INFRARED PHYSICS & TECHNOLOGY
·
2021
·
IF 2.638
Yuxin Pan,Hui Lin,Ruijin Hong,Dawei Zhang,Haojie Sun
A series of Yb 3+ , Ho 3+ , Ce 3+ :YAG ceramics have been sintered at 1780 °C by high temperature solid state reaction under oxygen atmosphere. The absorption spectra , fluorescence spectra and fluorescence decay curve were discussed. The Judd-Ofelt (J-O) theory was applied to obtain the values of Ω 2 = 13.95 × 10 −20 cm 2 , Ω 4 = 3.94 × 10 −20 cm 2 and Ω 6 = 0.87 × 10 −20 cm 2 , respectively. After doping the Ce 3+ ions, the σ em of Yb 3+ , Ho 3+ , Ce 3+ :YAG ceramic at 2094 nm increased from 5.67 × 10 −20 cm 2 to 7.26 × 10 −20 cm 2 . These results demonstrate that Yb 3+ , Ho 3+ , Ce 3+ :YAG ceramic could be promising for 2 μm region.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Huancheng Wu,Chaowei Yang,Xuejie Zhang,Bingfu Lei,Mingtao Zheng,Haoran Zhang
In this paper, a series of Ba2GaB4O9Cl:Ce 3+ ,Tb 3+ phosphors were synthesized by the conventional high-temperature solid-state reaction. The incorporation of Ce 3+ ions as sensitizers significantly enhances the absorption and luminescence intensity of Tb 3+ ions in the Ba 2 GaB 4 O 9 Cl phosphor. The energy transfer from Ce 3+ to Tb 3+ occurs through the electric quadrupole-quadrupole interaction, with an energy transfer efficiency of 48 %. The internal quantum efficiency of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor is 39.95 % upon 316 nm excitation. At 423 K, the emission intensity of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ can keep 53.28 % of its initial value at room temperature. All these results indicate that the Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor has potential application for white LED.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Teng Zheng,Laihui Luo,Peng Du,Stefan Lis,Ulises R Rodríguez-Mendoza,Víctor Lavín,Inocencio R. Martín,Marcin Runowski
To overcome the challenges of pressure monitoring with high sensitivity, we have designed a series of Ce 3+ -activated Ca 2 Gd 8 Si 6 O 26 phosphors with outstanding pressure sensing properties. Excited with UV light, the resultant phosphors can emit a blue-violet luminescence, originating from optically active Ce 3+ ions. The optimal doping content for Ce 3+ ions in the Ca 2 Gd 8 Si 6 O 26 host lattices is 3 mol%, for which the concentration quenching mechanism is dominated by the electric dipole–dipole interaction. The thermal stability of the prepared phosphors was explored by measuring temperature-dependent emission spectra, and determining the activation energy, which is ∼ 0.225 eV. Furthermore, in order to study the pressure sensing ability of the designed phosphors, their luminescence spectra were recorded as a function of pressure up to ∼ 10 GPa. With increasing pressure, an abnormal enhancement of emission intensity was observed, with an enormous red-shift of the emission band of 3.00 nm/GPa, and a decreasing full width at half maximum (FWHM) of − 2.45 nm/GPa for the synthesized phosphors. The determined performance of the sensors developed now classifies them as the most sensitive pressure gauges, i.e., the shift rate is approximately one order of magnitude higher than that of the commonly used ruby sensor. Importantly, the developed pressure sensor shows a negligible temperature dependence, i.e., 0.0023 nm/K for the line-shift and 0.0017 nm/K for the FWHM, and an ultrafast response due to the short emission lifetime of the Ce 3+ excited state of ∼ 20 ns. Additionally, the structural stability of the compounds under pressure is verified by Raman spectroscopy up to ∼ 11 GPa. These results make the Ce 3+ -activated Ca 2 Gd 8 Si 6 O 26 phosphors a promising candidate for ultrasensitive manometry and provide some guidelines for the development of novel pressure sensors.
研究领域:
材料科学
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光学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2024
·
IF 3.8
Pengchao Ren,Zhenzhou Zhang,Tingting Hu,Zhihui Fan,Shanshan Dang,Sifan Cheng,Weifeng Tu,Yi-Fan Han
Graphical The apparent rate coefficients for CH 3 OH synthesis from CO hydrogenation are a single-valued function of the CO 2 -to-CO ratio in the contacting gas phase, because this ratio determines the extent of surface oxidation of Ce 2 O 3 to CeO 2 , the relative abundance of surface Ce 3+ , and in turn the density of Cu 0 -Ce 3+ sites pair on the working Cu/CeO 2 catalyst. This study investigated the dynamic structure of a working Cu/CeO 2 catalyst and its catalytic consequences for CH 3 OH synthesis via CO hydrogenation by kinetics, high-precise chemical titration, and a series of in situ X-ray spectroscopies. We have revealed that the apparent rate coefficients for CH 3 OH synthesis from CO hydrogenation are a single-valued function of the CO 2 -to-CO ratio in the contacting gas phase. This ratio determines the extent of surface oxidation of Ce 2 O 3 to CeO 2 , the relative abundance of surface Ce 3+ and Ce 4+ sites, and in turn, the density of Cu 0 -Ce 3+ sites pair on the working Cu/CeO 2 catalyst, although the chemical state of Cu and elemental distribution of both Cu and Ce were insensitive to the ratio. The reactivity of CH 3 OH formation and the Cu 0 -Ce 3+ sites decrease monotonously with an increase in the CO 2 -to-CO ratio. The direct connection of the reactivity and the oxidant-to-reductant ratio appears to be general for heterogeneous catalysis, for which the oxidant oxidizes metal atoms. In contrast, the reductant scavenges surface oxygen atoms, thus dictating the density of surface sites and their thermodynamic activities.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Weihao Fan,Huaiyuan Wang,Chijia Wang,Zhanjian Liu,Yanji Zhu,Kaka Li
CeO 2 -PANI conductive polymer capsules were prepared by in-situ chemical oxidation polymerization. The capsules were dispersed in F51 epoxy resin and then sprayed onto the steel surface to form novel coatings after curing. The corrosion resistance of coatings was investigated by EIS in a 3.5 wt% NaCl solution. After 30 days, the 60-μm-thin coating containing CeO 2 -PANI capsules exhibited the highest corrosion resistance, and its impedance modulus was higher than 10 9 Ω·cm 2 , which was 10 times that of conventional PANI-Epoxy coatings. This improvement was attributed to the (Fe 3 O 4 + γ-Fe 2 O 3 + CeO 2 ) passive film actively formed by the synergistic effect of PANI and Ce 3+ ions. PANI polarized the anodic reaction and Ce 3+ inhibited the cathodic reaction.
研究领域:
材料科学
·
腐蚀工程
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Hao-Hua Deng,Bang-Yue Luo,Shao-Bin He,Rui-Ting Chen,Zhen Lin,Hua-Ping Peng,Xing-Hua Xia,Wei Chen
Although it has been demonstrated that rare-earth elements (REEs) disturb and alter the catalytic activity of numerous natural enzymes, their effects on nanomaterial-based artificial enzymes (nanozymes) have been seldom explored. In this work, the influence of REEs on the peroxidase-like activity of bare gold nanoparticles (GNPs) is investigated for the first time, and a new type of Ce3+-activated peroxidase mimetic activity of GNPs is obtained. The introduced Ce3+ can be bound to the bare GNP surface rapidly through electrostatic attraction, after which it donates its electron to the bare GNP. As H2O2 is a good electron scavenger, more •OH radicals are generated on the surfaces of the bare GNPs, which can considerably enhance TMB oxidation. Due to its redox cycling ability, the activation effect of Ce3+ is proved to be more efficient in comparison to those of the other reported metal ion activators (e.g., Bi3+, Hg2+, and Pb2+). In addition, it is determined that Ce3+ should directly contact with the gold core to trigger its activation effect. When the surface states of the bare GNPs are altered, the Ce3+-stimulated effect is strongly inhibited. Furthermore, a novel colorimetric method for Ce3+ is developed, on the basis of its enhancing effect on the peroxidase mimetic activity of bare GNPs. The sensitivity of this newly developed method for Ce3+ is excellent with a limit of detection as low as 2.2 nM. This study not only provides an effective GNP-based peroxidase mimic but also contributes in realizing new applications for nanozymes.
研究领域:
分析化学
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纳米生物学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2019
·Vol. 15
·期 17
·1900289
·
IF 10.856
Hao Dong,Lei Zhang,Lulu Li,Wanyu Deng,Congling Hu,Zhi-Jian Zhao,Jinlong Gong
The electroreduction of CO 2 to CO provides a potential way to solve the environmental problems caused by excess fossil fuel utilization. Loading transition metals on metal oxides is an efficient strategy for CO 2 electroreduction as well as for reducing metal usage. However, it needs a great potential to overcome the energy barrier to increase CO selectivity. This paper describes how 8.7 wt% gold nanoparticles (NPs) loaded on CeO x nanosheets (NSs) with high Ce 3+ concentration effectively decrease the overpotential for CO 2 electroreduction. The 3.6 nm gold NPs on CeO x NSs containing 47.3% Ce 3+ achieve CO faradaic efficiency of 90.1% at −0.5 V in 0.1 m KHCO 3 solution. Furthermore, the CO 2 electroreduction activity shows a strong relationship with the fractions of Ce 3+ on Au-CeO x NSs, which has never been reported. In situ surface-enhanced infrared absorption spectroscopy shows that Au-CeO x NSs with high Ce 3+ concentration promote CO 2 activation and *COOH formation. Theoretical calculations also indicate that the improved performance is attributed to the enhanced *COOH formation on Au-CeO x NSs with high Ce 3+ fraction.
研究领域:
材料科学
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环境科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yanran Hou,Zi-Han Chen,Hui Shen,Simin Li,Xinping Qu,Baimei Tan,Wei Yuan,Fan Zhang
In the pursuit of Moore's Law, the transition to integrated circuits (ICs) and atomic-scale device fabrication places pressure on chemical mechanical polishing (CMP) to deliver flawless surfaces. Moving beyond conventional abrasives, ultra-small and monodisperse ceria nanoparticles have arisen as a critical materials platform. Tailoring their size, composition, and surface properties is important to simultaneously achieving high polishing selectivity and sub-angstrom smoothness. However, CeO 2 abrasives with ultra-small particle sizes are plagued by challenges in production, colloidal instability leading to agglomeration, and relatively low polishing rates. Herein, we report a universal doping-mediated activity adjusting platform and successfully develop ultrasmall CeO 2 mesoporous nanoabrasive. USM-Ce, with sizes under 30 nm, exhibits uniform morphology and excellent dispersibility. Theoretical calculations combined with various characterization reveal that the constructed doping regulation platform effectively reduces the formation energy of oxygen vacancies in USM-Ce, thereby markedly increasing the concentration of both oxygen vacancies and Ce 3+ ions. Notably, USM-Ce can further enhance the material removal rate to 232% of the original through doping regulation. Meanwhile, the proposed ultrasmall abrasives deliver an atomically planarized, nearly scratch-free surface with an angstrom-level finish. The newly developed mesoporous CeO 2 nanoparticles offer a versatile platform for ultrasmall ceria-based nanoabrasives in critical advanced IC manufacturing processes.
研究领域:
材料科学
·
半导体制造
·
纳米技术
·
表面工程
·
化学机械抛光
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·6577-6585
·
IF 3.9
Yuting Zhang,Huan Tu,Guoying Zhao,Jingshan Hou,Yufeng Liu,Xin Qiao,Zhongzhi Wang,Bo Li,Ji-Guang Li,Feng Wang,Yongzheng Fang
Compared with other fluorescent crystal phases, garnet has better structural stability in a glass matrix and renders precisely controllable emissions due to the abundant lattice control positions. In this work, we regulate the coordination field of Ce 3+ ion based on the co-substitution method and achieve the spectra regulation in the yellow–green range. We used Ba 2+ –Si 4+ cations to replace Y 3+ –Al 3+ cations in Y 3 Al 5 O 12 (YAG) matrix to obtain blue-shift of the emission peak from 552 to 539 nm. The centroid shift and crystal field splitting decrease with the decreasing covalency of the bond between the Ce 3+ ion and the surrounding anions owing to the higher electronegativity of Si 4+ ions than Al 3+ ions. The corresponding fluorescent films were prepared by a low-temperature co-sintering process based on the as-made Ba 2+ –Si 4+ co-substituted phosphor. X-ray powder diffractometer and scanning electron microscopy images showed that the fluorescence crystals were less eroded and evenly dispersed in the glass matrix. Spectral analysis showed that the garnet phase was protected by using lead-free borosilicate glass with a low melting point, and the quantum efficiency of phosphor-in-glass (PiG) retains 98% of the corresponding phosphor. By adjusting the ratio of garnet phosphor to commercial red nitride phosphors, a warm white fluorescence with a color rendering index of 80.3 and color temperature of 3899 K was obtained. The prepared warm white film has potential application value in the whole spectra field.
研究领域:
材料科学
·
光电子学
·
固态照明
·
无机化学
·
晶体场理论
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）