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Synthesis and spectral analysis of fluorescent probes for Ce4+ and OCl? ions based on fluorescein Schiff base with amino or hydrazine structure: Application in actual water samples and biological imaging
摘要： Two Schiff base fluorescein probes (FDA, FDH) based on fluorescein-aldehyde and nitroaniline derivatives were synthesized. The effects of amino and hydrazine substituents in fluorescein backbones were examined via fluorescence and absorbance spectra. In the presence of Ce4+, the fluorescence of FDA was quenched due to the ligand to metal charge transfer (LMCT). Hypochloric acid can react with the C=N bond, and blocking the photo induced electron transfer (PET) of FDH leads to enhancement of the fluorescence. FDA showed detection limits for Ce4+ and OCl? as low as 63 nM in concentration range of 0 – 4 μM. FDH showed detection limits for OCl? as low as 0.8 μM in concentration rang 0 – 100 μM. Polyvinylidene fluoride (PVDF) membrane containing the probes were prepared for the real-time qualitative detection of Ce4+ and OCl? in real water samples. The probes were successfully applied to biological imaging in vascular smooth muscle cells (VSMCs) and are expected to find applications in biosensing.
关键词： Schiff base,Application,Nitroaniline derivatives,Hypochloric acid,Cerium ion,Fluorescein
更新于2025-09-23 15:22:29
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Ce(IO3)2F2·H2O: The First Rare Earth Iodate Fluoride with Large Second Harmonic Generation Response
摘要： The first rare earth iodate fluoride, Ce(IO3)2F2·H2O, has been synthesized via hydrothermal method. In the structure, the CeO5F4 polyhedra connect with isolated IO3 groups to form one-dimensional infinite 1∞[Ce(IO3)2F2] chains, which interconnect with each other by weak hydrogen bond to construct the whole structure. Ce(IO3)2F2·H2O produces a large second harmonic generation response, which is 3 times that of KDP. Theoretical calculations using density functional theory and dipole moments were executed to illustrate the relationships between the structure and the properties. The results show that Ce(IO3)2F2·H2O is a new iodate fluoride with novel structure and has potential applications in the field of nonlinear optics.
关键词： crystal structure,iodate fluorides,density functional calculations,cerium iodates,1∞[Ce(IO3)2F2] chain
更新于2025-09-23 15:21:21
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Optical Properties and Electronic Characteristics of Cerium in the Condensed State
摘要： The results of investigating optical properties of metallic cerium in the liquid and solid film state are presented. Optical constants were measured by the ellipsometric Beattie method in the range of 0.42–2.6 μm at ambient temperature. Based on the measured refractive indices and the absorption coefficients, spectra of light conductivity σ, reflectivity R, and characteristic loss function Im ε–1 were calculated. Based on experimental measurements in the IR region, electronic characteristics of liquid cerium and its polycrystalline film and their correlation with electrical conductivity have been determined.
关键词： optical properties,cerium,rare-earth metal,characteristics of conduction electrons,ellipsometry
更新于2025-09-23 15:21:21
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Characterization and application of cerium bromide spectrometers for analysis of γ-ray emitting radionuclides in food matrices
摘要： Cerium bromide (CeBr3) scintillators are useful room temperature gamma-ray detectors that provide the robustness of a scintillator with improved resolution over traditional sodium iodide (NaI) detectors. This makes them attractive for field deployment or emergency response operations especially when combined with the power of Monte-Carlo based efficiency determinations. This work documents the characterization of CeBr3 detectors and the efficiency determination of a portable CeBr3 detector based gamma-ray detection system for food measurements.
关键词： Gamma-ray measurement,Cerium bromide,Efficiency calculation,Food safety
更新于2025-09-23 15:21:21
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Enhanced UV and visible light - driven Photocatalytic degradation of Tartrazine by Nickel-doped Cerium oxide Nanoparticles
摘要： Nickel-doped cerium oxide nanoparticles were synthesized via a simple aqueous coprecipitation method. The synthesized nanoparticles were thoroughly characterized by PXRD, TEM, SEM, EDX, Raman, and UV-Vis spectroscopic techniques. XRD study confirmed the doping of nickel in the cerium oxide lattice. The shift in Raman spectra revealed the formation of nanoparticles in their pure phase with fluorite structure. EDX revealed the formation of a solid solution on doping Ni- to CeO2. SEM images revealed considerable agglomeration. TEM analysis asserted the average particle size of 8-10 nm with a well-defined spherical shape. The particle size was found to be sensitive to dopant concentration, i.e., it decreased with increase in the concentration of the dopant. A comparative UV-visible spectroscopic analysis showed the remarkable red shift in the band gap of nickel-doped cerium oxide nanoparticles. Investigation of photocatalytic activity towards degradation of azo dye tartrazine showed that 3 mol% and 5 mol% Ni- CeO2 nanoparticles exhibited 53.4% and 63.7% photodegradation respectively under visible irradiation while 57.4% and 65.4% respectively under UV irradiation. The study suggests that the band gap of cerium oxide nanoparticles can be easily tuned (decreased) by doping of nickel at different concentrations. The observed improved photocatalytic activity upon Nickel doping is attributed to the narrow band gap.
关键词： azo dye,mechanism,tartrazine,photocatalysis,Nickel-doped cerium oxide nanoparticles
更新于2025-09-23 15:21:01
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High Charge Carrier Storage Capacity in Lithium Lutetium Silicate Doped with Cerium and Thulium
摘要： It is demonstrated that LiLuSiO4:Ce,Tm has excellent charge carrier storage properties. Comparative studies are performed with the state-of-the art X-ray storage phosphor BaFBr(I):Eu. The thermoluminescence (TL) intensity of the optimized LiLuSiO4:Ce,Tm is four times higher than the TL of BaFBr(I):Eu. After 3 h of storage at room temperature (RT) there is still 94% of initial thermoluminescence and only 48% for BaFBr(I):Eu which demonstrates insignificant thermal fading. The signal can be read out by a blue LED and less efficiently by a red laser. It does require higher stimulation energy than in the case of BaFBr(I):Eu. The self-irradiation with a dose rate of 13 mGy h due to 176Lu isotopes is not a serious drawback for application.
关键词： storage phosphors,thulium,cerium,traps,thermoluminescence,fading,self-irradiation
更新于2025-09-23 15:21:01
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Effect of oxygen vacancy on structural, optical, and photocatalytic properties of ceria films grown by magnetron sputtering deposition
摘要： Cerium oxide is of crucial importance for intrinsic redox reaction, which is attributed to the active sites neighboring oxygen vacancies. However, the role of oxygen vacancy (Ov) on the various properties of ceria ?lms remains to be elucidated. Herein, ceria ?lms were deposited by magnetron sputtering and the e?ect of electric current intensity on the creation of Ov was systematically investigated. X-ray photoelectron spectroscopy (XPS) results show that the Ce4+ concentration decreases with the increase of current intensity, which demonstrates that Ov can be created and tuned during ?lm deposition by controlling electric current intensity. The ?lm fabricated by 6 A current intensity has 42% Ce4+, approaching that of rhombohedral-Ce7O12, which is a stabilized bulk phase ceria. X-ray di?raction patterns reveal that 6 A ?lm shows mixed crystalline phases with the majority of peaks very close to rhombohedral-Ce7O12, while 1 A, 2 A, and 4 A ceria ?lms show simple crystalline phase. Raman analysis presents that dioxygen species are heavily absorbed on the surface of 6 A ?lm with more active sites on di?erent crystalline surfaces, which is con?rmed by photocatalytic degradation of Methylene Blue. The calculated bandgap by DFT (density functional theory) + U is consistent with that obtained from Tauc plots curves. This work demonstrates that Ov plays an important role on the properties of the ceria ?lm.
关键词： XPS,Raman,Oxygen vacancy,Magnetron sputtering,Cerium oxide
更新于2025-09-23 15:21:01
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Temperature-dependent luminescence of Ce-doped SrO-B2O3 glasses
摘要： In this study, the photoluminescence (PL) and X-ray-induced scintillation of trivalent cerium, Ce3+, in strontium borate glasses was examined. As no precipitated crystallites were observed, the slight coloration of the glasses was attributed to the formation of defects that are inactive in electron spin resonance spectroscopy. Both the Ce3+/(Ce3++Ce4+) ratio, which was estimated based on the Ce LIII-edge in X-ray absorption near edge structure analysis, and the internal quantum efficiency of Ce-doped glasses increased as the amount of Ce(OCOCH3)3×H2O, which acted as a reducing agent, was increased. Although the PL intensity was independent of the temperature in the range of 10–300 K, the X-ray induced scintillation exhibited thermal quenching behavior with an activation energy of 0.14 eV.
关键词： borate glass,scintillation,thermal quenching,Ce L-edge X-ray absorption near edge structure (XANES),photoluminescence,cerium
更新于2025-09-23 15:21:01
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Plasmon-induced Ag decorated CeO <sub/>2</sub> nanorod array for photodetector application
摘要： In this work, glancing angle deposition (GLAD) has been used to grow Ag decorated CeO2 nanorod (NR) array on n-type Si substrate. The length of the NRs obtained was ～235 nm and the size of the Ag NPs varied from 13 to 41 nm. The polycrystalline and crystalline nature of CeO2 and Ag respectively was revealed via selected area electron diffraction (SAED) analysis as well as x-ray diffraction (XRD) pattern. Optical absorption measurement depicts a distinct broad peak around 413 nm that is ascribed to the localized surface plasmon resonance (LSPR) effect of Ag NPs. The Ag decorated CeO2 NR device exhibited a turn on voltage at ～3.2 V under dark, which then reduced to ～1.3 V under 35 min illumination along with the increase in device current from 2.8 to 24.5 μA cm?2 (4 V) on continuous exposure to light. Under white light illumination, a responsivity of 4.51 A W?1 was obtained at 370 nm along with the detectivity and noise equivalent power (NEP) values of 4.15×1012 jones and 0.01 pW respectively. Additionally, a fast response characteristic with rise and fall times of 74 ms and 42 ms respectively was demonstrated. Thus, these findings manifest the underlying LSPR mechanism at work in Ag/CeO2 heterojunction and reveal its high potential in UV photodetector application.
关键词： GLAD,surface plasmon,nanorod,silver,nanoparticle,cerium oxide
更新于2025-09-23 15:19:57
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Remote Measurements of X-rays Dose Rate using a Cerium-doped Air-clad Optical Fiber
摘要： Cerium doped silica glasses are attractive materials for radiation dosimetry. In this work, Ce-doped air-clad optical fiber has been fabricated for real-time X-ray dose rate measurements through the radioluminescence (RL) signal. The structural properties of the obtained material were studied using Raman spectroscopy. The presence of Ce3+ ions inside the sol-gel-derived silica core was confirmed using photoluminescence (PL) measurements. This optical fiber, with a high numerical aperture, was tested as active and guiding material in an all-fibered remote X-ray dosimeter configuration. We demonstrated that the response dependence of RL versus dose rate is linear from 52 mGy(SiO2)/s up to at least 1.5 Gy(SiO2)/s, allowing to monitor the dose rate evolution during an irradiation run. The presented results confirm the potentialities of this microstructured optical fiber to monitor ionizing radiations in harsh environments. They also pave the way towards an alternative to the widely used approach that uses a scintillator material at the end of a transport optical fiber.
关键词： radioluminescence,cerium,Dosimetry,X-ray radiation,optical fiber
更新于2025-09-23 15:19:57