Ce Ions Research Articles

Influence of cerium and iron substitution on the Bi2WO6 hierarchical microsphere and their enhanced photocatalytic degradation performance

A facile hydrothermal approach was employed to synthesize cerium and iron co-doped Bi2WO6 photocatalysts, and their photocatalytic performance for the degradation of cationic rhodamine B (RhB) and thionine (TH) dyes under UV–visible light illumination was investigated. Powder XRD investigation revealed that the Ce and Fe ions significantly influenced the Bi2WO6 crystal structure, while HR-XPS confirmed the valence states of Ce and Fe ions in the Bi2WO6 lattice. The light absorption wavelength of the co-doped samples was red-shifted when compared to the pristine Bi2WO6. The photoluminescence spectroscopy results showed that the synergistic effect of the Ce–Fe intermediate state in the Ce–Fe co-doped Bi2WO6 photocatalyst significantly reduced the recombination of photoinduced electron-hole pairs and boosted photocatalytic degradation activity. Furthermore, the stability of the best-performed catalyst was verified using recycling tests. The degrading efficiency of TH and RhB was not significantly affected after five repeated cycles. A potential mechanism for increased photocatalytic activity was also discussed.

Highly Conductive Peroxidase-like Ce-MoS2 Nanoflowers for the Simultaneous Electrochemical Detection of Dopamine and Epinephrine.

The accurate and simultaneous detection of neurotransmitters, such as dopamine (DA) and epinephrine (EP), is of paramount importance in clinical diagnostic fields. Herein, we developed cerium-molybdenum disulfide nanoflowers (Ce-MoS2 NFs) using a simple one-pot hydrothermal method and demonstrated that they are highly conductive and exhibit significant peroxidase-mimicking activity, which was applied for the simultaneous electrochemical detection of DA and EP. Ce-MoS2 NFs showed a unique structure, comprising MoS2 NFs with divalent Ce ions. This structural design imparted a significantly enlarged surface area of 220.5 m2 g-1 with abundant active sites as well as enhanced redox properties, facilitating electron transfer and peroxidase-like catalytic action compared with bare MoS2 NFs without Ce incorporation. Based on these beneficial features, Ce-MoS2 NFs were incorporated onto a screen-printed electrode (Ce-MoS2 NFs/SPE), enabling the electrochemical detection of H2O2 based on their peroxidase-like activity. Ce-MoS2 NFs/SPE biosensors also showed distinct electrocatalytic oxidation characteristics for DA and EP, consequently yielding the highly selective, sensitive, and simultaneous detection of target DA and EP. Dynamic linear ranges for both DA and EP were determined to be 0.05~100 μM, with detection limits (S/N = 3) of 28 nM and 44 nM, respectively. This study shows the potential of hierarchically structured Ce-incorporated MoS2 NFs to enhance the detection performances of electrochemical biosensors, thus enabling extensive applications in healthcare, diagnostics, and environmental monitoring.

Unique CSF lipid signature in asymptomatic subjects with a parental history of Alzheimer’s disease and its association with key apolipoprotein species

AbstractBackgroundCSF apolipoproteins exhibit lipid‐specific relationships (signatures) with Alzheimer’s disease (AD) pathological markers and APOE‐ε4 in asymptomatic individuals.MethodMass spectrometry‐based CSF lipid analysis was performed as described before (Sampaio et al. 2011). Lipids were extracted using a one‐step chloroform/methanol procedure. After extraction, resulting samples were analyzed by direct infusion on a QExactive mass spectrometer equipped with a TriVersa NanoMate ion source. Both MS and MSMS data were combined to monitor CE, DAG and TAG ions as ammonium adducts; PC, PC O‐, as acetate adducts; and CL, PA, PE, PE O‐, PG and PI as deprotonated anions. CSF levels of amyloid beta (Aβ42), and total Tau (t‐Tau) were measured by enzyme‐linked immunosorbent assay (Fujirebio, Sweden) whereas apolipoproteins (AI, AII, B, CI, CII, CIII, D, E and J) concentrations were assessed using the Luminex/Biorad assays kit (10‐plex magneto‐fluorescent immunoassays, BioRad, USA).ResultsTo characterize human CSF lipid signatures and their relationship to several apolipoproteins in pre‐symptomatic AD, we profiled and analyzed 21 classes of lipid species (for a total of 796 sub‐species) and 10 apolipoproteins in 120 cognitively unaffected subjects exhibiting various levels of total tau, p(181)tau and Aβ42. Figure 1 illustrates the signature profile (after FDR correction) following stratification by APOE‐ε4 genotype at the time of recruitment, when no cognitive deficit was detected. Please note the preferential associations between phosphatidylethanolamine acetate species and apoB levels in the CSF in non‐ε4 carrier. The apoD‐lipid signature profile was found to be very different in ε4 versus non‐ε4 carriers. Figure 2 illustrates the different associations between lipid species and the different apolipoproteins found in the CSF as a function of AD severity (stratified using the CSF T‐Tau/Aβ42 ratio). As ratio increases (top tertile) and pathology unfolds, the lipid signatures become markedly altered, with strong effects observed with apoB, apoD and apoJ interactions.ConclusionOur results suggest that early amyloid and tau pathologies modulate the release of specific lipid species in the CSF which alters their relationship with apolipoproteins in an APOE‐ε4‐dependent manner.

Zero- to One-Dimensional Zn24 Supraclusters: Synthesis, Structures and Detection Wavelength

A zinc supracluster [Zn24(ATZ)18(AcO)30(H2O)1.5]·(H2O)3.5 (Zn24), and a 1D zinc supracluster chain {[Zn24(ATZ)18(AcO)30(C2H5OH)2(H2O)3]·(H2O)2.5}n (1-D⊂Zn24) with molecular diameters of 2 nm were synthesized under regulatory solvothermal conditions or the micro bottle method. In an N,N-dimethylformamide solution of Zn24, Fe3+, Ni2+, Cu2+, Cr2+ and Co2+ ions exhibited fluorescence-quenching effects, while the rare earth ions Ce3+, Dy3+, Er3+, Eu3+, Gd3+, Ho3+, La3+, Nd3+, Sm3+, and Tb3+showed no obvious fluorescence quenching. In ethanol solution, the Zn24 supracluster can be used to selectively detect Ce3+ ions with excellent efficiency (limit of detection (LOD) = 8.51 × 10−7 mol/L). The Zn24 supracluster can also detect wavelengths between 302 and 332 nm using the intensity of the emitted light.

Ce2Pd21Si6 vs. Ce3Pd20Si6: Effect of Ce/Pd substitution on the physical properties

In this study, polycrystalline intermetallic compounds Ce3-xPd20+xSi6 (x = 0; 0.5; 1) as well as La-based analogues La3-xPd20+xSi6 (x = 0; 1) are synthesized. At the same time, R2Pd21Si6 (RCe, La) are new rare earth compounds presented here. An analysis of the crystal structure shows that the increase in x leads to partial (x = 0.5) or complete (x = 1) replacement of Ce/La ions by Pd in one of the two Wyckoff positions, namely, in position 4a. Ab initio DFT calculations demonstrate good agreement between the determined lattice parameters and those found experimentally for both Ce3-xPd20+xSi6 (x = 0; 0.5; 1) and La3-xPd20+xSi6 (x = 0; 1). A comparative analysis of resistivity and specific heat of Ce3-xPd20+xSi6 with x = 0; 0.5; 1 makes it possible to associate the Ce ions in the 8c position with Kondo behaviour in all three compositions, which manifests itself in an increase in resistivity with cooling, as well as in a broad peak of the magnetic contribution of specific heat. The Kondo temperature TK ≈ 25 K obtained from the analysis of the temperature dependences of the heat capacity turns out to be the same for all Ce compounds. The appearance of cerium ions in the position 4a in compositions with х = 0 and х = 0.5 leads to an additional contribution to the specific heat, the value of which increases with decreasing temperature, as well as, to the formation of a coherent Kondo-lattice state with a maximum of the resistivity at Tcoh ≈ 15 K, followed by the subsequent onset of negative magnetoresistance regime below Tinv≈ 7 K. Apparently, this behaviour is associated with the appearance of spin and orbital correlations proceeding the quadrupole and antiferromagnetic transitions occurring at lower temperatures. Magnetization measurements show more localized character of magnetic moments of Ce ions at T = 2 K in Ce3Pd20Si6 as compared to the Ce2Pd21Si6.

A mixed valence decanuclear cerium-oxo cluster CeIII4CeIV6 for efficient photocurrent response

Cerium-oxo clusters with mixed valence exhibit distinctive redox properties due to cerium ions switch between +3/+4 valence states. However, the design and synthesis of these clusters present formidable challenges, resulting in limited availability of such species, often necessitating the use of both CeIII and CeIV reactants. Herein, we successfully obtained a mixed valence cerium-oxo cluster CeIII4CeIV6(µ3-O)4(µ4-O)4(acac)14(CH3O)6(CH3OH)2 (CeIII4CeIV6, Hacac = acetylacetone) through low-temperature crystallization only using the trivalent cerium salt. The coexistence as well as the distribution of Ce ions in different valence states have been determined from a multifaceted analysis. In addition, the stability of the synthesized cluster was confirmed by the HRESI-MS study through redissolution of the single crystal sample in fresh methanol. Importantly, Importantly, this study reveals the mechanism for the generation of +4 valence state. Under alkaline conditions, the presence of trace oxygen and the involvement of acetylacetone ligand facilitated the partial oxidation of CeIII to CeIV. The cluster CeIII4CeIV6 has strong ultraviolet absorption and long visible light absorption. As the electrode precursor, CeIII4CeIV6 showed clear photocurrent response and high photocurrent intensity due to CeIII/CeIV redox reaction.

Development and evaluation of thiosalicylic-modified/ion-imprinted chitosan for selective removal of cerium (III) ion

Chitosan was used in this study as the bio-based product for the development of microparticles for the specifically targeted removal of cerium ions (Ce3+) by ion-imprinting technology. A thiosalicylic hydrazide-modified chitosan (TSCS) is produced via cyanoacetylation of chitosan, followed by hydrazidine derivatization to finally introduce the thiosalicylate chelating units. Ion-imprinted Ce-TSCS sorbent microparticles were prepared by combining the synthesized TSCS with Ce3+, crosslinking the polymeric Ce3+/TSCS complex with glutaraldehyde, and releasing the chelated Ce3+ using an eluent solution containing a mixture of EDTA and HNO3. Ce-TSCS had a capacity of 164 ± 1 mg/g and better removal selectivity for Ce3+ because it was smart enough to figure out which target ions would fit into the holes made by Ce3+ during the imprinting process. The kinetic data were well suited to a pseudo-second-order model, and the isotherms were well described by the Langmuir model, both of which pointed to chemisorption and adsorption through Ce3+ chelation. XPS and FTIR analyses demonstrate that the predominant adsorption mechanism is the coordination of Ce3+ with the -NH-, -NH2, and -SH chelating units of the thiosalicylic hydrazidine. These findings provide fresh direction for the development of sorbent materials that can effectively and selectively remove Ce3+ from aqueous effluents.

BILFF: All-Atom Force Field for Modeling Triazolium- and Benzoate-Based Ionic Liquids.

We present an extension of our previously developed all-atom force field BILFF (Bio-polymers in Ionic Liquids Force Field) to three different ionic liquids: 1-ethyl-3-methyl-1,2,3-triazolium acetate ([EMTr][OAc]), 1-ethyl-3-methyl-1,2,3-triazolium benzoate ([EMTr][OBz]), and 1-ethyl-3-methylimidazolium benzoate ([EMIm][OBz]). These ionic liquids are of practical importance as they have the ability to dissolve significant amounts of cellulose even at room temperature. Our force field is optimized to accurately reproduce the strong hydrogen bonding in the system with nearly quantum chemical accuracy. A very good agreement between the microstructure of the quantum chemical simulations over a wide temperature range and experimental density data with the results of BILFF were observed. Non-trivial effects, such as the solvation shell structure and π-π stacking of the cations, are also accurately reproduced. Our force field enables accurate simulations of larger systems, such as solvated cellulose in different (aqueous) ionic liquids, and is the first to present the optimized parameters for mixtures of these solvents and water.

Enhancement of Ni–Zn ferrite nanoparticles parameters via cerium element for optoelectronic and energy applications

This work is concerned with fabricating ferrite nanoparticles of nickel–zinc with the chemical formula: Ni0.55Zn0.45Fe2−xCexO4, 0 ≤ x ≤ 0.011 by co-deposition technique and modifying their electrical, microscopic, spectroscopic, optical, electrical and dielectric properties as advanced engineering materials through doping with the cerium (Ce) element. XRD patterns displayed that the samples have a monophasic Cerium–Nickel–zinc (CNZ) spinel structure without other impurities for cerium concentration (x) ≤ 0.066. Both values of crystallite size and lattice parameters decrease from 33.643 to 23.137 nm and from 8.385 to 8.353 nm, respectively, with the increasing Ce ions substitution content from 0 to 0.066. SEM images indicate that grains of the fabricated compounds are smaller, more perfect, more homogeneous, and less agglomeration than those of the un-doped Ni–Zn nano-ferrites. The maximum intensity of first-order Raman spectral peaks (Eg, F2g(2), A1g(2), and A1g(1)) of CNZ ferrite nanoparticles are observed at about (330, 475, 650, 695) cm−1, respectively, that confirms the CNZ samples have the cubic spinel structure. The direct and indirect optical energy bandgaps of CNZ samples have a wide spectrum of values from semiconductors to insulators according to cerium concentration. The results showed that the values of dielectric constant, dielectric loss factor, and Ac conductivity and the conductivity transition temperature are sensitive to cerium ions content. AC conductivity exhibited by the CNZ samples has the semiconductor materials behavior, where the AC conductivity increases due to temperature or doping concentration. The results indicate that Ni0.55Zn0.45Fe1.944Ce0.066O4 ferrite nanoparticles may be selected for optoelectronic devices, high-frequency circuits, and energy storage applications.

Electron Paramagnetic Resonance, Electronic Ground State, and Electron Spin Relaxation of Seven Lanthanide Ions Bound to Lanmodulin and the Bioinspired Chelator, 3,4,3-LI(1,2-HOPO).

The electron paramagnetic resonance (EPR) spectra of lanthanide(III) ions besides Gd3+ , bound to small-molecule and protein chelators, are uncharacterized. Here, the EPR properties of 7 lanthanide(III) ions bound to the natural lanthanide-binding protein, lanmodulin (LanM), and the synthetic small-molecule chelator, 3,4,3-LI(1,2-HOPO) ("HOPO"), were systematically investigated. Echo-detected pulsed EPR spectra reveal intense signals from ions for which the normal continuous-wave first-derivative spectra are negligibly different from zero. Spectra of Kramers lanthanide ions Ce3+ , Nd3+ , Sm3+ , Er3+ , and Yb3+ , and non-Kramers Tb3+ and Tm3+ , bound to LanM are more similar to the ions in dilute aqueous:ethanol solution than to those coordinated with HOPO. Lanmodulins from two bacteria, with distinct metal-binding sites, had similar spectra for Tb3+ but different spectra for Nd3+ . Spin echo dephasing rates (1/Tm ) are faster for lanthanides than for most transition metals and limited detection of echoes to temperatures below ~6 to 12 K. Dephasing rates were environment dependent and decreased in the order water:ethanol>LanM>HOPO, which is attributed to decreasing librational motion. These results demonstrate that the EPR spectra and relaxation times of lanthanide(III) ions are sensitive to coordination environment, motivating wider application of these methods for characterization of both small-molecule and biomolecule interactions with lanthanides.

Hydrothermal synthesis of cerium-doped Zn2SiO4 phosphor for futuristic lighting applications

In this study, Zn2SiO4:Ce3+ phosphor with varying weight percentages of cerium (Ce) was synthesized by using the hydrothermal process. The effect of Ce ion incorporation on the nanostructures, morphology, and optical characteristics was investigated by X-ray Powder Diffraction (PXRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray spectroscopy (EDX), Diffuse Reflectance Spectroscopy (DRS) using UV–Vis spectra, Photoluminescence (PL) spectroscopy, Commission Internationale de I'Elaairage (CIE)-1931 RGB color space diagrams and decay lifetime. According to PXRD measurements, Ce3+ ions were incorporated into the host material of Zn2SiO4, considerably altering their crystallinity. Due to strong crystallization, willemite crystal dispersion can be seen in FESEM images as rhombohedral-shaped crystals that successfully form closely packed grains, when the concentration of Ce3+ doping increased from 0 to 4 wt %, there was a noticeable reduction in the optical energy bandgap of the phosphor, which decreased from 5.01 to 3.22 eV. Photoluminescence spectra exhibited enhanced luminescent peak intensity at 591 nm emission, due to transitions of Ce3+ ions excited at 395 nm. Additionally, the luminescence intensity and decay lifetime of the Ce3+ ions in the Zn2SiO4 samples were determined using the tri-exponential fitting technique, and the average lifetime is 24.1 ns. This work provides valuable insight into the effect of doping element Ce3+ with various concentrations on the properties of luminescent Zn2SiO4, paving the way for its potential applications in advanced lighting technologies.

Magnetic properties of (Nd1-xCex) Fe11Ti alloys produce by melt - spinning process

Magnetic properties can be enhanced by doping of different elements and special preparation process which has an effect to the magnetic characteristics of NdFe11Ti alloys. The doping of Ce on the Nd site ((Nd1-xCex) Fe11Ti; with x = 0, 0.1, 0.2, 0.3 of the alloys produced by melt – spinning process have result to the proportion of the main phase with ThMn12-type structure exceeding 88 vol% of the alloys composition. The highest content of the 1:12 phase founds at, x = 0 and 0.2. However, a decrease in size of the unit cell with ThMn12-type structure phase observed due to increase in x values (x = 0 – 0.3). The impurity phase of the studied alloys found to be α-Fe. Moreover, the TEM result shows that, melt-spinning process can transform the initial multiphase alloys to an intermetallic compound with single phase of (Nd, Ce) Fe11Ti. However, the increase in coercive force and residual magnetization in comparison with that of the alloys as cast, can be explained by the increase in the dispersion of grain structure, an increase in field and the constant of magnetocrystalline anisotropy of ThMn12-type structure phase, due to the partial replacement of Nd ions with Ce ions.

Determination of naproxen in mixtures of water and an organic solvent based on chemiluminescence of reaction mixtures containing europium ions

A simple and sensitive method, based on chemiluminescence of a reaction system containing europium(III) ions, for determination of naproxen in mixed solvents of water and an organic solvent (methanol, ethanol, 1-propanol, 1-butanol and acetonitrile) is proposed. Organic solvents are often used in the preliminary procedures of sample preparation for determination of active ingredients. The method is based on chemiluminescence accompanying naproxen oxidation by Ce(IV) ions in the environment of sulfuric acid, sensitized with europium(III) ions. This environment ensures stable and reproducible conditions of measurements in water and mixed solvents. In such a system a linear relation was observed between the integrated intensity of chemiluminescence in the spectral range λ > 585 nm and naproxen concentration in the range from 6 × 10−8 molL−1 to 6 × 10−6 molL−1, and with the limit of detection of 1.5 × 10−8 molL−1 (0.004 μg/mL). The relation is described by the same linear equation in water and in mixed solvent of water and 0.1–20 % (v/v) of an organic solvent. The method is characterized by high tolerance of the presence of foreign substances, including other nonsteroid anti-inflammatory drugs (NSAIDs). The proposed method has been successfully used for determination of naproxen in pharmaceutical formulations and samples of human urine subjected to preliminary treatment with alcohol or acetonitrile.

Ce3+-Yb3+, Tb3+-Yb3+ and Pr3+-Nd3+-Yb3+ mixed-doped TeO2–ZnO–Na2O glasses for enhancing the efficiency of silicon solar cells

In general, the sunlight wavelength absorbed by silicon solar cells is mainly concentrated in the range of 600–1100 nm. Although silicon solar cells can also absorb sunlight in the ultraviolet and visible regions with <600 nm, the utilization of light is very low. In addition, some high-energy photons in the ultraviolet and visible region can cause serious damage to silicon solar panels, reducing its useful lifetime and lowering its photoelectric conversion efficiency. Therefore, in order to make full use of the light in this range, we studied three-layer light-conversion glass doped with three groups of rare-earth ion to improve the utilization rate of light in silicon solar cells and prolong the lifetime. A series of zinc tellurate glasses (TeO2–ZnO–Na2O) doped with Ce3+-Yb3+, Tb3+-Yb3+ and Pr3+-Nd3+-Yb3+, respectively, were prepared by melting quenching method. The crystalline state and interior structure of the prepared glasses are characterized by using X-ray diffraction (XRD) spectra and Raman spectra. And the lowest phonon energy of these glasses is about 773 cm−2. The photoluminescence properties of rare-earth ions doped in these glasses are studied. The results show that the near infrared emission (centered at 980 nm) of activator ion (Yb3+) is observed when the sensitizer ions (Ce3+, Tb3+, Pr3+ and Nd3+) are excited by using 430 nm, 355 nm and 488 nm ultraviolet and visible (UV–vis) photons, respectively. The down-conversion and down-shift energy transfer mechanisms between sensitizer ion and activator ion are discussed. Based on the above research, a triple-layer zinc tellurate glass sample doped with Ce3+-Yb3+/Tb3+-Yb3+/Pr3+-Nd3+-Yb3+ in a certain ratio is prepared. And the current density-voltage (J-V) curves of silicon solar cell covered with triple-layer zinc tellurate glass were tested. According to the data obtained from J-V curves, the relative efficiency (Δη) of Si solar cells covered with Ce3+-Yb3+/Tb3+-Yb3+/Pr3+-Nd3+-Yb3+ triple-layer zinc tellurate glass is increased by 2.37% compared with that of silicon solar cell covered with blank glass. So, the above results can show that the glass has important application values in improving the energy efficiency of silicon solar cells.

Influence of CeO2 on the structure and properties of borosilicate glass: An investigation from the perspective besides the refining process

CeO2 has been used as the refining agent in the melting of borosilicate glasses. The study of its influence on glass melt, structure and properties is inadequate. In this work, a series of borosilicate glasses were prepared with batches containing 0∼0.6wt% of CeO2. Besides the in-situ observation of refining process, the structure of the glasses was systematically investigated via IR, Raman,11B and 29Si NMR spectroscopy. The results showed that the viscosity of melts increased with CeO2 due to aggregation effect of Ce ions. However, the release of oxygen was dominant at high-temperature, thus the melt prepared with 0.6wt% CeO2 had the fastest refining rate, and was bubble-free within 60 min at 1550℃. With the increase of CeO2, both Q3 species and [BO3] in the glass network increased in the final sample, indicating the structure depolymerization, which led to the decrease of the chemical stability.

Computational study of thermophysical properties of cerium doped UO2: Effect of oxidation states

The interaction of fission products with UO2 fuel, which is generated during the nuclear fission, can amend the fuel behavior. Among different lanthanide (Ln) fission products produced, Cerium (Ce) shows considerable yield. The Ce substitution in UO2 with isovalent Ce4+ cation is interesting due to the absence of oxygen vacancies and no change in the oxidation state of U atoms in the doped system. In this study, the trivalent and tetravalent Ce atom substitution in UO2 and their effect on thermophysical properties is investigated using density functional theory. Further, the effect of Ce doping concentrations in UO2 is assessed by varying the Ce ion concentrations in the lattice (6.25 %, 12.5 %, 25 %, and 50 %) for various charge balancing mechanisms. The lattice volume of Ce doped UO2 structures show higher or lower values compared to undoped UO2 depending upon the oxidation state of Ce and U atoms. The bulk modulus tends to reduce for Ce substituted UO2 as compared to pure UO2. The electronic density of states analysis shows that Ce substitution levels as well as the oxidation state of Ce/U atoms strongly influences the band structure of the UO2 lattice. The specific heat capacity of Ce doped UO2 structures is calculated at different Ce doping concentrations and for disparate charge balancing procedures using the quasi harmonic approximation(QHA). Present results show good agreement with the experimental values reported for similar Ce substituted UO2 structures. Thus, the systematic investigation with varying Ce fission product concentrations and oxidation states of cations (Ce and U) can give insight into the fuel properties of UO2 under reactor conditions.

Reducing Luminescence Intensity and Suppressing Irradiation‐induced Darkening of Bi4Ge3O12 by Ce‐doping for Radiation Detection

AbstractDue to its short radiation length, moderate light output (8000‐9000 photons/MeV), high density (7.13 g cm−3), and non‐hygroscopicity, etc., Bi4Ge3O12 (BGO) material has been widely utilized as an advanced scintillator for irradiation detection. However, pure BGO cannot meet the requirements for future physics experiments and state‐of‐art industrial facilities coupled with a silicon photomultiplier (SiPM) due to its slow response time, poor radiation resistance, and excessive light output. Herein, a Ce‐doping strategy is reported for efficiently improving the overall performance (e.g., irradiation resistance, decay time, radioluminescence, and light output) of BGO that can be expectedly applied in future high energy physics detection. Ce‐doped BGO (BGO:Ce) displays higher radiation resistance ability under 10 h UV irradiation (97% of original) and a faster fluorescence lifetime (269 ns), superior to pure BGO. Furthermore, BGO:Ce shows ≈30% luminescence intensity of pure BGO, well eliminating the oversaturation of SiPM coupled with scintillation detectors. Theoretical calculations imply that an intense competition between electron or hole traps and Ce ions (Ce3+, Ce4+) can effectively reduce the concentration of color centers, thus enhancing irradiation resistance ability.

Effect of acetate ions and pH on the morphology of cerium oxide nanoparticles

Cerium oxide nanoparticles (CeNPs) are recognized as functional materials with suitability in diverse applications. Conventional synthesis of CeNPs involves direct addition of alkaline solutions and/or precipitating agents to cerium solutions. Rapid changes in solution concentrations and ligand introduction result in less control over particle size and dispersity. Here, we report a simple hydrothermal synthesis of cubic shaped CeNPs through homogenous precipitation, achieved by introduction of acetate molecules. A distinct trend in CeNPs transitioning from octahedral to cubic morphologies was observed through a series of experiments. Results from experimental and computational studies have demonstrated that acetate plays an important role in directing the morphological transition of CeNPs and providing a pH-buffered environment. The formation of Ce(IV)-acetate complexes not only stabilizes aqueous Ce(IV) but also inhibits its hydrolysis in conditions of lower pH. The stabilization of Ce(IV) ions is also favorably weakened during the hydrothermal treatment, leading to successful homogeneous precipitation and the formation of mono-dispersed cubic-shaped CeNPs.

Innovative g-C3N4/AX composite electrode for effective thorium elimination from aqueous solutions

Electrosorption is a technique that combines electrical and adsorption processes and has been established to displace Th(IV) from aqueous solutions. The present study successfully synthesised a novel electrode, where graphitic carbon nitride was modified with amidoxime amidoxime groups (g-C3N4/AX) via the hydrothermal method. The batch experiments conducted in this study revealed that the g-C3N4/AX electrode possessed a favourable thorium adsorption capacity of 275.74 mg.g−1 and a swift elimination equilibrium of within 30 min. Furthermore, the removal efficiency at − 1.0 V (84.46 %) of the electrode was almost threefold greater than the removal efficiency at open circuit potential (24.09 %). The results were due to the free electrical charges on the g-C3N4/AX electrode, which induced the electrical driving force and facilitated the adsorption of Th(IV) ions onto the g-C3N4/AX surface. The shifted bands from the Fourier transform-infrared (FT-IR) spectrum post-electrosorption demonstrated a substantial complexation of Th(IV) with the amine groups of amidoxime and g-C3N4. A significant transference in energy band peaks was also observed during the XPS assessment, indicating that the electrosorption process included oxygen (O), carbon (C), and nitrogen (N) species. In the practical real wastewater involving rare earth residue, which contains Ce, La, Nd and Pr ions, g-C3N4/AX exhibited good capabilities in selectively adsorbing Th(IV). The electrode synthesised in this study also exhibited the ability to regenerate with a reasonable ∼ 80 % removal ratio after five runs. The results indicated that the amidoxime-modified graphitic carbon nitride electrode demonstrated a good potential in removing thorium from aqueous solutions via electrosorption applications.

Extraction of heavy metals from wastewater using amine-modified mesoporous silica.

Presence of heavy metals in wastewater is a critical environmental issue, and efficient extraction of the metals remains a challenging task. In this study, the adsorption behavior of Ce(III), Hg(II), and Cu(II) metal ions using MCM-48 material modified with acid and base functional groups was examined. The modified materials were characterized using various techniques, including XRD, BET, FT-IR, NMR, and SEM, which revealed that the materials' properties remained unchanged after modification. The adsorption capacity of the modified materials for metal ions was then evaluated and was found that the amine-modified MCM-48 material exhibited the highest adsorption efficiency. Precisely, the amine-modified material achieved an adsorption capacity of 97% for Ce(III), 98% for Hg(II), and 90% for Cu(II) after 180min of adsorption. These results highlight the effectiveness of amine functionalization in enhancing the adsorption capacity of silica material for heavy metals.