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This study explores the impact of co-doping on ceria-based electrolyte materials with samarium (Sm) and gadolinium (Gd) to improve their structural, morphological, and ionic conductivity properties synthesized through a co-precipitation technique using sodium hydro-oxide (NaOH) as the precipitating agent for solid oxide fuel cell (SOFC) applications. The aforementioned approach provides benefits like uniformity, high purity, and simplicity of synthesis. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the crystal structure and morphology of the synthesized materials. No secondary phases were observed revealing the phase purity of the material. A decrease in lattice constant was detected due to the replacement of a small concentration of Gd with Sm having small ionic radii compared to Sm. Homogeneity and decrease in particle size of prepared samples were observed via SEM analysis predicting the enhancement in the grain size with the reduction in grain boundaries and elemental composition through EDX agreed with the starting composition. Impedance spectroscopy was employed to measure the ionic conductivity of the electrolyte samples. Our results demonstrate a significant decrease in grain and grain boundary resistances causing the increase in ionic conductivity with the introduction of Gd and Sm as co-dopants into the ceria structure. The optimal doping concentration was found to be 10 % Gd and 10 % Sm. The co-doped ceria had a high ionic conductivity of 6.28 × 10−2 S/cm at 750οC and a low activation energy of 0.44 eV, indicating improved ionic mobility. This study provides valuable insights into the role of Gd and Sm co-doping in enhancing the ionic conductivity of ceria-based electrolyte materials, which is crucial for the advancement of high-performance SOFCs. [ABSTRACT FROM AUTHOR]

Cerium dioxide (CeO2) has huge potential in many applications ranging from biochemical engineering to the coating industry. Here, the first example of visible light photo‐mediated Pickering emulsion polymerization of (meth)acrylate monomers is reported using CeO2 nanoparticles (NPs) as solid stabilizer. A ω,ω′−dicarboxylic acid diphenyl disulfide photoinitiator is anchored on the surface of the CeO2 NPs and used to initiate the emulsion polymerization of methyl methacrylate (MMA) and of MMA/n‐butyl acrylate (MMA/BA) under visible light leading to CeO2‐armored latexes. Radicals generated upon light irradiation trigger the formation of polymer chains chemically attached to the CeO2 NPs, promoting their subsequent adsorption on the latex surface. The composite films obtained from the CeO2‐armored P(MMA‐co‐BA) latexes exhibit a unique honeycomb nanostructure with the nanoceria located in the walls giving the materials excellent mechanical, anti‐UV, and photocatalytic properties. [ABSTRACT FROM AUTHOR]

Ethylene propylene diene monomer (EPDM) rubber is used in critical sectors such as national defense, military, and aerospace. However, it has performance limitations under high temperatures, affecting its dynamic mechanical properties, creep, and stress relaxation. To overcome these limitations, rare earth cerium oxide (CeO2) was incorporated as a filler into EPDM in this study, which enhances its properties and makes it suitable for the demanding applications. It could be seen that the CeO2‐enriched EPDM has significantly improved mechanical characteristics at elevated temperatures. The Young's modulus of CeO2‐enriched EPDM increased by about 100 %, while the energy storage modulus reaches a maximum increase of around 140 % at 165 °C. The addition of CeO2 improves its damping properties, provides better creep and stress relaxation resistance, and results in greater residual strain recovery. At room temperature, the impact on the stress relaxation rate at 50 % strain is minimal for the material EPDM, and it is almost negligible for the material EPDM/CeO2.These findings demonstrate that CeO2‐enriched EPDM has enhanced performance under high‐temperature conditions. Under elevated temperature conditions, EPDM enriched with CeO2 exhibits enhanced mechanical properties, superior creep resistance, and stable stress relaxation behavior, rendering it more adept at withstanding the rigorous conditions encountered in aerospace applications. [ABSTRACT FROM AUTHOR]

Producing hydrogen (H2) from biomass gasification offers exceptional benefits regarding renewable energy sources, zero‐carbon emission, cost‐effective processes, and high efficiency. The addition of catalysts to biomass gasification could accelerate the process and minimize the formation of coke. However, the catalyst deactivation caused by carbon deposition, poisoning, and sintering is still a significant problem in the gasification process. Therefore, achieving sustainable exploitation of the renewable natural resource of biomass requires substantial development and optimization of the present gasification process. The efficiency of gasification might decrease because of such a process. In this study, CeO2(111) is chosen to investigate the analysis of adsorption molecules during catalytic gasification using the density functional theory method. Three catalyst models, CeO2(111), Zr‐CeO2(111), and Ni‐CeO2(111), have been studied in this work in terms of structural, electronic, and adsorption molecule properties. The structural and electronic properties of the modified catalyst model show the ligand and strain effect on the alloy, with the addition of Zr and Ni as second metals promoting the adsorption capability. Searching for active sites is also carried out by adsorption of selected atoms and molecules and used as a preliminary study to find possible active sites for gasification reactions. The Zr‐CeO2(111) and Ni‐CeO2 catalysts exhibit better adsorption ability on atomics and molecules. The Zr and Ni metals are suitable second metal candidates for the catalyst to proceed with the gasification reaction and simultaneously reduce carbon deposition, poisoning, and sintering problems. [ABSTRACT FROM AUTHOR]

Improving the gas‐sensing properties of sensors is important for the detection of ultralow‐concentration gases. As sensor signals are generated from the reactions on the surface of the sensor material, improving the surface structure of the sensor material can enhance the sensing properties. In this study, nanosheet‐type tin oxide with a metastable (101) crystal facet surface was used as the gas sensor material. To enhance the sensing properties, crystal facet‐controlled cerium oxide with superior oxygen storage capacity at moderate temperatures was decorated on the surface of the nanosheet‐type tin oxide material. An investigation of the sensor properties revealed that the decorated sensor exhibited improved gas selectivity and enhanced sensitivity to all tested gases. Prior to decoration, selectivity was observed for acetone and ethanol, whereas the decorated sensor exhibited high selectivity for acetaldehyde. The limits of detection of the decorated sensors were 245, 459, and 934 ppt for acetone, ethanol, and acetaldehyde, respectively. Thus, the proposed material can effectively enhance the sensing of extremely low‐concentration gases. [ABSTRACT FROM AUTHOR]

CeO2 nanoparticles are synthesized at different reaction times, different reaction temperatures, and different pH of the starting precursor solution. Metal (Ni2+, Cd2+, and Nb5+) doped CeO2 nanoparticles are prepared with different concentrations of dopant ions by maintaining the reaction time at 24 hrs, reaction temperature at 180 °C, and pH of the starting precursor solution at 12. The physical properties of the prepared samples are studied by powder X-ray diffraction analysis (PXRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) specific surface area analysis, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy (UV–vis), and photoluminescence (PL) analysis. The photocatalytic activity of the prepared samples is studied by methylene blue (MB) degradation under sunlight irradiation. The effect of reaction time, reaction temperature, pH of the starting solution, and dopant ions concentration on the physical properties and photocatalytic activity of CeO2 nanoparticles are analyzed. All the synthesized samples are found to have a cubic fluorite structure. The crystallite size and lattice parameter of undoped CeO2 nanoparticles increase with the reaction time, reaction temperature, and pH of the precursor solution used for the synthesis and decrease with the dopant ions concentration. All of the samples have spherical morphology, as seen by SEM pictures. With increasing reaction time, reaction temperature, precursor solution pH, and dopant concentration, the particle size drops, and the specific surface area increases. However, for Nb5+ ions doped CeO2 nanoparticles, a decrease in the specific surface area with doping is observed which may be due to the formation of the fergusonite (CeNbO4) phase at higher doping levels. FTIR analysis confirms the presence of Ce–O-Ce or Ce–O-M stretching vibrations in the samples. The bandgap energy of Ni2+ doped samples increase from 3.57 to 3.85 eV and that of Cd2+ doped samples increases from 3.55 to 4.03 eV when the dopant concentration is increased from 5 to 15 M%. The observed increase in the bandgap energy of the Ni2+ and Cd2+ doped CeO2 samples could be due to the decrease in the particle size. The bandgap energy of Nb5+ ions doped CeO2 nanoparticles decreases with an increase in dopant concentration which could be ascribed to the increased formation of the Fergusonite phase at a higher doping level. A shift in the F2g peak position towards lower wavenumbers and a reduction of peak intensity with increased doping is observed in the Raman spectra confirming the enhancement of oxygen vacancies with an increase in dopant concentration. The PL studies show that the CeO2 nanoparticles and Ni2+, Cd2+, and Nb5+ ions doped CeO2 nanoparticles exhibit luminescence in the violet-blue-green wavelength region. The PL emission intensity of the doped samples decreases as the dopant concentration increases. The undoped CeO2 nanoparticles prepared at higher reaction time, higher reaction temperature and higher pH (= 12) of the precursor solution exhibit higher photocatalytic activity. In the case of doped CeO2 samples, the MB degradation efficiency of Ni2+ ions doped CeO2 NPs is found to be comparatively higher than that of undoped and Cd2+ and Nb5+ doped CeO2 NPs. 15 M% Ni2+ doped CeO2 NPs exhibited smaller particle size, higher specific surface area of 49.7m2/g and a higher MB degradation efficiency of 81.9% within 1 hr. [ABSTRACT FROM AUTHOR]

In this study, bismuth sulfide (Bi2S3)‐doped cerium oxide (CeO2) was prepared via hydrothermal method, and by depositing ethyl 3,4‐dihydroxybenzoate (EDHB) on the surface of Bi2S3/CeO2 (Bi2S3/CeO2/EDHB and BCE). The samples were characterized by FTIR, XRD, TEM, and UV–vis absorption spectrum means. According to the characterizations, Bi2S3 was successfully incorporated into the CeO2 structure (Bi2S3/CeO2), and the prepared BCE/PVC composite films display excellent UV‐shielding property. Moreover, the result of thermogravimetric analysis (TGA) tests indicated that BCE also was barely catalytic thermal decomposition of PVC matrix. This work not only paves an attractive way for the design of the CeO2‐based UV‐shielding agent, but also provides valuable insights into the inspiration to construct high‐performance UV‐shielding composites. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO2) nanoparticles, as a metal oxide nanomaterial, are increasingly used for various industrial and biomedical applications. Although their cytotoxicity to bacteria and the associated mechanisms have attracted particular attention, the mechanisms behind their antifungal effects have remained unclear. This study investigated the antifungal properties of CeO2, focusing on Aspergillus oryzae. CeO2 inhibited fungal spore germination on solid substrates, and the effect was fungistatic rather than fungicidal. CeO2 inhibited fungal growth, especially under UV irradiation, and induced reactive oxygen species (ROS) production. Tocopherol reduced the intracellular ROS levels and the growth-inhibitory effects of CeO2, suggesting that ROS are involved in these growth-inhibitory effects. Transcriptomic analysis revealed upregulated expression of genes related to phospholipases and phosphate metabolism. CeO2 affected phosphate ion concentration in the medium, potentially influencing cellular responses. This research provided valuable insights into the antifungal effects of CeO2 application, which differ from those of conventional photocatalysts like TiO2. [ABSTRACT FROM AUTHOR]

The global water resource shortage has evolved into a pressing concern, necessitating the advancement of effective and environmentally sustainable water treatment techniques. Photocatalysis has surfaced as a hopeful technology for eliminating organic contaminants from wastewater because of its efficiency, cost-effectiveness, and eco-friendliness. Here, CeO 2 microspheres and Ni 0.5 Zn 0.5 Fe 2 O 4 (NiZn-ferrite) nanoparticles were synthesized using the hydrothermal method, followed by the fabrication of ternary hybrid composites CeO 2 /NiZn ferrite/multiwalled carbon nanotubes (MWCNT) via ultrasonic treatment. Various analytical techniques including XRD, FESEM, VSM, PL, BET and UV–Visible spectroscopy were employed to characterize the resulting synthesized samples. The hybrid ternary composites demonstrate remarkable efficiency in degradation of reactive red-35 dye through photocatalysis attributed to enhanced surface area. This efficiency is further enhanced when coupled with ultrasonic treatment, leading to a synergistic effect. The catalysts can be easily separated from the suspension due to their magnetic behaviour and thus hold great potential for utilizations in the field of wastewater treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

The paper presents the results of an investigations of the sintered zirconia ceramics that have been stabilized with Y 2 O 3 and CeO 2. The initial powders were synthesized via decomposition of the fluoride salts, which determined morphological features and dimensions of the particles. The specific electroconsolidation process, performed using the modified spark plasma sintering device, allowed for the retention of the nanoscale grain sizes and related properties of the sintered ceramic composites. It was found that the as-obtained materials with cerium oxide exhibited high bending strength of 609 MPa, by ca. 33 % higher than that of yttria-stabilized ones (410 MPa). In turn, the best combination of hardness and fracture toughness, K 1С = 5.8 МPа·m1/2 аnd Н v = 14.8 GPа, respectively, exhibited ZrO 2 +3 wt% Y 2 O 3. This result can be attributed to the chemical composition and morphology of the powders, which in turn is influenced by the synthesis conditions and calcination time and temperatures, as well as to the sintering parameters. In particular, yttria-stabilized zirconia showed higher sensitivity to the variations of the sintering temperatures and holding times. [ABSTRACT FROM AUTHOR]

Porous boron nitride material (p-BN), as a nanomaterial, is often used in pollutant removal (antibiotics and heavy metal ions in water, etc.), but its effectiveness for the removal of anionic pollutants has rarely been reported. Here, a cerium oxide modified p-BN (Ce/p-BN-X) was prepared and used for phosphate removal. It has a high specific surface area, a rich pore structure, abundant reactive groups such as amino groups, positively charged oxygen vacancies, and high stability, which enhanced the adsorption of phosphate. Moreover, the adsorption kinetics and isotherms analysis revealed that the adsorption capacity of Ce/p-BN-4 was 22.05 times higher than that of p-BN at an initial concentration of 20 mg L–1. The adsorption mechanism mainly includes ion exchange, inner-sphere complexation, and electrostatic attraction. In summary, this work provides a simple strategy to improve the adsorption of p-BN on phosphate, which greatly compensates for the deficiency of p-BN in anion adsorption and has great potential for application. [ABSTRACT FROM AUTHOR]

Catalysts of nickel-ceria, nickel-copper-ceria, and copper-ceria were explored with respect to their properties for hydrogen production through ethanol steam reforming (ESR). They were prepared by coprecipitation of the components within inverse microemulsions to achieve intimate contact between them, and the catalysts were characterized by N2 adsorption measurements, XRD, Raman spectroscopy, TPR, and XPS. The catalysts were tested for the ESR reaction, and they were regenerated with oxygen when significant deactivation took place, as occurred for the copper-containing systems. In contrast, the nickel–ceria catalyst exhibits a high activity and stability despite the formation of an important amount of carbon deposits during the course of the ESR test. The presence of nickel sites, which strongly interact with the ceria support, and which are affected by the presence of copper, and the limitation of copper for C-C bond breaking are invoked to explain the results obtained on the whole. [ABSTRACT FROM AUTHOR]

Nanostructured photodetectors have garnered great attention due to their enriched electronic and optical properties. In this work, we aim to fabricate a high-performance CeO2/Si photodetector by growing a CeO2 nanostructure film on a silicon substrate using the pulsed laser deposition (PLD) technique at different laser energy densities. The impact of laser energy density and the number of pulses on the morphological, optical, and electrical properties was studied. Field emission scanning electron microscopy (FESEM) results show that the CeO2 film has a spherical grain morphology with an average grain size ranging from 33 to 54 nm, depending on the laser energy density. The film deposited at various numbers of laser pulses also has spherical grains with an average grain size ranging from 39 to 54 nm, depending on the number of pulses. The optical properties of the CeO2 film showed that the optical energy gap of the films decreased from 3.5 to 3 eV as the laser energy density increased from 63.66 to 101.86 J/cm2. The photoluminescence (PL) spectra of the nanostructured CeO2 film reveal that the main emission peaks were observed at 682 nm when excited at 450 nm. The effect of laser energy density on the electrical properties, including carrier concentration, mobility, and current-voltage characteristics under dark and illuminated conditions, was investigated. The CeO2/Si photodetector fabricated at 63.66 J/cm2 showed the highest responsivity of 0.69 A/W at 450 nm, detectivity as high as 1.5 × 1010 Jones at 450 nm, and an external quantum efficiency of 92% when biased to 5 V. The photodynamic response time was measured. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) can be used as a fertilizer, a chemical or a new generation of fuel and has important agricultural and industrial value. Electrochemical NO3–-to-NH3 (NITRR) can realize the conversion of waste into treasure and waste resources, which is a promising method for ammonia synthesis. However, the process of NITRR is very complicated, resulting in product diversification and poor selectivity. In this work, an iron modified cerium oxide in rod form (Fe/CeO2-rod) catalysts was designed and used for the NITRR. The Fe/CeO2-rod catalyst showed excellent activity, and achieves high Faradaic efficiency (FE 95%) and NH3 yield rate (4.04 mg h–1 cm–2) in 0.1 M KOH electrolyte at – 0.52 V versus reversible hydrogen electrode. Furthermore, this catalyst exhibits a negligible activity decay during continuous electrolysis for 25 h. Further experiments provide the important role of Fe, which promote the formation of hydrogen radicals (H*). This study may provide new pathways to improve the activity of inexpensive catalysts for NITRR. [ABSTRACT FROM AUTHOR]

Diabetes is a chronic metabolic disorder characterized by prolonged elevated blood glucose levels. This research endeavours to assess the efficacy of a surface plasmon resonance (SPR)-based sensor for continuous diabetes monitoring. The proposed sensor structure follows the Kretschmann configuration, incorporating key components such as a prism, Silver/Copper, Cerium Oxide, black phosphorus (BP), and a specialized sensing medium. Within this investigation, two distinct sensor structures, denoted as Structure I and Structure II, have been meticulously constructed using the specified layers. The research employs advanced techniques, including the transfer matrix method and angular interrogation, to evaluate the SPR sensor's performance at a wavelength of 633 nm. The study rigorously analyses the detection capabilities for a specific biological sample, considering parameters such as sensitivity (S), detection accuracy (DA), quality factor (QF), and dip-of-figure of merit (DFOM). Notably, the glucose detection process achieves remarkable results, with Structure I and Structure II exhibiting maximum sensitivities of 217 degree/RIU and 217 degree/RIU, DA values of 0.41 and 0.315, QF values of 89.13 RIU−1 and 68.45 RIU−1, and DFOM values of 31,281.53 and 24,213.34, respectively. Ultimately, this research culminates in a comparative study, underscoring the potential of the proposed sensor as a high-performance tool for glucose level detection, thereby paving new avenues in the realms of biological and biomedical technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • This is the first application of NO in the treatment of oral ulcers. • MPCST still has reliable stickiness in humid oral environments. • Through NIR activation, MPCST can release NO accurately. • Based on animal evaluation, MPCST exhibited superior healing effects than dexamethasone patches. Oral mucosal ulcer is the most prevalent oral mucosal lesion, affecting over 25 % of general population. The current treatment regimens lack efficacy in addressing challenges such as wound bleeding, bacterial infection and inflammation on a continuous basis. Hence, a multi-functional oral gel (termed MPCST) with a long-acting duration is designed. It is based on a tannic acid-thioctic acid (TATA) supramolecular hydrogel which absorbs tissue exudate while exhibiting robust tissue adhesion properties. To form MPCST, TATA is loaded with MPCS, which are composed of polydopamine (PDA)-coated molybdenum disulfide (MoS 2) nanoflakes (MoS 2 @PDA) with high photothermal conversion efficiency, nitric oxide (NO) precursor nitroprusside (SNP) and cerium oxide (CeO 2) with high reactive oxygen species (ROS) scavenging rate. Upon exposure to 808 nm near-infrared (NIR) irradiation, MPCS rapidly heats up and releases NO to promote angiogenesis, while exhibiting strong ROS scavenging, antibacterial (including oral common Streptococcus mutans), and anti-inflammatory properties. Animal experiments show that the MPCST oral gel, composed of MPCS and TATA hydrogel, exhibits superior therapeutic efficacy compared to the commonly used dexamethasone patch. [ABSTRACT FROM AUTHOR]

CO2 regeneration and reutilization is considered to be a green and effective route with highly potential for development. CeO2 showed high catalytic activity for the production of N,N′-dibutylurea through n-butyl amine and CO2. Herein, V-doped CeO2 with different molar ratios of V/Ce (Vx%-CeO2, x = 0, 0.4, 0.6, 0.8 and 1.0) were further successfully synthesized and firstly applied to the reaction of CO2 with n-butyl amine. The reaction results displayed the catalytic performance of CeO2 were prominently enhanced by doping V5+ and followed an order of V0.8%-CeO2 > V0.6%-CeO2 > V1.0%-CeO2 > V0.4%-CeO2 > CeO2. The reason for the changes in the catalytic activities of CeO2 with different doping amounts of V5+ could be closely related to the surface oxygen vacancy and surface weak acidity and weak basicity based on specific analysis of relevant characterization including XRD, BET, Raman, XPS, EPR and NH3/CO2-TPD. [ABSTRACT FROM AUTHOR]

CO2 regeneration and reutilization is considered to be a green and effective route with highly potential for development. CeO2 showed high catalytic activity for the production of N,N′-dibutylurea through n-butyl amine and CO2. Herein, V-doped CeO2 with different molar ratios of V/Ce (Vx%-CeO2, x = 0, 0.4, 0.6, 0.8 and 1.0) were further successfully synthesized and firstly applied to the reaction of CO2 with n-butyl amine. The reaction results displayed the catalytic performance of CeO2 were prominently enhanced by doping V5+ and followed an order of V0.8%-CeO2 > V0.6%-CeO2 > V1.0%-CeO2 > V0.4%-CeO2 > CeO2. The reason for the changes in the catalytic activities of CeO2 with different doping amounts of V5+ could be closely related to the surface oxygen vacancy and surface weak acidity and weak basicity based on specific analysis of relevant characterization including XRD, BET, Raman, XPS, EPR and NH3/CO2-TPD. [ABSTRACT FROM AUTHOR]

Ce(2-x–y)GdxDyyO2-δ nanoparticles with x = 0.02 and y = 0.02, 0.04, 0.06, and 0.08 with a size range of 15.81 to 40.42 nm have been obtained by annealing the solid-state reaction-derived nanocrystalline powders. Correlations between Gd and Dy doping and lattice expansion were found; lattice parameters increased from 5.423 to 5.468 Å. When Gd and Dy content increased, optical investigations showed unexpected bandgap behaviour that did not follow the predicted reduction. Red, green, blue, and violet emissions have been identified via photoluminescence analysis. SEM and EDS verified the homogenous elemental distribution of spherical nanoparticles. With a growing magnetic moment and coercive field, magnetic measurements showed paramagnetic activity. [ABSTRACT FROM AUTHOR]

Abstract Background Despite recent advances the prognosis of pulmonary hypertension remains poor and warrants novel therapeutic options. Extensive studies, including ours, have revealed that hypoxia-induced pulmonary hypertension is associated with high oxidative stress. Cerium oxide nanozyme or nanoparticles (CeNPs) have displayed catalytic activity mimicking both catalase and superoxide dismutase functions and have been widely used as an anti-oxidative stress approach. However, whether CeNPs can attenuate hypoxia-induced pulmonary vascular oxidative stress and pulmonary hypertension is unknown. Results In this study, we designed a new ceria nanozyme or nanoparticle (AuCeNPs) exhibiting enhanced enzyme activity. The AuCeNPs significantly blunted the increase of reactive oxygen species and intracellular calcium concentration while limiting proliferation of pulmonary artery smooth muscle cells and pulmonary vasoconstriction in a model of hypoxia-induced pulmonary hypertension. In addition, the inhalation of nebulized AuCeNPs, but not CeNPs, not only prevented but also blunted hypoxia-induced pulmonary hypertension in rats. The benefits of AuCeNPs were associated with limited increase of intracellular calcium concentration as well as enhancement of extracellular calcium-sensing receptor (CaSR) activity and expression in rat pulmonary artery smooth muscle cells. Nebulised AuCeNPs showed a favorable safety profile, systemic arterial pressure, liver and kidney function, plasma Ca2+ level, and blood biochemical parameters were not affected. Conclusion We conclude that AuCeNPs is an improved reactive oxygen species scavenger that effectively prevents and treats hypoxia-induced pulmonary hypertension. Graphical Abstract

The management of burn injuries presents a significant challenge in clinical settings, yet an optimal solution remains elusive. Therefore, this study aimed to develop a topical therapeutic formulation to address the complex issues hindering burn wound healing. Emphasizing the sustained presence of bioactive principles, we synthesized a bioactive gel derived from decellularized caprine small intestine submucosa (D-CIS) and encapsulated it with nano-formulations of cerium oxide and curcumin to create a burn wound dressing material with enhanced properties. The choice of encapsulated components was guided by their antimicrobial, antioxidant, and immune-modulating characteristics, along with their inherent ability to gradually release bioactive substances. The encapsulated (cerium oxide and curcumin) D-CIS bioactive gel demonstrated a range of properties, including antimicrobial, antioxidant, and anti-inflammatory effects, along with sustained release kinetics of bioactive molecules. These combined effects facilitated accelerated burn wound healing by mitigating oxidative stress, reducing inflammation, and promoting cell recruitment for epithelial and vascular regeneration. This study contributes to the development of a novel bioactive gel incorporating cerium oxide and curcumin, offering a promising approach to enhance burn wound healing.

Engineered nanomaterials (ENMs) are ubiquitous in contemporary applications, yet their environmental and human health impacts remain inadequately understood. This study addresses the challenge of identifying potential risks associated with ENM exposure by highlighting the significant variability in existing research methodologies. Without a systematic collection of toxicological data that encompasses standardized materials, relevant platforms, and assays, the task of identifying potential risks linked to ENM exposure becomes an intricate challenge. In vitro assessments often use media rich in ionic species, such as RPMI and fetal bovine serum (FBS). Zebrafish embryos, known to develop normally in low-ionic environments, were exposed to Cerium Oxide, Zinc Oxide, and Graphene Oxides in different media at varying concentrations. Here, we discovered that zebrafish embryos tolerated a mix of 80 % RPMI, 2 % FBS, and 1 % antibiotic cocktail. The results revealed that adverse effects observed in zebrafish with certain nanomaterials in Ultra-Pure (UP) water were mitigated in cell culture medium, emphasizing the importance of revisiting previously considered non-toxic materials in vitro. The zebrafish results underscore the importance of utilizing a multidimensional in vivo platform to gauge the biological activity of nanomaterials accurately.

Dispersion of single atoms (SAs) in the host is important for optimizing catalytic activity. Herein, we propose a novel strategy to tune oxygen vacancies in CeO2−X directionally anchoring the single atom platinum (PtSA), which is uniformly dispersed on the rGO. The catalyst's performance for the hydrogen evolution reaction (HER) can be enhanced by controlling different densities of CeO2‐X in rGO. The PtSA performs best optimally densified and loaded on homogeneous and moderately densified CeO2‐X/rGO (PtSA−M−CeO2−X/rGO). It exhibited higher activity in HER with an overpotential of 25 mV at 0.5 M H2SO4 and 33 mV at 1 KOH than that of almost reported electrocatalysts. Furthermore, it exhibited stability for 90 hours at −100 mA cm−2 in 1 KOH and −150 mA cm−2 in 0.5 M H2SO4 conditions, respectively. Through comprehensive experiments and theoretical calculations, the suitable dispersion density of PtSA on the defects of CeO2−X with more active sites gives the potential for practical applications. This research paves the way for developing single‐atom catalysts with exceptional catalytic activity and stability, holding promise in advanced green energy conversion through defects engineering. [ABSTRACT FROM AUTHOR]

Background: Despite recent advances the prognosis of pulmonary hypertension remains poor and warrants novel therapeutic options. Extensive studies, including ours, have revealed that hypoxia-induced pulmonary hypertension is associated with high oxidative stress. Cerium oxide nanozyme or nanoparticles (CeNPs) have displayed catalytic activity mimicking both catalase and superoxide dismutase functions and have been widely used as an anti-oxidative stress approach. However, whether CeNPs can attenuate hypoxia-induced pulmonary vascular oxidative stress and pulmonary hypertension is unknown. Results: In this study, we designed a new ceria nanozyme or nanoparticle (AuCeNPs) exhibiting enhanced enzyme activity. The AuCeNPs significantly blunted the increase of reactive oxygen species and intracellular calcium concentration while limiting proliferation of pulmonary artery smooth muscle cells and pulmonary vasoconstriction in a model of hypoxia-induced pulmonary hypertension. In addition, the inhalation of nebulized AuCeNPs, but not CeNPs, not only prevented but also blunted hypoxia-induced pulmonary hypertension in rats. The benefits of AuCeNPs were associated with limited increase of intracellular calcium concentration as well as enhancement of extracellular calcium-sensing receptor (CaSR) activity and expression in rat pulmonary artery smooth muscle cells. Nebulised AuCeNPs showed a favorable safety profile, systemic arterial pressure, liver and kidney function, plasma Ca2+ level, and blood biochemical parameters were not affected. Conclusion: We conclude that AuCeNPs is an improved reactive oxygen species scavenger that effectively prevents and treats hypoxia-induced pulmonary hypertension. [ABSTRACT FROM AUTHOR]

This study investigated gelatin methacryloyl (GelMA) and polycaprolactone (PCL) blend scaffolds incorporating cerium oxide (CeO) nanoparticles at concentrations of 0%, 5%, and 10% w/w via electrospinning for periodontal tissue engineering. The impact of photocrosslinking on these scaffolds was evaluated by comparing crosslinked (C) and non-crosslinked (NC) versions. Methods included Fourier transform infrared spectroscopy (FTIR) for chemical analysis, scanning electron microscopy (SEM) for fiber morphology/diameters, and assessments of swelling capacity, degradation profile, and biomechanical properties. Biological evaluations with alveolar bone-derived mesenchymal stem cells (aBMSCs) and human gingival fibroblasts (HGFs) encompassed tests for cell viability, mineralized nodule deposition (MND), and collagen production (CP). Statistical analysis was performed using Kruskal–Wallis or ANOVA/post-hoc tests (α = 5%). Results indicate that C scaffolds had larger fiber diameters (~250 nm) compared with NC scaffolds (~150 nm). NC scaffolds exhibited higher swelling capacities than C scaffolds, while both types demonstrated significant mass loss (~50%) after 60 days (p < 0.05). C scaffolds containing CeO showed increased Young's modulus and tensile strength than NC scaffolds. Cells cultured on C scaffolds with 10% CeO exhibited significantly higher metabolic activity (>400%, p < 0.05) after 7 days among all groups. Furthermore, CeO-containing scaffolds promoted enhanced MND by aBMSCs (>120%, p < 0.05) and increased CP in 5% CeO scaffolds for both variants (>180%, p < 0.05). These findings underscore the promising biomechanical properties, biodegradability, cytocompatibility, and enhanced tissue regenerative potential of CeO-loaded GelMA/PCL scaffolds for periodontal applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: The increase in multi-drug resistant bacterial infections has become a major problem in modern healthcare due to the development of bacterial resistance to antibiotics and the development of new antibacterial alternative drug materials is of great importance. OBJECTIVE: To synthesize and perform a series of characterization of a CeO2 nanoenzyme to investigate its biocompatibility and antibacterial properties against Escherichia coli. METHODS: CeO2 nanoenzymes were synthesized using a hydrothermal method. The morphology, product composition, and chemical composition were analyzed using characterization methods such as X-ray diffraction, X-ray photoelectron spectroscopy, Fourier infrared analysis, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The peroxide-mimetic enzyme activity of CeO2 nanoenzymes was characterized using TMB color development assay. The toxic effect of CeO2 nanoenzymes at different concentrations (10, 25, and 50 μg/mL) on mouse fibroblast L929 cells was evaluated using the CCK-8 assay. The antibacterial properties of CeO2 nanoenzymes against Escherichia coli under different conditions were evaluated using the plate coating method. Changes in intra-bacterial reactive oxygen species after treatment with different conditions were detected using a reactive oxygen species detection kit. RESULTS AND CONCLUSION: (1) The morphology of the synthesized CeO2 nanoparticles was rod-shaped, with Ce3+ accounting for 29.87% of the total Ce3+/ Ce4+ and an average grain size of 7.4 nm. In a slightly acidic environment containing TMB and pH=5.5, CeO2 nanoenzymes mixed with H2O2 showed excellent peroxidase activity, but did not show peroxidase simulated activity at pH=7.4. (2) There was no statistically significant difference in the toxic effects of CeO2 nanoparticles at various mass concentrations on mouse fibroblast L929 cells. (3) In a slightly acidic environment at pH 5.5, Escherichia coli was inhibited to a certain extent in the presence of CeO2 nanoenzyme alone at a concentration of 10 μg/mL, with a decrease in CFU results of about 0.5 log (P < 0.01); in a slightly acidic environment containing 50 μmol/L H2O2, CeO2 nanoenzyme showed excellent antibacterial effects against Escherichia coli, with a decrease in Escherichia coli CFU results of by about 1.5 log (P < 0.001). After CeO2 nanoenzymes interacted with Escherichia coli, the level of reactive oxygen species in Escherichia coli increased (P < 0.05); after CeO2 nanoenzymes interacted with Escherichia coli together with H2O2, the level of reactive oxygen species in Escherichia coli increased significantly (P < 0.001). (4) The results show that the CeO2 nanoenzymes have good biocompatibility, are inherently antibacterial, and can exhibit peroxidase activity in a slightly acidic environment containing low concentrations of H2O2, and generate reactive oxygen species to kill bacteria, thus showing excellent antibacterial effects. [ABSTRACT FROM AUTHOR]

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

Hybrid poly‐ion complexes were synthesized through the complexation of a double hydrophilic copolymer with Ce(III) ions. These colloids act as reservoirs for cerium ions, enabling the synthesis of cerium‐based Prussian blue nanoparticles with a cubic structure, a narrow size distribution around 100 nm, and good colloidal stability in water. Upon high‐temperature calcination, these nanoparticles are transformed into a cerium/iron‐based metal oxide catalyst (CeO2/Fe2O3). The resultant composite catalyst demonstrates superior performance in the photo‐Fenton oxidation of methylene blue pollutants, achieving a conversion efficiency that rivals other metal‐based oxides and cerium‐based catalysts. [ABSTRACT FROM AUTHOR]

Abstract—The influence of various technological conditions of crystallization melting of corundum with cerium on its electrical conductivity and electroluminescence has been studied. The relation between the electrical conductivity of the samples and Ce4+ ions in the crystal lattice is discussed. The relation between electroluminescence of the samples and Ce3+ ions in electrically conducting samples is considered. [ABSTRACT FROM AUTHOR]

The increase in demand for petroleum fuels attracted the attention of the research community to identify a control measure for petroleum source depletion. On the other hand, the heavy usage and burning of petroleum products cause environmental pollutants like oxides of nitrogen, carbon monoxide, hydrocarbons, etc. Therefore, it is important to control all the problems caused by the increasing use of petroleum products, such as diesel, petrol, Kerosene, fuel oil, etc. This investigation aims to reduce the usage of fossil-based petroleum diesel by producing an effective substitute bio-diesel from Juliflora seeds, which exhibit similar properties to diesel. Furthermore, the operational and emission behaviors of the biodiesel in the Reactive Controlled Compression Ignition (RCCI) engine are analyzed by including nanoadditives such as ZnO, Al 2 O 3 and CeO 2 . Furthermore, the obtained performance and emission results are optimized using a hybrid deep neural network (DNN) using the Aquila optimization algorithm (AOA). The algorithm chooses the diesel-biodiesel blend with 75 ppm of alumina nanoparticle as the optimum blend. This considered blend provided better performance and emission results at 72.86% loading condition. The obtained results are 28.19% for brake thermal efficiency (BTE), 446.14 g/kWh for brake-specific fuel consumption, 0.105% for carbon monoxide emission, 19.82 ppm of unburnt hydrocarbon, 457 ppm of NO x emission and 21.98% of smoke emission. [ABSTRACT FROM AUTHOR]

The proposed study is devoted to highlighting the importance of mixed oxides preparation through the layered double hydroxide route for undesirable gas pollutants abatement. Different series of Cu/Al/Ce mixed oxides with similar or different stoichiometrics were prepared and compared for toluene and/or CO oxidation. Catalyst synthesis methods influence material properties and activity for oxidation reactions. The high activity for the oxidation reactions of mixed oxides derived from LDH is explained by the Cu/Ce synergy. The presence of CO in the CO/toluene mixture does not affect the total toluene oxidation, and the toluene does not affect the total oxidation of CO conversion at low temperatures. The most effective catalytic material (Cu6Al1.2Ce0.8) presents a long lifetime stability for total toluene oxidation and resistance to CO poisoning in mixtures. [ABSTRACT FROM AUTHOR]

The research on metal oxide nanoparticles (MONs) has witnessed incredible growth in recent decades as they are promising electrode materials for multiple applications. This work presents the hydrothermal synthesis of morphologically different MONs based on zinc, cobalt and cerium metals and their modifications with benzene tricarboxylic acid (BTC) using layer-by-layer assembly method. The simple and modified nanoparticles were structurally characterized by FTIR, XRD, SEM–EDX and TGA. Modified carbon paste electrodes (1% w/w) were fabricated using each of the ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC materials separately with graphite powder in paraffin oil using 3 cc portable plastic syringe. The XRD results showed 35.5, 10.8, 14.1, 11.6, 10.2 and 8.6 nm average crystal size for ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC, respectively. The electrochemical characterizations of each electrode were performed by EIS as well as CV. The electrochemical surface area of electrodes fabricated from ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC materials was calculated to be 153.4, 610.4, 746.1, 951.5, 161.7, and 951.8 cm2, respectively. The results from EIS plots indicated that electrodes based on modified metal oxide nanoparticles experienced lesser charge transfer resistance as compared to that in simple metal oxide-based electrodes. All the results indicated that electrodes based on modified MONs provide better surface area, surface coverage, charge transfer coefficients and rate constants as compared to those for simple MON-based electrodes. It is concluded that modification of simple MONs with BTC provided smaller particles size, better structural morphology and redox reactions assistance, making them suitable for better electrochemical applications. [ABSTRACT FROM AUTHOR]

The creation of an electrochemical sensor based on a CeO2/CNT nanocomposite is presented in this study as a means of detecting Lupron (LPR) in water sources, pharmaceutical waste, and clinical samples. Leuprolide, marketed under the name LPR, is a drug that is frequently used to treat uterine myoma and fibroids. Accurate identification of lupron is essential for both guaranteeing efficacious therapy and keeping an eye on its existence in pharmaceutical waste and environmental sources, since it may present hazards to both human and environmental health. Comprehensive insights into the manufacture and application of the sensor were provided by the full synthesis of the CeO2/CNT nanocomposite and the electrode modification process. Characterizations using XRD, FT-IR, and TEM demonstrated the structural integrity and morphology of the CeO2/CNT nanocomposite, confirming its effective production. The CeO2/CNT nanocomposite modified electrode's electrochemical behavior for LPR showed a strong linear relationship between the peak current and LPR concentrations ranging from 20 to 2520 ng/ml. This resulted in low detection limits (LOD = 0.01 ng/ml) and high sensitivity (0.63398 µA/ng ml−1). The remarkable storage capacity and operational stability of the CeO2/CNT/GCE sensor were validated by long-term stability studies. Additionally, the sensor showed strong selectivity towards LPR even in the presence of structurally similar compounds, indicating that it is a suitable tool for selective detection in complex biological samples. The usefulness of the sensor for real-world applications was validated by analyzing real samples. The great potential of the CeO2/CNT nanocomposite to transform LPR detection is demonstrated in this study, along with its significance for the development of electrochemical sensing in critical applications such as environmental monitoring and clinical diagnostics. [ABSTRACT FROM AUTHOR]

In this study, thin films of Cerium Oxide CeO2 were fabricated using the sol–gel technique and deposited onto a glass substrate. The annealing process was carried out at various temperatures ranging from 200 to 600  ° C  to investigate the structural, morphological, and optical properties of the films and their interrelations. X-ray diffraction (XRD) patterns revealed the crystalline nature of the prepared films, with film quality exhibiting enhancement with increasing annealing temperature. The average crystallite size, dislocation density, microstrain, and lattice constant were determined from XRD patterns. Higher annealing temperatures were found to increase the crystallite size values from 4.71 to 15.33 nm and decrease the dislocation density and microstrain of the unit cell. Scanning electron microscope (SEM) images illustrated the uniformity of the films, presenting a spheroid shape. Optical properties such as transmittance, absorbance, reflectance, the direct band gap, extinction coefficients, the refractive index, and optical conductivity were assessed using optical measurements. The direct optical band gap of the CeO2 film was observed to decrease from 3.99 to 3.75 eV with increasing film thickness. Using the Wemple and DiDomenico (WDD) single-oscillator model, dispersion energy parameters were calculated based on the refractive index. The nonlinear optical properties of the CeO2 thin films were evaluated using these dispersion energy parameters. The improvement of optical parameters holds significance in standardizing CeO2 thin films for various optoelectronic applications. [ABSTRACT FROM AUTHOR]

Due to the remarkable progress in photovoltaic technology, enhancing efficiency and minimized the costs have emerged as global challenges for the solar industry. A crucial aspect of this advancement involves the creation of solar cell antireflection coating, which play a significant role in minimizing sunlight reflection on the cell surface. In this study, we report on the optimization of the characteristics of CeO2 films prepared by pulsed laser deposition through the variation of laser energy density. The deposited CeO2 nanostructure films have been used as an effective antireflection coating (ARC) and light-trapping morphology to improve the efficiency of silicon crystalline solar cell. The film's thickness increases as laser fluence increase. The refractive index of the antireflective film is measured as a function of laser fluence. The properties of CeO2 thin films' were characterized by various techniques. X-ray diffraction measurements show the grown films were crystalline with cubic and hexagonal phases. The degree of crystallinity of the film increases with the increase in the laser fluence. Scanning electron microscope results reveal that the film's morphology and film uniformity improved as the laser fluence increases. Raman shift of the CeO2 film as a function of laser energy density was investigated. Photovoltaic properties show that the conversion efficiency of the silicon solar cell increases from 8.37 to 14.04% after deposited with ARC CeO2 film at laser energy density of 76.39 J/cm2. The CeO2 films deposited at 76.39 J/cm2 laser pulse energy density have highest hydrophobicity among all the prepared samples. [ABSTRACT FROM AUTHOR]

In this work, Ru–CeO2 prepared by a "melting" method and used as a heterogeneous catalyst for ethylene methoxy-carbonylation was investigated, together with two other catalysts prepared by impregnation and aerosol methods. The Ru–CeO2 (1%-M) catalyst demonstrates activity significantly higher than that of the other catalysts with the same Ru content. The XPS and Raman analysis results suggest that the Ru–CeO2 (1%-M) oxygen vacancy content is not the highest among the catalysts prepared using the three methods, even though the content oxygen vacancies have been reported to play a crucial role in carbonylation when using a Ru–CeO2 catalyst. It was discovered that the available Ru0 (Ru0 in the freshly prepared sample plus that being transformed from Run+ during reduction) is the other decisive factor in determining the catalyst's performance. We further investigated the high reducibility of the catalyst prepared by using the melting method and discovered that a weak metal–support interaction could be obtained because of the independent formations of Ru and CeO2 crystals with graphite carbon as the barrier. Removing carbon under the optimal conditions could facilitate the as-formed Ru crystals anchored onto CeO2; therefore, there is no strong interaction between Ru and CeO2. [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]

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]

Alkaline-cerium silicate glasses based on the 30CaO-20MgO-5P2O5-45SiO2 (mol%) + CeO2 system were successfully prepared by the melt-quenching route. Cerium dioxide was added as 0.0 g (G1), 0.5 g (G1), 1.5 g (G3), 3 g (G4), and g 5 (G5) over a 100% glass batch. The prepared glasses were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and vibrating-sample magnetometry. The efficiency of the prepared glass as γ-ray protection was evaluated. The amorphous nature of the designed materials was observed for all samples by XRD analysis. The FTIR results confirmed that the bands appearing for G1–G5 represented the main properties of the tetrahedral silicate network SiO4, as silica was the major constituent of the amorphous samples. Values of optical energy band gap (Eg) changed from 3.561 eV to 2.552 eV in the direct transition, while for the indirect transition, the Eg reduced from 3.183 eV to 2.292 eV. The Urbach energy (EU) values ranged from 0.265 eV to 0.205 eV. The refractive index (n) of the investigated glasses improved from 1.253 to 1.572. The energy of the single oscillator (Eo) reduced from 3.988 eV for the G1 sample to 2.915 eV for the G5 sample. The saturation magnetization (Ms) values for the G1, G3, and G5 samples were 0.33414, 0.40572, and 0.49505 emu/g, respectively. The coercivity (Hci) ranged from 36.669 G to 53.321 G, while the remanence magnetization (Mr) ranged from 3.356 to 6.325 (emu/g) E−3. The hysteresis area showed a range of 32.687 to 46.325 (erg/g) at ± 20 kOe. The G5 sample possessed the lowest EBF and EABF values among all investigated glasses. These results validate the suitability of the examined G1–G5 glasses for use in the fields of optical and γ-ray shielding. [ABSTRACT FROM AUTHOR]

Hard x-ray photoelectron spectroscopy (HAXPES) using monochromatic Cr Kα radiation (5414.8 eV) has been used to acquire XPS and Auger data on an argon gas cluster-sputtered CeO2 sample. Survey data, high-resolution scans of all observed photoelectron peaks, and high-resolution scans of Auger lines are presented herein. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO2) was synthesized using the precipitation method at various calcination temperatures ranging from 500 to 700°C. Cerium(III) nitrate hexahydrate (Ce(NO)3.6H2O) was used as the precursor for cerium, while Cetyltrimethylammonium bromide (CTAB) acted as the morphology-directing agent. Characterization results indicated that pure CeO2 was obtained at all calcination temperature variations. Calcination temperature influences crystallinity, crystal size, and CeO2 crystal parameters. The crystallinity and crystal size of CeO2 increased with the rising calcination temperature, reaching values of 81.1–84.5% and 15.58–23.12 nm, respectively, along with larger crystal parameters as the temperature increased (a = 5.406–5.410 Å). Surface morphology showed irregular shapes of CeO2 particles, with decreasing sizes as the calcination temperature increased, ranging from 0.2-5.6 μm at 600°C to 0.12-2.9 μm at 700°C. The Ce/O ratio on the surface increased with the rising calcination temperature, reaching a range of 0.48–0.57. CeO2 obtained from calcination at 600°C exhibited the highest fluorescence emission intensity (λ= 496 nm), indicating the least oxygen vacancies presence. Therefore, for antioxidant and catalyst applications, it is preferable to calcinate CeO2 at 700°C.

The study investigated the microstructures and corrosion behaviors of Hastelloy X (HX) and HX reinforced by cerium oxide particles (HX-C) produced by selective laser melting (SLM) and compared to the wrought equivalent (HX-W). The aim was to eliminate hot cracking and investigate the HX's corrosion behavior in the presence of cerium oxide particles. The HX samples showed fine cellular and columnar solidification structures with uniform-size sub-cells and severe microcracking. Incorporating cerium oxide particles (1 wt%) resulted in finer and relatively equiaxed grains without microcracking. The HX-W alloy contained a micron-sized carbide (Mo-rich M6C type) within the matrix. The HX-C sample displayed higher porosities compared to the HX sample (1.8 % against 0.3 %). Potentiodynamic polarization and electrochemical impedance spectroscopy tests were conducted in a standard NaCl solution at temperatures of 25, 50, and 70 °C to assess the corrosion behavior of Hastelloy samples. The HX-C matrix showed superior corrosion resistance compared to the HX-W and HX samples due to its finer grain structure and stable passive layer formation. Cerium oxide particles were found to be efficient in decreasing hot cracking and improving corrosion resistance.

The hydrothermal synthesis of In2O3 and CeO2–In2O3 is investigated as well as the properties of sensor layers based on these compounds. During the synthesis of In2O3, intermediate products In(OH)3 and InOOH are formed, which are the precursors of stable cubic (c-In2O3) and metastable rhombohedral (rh-In2O3) phases, respectively. A transition from c-In2O3 to rh-In2O3 is observed with the addition of CeO2. The introduction of cerium into rh-In2O3 results in a decrease in the sensor response to hydrogen, while it increases in composites based on c-In2O3. The data on the sensor activity of the composites correlate with XPS results in which CeO2 causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In2O3. The reverse situation is observed in composites based on c-In2O3. Compared to In2O3 and CeO2–In2O3 obtained by other methods, the synthesized composites demonstrate maximum response to H2 at low temperatures by 70–100 ​°C, and have short response time (0.2–0.5 ​s), short recovery time (6–7 ​s), and long-term stability. A model is proposed for the dependence of sensitivity on the direction of electron transfer between In2O3 and CeO2.

Abstract This work focuses on the structural, morphological, optical, photocatalytic, antibacterial properties of pure CeO2 nanoparticles (NPs) and graphene oxide (GO) based CeO2 nanocomposites (GO-1/CeO2, GO-5/CeO2, GO-10/CeO2, GO-15/CeO2), synthesized using the sol–gel auto-combustion and subsequent sonication method, respectively. The single-phase cubic structure of CeO2 NPs was confirmed by Rietveld refined XRD, HRTEM, FTIR and Raman spectroscopy. The average crystallite size was calculated using Debye Scherrer formula and found to increase from 20 to 25 nm for CeO2 to GO-15/CeO2 samples, respectively. The related functional groups were observed from Fourier transform infrared (FTIR) spectroscopy, consistent with the outcomes of Raman spectroscopy. The optical band gap of each sample was calculated by using a Tauc plot, which was observed to decrease from 2.8 to 1.68 eV. The valence state of Ce (Ce3+ and Ce4+) was verified using X-ray photoelectron spectroscopy (XPS) for CeO2 and GO-10/CeO2. The poisonous methylene blue (MB) dye was used to evaluate the photocatalytic activity of each sample in direct sunlight. The GO-15/CeO2 nanocomposite showed the highest photocatalytic activity with rate constant (0.01633 min–1), and it degraded the MB dye molecules by 100% within 120 min. The high photocatalytic activity of this material for degrading MB dye establishes it as an outstanding candidate for wastewater treatment. Further, these nanocomposites also demonstrated excellent antimicrobial activity against Pseudomonas aeruginosa PAO1.

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is an important platform chemical compound that is invariably produced from pyrolysis of various categories of biomass. Hydrodeoxygenation (HDO) of vanillin has been a thematic topic in catalysis with the underlying aim to devise processes and reactions for catalytic upgrading of bio-oil and in the production of value-added products. Herein, we investigate the HDO of an evaporated stream of vanillin over a 4 % load of palladium supported on ceria; a Pd/CeO2 catalyst. The synthesized catalyst was characterized by various techniques including XRD, XPS, EDX-SEM, HR-TEM, and TPR. The HDO reaction (carried out at temperatures from 100 °C to 300 °C at 10 °C/min ramp rate with a 5 % H2 feed ratio) resulted in a 95 % conversion of vanillin with an 85 % yield of guaiacol (2-methoxyphenol). Minute loads of alkylbenzene compounds (mainly xylene and ethylbenzene) also emerged. DFT computations elucidate pathways for the observed formation of guaiacol where synergistic effects of both Pd and vacant oxygen sites are highlighted. Overall, we presented a viable HDO route for an oxygenated biomass model compound at mild operational conditions (intermediate temperatures, ambient pressure, and moderate H2/Feed ratio).