 /20%CaO showed highly efficient UV absorption capacity. After adding calcium oxide, the catalytic activity of the material is reduced, due to which the generation of free radicals is demoted, and the harm to human body is decreased. After the addition of 3 wt% nanomaterials into sunscreen, the sun protection factor（SPF ）values of pure cerium oxide and CeO 2 /20%CaO are 1.95 and 2.81, and their sun protection coefficient is increased by 69.39%. Therefore, it is an ideal candidate as a component of ultraviolet screening agent in sunscreens and provides a new idea for the research direction of cerium oxide in anti-ultraviolet applications. [ABSTRACT FROM AUTHOR]

In this work, flower shape cerium oxide (CeO2) nanosheets were synthesized at room temperature through a facile precipitation method without adding any surfactant. The synthesized nanosheets were characterized by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffractometry (XRD) and X‐ray photoelectron spectroscopy (XPS). Results showed that the CeO2 nanosheets form a petal‐like morphology and have fluorite crystal structure with no crystal phase impurity while the average crystallite size of nanosheets i. e. ~10 nm. The CeO2 nanosheets are applied as an antimicrobial agent and the antibacterial property against G+ and G− bacteria i. e. (E. coli and S. Aureus) were studied. The obtained results showed that the synthesized CeO2 nanosheets had good antibacterial performance at different concentrations, which should be attributed to the reversible Ce3+/Ce4+ valence states and greater oxygen vacancies. XPS study of CeO2 nanosheets after antibacterial test confirmed the existence of Ce3+ ions and oxygen vacancies. CeO2 nanosheets have showed the greater potential as antibacterial nanomaterials against both the bactericides. [ABSTRACT FROM AUTHOR]

The sulfate radical (SO 4 •-), known for its high reactivity and long lifespan, has emerged as a potent antimicrobial agent. Its exceptional energy allows for the disruption of vital structures and metabolic pathways in bacteria that are usually inaccessible to common radicals. Despite its promising potential, the efficient generation of this radical, particularly through methods involving enzymes and photocatalysis, remains a substantial challenge. Here, we capitalized on the peroxidase (POD)-mimicking activity and photocatalytic properties of cerium oxide (CeO 2) nanozymes, integrating these properties with the enhanced concept of plasma gold nanorod (GNR) to develop a half-encapsulated core@shell GNRs@CeO 2 Janus heterostructure impregnated with persulfate. Under near-infrared irradiation, the GNRs generate hot electrons, thereby boosting the CeO 2 's enzyme-like activity and initiating a potent reactive oxygen species (ROS) storm. This distinct nanoarchitecture facilitates functional specialization, wherein the heterostructure and efficient light absorption ensured continuous hot electron flow, not only enhancing the POD-like activity of CeO 2 for the production of SO 4 •- effectively, but also contributing a significant photothermal effect, disrupting periodontal plaque biofilm and effectively eradicating pathogens. Furthermore, the local temperature elevation synergistically enhances the POD-like activity of CeO 2. Transcriptomics analysis, as well as animal experiments of the periodontitis model, have revealed that pathogens undergo genetic information destruction, metabolic disorders, and pathogenicity changes in the powerful ROS system, and profound therapeutic outcomes in vivo , including anti-inflammation and bone preservation. This study demonstrated that energy transfer to augment nanozyme activity, specifically targeting ROS generation, constitutes a significant advancement in antibacterial treatment. Schematic illustration of the processes related to combating biofilm infections and diminishing periodontal inflammation of h-GNRs@CeO2@PDS NCs with aPTT, PCAT, and ROS storm functions. The perfect combination of noble metal GNRs and variable valence photocatalyst CeO2 promoted the production of SO4•- and •OH and enhanced the dissipation of dental plaque biofilm and the killing efficiency of periodontal bacteria with the help of aPTT. [Display omitted] [ABSTRACT FROM AUTHOR]

Zirconium (Zr) is an important material in the field of ceramics, dentistry, and nuclear energy. It is also present in particulate form in our environment and can come from naturally occurring minerals such as zircon (ZrSiO4) or from anthropogenic sources such as zirconia (ZrO2). In this study, we present the detection and classification of Zr-particles at the individual particle level by using single-particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS). Neat suspensions of engineered zirconia particles (Zr-eng) and natural zircon particles (Zr-nat) were analyzed by spICP-TOFMS, and a decision tree-based classification strategy was developed to distinguish the particle types based on their multi-elemental compositions. In both Zr-eng and Zr-nat particles, the only well-correlated element with Zr was hafnium (Hf), with Zr : Hf mass ratios converging to 47 : 1 and 75 : 1 for Zr-eng and Zr-nat, respectively. The detection of Hf along with Zr is indicative of both Zr-eng and Zr-nat particle types; however, the Zr : Hf mass ratios are too similar to be used to distinguish between individual nano- and sub-micron Zr-eng and Zr-nat particles. Instead, Zr-nat particles can be distinguished from Zr-eng particles based on the detection of minor-elements, such as iron, yttrium, lanthanum, cerium, and thorium, along with Hf in the Zr-nat particles. With our classification scheme, we demonstrate true-positive classification rates of 40% and 80% for Zr-eng and Zr-nat particle types, respectively. False-positive classification of Zr-nat as Zr-eng was below 2%. We validate our classification scheme by classifying the Zr-particles in controlled mixtures of Zr-nat and Zr-eng particles. In these mixtures, Zr-eng particles are classified at particle-number concentrations (PNCs) down to 49-times lower than that of Zr-nat particles and across a PNC range of 3 orders of magnitude. [ABSTRACT FROM AUTHOR]

In this study, two morphologies of cerium oxide (CeO2) abrasive particles, octahedral and spheroidal, are synthesized by solvothermal method using cerium nitrate hexahydrate (Ce(NO3)3‐6H2O) as raw material. Fourier infrared spectroscopy, X‐ray diffractometer (XRD) and scanning electron microscopy (SEM) are used to characterize the composition and morphology of CeO2 abrasive particles. The synthesized CeO2 is used for chemical mechanical polishing (CMP) of the Si surface of 6H‐SiC wafers, and the surface morphology of the polished wafers are observed using atomic force microscopy (AFM). After polishing with octahedral and spheroidal abrasive particles, the surface roughness of the wafers are 0.327 and 0.287 nm, and the material removal rates (MRR) are 870 and 742 nm h−1, respectively. Calculations comparing the ultraviolet absorption spectra and bandgap energies of the two types of abrasive particles as well as molecular dynamics (MD) simulations reveal that the synthesized octahedral CeO2 particles possessed stronger surface chemical activity and material removal performance. [ABSTRACT FROM AUTHOR]

Alumina based ceramic materials, such as LaMgAl 11 O 19 (LMA) containing amounts of Al, usually resist the CMAS corrosion through forming a compact layer of the CaAl 2 Si 2 O 8. In this work, the LMA/CeO 2 mixed powders in mole ratios of 5:5 (L5C5), 7:3 (L7C3) and 9:1 (L9C1) were pressed and sintered to prepare the ceramic bulks. The resistance to CMAS corrosion of the LMA/CeO 2 , the CeO 2 and the LMA ceramic bulks were tested and compared at 1250ºC and 1350ºC for 1 h, 5 h and 10 h. Results showed that the added CeO 2 in the LMA can decrease the porosity and improve the resistance to CMAS corrosion. The combined effects of the LMA and CeO 2 promoted the formation of the CaAl 2 Si 2 O 8. The L5C5 and the L9C1 with appropriate composition have good resistance to CMAS corrosion at 1250ºC, and the L9C1 can alleviate CMAS infiltration compared with the LMA and other proportional materials at 1350ºC. [ABSTRACT FROM AUTHOR]

[Display omitted] Amorphous engineering and atomistic doping provide an effective way to improve the catalytic activity in the oxygen evolution reaction (OER) of transition metal layered double hydroxides. Herein, Cerium (Ce) was introduced into NiFe-based oxyhydroxide using a modified aqueous sol–gel procedure. Ce as an electron acceptor promoted the coupling oxidation of Ni2+/3+ in NiFe oxyhydroxide, and the activated oxyhydroxide showed excellent catalytic activity in OER. The amorphous NiFeCe oxyhydroxide electrocatalyst demonstrated great modified OER catalytic activity under alkaline conditions and excellent cyclic stability, with an overpotential of only 284 mV at 50 mA cm−2, which was significantly better than amorphous NiFe oxyhydroxide and crystalline NiFeCe oxyhydroxide. Theoretical investigations further indicated that the overpotential of the rate-determining step (*OOH deprotonation) decreased from 0.66 to 0.41 V after Ce doping and strong electron interaction, effectively reducing the dependence of proton activity in the solution of OER, and optimizing the adsorption/desorption process of related oxygen-containing species in the reaction. This work also provides a good reference for optimizing OER activity by using rare-earth-metal induced electronic regulation strategies. [ABSTRACT FROM AUTHOR]

BaCO3 nanoparticles are demonstrated as outstanding catalysts for high-temperature oxygen reduction reaction on the La0.8Sr0.2FeO3-δ (LSF)-Sm0.2Ce0.8O2−δ (SDC) cathode for solid oxide fuel cells (SOFCs). X-ray diffraction shows that BaCO3 is chemically compatible with LSF and SDC under the fabrication and operation conditions of intermediate-temperature SOFCs. The BaCO3 nanoparticles can greatly reduce the interfacial polarization resistance; from 1.65 to 0.35 Ω cm2 at 700 °C when 7.6wt% BaCO3 is infiltrated to the porous LSF-SDC electrode. Electrochemical impedance spectra also show that there are both significantly decrease in high- and low-frequency resistance, indicating that BaCO3 nanoparticles can greatly enhance the oxygen ions transfer and surface reaction steps in LSF-SDC composite cathode. In addition, LSF-SDC cathodes with infiltrated BaCO3 nanoparticles have shown excellent stability and substantially enhanced single-cell performance, suggesting BaCO3 nanoparticles are very effective as a catalytic phase for LSF-SDC cathode. [ABSTRACT FROM AUTHOR]

(ZrO2)1 − x −y(Y2O3)x(CeO2)y (x = 0.08–0.10; y = 0.0–0.01) solid solution crystals were grown by skull melting technique. The effects of CeO2 addition on the crystal structure and high-temperature conductivity of the crystals have been investigated. According to X-ray absorption near-edge structure spectroscopy, it was found that Ce cations in crystals are present mainly as Ce4+ ions. The study of the grown crystals by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy showed that all the grown crystals were single-phase and had either a tetragonal t'' or cubic structure, the latter having crystals containing 10 mol% Y2O3 and doped with CeO2. Doping of the crystals with CeO2 was accompanied by a linear increase in the lattice parameter. This indicates the entry of CeO2 into the crystal lattice with the formation of a solid solution. The study of the ionic conductivity of crystals by impedance spectroscopy in the temperature range 400–900 °C showed that the substitution of Zr4+ ions with Ce4+ ions manifests itself in different ways and can either increase or decrease the value of high-temperature conductivity depending on the content of stabilizing yttrium oxide. Possible reasons for this behavior are discussed. [ABSTRACT FROM AUTHOR]

The structure, oxygen non-stoichiometry, thermomechanical and electrical properties of perovskite-type BaFe1−xCexO3−δ (x = 0.05, 0.10, 0.15) were studied in the light of the potential use of these oxides as electrode materials of solid oxide fuel cells. Partial substitution of iron by cerium in barium ferrite was shown to stimulate water incorporation into oxygen vacancies. This phenomenon is manifested by dehydration during heating, which is clearly registered by thermogravimetric and dilatometric measurements. Different behavior of cerium ions residing in the A- and B-sublattices of perovskite-type ferrites was revealed. In contrast to Sr1−xCexFeO3−δ oxide series, in which the concentration of Ce3+ ions under reducing conditions can exceed that of Ce4+, no signs of Ce4+ reduction were detected in BaFe1−xCexO3−δ under the same conditions. A negative influence of cerium substitution for iron on electrical conductivity was detected. The oxygen-ion conductivity of the x = 0.05 composition at 950 °C was found to be as high as 0.358 ± 0.002 S·cm−1, whereas the ion conductivity of the oxide with x = 0.10 was only 0.041 ± 0.001 S·cm−1. Such a strong suppression of oxygen transport is argued to be the result of a local lattice strain caused by a considerable difference between the sizes of cerium and iron ions. The unfavorable impact of cerium in BaFe1−xCexO3−δ on n- and p-type conductivity is attributed to its impeding role in the Fe–O–Fe electron transport network. [ABSTRACT FROM AUTHOR]

Multilayer Y 3 Al 5 O 12 (YAG)/MgAl 2 O 4 (MAS) ceramics doped with europium and cerium ions exhibiting functionally graded properties was consolidated by the SPS method using during layer-by-layer formation powders approach. The optimal modes for YAG/MAS ceramics doped with rare earth ions preparation were obtained during the SPS process. It was observed that at the isothermal exposure stage at a temperature of 1450 °C shrinkage process stops. Introduction of CeO 2 , Eu 2 O 3 into the YAG/MAS ceramics leads to a shift in the range of intense shrinkage to lower temperatures. Morphological, optical and luminescent properties have been studied in detail for fabricated YAG/MAS ceramics with different arrangement of the layers. The luminescent properties using time-resolved cathodoluminescence (CL) and steady state photoluminescence (PL) were investigated in detail. The spectral dynamics in nanosecond and millisecond time range was demonstrated after e-beam excitation. The PL efficiency of YAG/MAS ceramics and nature of luminescence centers were analyzed. The novel kind of YAG/MAS functional ceramics could be promising candidate for efficient luminescent converter. [ABSTRACT FROM AUTHOR]

Future low-voltage driven capacitor devices are appealed to employ the eco-friendly ceramics featured with high-stable dielectric energy storage capabilities. Herein, the dielectric energy storage properties of (Bi 0 · 5 Na 0.5) 0.65 (Ba 0 · 3 Sr 0.7) 0.35 (Ti 0 · 98 Ce 0.02)O 3 +8 wt% K 0 · 5 Na 0 · 5 NbO 3 + x wt% CeO 2 (BNBSTCK + C x) lead-free relaxor ferroelectric ceramics were comprehensively investigated. By maintaining the relaxor ferroelectric phases near room temperature and disrupting the ferroelectric long-range order via CeO 2 additive, the EIA X9R specification was fulfilled at the best composition of x = 8 over a wide range of −74∼208 °C with a relatively high dielectric constant ε r = 904 and low loss tan δ = 10−3 (@25 °C & 1 kHz). Meanwhile, the good recoverable energy storage density W rec = 0.77 J/cm3 and high efficiency η = 91.6% were achieved only at a low electric field of 95 kV/cm. Furthermore, these ceramics exhibited exceptional frequency and cycle dependent energy storage stability, which could guide the design ideas of long-life X9R ceramic capacitors suitable for high and low working temperature environments in low-voltage driven energy storage applications. [ABSTRACT FROM AUTHOR]

Bi 3 Ti 1.5 W 0.5 O 9 –Bi 4 Ti 3 O 12 intergrowth Aurivillius piezoceramics with 0.3mol Nb5+ replacing B site and x mol CeO 2 (x = 0–0.25, abbreviated as BTNW-BITN- x Ce) replacing A site were synthesized by the conventional solid-state reaction method. The structures and electrical properties of BTNW-BITN- x Ce samples were systematically explored. The results of XRD, Raman, and SEM showed that a single phase was formed. The results of XPS showed that the introduction of Ce ions reduces the concentration of oxygen vacancies, which is beneficial to improving piezoelectric performance. In addition, the results of PFM indicated that the introduction of Ce ions increased the diversity of domains and made it easier for domains to respond under the same voltage, which is also conducive to the improvement of piezoelectric properties. The d 33 of the optimal component BTNW-BITN- x Ce ceramics is 23.6 pC/N and it possesses 21.6 pC/N after 500 °C annealing treatment, which implies potential in the application of high-temperature sensors. [ABSTRACT FROM AUTHOR]

Chemical looping air separation (CLAS) represents a promising approach to use thermal energy for high-purity oxygen production. CeO 2 represents a class of material that uncouples oxygen using thermal energy, but the required temperature is usually very high (>1400 °C). This limits the potential use for CeO 2 -based materials in CLAS. This study reports a Pr doped CeO 2 oxygen sorbents for chemical looping air separation at ultra-low temperatures. The as-formed Ce 1-x Pr x O 2 solid solution can uncouple oxygen effectively, achieving a redox oxygen capacity of 0.88 wt% at isothermal condition as low as 500 °C. The redox oxygen capacity can be further enhanced to 1.63 wt% in temperature-swing cycles between 400 °C and 900 °C. Moreover, oxygen partial pressure-swing cycles show that the Ce 1-x Pr x O 2 solid solution maintains 95% of its redox oxygen capacity at oxygen partial pressure as low as 0.02 atm, indicating its potential applications in oxygen separation from diluted air. DFT calculations and other physio-chemical characterizations indicate that Pr doping can effectively reduce the oxygen vacancy formation energy, and gaseous oxygen is uncoupled when Pr4+ and Ce4+ are reduced in the Ce 1-x Pr x O 2 solid solution. Overall, this study highlights the novel performance of CeO 2 with Pr doping and could offer insights into CeO 2 modification strategies for thermal chemical applications. [ABSTRACT FROM AUTHOR]

The CeO 2 @γ-Fe 2 O 3 nanocomposites with varying CeO 2 content (0–50 mol%) were prepared by the sol-gel electrospinning. XRD analysis confirmed the phase transition from α-Fe 2 O 3 to cubic γ-Fe 2 O 3 with addition of Ce ions and dominant phase for 30, and 50% CeO 2 @γ-Fe 2 O 3 nanocomposites was cubic CeO 2. FESEM images revealed that the ribbon-like α-Fe 2 O 3 convert to the CeO 2 @γ-Fe 2 O 3 nanofibers. The EDS map images and FTIR confirmed the homogenous distribution of elements and chemical bonds, respectively. Interestingly, the induced phase transition resulted in superparamagnetic behavior of 10% CeO 2 @γ-Fe 2 O 3. The supercapacitive performance of the CeO 2 @γ-Fe 2 O 3 nanofibers grown on the nickel foam were examined by electrochemical analyzes. The 50% CeO 2 @γ-Fe 2 O 3 electrode demonstrated the highest specific capacitance of 1169.3 F g−1 at a current density of 1 A g−1 and the capacitance retention of 89.7% after 1000 cycles at 7 A g−1. Additionally, asymmetric supercapacitor (ASC) was assembled using CeO 2 @γ-Fe 2 O 3 and rGO as cathode and anode electrodes, respectively. The CeO 2 @γ-Fe 2 O 3 //rGO ASC displayed an energy density of 36.8 Wh kg−1 at a power density of 700 W kg−1, demonstrating its potential for use in energy storage systems. [ABSTRACT FROM AUTHOR]

The objective of this study was to synthesize and evaluate the biological effectiveness of cerium oxide (CeO2) against various bacterial and fungal strains. The chitosan‐CeO2 nanocomposite was comprehensively characterized. The Fourier transform infrared (FTIR) spectra displayed a combination of bands that provided evidence for the existence of a composite complex between the chitosan (CS) structure and the Ce–O bands originating from CeO2 nanoparticles. SEM measurements showed uniform dispersion across the whole CS surface, and the morphological changes were clearly observed as the CeO2 nanoparticle content was increased. In contrast, CS‐CeO2 demonstrates enhanced antibacterial efficacy against both Gram‐positive and Gram‐negative pathogens. The MTT method was utilized to assess the cytotoxicity of the examined CS‐CeO2, with the aim of evaluating the cell viability of various cancer cell lines under varying ultraviolet (UV) exposures. The enhanced penetration of CS and CeO2 nanocomposites into cancer cells during their anticancer activity, even in the absence of UV light, led to an increased rate of cell death. The administration of greater dosages of CS and its CeO2 nanocomposites led to an increased generation of reactive oxygen species (ROS), which was observed to be associated with an enhancement in the efficacy of anticancer activity. The impact was additionally amplified through exposure to UV radiation. The nanocomposite thin films demonstrated much higher antioxidant activity against the DPPH radical as compared to ordinary vitamin C. The aforementioned observation was derived from an evaluation of the antioxidant properties of the subject utilizing the DPPH free radical scavenging technique. [ABSTRACT FROM AUTHOR]

Herein, a convenient and environment-friendly reduction strategy was employed to attach silver nanoparticles onto ceria nanorods (AgCe). Nanorods were synthesised through a green chemistry approach with varied silver contents and Citrus maxima peel extract as a reducing agent. The resulting AgCe nanocomposites were evaluated for their efficacy in reducing methyl orange (MO) at ambient temperature by employing NaBH4 as a protonating agent. The as-prepared samples were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray energy-dispersive spectroscopy, Raman spectroscopy, Brunauer–Emmett–Teller method, and high-resolution transmission electron microscopy. The as-prepared sample exhibited outstanding activity on the catalytic reduction of MO, and the synergistic effect between Ag nanoparticles and CeO2 nanorods was proved. Silver nanoparticles were formed and dispersed well on the surface of ceria nanorods. Based on the UV–Vis results, the activity of the samples with silver was superior to that of pure ceria. The 0.2AgCe sample was the most effective when the catalyst concentration was 0.08 g/L, and the molar ratio between MO and NaBH4 was 1/200. The entire catalytic reduction was thought to follow pseudo-first-order kinetics. Hence, Ag nanoparticles decorated on CeO2 efficiently offered excellent catalytic efficiency and stability in MO reduction and that the catalyst was suitable for practical applications, such as wastewater treatment. [ABSTRACT FROM AUTHOR]

Doubly ionized cerium (Ce2+) is one of the most important ions to understand the kilonova spectra. In particular, near-infrared (NIR) transitions of Ce  iii between the ground (5p6 4f2) and first excited (5p6 4f 5d) configurations are responsible for the absorption features around 14 500 Å. However, there is no dedicated theoretical studies to provide accurate transition probabilities for these transitions. We present energy levels of the ground and first excited configurations and transition data between them for Ce  iii. Calculations are performed using the grasp 2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. Compared with the energy levels in the NIST data base (Kramida et al. 2024), our calculations reach the accuracy with the root-mean-square (rms) of 2732 or 1404 cm−1 (excluding one highest level) for ground configuration, and rms of 618 cm−1 for the first excited configuration. We extensively study the line strengths and find that the Babushkin gauge provides the more accurate values. By using the calculated gf values, we show that the NIR spectral features of kilonova can be explained by the Ce  iii lines. [ABSTRACT FROM AUTHOR]

BACKGROUND: The repair process of skin trauma is complex and susceptible to infection, easy to lead to poor healing, is the current difficulty and hot spot in wound repair research, and has received extensive attention in the fields of traditional Chinese medicine and tissue engineering. OBJECTIVE: To investigate the effect of moxibustion and reduced graphene oxide/cerium oxide nanocomposite on promoting the healing of infectious wounds. METHODS: (1) Reduced graphene oxide/cerium dioxide nanocomposites with mass ratios of 2:1, 1:1 and 1:2 were synthesized by hydrothermal method. The resulting composites were recorded as G2C1, G1C1and G1C2, respectively. The photothermal properties, cytotoxicity and antibacterial properties of the three kinds of materials were tested. After taking moxa sticks, three kinds of moxibustion distances were set (3.0-3.5 cm, recorded as moxibustion 1; 2.5-3.0 cm, recorded as moxibustion 2; 2.0-2.5 cm, recorded as moxibustion 3). Moxibustion was applied to the surface of human skin for 10 minutes to detect the photothermal properties. The antibacterial properties of moxibustion were tested at three different distance intervals. Simultaneously, the back body surface infrared imaging of rats with different mass concentrations of G1C1material, moxibustion (three kinds of moxibustion distances) and moxibustion 2+G1C1material was detected. (2) Sixty male Sprague-Dawley rats were selected to model the wound of Staphylococcus aureus infection. 48 hours later, they were randomly divided into 10 groups with 6 rats in each group: control group (did not receive any treatment), mupirocin group, moxibustion 2+G1C1group, moxibustion 1 group, moxibustion 2 group, moxibustion 3 group and 60, 80, 100, and 120 μg/mL G1C1groups (The G1C1group was given 808 nm near-infrared laser irradiation for 10 min/time, and the G1C1suspension was loaded on the wound surface before each treatment. Each group of moxibustion underwent insitu suspension moxibustion, and the intervention time was 10 min/time. Moxibustion 2+G1C1group was loaded with G1C1suspension on the wound surface before each treatment, and moxibustion was suspended in situ with moxa strips, and the intervention time was 10 min/time). The frequency of treatment was 2 days once. Wound healing, wound colony count and repair were detected after 7 days of intervention. RESULTS AND CONCLUSION: (1) The three kinds of reduced graphene oxide/cerium dioxide nanocomposites had good photothermal properties, and the higher the mass concentration of the composites, the better the photothermal properties. The temperature of the moxibustion 2 group reached 47.6 °C for 10 minutes without causing thermal damage, which was more suitable for animal experiments. The results of co-culture with NIH-3T3 cells exhibited that 60, 80, and 100 μg/mL G1C1had good biocompatibility. The results of a co-culture experiment with Staphylococcus aureus suspension displayed that G2C1, G1C1and G1C2 had good antibacterial activity, among which G1C1group demonstrated excellent antibacterial performance, and the antibacterial rate reached 100% when its mass concentration was 80 μg/mL. 60-120 μg/mL G1C1could effectively remove Staphylococcus aureus biofilm, and the higher the material mass concentration, the better the removal effect. Moxibustion could also effectively remove Staphylococcus aureus biofilm, and the closer the moxibustion was, the better the removal effect. (2) Compared with the control group, the wound area of the mupirocin group, moxibustion 2 group, moxibustion 2+G1C1group and 80, 100 μg/mL G1C1groups was significantly reduced on day 7 of treatment, and the quality of wound repair was better. Mupirocin, G1C1, moxibustion and moxibustion 2+G1C1could effectively remove the residual bacteria on the wound surface, and the higher the mass concentration of G1C1, the lower the residual bacteria. Among them, the wound repair efficiency and bacterial residue of 80 μg/mL G1C1group and moxibustion 2 group were very similar, and the wound repair efficiency of both was better than that of mupirocin group. In addition, it was also observed that the combination of materials and moxibustion had a better ability to clear wound bacteria than that used alone. (3) The results confirm that moxibustion, reduced graphene oxide/cerium dioxide nanocomposites and their combination have good anti-infection and wound healing effects. [ABSTRACT FROM AUTHOR]

Amyloid-β (Aβ) readily misfolds into neurotoxic aggregates, generating high levels of reactive oxygen species (ROS), leading to progressive oxidative damage and ultimately cell death. Therefore, simultaneous inhibition of Aβ aggregation and scavenging of ROS may be a promising therapeutic strategy to alleviate Alzheimer's disease pathology. Based on the previously developed antibody 1F12 that targets all forms of Aβ42, we developed an Aβ42 and ROS dual-targeting nanocomposite using biodegradable mesoporous silica nanoparticles as carriers to load ultra-small cerium oxide nanocrystals (bMSNs@Ce-1F12). By modifying the brain-targeted rabies virus glycoprotein 29 (RVG29-bMSNs@Ce-1F12), this intelligent nanocomposite can efficiently target brain Aβ-rich regions. Combined with peripheral and central nervous system treatments, RVG29-bMSNs@Ce-1F12 can significantly alleviate AD symptoms by inhibiting Aβ42 misfolding, accelerating Aβ42 clearance, and scavenging ROS. Furthermore, this synergistic effect of ROS scavenging and Aβ clearance exhibited by this Aβ42 and ROS dual-targeted strategy also reduced the burden of hyperphosphorylated tau, alleviated glial cell activation, and ultimately improved cognitive function in APP/PS1 mice. Our findings indicate that RVG29-bMSNs@Ce-1F12 is a promising nanodrug that can facilitate multi-target treatment of AD. [ABSTRACT FROM AUTHOR]

Herein, we synthesised a series of nonstoichiometric Nd−Ce−O composite oxides with a fluorite or rare‐earth C‐type phase structure using the glycine combustion method for the oxidative coupling of methane (OCM) reaction. As the amount of Nd3+ increases, the oxygen vacancies in this series of composite oxides gradually increase, leading to an amount increasing in the C2‐selective oxygen species O2− generated by the oxygen vacancies. In addition, with the increase in Nd3+, the number of moderate basic sites on the catalyst surface also improves, another significant factor affecting the OCM reaction performance of the composite oxides. Nd0.9Ce0.1O1.55 possesses optimal low‐temperature OCM reaction performance, achieving 8.0 % C2 yield at 450 °C and 14.1 % C2 yield at 700 °C. This can be attributed to the nonstoichiometric rare‐earth C‐type crystalline phase structure of Nd0.9Ce0.1O1.55, which exhibits the highest abundance of oxygen vacancies, selective oxygen species O2−, and moderate basic sites. [ABSTRACT FROM AUTHOR]

Membrane reformers emerge as an efficient technology for 'on‐site' ultra‐pure hydrogen production. The membrane reformer can be integrated with PEM fuel cell (PEMFC) to provide power. However, as the PEMFC works at lower temperature hence, such integration requires a low temperature catalyst. Further, for successful integration of membrane reformer with PEMFC, a low CO selective catalyst is vital. In current work, Ni‐based alumina and ceria supported catalysts are used. The effect of La and Fe promoters on the performance of Ni‐based alumina and ceria supported catalysts are investigated. The catalysts are synthesized using wet impregnation method. A complete characterization of catalysts is performed using BET, XRD, FESEM, and EDX. Fe promoted catalysts shows low CO and high CO2 selectivity which is desirable for membrane reformer. However, the catalytic activity of Fe promoted Ni‐based alumina and ceria supported catalysts were low. La promoted Ni‐based catalysts show high catalytic activity on both alumina and ceria supported catalysts. La promoted catalysts also gives low start up time, high catalytic activity and low CO selectivity at low temperature. Ni−La/Al2O3 catalyst provides 50 % conversion and 12 % CO selectivity at 500 °C. This makes it suitable for 'on‐site' generation of ultra‐pure hydrogen through membrane reformer. [ABSTRACT FROM AUTHOR]

The dry reforming of glycerol (GDR) is one of the alternatives for syngas production by utilizing biodiesel byproduct glycerol and CO 2. The development of highly active and stable catalyst is significantly important to achieve GDR process, and the current work provides insights into Co and Fe-doping effects of mesoporous CeO 2 (CoFeCe) catalysts synthesized by the colloidal solution combustion method. The prepared catalysts presented the uniform mesoporous structure, the doping of Co and Fe metals resulted in stronger metal-support interaction. The GDR experimental data were compared with the non-stoichiometric thermodynamic equilibrium values. The conversions of glycerol and CO 2 were increased with increasing the reaction temperatures due to the endothermic GDR reaction, and the H 2 /CO produced in syngas was in the range of 0.7–1.4. Due to the improvement of Co and Fe metals in the mesoporous structure of CeO 2 catalyst, the 7CoFeCe catalyst exhibited excellent and stable GDR performance and no significant signs of deactivation were observed during 76 h test, and the results indicated that the enhanced interaction and high dispersion of Co and Fe in mesoporous CeO 2 catalyst could inhibit carbon formation and promote GDR reaction. [Display omitted] • Co and Fe co-doping on CeO 2 catalyst enhanced GDR reactions. • Increasing in Co-doping improved conversions of glycerol and CO 2 to syngas. • Co–Fe interaction and CeO 2 redox ability inhibited the formation of carbon. • Catalyst with CoFeCe of mole ratio 7: 5:10 exhibited high activity and stability. [ABSTRACT FROM AUTHOR]

Photothermal synergistic catalysis (PTSC) offers promising potential for the dry reforming of methane (DRM) to produce syngas, but designing suitable catalysts suitable for photothermal processes poses significant challenges. In this study, we present a core-shell catalyst consisting of a SiO2 shell encapsulating Ni loaded on the CeO2–ZrO 2 support, which proved to be well-suited for PTSC-DRM under milder conditions. Compared to traditional thermal catalysis (TC), PTSC at 600 °C exhibited superior CH4/CO2 conversions (63.5 %/55.9 %) and higher H 2 /CO yields (137.0 mmol·g -1 ·h -1 /182.9 mmol·g -1 ·h -1). The TOFs under PTSC-DRM are 1.3–2.9 times higher than the corresponding TOFs in TC-DRM. The catalyst demonstrated strong stability during a 60-h aging test, which can be attributed to the restricted migration of Ni and the accelerated movement of oxygen induced by illumination via structure effect which also lead to the boosted activity benefited from a reduced bandgap of 2.2 eV and improved charge separation/migration efficiency during PTSC reaction. [Display omitted] • Boosted syngas production via photothermal synergistic dry reforming of CH 4. • A novel core-shell structured Ni/CeO 2 –ZrO 2 @SiO 2 catalyst tailored for photothermal synergistic reaction. • Enhanced activity and anti-carbon performance of the catalyst due to the encapsulation of SiO 2. [ABSTRACT FROM AUTHOR]

Within this work, reticulated monolithic foams and granules made from CaMnO3 − δ and strontium substituted variations are demonstrated to significantly improve the performance of a water splitting redox oxide when employed as a thermochemical oxygen pumping material. Two different process procedures are tested and foams made from Ca0.9Sr0.1MnO3 − δ with a strontium content of 10% outperform all other specimens in both process configurations. Additionally, the performance of Ca1 − xSrxMnO3 − δ with varying strontium content as a thermochemical oxygen pumping material is studied by means of a newly developed theoretical process model. While the model does not precisely predict the excellent experimental performance of strontium‐substitute compositions, it provides valuable insights into the impact of geometry and structure on the specimen's performance in thermochemical oxygen‐pumping processes. This work demonstrates the practical application of monolithic 3D structures made entirely from perovskite material in thermochemical oxygen pumping processes and provides a process model that can serve as basis for material screening and process optimization in future work. [ABSTRACT FROM AUTHOR]

Developing ecofriendly anticorrosion coating has great demand for marine protection. Incorporation of nontoxic inorganic fillers into waterborne epoxy (WEP) coating shows tremendous potential for enhancing corrosion resistance. However, the application of MXene/WEP coating is limited by the poor dispersion of MXene in WEP and insufficient corrosion resistance. Herein, a polydopamine (PDA) modified MXene‐CeO2@PDA (MCP) filler is constructed by a combination of CeO2 with MXene and embedded into WEP to form ecofriendly anticorrosion MCP/WEP coating. Dispersion of MXene in WEP is improved by the introduction of CeO2 and PDA modification. Benefiting from the synergy of the physical labyrinth effect of MXene and the chemical inhibition effect of CeO2, MCP/WEP coating exhibits remarkable anticorrosion behavior in 3.5 wt% NaCl solution with a low corrosion rate (CR) of 4.48 × 10−6 mpy, which is three orders of magnitude lower than that of blank WEP (4.78 × 10−3 mpy). Moreover, MCP/WEP presents long‐term and stable corrosion protection for over 30 days. The results reveal the incorporation of MCP significantly promotes the anticorrosion performance of WEP. [ABSTRACT FROM AUTHOR]

Nitrogen dioxide (NO2) gas sensors are pivotal in upholding environmental integrity and human health, necessitating heightened sensitivity and exceptional selectivity. Despite the prevalent use of metal oxide semiconductors (MOSs) for NO2 detection, extant solutions exhibit shortcomings in meeting practical application criteria, specifically in response, selectivity, and operational temperatures. Here, we successfully employed a facile microwave-solvothermal method to synthesize a mesoporous CeO2/CNCs nanocomposite. This methodology entails the rapid and comprehensive dispersion of CeO2 nanoparticles onto helical carbon nanocoils (CNCs), resulting in augmented electronic conductivity and an abundance of active sites within the composite. Consequently, the gas-sensing sensitivity of the nanocomposite at room temperature experienced a notable enhancement. Moreover, the presence of cerium oxide and the conversion of Ce3+ and Ce4+ ions facilitated the generation of oxygen vacancies in the composites, thereby further amplifying the sensing performance. Experimental outcomes demonstrate that the nanocomposite exhibited an approximate 9-fold increase in response to 50 ppm NO2 in comparison to pure CNCs at room temperature. Additionally, the CeO2/CNCs sensor displayed remarkable selectivity towards NO2 when exposed to gases such as NH3, CO, SO2, CO2, and C2H5OH. This straightforward microwave-solvothermal method presents an appealing strategy for the research and development of intelligent sensors based on CNCs nanomaterials. [ABSTRACT FROM AUTHOR]

[Display omitted] To meet the requirements in air quality monitors for the public and industrial safety, sensors are required that can selectively detect the concentration of gaseous pollutants down to the parts per million (ppm) and ppb (parts per billion) levels. Herein, we report a remarkable NH 3 sensor using Ni-doped CeO 2 octahedral nanostructure which efficiently detects NH 3 as low as 45 ppb at room temperature. The Ni-doped CeO 2 sensor exhibits the maximum response of 42 towards 225 ppm NH 3 , which is ten-fold higher than pure CeO 2. The improved sensing performance is caused by the enhancement of oxygen vacancy, bandgap narrowing, and redox property of CeO 2 caused by Ni doping. Density functional theory confirms that O vacancy with Ni at Ce site (V O Ni Ce) augments the sensing capabilities. The Bader charge analysis predicts the amount of charge transfer (0.04 e) between the Ni-CeO 2 surface and the NH 3 molecule. As well, the high negative adsorption energy (≈750 meV) and lowest distance (1.40 Å) of the NH 3 molecule from the sensor surface lowers the detection limit. The present work enlightens the fabrication of sensing elements through defect engineering for ultra-trace detection of NH 3 to be useful further in the field of sensor applications. [ABSTRACT FROM AUTHOR]

The electrolysis of seawater has become a preferred method for hydrogen production since the current shortage of freshwater resources, offering an effective strategy to address the energy crisis. Nevertheless, this technology is limited by the following two factors: (i) low stability of catalytic materials at high-current density and (ii) accelerated corrosion rate of the electrode due to high concentrations of chloride ions (Cl−). Herein, an ultrafine phosphorus (P) and ruthenium (Ru) co-doped cerium dioxide (CeO2) self-supporting electrode (P, Ru–CeO2) was constructed via a high-pressure treatment strategy. Under the oxygen vacancies (Ov) in the CeO2 support and the anionic protective layer formed by the P–O bond, the electrode exhibits exceptional catalytic activity and durability in saline-alkali water, which only requires 291 mV to reach 1000 mA cm−2 in 1 M KOH + 1.5 M NaCl electrolyte. Besides, the electrode could operate stably at 1000 mA cm−2 over 100 h without significant attenuation, which can reach the level of industrial water electrolysis. This work presents a novel approach to designing and engineering excellent catalysts for industrial water electrolysis. [ABSTRACT FROM AUTHOR]

This study introduces a novel approach to synthesising a three-dimensional (3D) micro-nanostructured amorphous biosilica. The biosilica is coated with cerium oxide nanoparticles obtained from laboratory-grown unicellular photosynthetic algae (diatoms) doped metabolically with cerium. This unique method utilises the ability of diatom cells to absorb cerium metabolically and deposit it on their silica exoskeleton as cerium oxide nanoparticles. The resulting composite (Ce-DBioSiO2) combines the unique structural and photonic properties of diatom biosilica (DBioSiO2) with the functionality of immobilised CeO2 nanoparticles. The kinetics of the cerium metabolic insertion by diatom cells and the physicochemical properties of the obtained composites were thoroughly investigated. The resulting Ce-DBioSiO2 composite exhibits intense Stokes fluorescence in the violet–blue region under ultraviolet (UV) irradiation and anti-Stokes intense violet and faint green emissions under the 800 nm near-infrared excitation with a xenon lamp at room temperature in an ambient atmosphere. [ABSTRACT FROM AUTHOR]

Due to the limitations of the Kramers-Kronig relationship, how to achieve ultra-wide effective absorption bandwidth remains a challenge for typical magnetic-dielectric absorbers. In the present work, we have explored the possibility of obtaining ultra-wide absorption bandwidth in FeSiAl composites with help of efficient electromagnetic (EM) simulation software-Computer Simulation Technology (CST). Flaky FeSiAl powders covered by CeO 2 have been prepared, in which EM parameters can be tuned by filling ratio of FeSiAl/CeO 2 in FeSiAl/CeO 2 -paraffin composites. The filling ratio has an effect on impedance matching and EM parameters by the arrangement of particles in the paraffin. The composite with 30 wt% flaky FeSiAl/CeO 2 achieves an effective absorption bandwidth (EAB) of 6.48 GHz and the optimal microwave absorption efficiency of 1499.3 dB GHz/(wt%⋅m) at 1.9 mm. Integrated with a macroscale honeycomb structural design, the FeSiAl/CeO 2 composites based metastructure exhibits broadband microwave absorption with an EAB of 14.224 GHz covering from 3.776 GHz to 18 GHz and reflection loss of-65.61 dB at 8.5 GHz. The excellent performances of the designed absorber are ascribed to multiple loss by integrating EM parameters of flaky FeSiAl/CeO 2 and the geometry parameters of honeycomb metasrtucture. The present work makes flaky FeSiAl/CeO 2 composites possible to achieve broadband microwave absorption. [ABSTRACT FROM AUTHOR]

While Ce3+-doped ZnO nanoparticles have been extensively explored for UV light photocatalytic applications, harnessing their efficacy for visible light photocatalysis remains a significant challenge. This study demonstrates the outstanding degradation efficiency under visible light of Ce3+-doped ZnO nanoparticles synthesized via the sol-gel route. At lower concentrations (<3 mol%), Ce3+ ions seamlessly substitute Zn2+ ions within the ZnO lattice, while at higher dopant levels (≥3 mol%), the formation of CeO 2 nanoparticles on the ZnO surface becomes an additional noteworthy feature. This unique combination in highly Ce3+-doped ZnO nanoparticles leads to the creation of Ce-impurity states (e.g., Ce3+/Ce4+) within the ZnO structure, effectively separating electrons and holes. Consequently, the generation of superoxide radical anions is enhanced, boosting the remarkablely DB71 dye degradation efficiency (>90%) of all highly Ce3+-doped ZnO samples (≥3 mol%) in comparison with pristine and lightly Ce3+-doped ZnO samples (<3 mol%). In all highly Ce3+-doped ZnO samples, 5-mol% doped sample shows the highest DB71 degradation efficiency of 98.4%. This remarkable achievement is observed when utilizing 0.1 g of 5-mol% doped sample, 50 mg/L of initial DB71 concentration, pH of 5, and notablely under visible light irradiation. Furthermore, the DB71 degrading efficiency of ZnO:5%Ce3+ maintains an impressive 90.3% over five cycles from its initial value of 98.4%, underscoring the potential of ZnO:Ce3+ as a promising photocatalyst for practical wastewater treatment. [ABSTRACT FROM AUTHOR]