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In the present study, CeO2 nanoparticles were synthesized using one-pot green route with high yield using microalgae Chlorella sorokiniana. The synthesized CeO2 nanoparticles (CeO2-np) exhibited rapid photocatalytic degradation 98.2% of doxycycline (DC) (20 mg/L) in only 30 min under visible light at pH7 in water. It was encouraging that CeO2-np did not demonstrate a loss of photocatalytic activity up to five repeated cycles, confirming its stability during the degradation process. Moreover, cytotoxicity evaluation of CeO2-nps on the green alga Chlorella sorokiniana advocated its non-toxic nature by supporting algal growth (0.52 g/L biomass) with 13% total lipids after 12 days in DC treated water. Ultimately, the produced algal biomass could be further utilized as a feedstock of biofuel production. [ABSTRACT FROM AUTHOR]

In this study, CeO2 nanoparticles were synthesized by the sol–gel method using gelatine templates. The prepared CeO2 analyzed by analytical techniques displayed the fluorite structure with uniform sizes of 10–25 nm, a BET‐specific surface area of 65.8 m2/g, a pore volume of 0.144 cm3/g, and the existence of oxygen vacancies, suggesting their compatibility for adsorption removal of pollutants. The adsorption of arsenate and fluoride on CeO2 exhibited the maximal adsorption capacity of 224 and 64 mg/g, respectively. The kinetics of the adsorption fitted the pseudo‐second‐order model perfectly. Compared to fluoride, the adsorption of arsenate was found kinetically more but thermodynamically less favored. It can lie on the more stable complexes formed between arsenate and the prepared CeO2, the larger size of arsenate ions, and the mesoporosity of the prepared CeO2. As a result, the pore of the prepared CeO2 is filled quickly with arsenate ions, becoming full after a specific time that prevents the filling of further arsenate ions. Moreover, the CeO2 adsorbent demonstrated its high reusability up to 9 times without losing remarkable adsorption capacity (≤10%). Overall, the prepared CeO2 can be applied for the treatment of drinking water and wastewater in several regions of Vietnam. [ABSTRACT FROM AUTHOR]

Water repellency has significant potential in applications like self-cleaning coatings, anti-staining textiles, and electronics. This study introduces a novel nanocomposite system incorporating functionalized Al2O3 and CeO2 nanoparticles within a polyurethane matrix to achieve hydrophobic and UV-blocking properties. The nanoparticles were functionalized using an octadecyl phosphonic acid solution and characterized by FTIR and XPS, confirming non-covalent functionalization. Spin-coated polyurethane coatings with functionalized and non-functionalized Al2O3, CeO2, and binary Al2O3-CeO2 nanoparticles were analyzed. The three-layered Al2O3-CeO2-ODPA binary system achieved a contact angle of 166.4° and 85% transmittance in the visible range. Incorporating this binary functionalized system into a 0.4% w/v polyurethane solution resulted in a nanocomposite with 75% visible transmittance, 60% at 365 nm UV, and a 147.7° contact angle after three layers. These findings suggest that ODPA-functionalized nanoparticles, when combined with a polymer matrix, offer a promising approach to developing advanced hydrophobic and UV-protective coatings with potential applications across various industrial sectors. [ABSTRACT FROM AUTHOR]

The extensive adoption of photovoltaic arrays and the resulting reduction in carbon pollution depend on the efficiency of PV systems being improved. The photovoltaic panels' ability to generate electricity is greatly influenced by the air temperature. Therefore, reducing the temperature of the photovoltaic surface can increase its efficiency and performance. Scholars have come up with a wide variety of active and passive approaches to cooling the PV arrays. Nanofluid has recently been suggested as a viable method to cool PV panels and increase solar PV performance. In this research, a nano-CeO2/water-based nanofluid was tested to see whether it may improve the efficiency of an experimented PV panel. The nanofluid has been developed by dispersing nano-CeO2 in clean water at a low concentration. The results showed that by using the nano-CeO2/water-based nanofluid, the PV's temperature could be reduced by 15 °C and the efficiency could be increased by 1.28%. [ABSTRACT FROM AUTHOR]

Inflammatory responses and neuronal ferroptosis, which are associated with abnormal accumulation of reactive oxygen species (ROS), exert crucial damaging effects on the brain after intracerebral hemorrhage (ICH). In this study, minocycline (MC)‐loaded cerium oxide nanoparticles (CeO2‐MC) are constructed for combined ICH treatment. Ultra‐small CeO2 (≈5 nm) synthesized via a high‐temperature approach exhibits powerful free‐radical scavenging and iron‐chelating abilities. In vitro experiments demonstrated that CeO2‐MC effectively attenuated the ROS levels in mouse microglial cells and neurons following oxyhemoglobin stimulation. In addition, CeO2‐MC exhibits iron chelation properties and stabilizes the mitochondrial membrane potential, thereby promoting anti‐inflammatory responses and preventing neuronal ferroptosis. In an intracerebral hemorrhage (ICH) mouse model, CeO2‐MC exhibited robust free radical scavenging capabilities and demonstrated the ability to preserve mitochondrial morphology and function, mitigate brain edema, and maintain blood–brain barrier integrity by inhibiting neuroinflammation and ferroptosis. Neurobehavioral tests demonstrated that CeO2‐MC significantly ameliorated spatial learning ability and sensorimotor function after ICH. Consequently, a general strategy using CeO2 nanoparticles to augment the therapeutic efficacy of MC highlights a new perspective for the in‐depth treatment of ICH. [ABSTRACT FROM AUTHOR]

The development of efficient and robust metal nanoparticle catalysts for the aerobic oxidation of benzyl alcohol is crucial for advancing green chemistry. This study presents a class of ceria nanoparticle catalysts, designated as Ce-NC/CFMX-T, where "T" denotes the pyrolysis temperature. These catalysts are synthesized by pyrolyzing a mixture of Ce-MOF-801/CFMX and dicyandiamide at high temperatures, aimed at the liquid-phase aerobic oxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde, using molecular oxygen as the oxidizing agent and avoiding harmful additives or bases. Among the synthesized catalysts, Ce-NC/CFMX-973 exhibited exceptional catalytic efficiency, achieving over 99.9% conversion of 4-methoxybenzyl alcohol and complete selectivity for 4-methoxybenzaldehyde. This performance was achieved under moderate conditions, using xylene as the solvent at 373 K over 8 h and an oxygen pressure of 1 atm. Kinetic analysis revealed that the activation energy for oxidizing 4-methoxybenzyl alcohol using Ce-NC/CFMX-973 was 68.5 ± 3.0 kJ/mol, which is lower than the values observed for Ce-C/CFMX-973, Ce-NC-973, and Ce-C-973. The remarkable catalytic performance of the Ce-NC/CFMX-973 catalyst is attributed to the synergistic effects between CeO2 nanoparticles and oxygen vacancies, along with the support's balanced acidity and basicity properties. [ABSTRACT FROM AUTHOR]

This work aims to modify the surface characteristics of cerium oxide (ceria, CeO 2) nanoparticles using different surface modification strategies for improved CeO 2 nanoparticle dispersion and suspension stability. Analysis and discussion were conducted on the two surface modification processes used by a cationic surfactant like hexadecyl cetyltrimethylammonium bromide (CTAB) and a silane agent like tetraethyl orthosilicate (TEOS). Untreated CeO 2 was used as reference material. The dispersion effect of surface-modified CeO 2 nanoparticles at different pHs was determined by zeta potential measurements. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Particle size analysis (PSA), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Brunauer–Emmett–Teller analysis (BET), and X-ray diffraction (XRD) were used to confirm the efficacy of the surface modification of CeO 2 nanoparticles. First, the results obtained in this experimental work demonstrate that both advanced modifications greatly enhance the dispersion and suspension stability of surface-modified CeO 2 nanoparticles in comparison with untreated CeO 2 nanoparticles. Second, it is also shown that the surface-modified CeO 2 nanoparticles obtained through a silanization surface process with TEOS silane agent had a better dispersion effect and dispersion stability than the surface-modified CeO 2 nanoparticles obtained by surface modification with CTAB cationic surfactant. These results can help better understand how advanced surface modifications can assist the application of well-dispersed CeO 2 nanoparticles in technological applications. [Display omitted] • Surface modification significantly improved the aqueous dispersion and stability of CeO 2 nanoparticles. • The modification improved the CeO 2 dispersion by increasing the spacing and negative charge. • CeO2 dispersion was optimal at a specific pH, with a significant effect of pH. • The modification strategy is crucial for the performance of CeO 2 in technological applications. [ABSTRACT FROM AUTHOR]

Organophosphate hydrolysis is important for degrading environmentally harmful compounds and recovering phosphate ions in biological molecules. CeO2 nanoparticles have been well-studied for dephosphorylation via hydrolysis owing to the accessible and tunable distribution of Ce3+ and Ce4+ ions. However, there remains uncertainty in the literature regarding which surface defect properties direct catalytic activity, such as the Ce3+/Ce4+ distribution, oxygen vacancies, faceting, and dopants, and to what degree they contribute to efficient hydrolysis. Trivalent (M3+) dopants serve as a tool for manipulating defects, including the concentration of Ce3+ and oxygen vacancies, thereby influencing the hydrolytic activity of CeO2. Herein, trivalent metal ions (M = Y3+, Cr3+, In3+, and Gd3+) were employed to modulate the active sites on the CeO2 nanoparticle surface, and their effects on organophosphate hydrolysis were investigated. M-doped CeO2 nanoparticles were synthesized via hydrothermal methods, followed by annealing to remove ligands and prime the nanocrystal surface for catalysis. Catalytic performance was evaluated using dimethyl-p-nitrophenyl phosphate (DMNP) as a model organophosphate substrate, with degradation monitored over time using ultraviolet–visible (UV–vis) absorption spectroscopy. Powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy revealed successful doping of CeO2 in all cases, albeit with distinctive characteristics demonstrating how M3+ dopants affect catalysis. We show that CeO2 exhibits high sensitivity to dopants that generate Ce3+ ions, oxygen vacancy defects, and lattice strain. Consequently, achieving high catalytic efficiency within CeO2 requires a balanced active site ensemble, wherein defects are maintained at optimal concentrations and distributions on the nanocrystal surface. [ABSTRACT FROM AUTHOR]

The overuse of antibiotics has led to the severe contamination of water bodies, posing a considerable hazard to human health. Therefore, the development of an accurate and rapid point-of-care testing (POCT) platform for the quantitative detection of antibiotics is necessary. In this study, Cerium oxide (CeO2) and Ferrosoferric oxide (Fe3O4) nanoparticles were simultaneously encapsulated into N-doped nanofibrous carbon microspheres to form of a novel nanozyme (CeFe-NCMzyme) with a porous structure, high surface area, and N-doped carbon material properties, leading to a considerable enhancement of the peroxidase (POD)-like activity compared with that of the CeO2 or Fe3O4 nanoparticles alone. The POD-like activity of CeFe-NCMzyme can be quenched using L-Cysteine (Cys) and subsequently restored by the addition of a quinolone antibiotic (norfloxacin, NOR). Therefore, CeFe-NCMzyme was used as a colorimetric sensor to detect NOR via an “On-Off” model of POD-like activity. The sensor possessed a wide linear range of 0.05–20.0 μM (R2 = 0.9910) with a detection limit of 35.70 nM. Furthermore, a smartphone-assisted POCT platform with CeFe-NCMzyme was fabricated for quantitative detection of NOR based on RGB analysis. With the use of the POCT platform, a linear range of 0.1–20.0 μM and a detection limit of 54.10 nM were obtained. The spiked recoveries in the water samples were ranged from 97.73% to 102.01%, and the sensor exhibited good accuracy and acceptable reliability. This study provides a portable POCT platform for the on-site and quantitative monitoring of quinolone antibiotics in real samples, particularly in resource-constrained settings.

In this study, synthesis of cerium dioxide nanoparticles (CeO2 NPs) and preparation of chitosan-CeO2 nanocomposite (CH-CeO2 NC) were done and examined their inhibitive nature on mild steel surface in 1 mol/L HCl solution. Characterization was done through ultraviolet-visible (UV–Vis) and Fourier transform infrared (FT-IR) spectroscopy. Mass loss, electrochemical studies were used to determine the anticorrosive parameters of the prepared materials. Morphology, composition, and size were evaluated with scanning electron microscopy/energy dispersive spectrometry and X-ray diffraction. The inhibition efficiency was increased from 76.9% to 98.9% with the introduction of NPs in the CH. Atomic force microscopy and density functional theory results are in compliance with experimental studies and confirm the better performance of CH-CeO2 NC over chitosan.

Abstract This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it.

The development of economical, high-efficiency synthesis approaches is the primary field of concern for research on microwave-absorbing materials (MAMs). In this work, we used the hydrothermal approach to effectively manufacture CeO2 nanoparticles/porous carbon composites enriched with oxygen vacancies under urea-assisted conditions. The carbon source for these composites was the porous carbon generated from bamboo powders. We adjusted the electromagnetic characteristics of the composites to optimize their electromagnetic wave (EMW) attenuation mechanisms and impedance matching properties by altering the heat treatment temperatures and the extra quantity of cerium salts. The creation of many defects and heterostructures as a result of the nitrogen/oxygen doping and oxygen vacancy-rich CeO2 leads to better EMW attenuation, conductivity loss, and increased polarization effects. The remarkable microwave absorption ability of the C2-500 composite is attributed to good impedance matching and interfacial polarization as well as dipole polarization induced by a significant number of heterogeneous interfaces and oxygen vacancies, particularly from N/O heterogeneous elements. At a filler loading of 10 wt %, C2-500 exhibits a minimum reflection loss (RLmin) of −44.94 dB at 16.16 GHz, accompanied by an effective absorption bandwidth (EAB) of 4.72 GHz. In comparison, the C3-500 composites demonstrate an EAB of 4.88 GHz and an RLmin of −46.81 dB at 9.28 GHz. This study is expected to be instrumental in the design of high-performance biomass-derived porous carbon-based MAMs, providing valuable insights for future research in this field. [ABSTRACT FROM AUTHOR]

Air pollution is an environmental factor associated with an increased risk of neurodegenerative diseases, such as Alzheimer's and Parkinson's, characterized by decreased cognitive abilities and memory. The limited models of sporadic Alzheimer's disease fail to replicate all pathological hallmarks of the disease, making it challenging to uncover potential environmental causes. Environmentally driven models of Alzheimer's disease are thus timely and necessary. We used live-cell confocal fluorescent imaging combined with high-resolution stimulated emission depletion (STED) microscopy to follow the response of retinoic acid-differentiated human neuroblastoma SH-SY5Y cells to nanomaterial exposure. Here, we report that exposure of the cells to some particulate matter constituents reproduces a neurodegenerative phenotype, including extracellular amyloid beta-containing plaques and decreased neurite length. Consistent with the existing in vivo research, we observed detrimental effects, specifically a substantial reduction in neurite length and formation of amyloid beta plaques, after exposure to iron oxide and diesel exhaust particles. Conversely, after exposure to engineered cerium oxide nanoparticles, the lengths of neurites were maintained, and almost no extracellular amyloid beta plaques were formed. Although the exact mechanism behind this effect remains to be explained, the retinoic acid differentiated SH-SY5Y cell in vitro model could serve as an alternative, environmentally driven model of neurodegenerative diseases, including Alzheimer's disease. [ABSTRACT FROM AUTHOR]

This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it. [ABSTRACT FROM AUTHOR]

The designed high-performance bifunctional catalyst integrated with CoFe alloy doped NCNTs and cerium(IV) oxide nanoparticles demonstrated outstanding current density of 281.40 mA cm−2 at a scan rate of 200 mV/s and ideal half-wave potential (E 1/2) values of 0.834 V (vs. RHE). [Display omitted] • Ultrafine cobalt iron alloy uniformly embedded in NCNTs was obtained successfully. • Electron transfer and synergistic effect at the interface between CoFe alloy and CeO 2 are discussed. • The formation mechanism of CeO 2 /CoFe-NCNTs was deduce. • The CeO 2 /CoFe-NCNTs exhibited an enhanced bifunctional characteristic. In this study, we designed a novel strategy that utilizes N -doped carbon nanotubes as the chemical bond supporter to stabilize ultrafine CoFe alloy and introduces secondary CeO 2 active sites into the hybrid, resulting in the formation of CeO 2 /CoFe-NCNTs heterostructures with exceptional bifunctional electrocatalytic capabilities. To be specific, solution dispersion and high-temperature calcination methods were employed to create the CoFe-NCNTs active sites through the introduction of ethylenediamine into the network interstitials of Co-EDTA and Fe-EDTA. The CeO 2 /CoFe-NCNTs hybrid not only promotes oxygen absorption and conversion of intermediates, but also accelerates charge transfer capability, thus enhancing oxygen reduction reaction (ORR) performance, while simultaneously inducing boosted the methanol oxidation reaction (MOR) activity. Moreover, the well-dispersed CoFe nanoparticles within the hybrid hold significant potential for establishing metal-nitrogen bonds with the N -doped carbon nanotube network, resulting in efficient catalytic behavior driven by synergistic effects with CeO 2 nanoparticles, which contributes to reactant activation. As expected, the resultant CeO 2 /CoFe-NCNTs-2 exhibits remarkable electrocatalytic performance, with a current density of 281.40 mA cm−2 at a scan rate of 200 mV s−1 and a low Tafel slope (71.3 mV dec−1) for MOR, as well as achieving excellent half-wave potential and onset potential values of 0.834 and 0.90 V (vs. RHE) for ORR. Additionally, it exhibits durable cycle stability for both MOR and ORR, retaining 92.8% and 96.4% of its initial current density during the I- t test, respectively. This work establishes a highly efficient bifunctional earth-abundant electrocatalysts for both anode and cathode reactions in methanol fuel cells. [ABSTRACT FROM AUTHOR]

Our study is focused on the structural and morphological characteristics, optical behaviour and photocatalytic properties of undoped and 5 at% Eu3+-, Gd3+- and Y3+-doped CeO2 nanoparticles prepared by a green hybrid sol-gel combustion method. Several techniques such as X-ray diffraction powder (XRD), Transmission Electron Microscopy (TEM), UV-Vis spectroscopy, Photoluminescence spectroscopy (PL) and Electron Paramagnetic Resonance (EPR) have been used to investigate the obtained samples. Moreover, the correlation between the characteristics and properties has been studied. The nanoparticles observed by TEM exhibit a pseudo-spherical shape, except for Y3+-doped CeO2, which presents an acicular shape. The average size of undoped and rare-earth-doped CeO2 nanoparticles is below 10 nm, in good agreement with the calculations performed based on XRD analyses. From UV-Vis analyses it has been deduced that with doping the band gap energy decreases, which shows that additional levels are introduced by doping into the CeO2 band gap. The EPR spectra evidence similar behaviour for all doped samples. The photocatalytic activity was evaluated by the degradation of rhodamine B (RhB) under UV light irradiation. The photodegradation mechanism has been studied in depth based on the formation of electron-hole pairs, and to evidence the reactive oxygen species, ESR coupled with spin-trapping experiments was performed. In the case of Y-doped CeO2 nanoparticles, the generation of both •OOH and • O 2 − radicals involved in RhB photodegradation was highlighted. [ABSTRACT FROM AUTHOR]

The hazardous effect of the pollution of fossil fuels has brought the necessity of shifting conventional energy sources to renewable and clean ones. In this study, the effect of hydrogen addition and CeO 2 nanoparticle addition in waste cooking palm biodiesel on a CRDI engine is evaluated. The dosage of the nanoparticle is fixed at 75 ppm and a hydrogen flow rate of 10 L/min is selected for the engine operations. The crystalline structure of the nanoparticles is determined by XRD analysis. Results showed that on the addition of both H 2 and CeO 2 in a B20 biodiesel blend (80% diesel and 20% biodiesel) the performance, emission, and combustion parameters of the diesel engine improved compared to neat diesel. The brake thermal efficiency was improved by 3.53% and brake fuel consumption was reduced by 16.12% in comparison to diesel at 90% loading condition. The addition of both nanoparticles and hydrogen in the biodiesel blend lowered the emissions of CO by 30%, and HC and smoke by 50% and 42% respectively. However, NO x increased by 11% as compared to diesel. A 6% higher HRR values and 8% higher in-cylinder pressure were obtained while using hydrogen and CeO 2 nanoparticle blended biodiesel. This blend also shows the lowest ignition delay period at full load condition which results in more engine power and efficiency. This experimental study has helped pave the way for the use of hydrogen-enriched and nanoparticle-blended biodiesel in place of fossil fuel for the applications of diesel engines. • H 2 enriched and CeO 2 added waste cooking palm biodiesel is used in diesel engine. • The hydrogen flow rate and dosage of is fixed at 10 L/min and 75 ppm respectively. • The BTE and BSFC is improved on addition of nanoparticles and hydrogen. • The emissions of CO, HC and smoke are reduced by 30%, 50% and 42% respectively. • Higher ICP and HRR are observed on addition of both CeO 2 and hydrogen. [ABSTRACT FROM AUTHOR]

In this study, different weight fractions (0, 0.2, 0.5, 0.7, and 1.0 wt%) of cerium oxide (CeO2) nanoparticles were used to enhance the properties of Sn–58Bi–1Ag (SBA) solder alloys. As expected in the design, the CeO2 nanoparticles are diffusely distributed in the solder matrix. The microstructure evolution, growth of intermetallic compound (IMC) at the interface, and shear properties of the composite solder were systematically investigated using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) probes. The results showed that adding an appropriate amount of CeO2 nanoparticles can refine the microstructure of the composite solder. Many β-Sn twin structures were observed in the SBA-0.5CeO2 and SBA-0.7CeO2 solder matrix, bringing better deformability to the β-Sn phase and improving the plasticity of the solder matrix. Moreover, with the addition of nanomaterials, there was a notable decrease in the thickness of the interfacial IMC layer of the solder/Cu joint, accompanied by a refinement in the grain size of the IMC. To our satisfaction, the addition of CeO2 nanoparticles in the appropriate proportion exhibited a remarkable enhancement in both shear strength and toughness of the composite solder alloys, working in tandem to transform the fracture mechanism from a purely brittle mode to a mixed mode of ductility and brittleness. It is indicated that the doping of CeO2 improves the reliability of SBA solder, potentially paving the way for a novel approach to particle-enhanced modification of Sn–Bi–Ag-based low-temperature solders.

A CeO2-doped plasma electrolytic oxidation (PEO) composite coating was prepared on the surface of Cu–Zn alloys by adding CeO2 nanoparticles into the mixed electrolytes of Na2SiO3·9H2O and sodium hydroxide. Surface microstructure and element composition of PEO coatings were studied by a scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Microstructure analysis showed that CeO2 nanoparticles were uniformly deposited on the sample surface, and most of the particles were embedded into PEO coatings. Ce element found in the EDS and XRD analysis confirmed the successful incorporation of CeO2 nanoparticles. Furthermore, with the addition of CeO2 nanoparticles, the coating porosity decreased gradually, while the thickness and surface roughness of PEO coatings decreased and then increased. Corrosion resistance of PEO coatings was investigated by using a potentiodynamic polarization test. The results show that the addition of CeO2 nanoparticles has significantly improved the corrosion resistance of PEO coatings. Especially, the corrosion current density of the PEO coating with 4 g/L CeO2 concentration is 3 orders of magnitude more than that of the bare alloy substrate. [ABSTRACT FROM AUTHOR]

The conversion of carbon dioxide to dimethyl carbonate (DMC) is an attractive process, but thermodynamic limitations of the reaction hinder its further development. Herein, a simple solution coprecipitation strategy for the synthesis of a series of Ce–metal organic framework (MOF)‐derived CeO2 nanoparticles is proposed to rapidly break the thermodynamic equilibrium and achieve highly efficient activation of CO2/CH3OH under photothermal system. The CeO2–M–5, Ce(NO3)3·6H2O/2‐methylimidazoles molar ratio of 1:5, exhibits the highest DMC yield of 2.52 mmolDMC g−1cat under photothermal system, higher 3.26 times than CeO2–C (nanoparticle by high‐temperature calcination). Moreover, the DMC yield of CeO2–M–5 nanoparticles increases by 10% under the photothermal synergistic system compared to thermocatalytic system. This superior catalytic performance is attributed to the abundant Lewis acid–base sites, excellent light absorption capacity, and hydrophobicity. Besides, in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrates that Ce–MOF‐derived CeO2 nanoparticles can effectively activate CO2/CH3OH to enhance the formation of the key intermediate methyl carbonate upon light irradiation. Finally, combining characterization and experimental results, the reaction mechanism of photothermal catalysis of CO2/CH3OH for DMC synthesis over Ce–MOF‐derived CeO2 nanoparticles is proposed. This work would provide new insights into the rational design of an effective catalyst for CO2 to produce high value‐added chemicals. [ABSTRACT FROM AUTHOR]

The synthesis of CeO2 nanoparticles for CeO2 based slurry gains continuous emphasis on improving its performance in the chemical mechanical polishing of dielectric materials. Urea was selected to dominate the growth and morphology during the calcination process. Thermogravimetry experiments were used to analyze the the decomposition behavior. Particle morphology and size were analyzed. Crystalline phase information and surface valence were used to compare the differences in surface physical and chemical properties of ceria by different synthesis process. The CeO2 nanoparticles synthesized with urea were dispersed in water as slurry. The particle sizes of CeO2 were measured by dynamic light scattering. The Zeta potential of CeO2 dispersion were measured to show dispersing performance. The CeO2 nanoparticles synthesized with urea condensation show good monodisperse properties. The material removal rate of silicon oxide and surface quality after chemical mechanical polishing were selected to evaluate the chemical mechanical polishing performance. The CeO2 nanoparticles synthesized with urea condensation not only yielded better surface quality results than the commercial slurry but also showed a 153% (pH = 4) and 100% (pH = 10) increase in the material removal rate of silicon oxide compared to commercial. [ABSTRACT FROM AUTHOR]

Polymer self‐lubricating composite coatings have been widely used on the surface of machinery to extend the life of the moving systems/parts by controlling friction and wear. In this work, epoxy nanocomposite coating with the thickness of about 60 μm was fabricated with addition of hexagonal boron nitride nanosheets (BNNSs)/CeO2 nanohybrid for enhancement in antifriction and wear resistance. The active BNNSs were first obtained by exfoliating h‐BN with alkaline solution, and then the rare earth oxide of CeO2 nanoparticles were immobilized on the surface of BNNSs through hydrothermal method. The microstructure morphology and chemical composition of as‐proposed BNNSs/CeO2 were characterized by field emission scanning electron microscopy, HRTEM, Fourier transform infrared spectroscopy, RS, X‐ray diffraction, and X‐ray photoelectron spectroscopy. And the tribological behaviors of epoxy nanocomposite coatings containing BNNSs, CeO2, and BNNSs/CeO2 were investigated comparatively using ball‐on disc friction tester (MPX‐3). And the 440C stainless‐steel ball with diameter of 8 mm was used as the counterface material. Tribological tests showed that epoxy‐BNNSs/CeO2 had the best friction and wear reduction properties, and the lowest coefficient of friction and wear rate of epoxy‐based composite coating were achieved when the content of BNNSs/CeO2 was 0.5 wt%, with 84.9% and 96.3% reduction, respectively. Moreover, the effect of sliding conditions on the tribological performance of epoxy‐BNNSs/CeO2 was investigated. The corresponding enhancing mechanisms of BNNSs/CeO2 were discussed as well. [ABSTRACT FROM AUTHOR]

As one of the most widely used nanomaterials, CeO2 nanoparticles (NPs) might be released into the aquatic environment. In this paper, the interaction of CeO2 NPs and Ce3+ ions (0~10 mg/L) with duckweed (Lemna minor L.) was investigated. CeO2 NPs significantly inhibited the root elongation of duckweed at concentrations higher than 0.1 mg/L, while the inhibition threshold of Ce3+ ions was 0.02 mg/L. At high doses, both reduced photosynthetic pigment contents led to cell death and induced stomatal deformation, but the toxicity of Ce3+ ions was greater than that of CeO2 NPs at the same concentration. According to the in situ distribution of Ce in plant tissues by μ-XRF, the intensity of Ce signal was in the order of root > old frond > new frond, suggesting that roots play a major role in the uptake of Ce. The result of XANES showed that 27.6% of Ce(IV) was reduced to Ce(III) in duckweed treated with CeO2 NPs. We speculated that the toxicity of CeO2 NPs to duckweed was mainly due to its high sensitivity to the released Ce3+ ions. To our knowledge, this is the first study on the toxicity of CeO2 NPs to an aquatic higher plant. [ABSTRACT FROM AUTHOR]

High-performance solid polymer electrolytes are promising candidates for lithium-ion batteries with enhanced prolonged service life, increased lifetime, and improved safety for grid storage and electric vehicles. Herein, we present a low-cost conductive supramolecular polymer composite comprising UPysynthon, polyethylene glycol with LiClO4 salt, and CeO2(UPy-PEG-CeO2) designed and fabricated by dispersion method, which includes altering compositions. The supramolecular lithium-ion conductor utilizes UPy and PEG functionalized CeO2 in the polymer matrix containing UPy units. The prepared electrolyte membranes form a supramolecular network with the UPy polymer on CeO2 via the quadruple hydrogen bonding. The supramolecular interactions were confirmed by FT-IR and NMR spectroscopy. The surface morphology of UPy-PEG-CeO2 reduces the agglomeration and uniformly disperses, ultimately improving the ionic conductance. The suprmolecular polymer (1):LiClO4(Li)(0.95):nano CeO2(0.05) (1:0.95:0.05) solid electrolyte shown superior lithium-ion transference number. Consequently, the supramolecular polymers:LiClO4(Li):CeO2 in 1:0.95:0.05 ratio exhibit enhanced ionic conductivity of 4.03×10−5 S cm−1 at room temperature. Furthermore, the solid polymer electrolyte thermal stability was confirmed by DSC studies. [ABSTRACT FROM AUTHOR]

In this work, CeO2 nanocubes prepared by a simple co-precipitation method were employed for the determination of dopamine (DA) using an electrochemical method. The prepared material was characterized using morphological analysis like Transmission Electron Microscope (TEM) and the chemical structure was elucidated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman and Fourier Transform Infrared (FTIR) spectroscopy respectively. From the TEM analysis, the growth of CeO2 nanocubes into nanorods was observed and particle size was determined to be 10 nm. The presence of cubic crystalline structure was confirmed through XRD and the structural analysis was confirmed using FTIR and Raman spectroscopy. The oxidation state of the elements was confirmed through XPS analysis. For the electrochemical redox reaction of DA, the CeO2-modified glassy carbon electrode (GCE) showed excellent catalytic activity towards the DA oxidation compared to bare GCE. The detection of DA using differential pulse voltammetry (DPV) showed a limit of detection (LOD) of 3.2 µM and a linear range of 10-300 µM, respectively. Similarly, for UA and AA, the detection limit and linear range were found to be 4.3 µM and 10 µM-700 µM for UA; 14 µM and 10 µM-250 µM, respectively for AA. The repeatability and reproducibility of the sensor were studied and the veracity of the sensor towards the estimation of DA in blood serum samples was analyzed. The admirable performance of the present biosensor could be potentially useful for biomedical applications. CeO2 nanocubes were prepared by a facile chemical method. The enhanced catalytic activity was exhibited by CeO2 nanocubes towards the electro-oxidation of dopamine and excellent selectivity in the presence of uric acid and ascorbic acid. [ABSTRACT FROM AUTHOR]

To achieve the Fe−N−C materials with both high activity and durability in proton exchange membrane fuel cells, the attack of free radicals on Fe−N4 sites must be overcome. Herein, we report a strategy to effectively eliminate radicals at the source to mitigate the degradation by anchoring CeO2 nanoparticles as radicals scavengers adjacent (Scaad‐CeO2) to the Fe−N4 sites. Radicals such as ⋅OH and HO2⋅ that form at Fe−N4 sites can be instantaneously eliminated by adjacent CeO2, which shortens the survival time of radicals and the regional space of their damage. As a result, the CeO2 scavengers in Fe−NC/Scaad‐CeO2 achieved ∼80 % elimination of the radicals generated at the Fe−N4 sites. A fuel cell prepared with the Fe−NC/Scaad‐CeO2 showed a smaller peak power density decay after 30,000 cycles determined with US DOE PGM‐relevant AST, increasing the decay of Fe−NCPhen from 69 % to 28 % decay. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations. [ABSTRACT FROM AUTHOR]

Alternative fuels have sparked a lot of interest as oil deposits have decreased and environmental concerns have grown. Biodiesel is an alternative fuel that is being researched as a possible replacement for fossil fuels. In the current investigation, the combustion performance, and emission characteristics of CI(Compression Ignition) engine were examined by changing the fuel injection pressure (180, 200, 220 and 240 bar). The biodiesel (B20) used in this analysis was obtained from Mahua oil at 20% v/v blended with neat diesel (20% Mahua Biodiesel + 80% Diesel). CeO 2 (Cerium Oxide) nanoparticles were introduced to the B20 fuel at four distinct concentrations are 25, 50, 75, and 100 ppm. Performance characteristics such as BTE(Brake Thermal Efficiency) and BSFC(Brake Specific Fuel Consumption) were inferior to diesel, at 240 bar B20 with 25 ppm CeO 2 indicated 1.9% increased BTE and 3.8% reduced BSFC compared B20 and 6% lower EGT (Exhaust Gas Temperature) compared diesel. At 200 bar, fuel samples indicated slightly higher In-Cylinder pressure and lower HRR (Heat release rate) compared to diesel. At 200 bar FIP(Fuel Injection Pressure), HC(Hydro Carbon) and CO(Carbon Monoxide) emissions were reduced significantly compared to diesel. The largest reduction in smoke opacity and NOx(Nitrous Oxide) emissions were observed at 240 bar with 75 ppm dosage, but CO 2 (Carbon Dioxide) emissions were higher at 220 bar. • Engine performance, Combustion and emissions of a single-cylinder diesel engineare studied. • At 240 bar FIP, B20 with 25 ppm CeO 2 indicated 1.9% increased BTE and 3.8% reduced BSFC compared to B20. • At 200 bar FIP, fuel samples indicated slightly higher In-Cylinder pressure and lower HRR compared to diesel. • Compared to diesel, the emissions of HC and CO were significantly reduced at 200 bar FIP. [ABSTRACT FROM AUTHOR]

Acetylcholinesterase (AChE), a crucial enzyme related to liver function, is involved in numerous physiological processes such as neurotransmission and muscular contraction. The currently reported techniques for detecting AChE mainly rely on a single signal output, limiting their high-accuracy quantification. The few reported dual-signal assays are challenging to implement in dual-signal point-of-care testing (POCT) because of the need for large instruments, costly modifications, and trained operators. Herein, we report a colorimetric and photothermal dual-signal POCT sensing platform based on CeO2-TMB (3,3′,5,5′-tetramethylbenzidine) for the visualization of AChE activity in liver-injured mice. The method compensates for the false positives of a single signal and realizes the rapid, low-cost portable detection of AChE. More importantly, the CeO2-TMB sensing platform enables the diagnosis of liver injury and provides an effective tool for studying liver disease in basic medicine and clinical applications. [ABSTRACT FROM AUTHOR]

A flexible CeO2 nanostructured polydopamine-modified carbon cloth (CeO2/PDA/CC) interface was fabricated via electrodeposition for ethanol detection. The fabrication method involved two consecutive electrochemical steps in which dopamine was firstly electrodeposited on carbon fibers, followed by the electrochemical growth of CeO2 nanoparticles. The CeO2/PDA-based electroactive interface exerts an impressive electrochemical performance on the flexible sensor due to strong synergistic effect of the PDA functionalization with more active sites. Moreover, catalytic activity of CeO2 nanostructures anchored on highly conductive CC incorporate superior electrocatalytic performance of the fabricated interface. The designed electrochemical sensor showed a wide response to ethanol in the linear range 1 to 25 mM with a detection limit of 0.22 mM. The CeO2/PDA/CC flexible sensor showed good anti-interference ability and excellent repeatability and reproducibility (RSD = 1.67%). The fabricated interface performed well in saliva samples with satisfactory recoveries, corroborating the viability of CeO2/PDA/CC integrated interface for practical implementation. [ABSTRACT FROM AUTHOR]

The synthesis of medium-chain carboxylates (MCCs) from waste-activated sludge (WAS) upgrading has received considerable attention. However, limited research has been conducted on the effects of CeO2 nanoparticles (NPs) on this process. This study showed that 1 mg/g−TS of CeO2 NPs improved the solubilization of WAS, resulting in higher production of MCCs. At 5 mg/g−TS, CeO2 NPs weakly inhibited 3 biological steps. Despite this, there was an enhancement in WAS solubilization, thus the overall production of MCCs was similar to the control. However, doses of CeO2 NPs ranging from 25–100 mg/g−TS were unable to offset biological inhibition, leading to a decrease in MCC production. The toxic mechanisms involved were not the generation of reactive oxygen species or Ce ions from CeO2 NPs to anaerobic sludge, but instead the decline of extracellular polymeric substance (EPS) and destruction of the cell membrane through physical penetration. Microbial community analysis confirmed that 1 mg/g−TS of CeO2 NPs increased the relative abundance of key bacteria involved in the anaerobic fermentation of WAS. The MCC microbe Clostridium sensu stricto was enriched in the control group, while the relative abundance of this genus was significantly reduced with 100 mg/g−TS CeO2 NPs. [ABSTRACT FROM AUTHOR]

Films of PVA/PEG/CeO2 nanocomposites are fabricated to be used in different electronic applications. The A.C. electrical properties of PVA/PEG/CeO2 nanocomposites are studied. The dielectric properties are examined at frequencies from 100 Hz to 5 MHz. The experimental results indicate that the A.C. electrical properties of PVA/PEG/CeO2 nanocomposites are enhanced with increase in the CeO2 nanoparticles’ content. The dielectric parameters are changed with rise in the frequency. [ABSTRACT FROM AUTHOR]

Our study is focused on the structural and morphological characteristics, optical behaviour and photocatalytic properties of undoped and 5 at% Eu3+-, Gd3+- and Y3+-doped CeO2 nanoparticles prepared by a green hybrid sol-gel combustion method. Several techniques such as X-ray diffraction powder (XRD), Transmission Electron Microscopy (TEM), UV-Vis spectroscopy, Photoluminescence spectroscopy (PL) and Electron Paramagnetic Resonance (EPR) have been used to investigate the obtained samples. Moreover, the correlation between the characteristics and properties has been studied. The nanoparticles observed by TEM exhibit a pseudo-spherical shape, except for Y3+-doped CeO2, which presents an acicular shape. The average size of undoped and rare-earth-doped CeO2 nanoparticles is below 10 nm, in good agreement with the calculations performed based on XRD analyses. From UV-Vis analyses it has been deduced that with doping the band gap energy decreases, which shows that additional levels are introduced by doping into the CeO2 band gap. The EPR spectra evidence similar behaviour for all doped samples. The photocatalytic activity was evaluated by the degradation of rhodamine B (RhB) under UV light irradiation. The photodegradation mechanism has been studied in depth based on the formation of electron-hole pairs, and to evidence the reactive oxygen species, ESR coupled with spin-trapping experiments was performed. In the case of Y-doped CeO2 nanoparticles, the generation of both •OOH and •O2− radicals involved in RhB photodegradation was highlighted.

A novel regenerated cellulose (RC) membrane containing cerium oxide (CeO2) nanoparticles is described in detail. In this work, CeO2 nanoparticles with high surface area and mesoporosity were prepared by a modified template-assisted precipitation method. Successful synthesis was achieved using cerium nitrate as a precursor, adjusting the final pH solution to around 11 by ammonium hydroxide and ethylene diamine, and annealing at 550 °C for 3 hours under a protective gas flow. This resulted in a surface area of 55.55 m².g–1 for the nanoparticles. The regenerated cellulose membrane containing CeO2 particles was synthesized by the novel and environmentally friendly method. The catalyst CeO2 and cellulose/CeO2 membrane were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Electron paramagnetic resonance (EPR), and Brunauer-Emmett-Teller (BET) measurements. The g-value of 2.276 has confirmed the presence of the surface superoxide species of CeO2 nanoparticles in EPR. The photocatalytic activity of the catalyst and the membrane containing the catalyst was evaluated through the degradation of methylene blue under visible light irradiation by UV-VIS measurements. The cellulose/CeO2 membrane degraded 80% of the methylene blue solution in 120 minutes, showing a better photocatalytic activity than the CeO2 catalyst, which degraded approximately 62% in the same period. It has been proven that the RC membrane is not only a good transparent supporting material but also a good adsorption for high-performance of CeO2 catalyst. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The direct uptake of extracellular DNA (eDNA) via transformation facilitates the dissemination of antibiotic resistance genes (ARGs) in the environment. CeO2 nanoparticles (NPs) have potential in the regulation of conjugation-dominated ARGs propagation, whereas their effects on ARGs transformation remain largely unknown. Here, CeO2 NPs at concentrations lower than 50 mg L−1 have been applied to regulate the transformation of plasmid-borne ARGs to competent Escherichia coli (E. coli) cells. Three types of exposure systems were established to optimize the regulation efficiency. Pre-incubation of competent E. coli cells with CeO2 NPs at 0.5 mg L−1 inhibited the transformation (35.4%) by reducing the ROS content (0.9-fold) and cell membrane permeability (0.9-fold), thereby down-regulating the expression of genes related to DNA uptake and processing (bhsA, ybaV, and nfsB, 0.7–0.8 folds). Importantly, CeO2 NPs exhibited an excellent binding capacity with the plasmids, decreasing the amounts of plasmids available for cellular uptake and down-regulating the gene expression of DNA uptake (bhsA, ybaV, and recJ, 0.6–0.7 folds). Altogether, pre-exposure of plasmids with CeO2 NPs (10 and 25 mg L−1) suppressed the transformation with an efficiency of 44.5–51.6%. This study provides a nano-strategy for controlling the transformation of ARGs, improving our understanding on the mechanisms of nanomaterial-mediated ARGs propagation. [ABSTRACT FROM AUTHOR]

Water pollution by antibiotics is a global crisis, and its risk is critically more severe due to the explosive use of these drug compounds. A critical effective removal method to diminish this risk is heterogeneous photocatalysis and optimizing the conditions to reach higher mineralization efficiency. CeO2 anoparticles (NPs) were synthesized and characterized by X-ray diffraction (XRD), UV–Vis diffuse reflection spectroscopy (DRS), and Fourier transform infrared spectroscopy (FTIR) techniques. A cubic structural crystallite phase was detected that had crystallite sizes of 17.9 and 16.7 nm estimated by the Scherrer and Williamson-Hall models. A typical FTIR absorption band for the Ce–O stretching absorption has appeared at 554 cm−1. Based on DRS data and the Kubelka–Munk and Tauc models, Eg values of 2.80, 3.06, 3.12, and 3.13 eV were obtained for n-values of 1/2, 2, 3/2, and 3, respectively. pHpzc of CeO2 NPs was about 5.7. The direct photolysis and surface adsorption processes have no critical role in phenazopyridine (PP) removal by appearing with 2.7 and 6.7% removal efficiencies, respectively. Due to the highest photocatalytic activity of CeO2 NPs toward PP, the effects of the critical operating variable on the activity were evaluated, and the optimal conditions were as catalyst dose, 0.7 g/L; pH, 6; irradiation time, 90 min; and CPP, 20 ppm. The Hinshelwood kinetics equation plot was y = − 6.6442 – 0.4677x (r2 = 0.9296), in which its slope as the rate constant of the photodegradation process was 0.4677 min−1 (corresponding to a t1/2 value of 1.48 min). [ABSTRACT FROM AUTHOR]

The structural, optical, and magnetic properties of CeO2 were modified and improved by fractionally substituting Ce4+ ions with Gd3+ ions in the host structure of CeO2. A series of samples was synthesized using a sol–gel combustion process. Multiple characterization techniques were used to determine the effect of Gd ions on the structural, optical, and magnetic properties of the synthesized CeO2. An X-ray diffractogram was recorded to validate the cubic structure of the CeO2. Transmission electron microscopy (TEM) examination of all samples was consistent with the results obtained from the X-ray diffraction analysis. X-ray photoelectron spectroscopy (XPS) confirmed the + 3-valence state of the Gd ions and the presence of defects in the doped samples. Diffuse reflectance spectroscopy (DRS) was used to investigate the optical properties, and the bandgap decreased when Gd ions were added to the host structure. The photoluminescence (PL) spectra suggest that the defect concentration increased with increasing Gd content. In addition, increasing the number of Gd ions resulted in an increase in magnetization. CeO2 nanoparticles doped with Gd ions may be promising metal oxide semiconductors for applications in spintronics and optoelectronics owing to their improved optical and magnetic properties. [ABSTRACT FROM AUTHOR]

Due to its unique redox chemistry, nanoceria is considered as potent free radical scavenger and antioxidant. However, their protective capacity in aging organisms remains controversial. To detect the anti-aging effects associated with the redox activity of 2 and 10 nm nano-CeO2, different test systems were used, including in vitro analysis, in situ assay of mitochondria function and in vivo studies of suitable nano-CeO2 on aging of male Wistar rats from 22 months-old to the end of life. The 2 nm nanoparticles exhibited not only antioxidant (·OH scavenging; chemiluminescence assay; decomposition of H2O2, phosphatidylcholine autooxidation) but also prooxidant properties (reduced glutathione and reduced nicotinamide adenine dinucleotide phosphate oxidation) as well as affected mitochondria whereas in most test systems 10 nm nano-CeO2 showed less activity or was inert. Prolonged use of the more redox active 2 nm nano-CeO2 (0.25–0.3 mg/kg/day) in vivo with drinking water resulted in improvement in physiological parameters and normalization of the prooxidant/antioxidant balance in liver and blood of aging animals. Survival analysis using Kaplan–Meier curve and Gehan tests with Yates' correction showed that by the time the prooxidant-antioxidant balance was assessed (32 months), survival rates exceeded the control values most considerably. The apparent median survival for the control rats was 900 days, and for the experimental rats—960 days. In general, the data obtained indicate the ability of extra-small 2 nm nano-CeO2 to improve quality of life and increase the survival rate of an aging organism. [ABSTRACT FROM AUTHOR]

This research work aims at the eco-friendly preparation of cerium oxide nanoparticles (CeSD NPs) utilizing the natural extract of Scoparia dulsis L. An attempt was made to analyze the influence of the fuel load on the size, shape, and optical properties of the nanoparticles. The p-XRD studies revealed the controlled formation of NPs with a size not more than 12.74 nm. The surface area studies appraise the mesoporous nature of the synthesized ceria particles, with the maximum specific surface area of 36.06 m2g−1. The nano-regime CeO2 nanoparticles had a definite impact on biomedical and electrochemical studies. The CeSD NPs with minuscule size (10.69 nm) manifested promising antioxidant and human RBC protection activity. The antioxidant properties were evaluated using % DPPH inhibition with of maximum of 83.38. The stabilization of RBC's by CeSD NPs was maximum at 94.97%. However, the CeSD NPs with apparent size (12.74 nm) that utilized greater volume fuel (25 mL) had noticeable results on adenocarcinomic lung (A549) cancer cell viability and antidiabetic study which was maximum of 70.16% at concentration 500 μg/mL. A satisfactory antibacterial application was proffered against chosen bacterial stains. The smallest size CeO2 NPs exhibited the best proton diffusion coefficient (8.16 × 10−6 cm2s−1), and the capacitance values of the CeSD NPs are near in all samples (~ 1.17 to 2.00 F) manifest their compact nano-regime sizes. The paracetamol drug was chosen as analyte to appreciating the superlative efficiency for sensing paracetamol drug with the lowest detection limit. [ABSTRACT FROM AUTHOR]

This research paper aims to study the influence of some of the main parameters applied to the electrodeposition process on the nanocomposite layers obtained by strengthening the cobalt matrix with cerium oxide nanoparticles. Thus, the current efficiency (process efficiency) and the degree of inclusion of cerium oxide nanoparticles into cobalt matrix are analyzed according to the current density, the concentration of nanoparticles dispersed in the deposition electrolyte and time of the process. The choice of the optimal parameters imposed on the electrodeposition process lead to the improvement of the quality of the obtained layers, to the reduction of production costs and last but not least to the improvement of corrosion and tribocorrosion resistance of the material. The obtained results show an increase of current efficiency in the process of the deposited layers with the increase of time and current density applied. There is also a slight increasing in the current efficiency of the obtained layers with the increase of the concentration of nanoparticles dispersed in the deposition electrolyte. The increase of the current density, time and the concentration of nanoparticles also have an effect on the degree of embedded CeO2 nanoparticles into cobalt matrix for the studied nanocomposite layers. The degree of inclusion of nanoparticles decreases for the same studied system with the increasing of the current density.

Nanoplasmonic sensing, based on the plasmonic resonance absorption of thin, irregularly-shaped Au nanostructures film, with a starting thickness of about 15 nm (±3 nm) sputtered on a quartz substrate, is used to monitor the CeO2 NPs (with an average diameter of 50 nm) film refractive index variations using different film thicknesses (90 nm, 146 nm, 172 nm, and 196 nm). Increasing the film thickness of solution-processed CeO2 NPs film, with layer-by-layer deposition on top of Au nanostructures, shows a significant redshift in the plasmonic resonance absorption of the plasmonic metal, from 580 nm to 611 nm. Such an increase is related to the change in the building microstructure of the semiconductor’s film which is reflected in changing its refractive index. Plasmonic surface refractive index sensitivity of 437.5 nm/RIU with FOM of 4.2 has been recorded. Such a sensing technique offers a large potential for developing cost-effective plasmonic nanosensing devices for clinical applications. This sensor structure is versatile and can be utilized to sense and monitor a large variety of materials and chemicals.

SOD-like activity of CeO2 nanoparticles (Ce NPs) is driven by Ce3+/Ce4+, high oxidative stress can oxidize Ce3+ to reduce the ratio of Ce3+/Ce4+, inactivating the SOD activity of Ce NPs. Herein, we found Au@Ce NPs, assembled by Au NPs and Ce NPs, exhibited high-performance of SOD mimetic enzyme activity even upon the oxidation of H2O2. Ce NPs supported by nano-Au can acquire the electrons from Au NPs through the enhanced localized surface plasmon resonance (LSPR), maintaining the stability of Ce3+/Ce4+ and SOD-like activity. Meanwhile, Au@Ce NPs retained the peroxidase function and catalase function. As a result, Au@Ce NPs effectively scavenged O2•- and the derived ROS in AML cells, which are the important signaling source that drives AML cell proliferation and accelerates cell cycle progression. When HL-60 cells were treated by Au@Ce NPs, the removal of endogenous ROS signal significantly arrested cell cycle at G1 phase and suppressed the cell proliferation by blocking the mitogen-activated protein kinases (MAPKs) signaling and the Akt/Cyclin D1 cell cycle signaling. Importantly, this treatment strategy showed therapeutic effect for subcutaneous transplantation of AML model as well as a satisfactory result in diminishing the leukocyte infiltration of liver and spleen particularly. Thus, assembled Au@Ce NPs show the high-performance SOD-like activity, promising the potential in treating AML and regulating abnormal ROS in other diseases safely and efficiently.

[Display omitted] • A simple and eco-friendly synthesis of CeO 2 nanoparticles using Morinda citrifolia L. leaf extract as a reducing and capping agent. • CeO 2 nanoparticles was synthesized with average size, and FTIR confirms presence of Ce-O bonds. • The antibacterial activity of CeO 2 NPs was studied against the Staphylococcus luteus , Micrococcus lylae , Bacillus subtilis , and Pseudomonas aeruginosa. • The CeO 2 nanoparticles exhibited significant anti-inflammatory activity, highlighting their potential in biomedical applications. The current study presents an eco-friendly synthesis method to produces cerium oxide nanoparticles (CeO 2 NPs) using leaf extract from Morinda citrifolia L. To study the synthesized CeO 2 NPs, different methods of analysis were used, such as UV–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). With dynamic light scattering (DLS), the particle size distribution (PSD) of the synthesized CeO 2 NPs was measured. The CeO 2 NPs were spherical, highly stable, and possessed a particle size of 29.2 nm. In addition, the as-formed CeO 2 NPs exhibited strong antibacterial activity against both Gram-positive (Staphylococcus luteus , Micrococcus lylae, and Bacillus subtilis) and Gram-negative (Pseudomonas aeruginosa) bacteria. While the antifungal activity of CeO 2 NPs was examined, similar trends observed. The biocompatibility of cerium oxide nanoparticles, which suggests the potential for use in biomedical applications, has been tested using cell lines. The synthesized CeO 2 NPs also shown notable anti-inflammatory activity, highlighting their potential for use in biomedical studies and applications. [ABSTRACT FROM AUTHOR]

With the growing awareness on the adverse effects of conventional fertilizers; the use of sustainable and controlled release fertilizers has garnered much significance. In the present study, we report the synthesis of chitosan-benzaldehyde Schiff base xerogel incorporated with green synthesized cerium oxide nanoparticle using Psidium guajava leaves extract as a sustainable fertilizer. Spherical CeO 2 NPs having an average particle size of 15.3 nm and zeta potential of – 39.9 mV was obtained. The urea-loaded nanocomposite xerogel (CsB@U/CeO 2) was examined for cabbage growth. The water retention capacity extended for >2 weeks. A controlled release profile for urea was accomplished from CsB@U/CeO 2 for a period extending for 30 days. The kinetics assay suggested that presence of CeO 2 NPs asserted a greater role in urea-controlled release from the CsB@U/CeO 2 nanocomposite hydrogel owing to polymer relaxation. The growth parameters of cabbages such as head height, diameter, fresh head weight, head circumference was enhanced in plants fertilized by CsB@U/CeO 2 as compared to urea. Furthermore, the phenolic content, free radical scavenging activity, protein content, sugar and flavonoid content were also found higher in CsB@U/CeO 2 fertilized plants. This study puts forth CsB@U/CeO 2 xerogel can be potentially harnessed as an alternative to urea in sustainable agriculture. [Display omitted] • Green synthesis of CeO 2 nanoparticles accomplished from guava leaves extract. • Chitosan-benzaldehyde Schiff base hydrogel embedded with green CeO 2 NP synthesized. • Hydrogel has good water-retention capacity, biodegradability and lower salt index • Controlled release of urea was observed for >30 days. • Cabbage plants showed improved growth and metabolite content by the designed hydrogel. [ABSTRACT FROM AUTHOR]