CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xin Wang,Yunfei Gao,Zhiyang Cai,Shan Hu,Junxian Zhang,Fuchen Wang,Yifei Wang
Chemical looping air separation (CLAS) represents a promising approach to use thermal energy for high-purity oxygen production. CeO 2 represents a class of material that uncouples oxygen using thermal energy, but the required temperature is usually very high (>1400 °C). This limits the potential use for CeO 2 -based materials in CLAS. This study reports a Pr doped CeO 2 oxygen sorbents for chemical looping air separation at ultra-low temperatures. The as-formed Ce 1-x Pr x O 2 solid solution can uncouple oxygen effectively, achieving a redox oxygen capacity of 0.88 wt% at isothermal condition as low as 500 °C. The redox oxygen capacity can be further enhanced to 1.63 wt% in temperature-swing cycles between 400 °C and 900 °C. Moreover, oxygen partial pressure-swing cycles show that the Ce 1-x Pr x O 2 solid solution maintains 95% of its redox oxygen capacity at oxygen partial pressure as low as 0.02 atm, indicating its potential applications in oxygen separation from diluted air. DFT calculations and other physio-chemical characterizations indicate that Pr doping can effectively reduce the oxygen vacancy formation energy, and gaseous oxygen is uncoupled when Pr 4+ and Ce 4+ are reduced in the Ce 1-x Pr x O 2 solid solution. Overall, this study highlights the novel performance of CeO 2 with Pr doping and could offer insights into CeO 2 modification strategies for thermal chemical applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2022
·Vol. 51
·期 3
·1180-1188
·
IF 2.047
Ji Xinran,Zhou Ke,Zhao Ye,Sun Meiling,Dong Shijun,Zhang Hongbo,Cao Hechun,Zheng Hui,Wu Qiong,Zhang Yang
The regulation of magnetic and dielectric properties for yttrium iron garnet ferrites by ion doping is highly desirable in microwave devices. In this work, yttrium iron garnet ferrites co-doped with Pr-Zn-Zr atoms with the chemical formula Pr x Y 3-x Zn 0.1 Zr 0.1 Fe 4.8 O 12 (x = 0, 0.1, 0.15, and 0.2) were prepared. The dependence of the crystal structure, microstructure, magnetic, and dielectric properties of the obtained samples on the Pr doping concentration was investigated. The morphologies and crystal structure characterizations confirm that the Pr ion has effectively doped in the yttrium iron garnet ferrites and increased the lattice parameter and grain size. The magnetic characterization shows that the saturation magnetization also increases with the Pr concentration and obtains a maximum value of 27.68 emu/g at x = 0.15. Additionally, the doping of Pr increases the magnetic anisotropy constant K 1 which increases ferromagnetic resonance linewidth. Lastly, the dielectric properties measurement further indicates that Pr doping improves both real and imaginary parts of permittivity, and the highest value of the real part of the permittivity is obtained at x = 0.15. Consequently, the crystal structure, microstructure, magnetic properties, and dielectric properties of garnet ferrite can be effectively regulated by the Pr doping concentration, and excellent properties of the ceramic can be obtained at x = 0.15, which allows potential applications in microwave devices.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 14
·3417
·
IF 4.2
Pengfei Zhu,Zhaoxia Hu,Shouwen Chen
The development of economical catalysts that exhibit both high activity and durability for chlorinated volatile organic compounds (CVOCs) elimination remains a challenge. The oxidizing and acidic sites play a crucial role in the oxidation process of CVOCs; herein, praseodymium (Pr) was introduced into CrOx catalysts via in situ pyrolysis of MIL-101(Cr). With the decomposition of the ligand, a mixed micro-mesoporous structure was formed within the M-Cr catalyst, thereby reducing the contact resistance between catalyst active sites and the 1,2-dichloroethane molecule. Moreover, the synergistic interaction between chromium and praseodymium facilitates Oβspecies and acidic sites, significantly enhancing the low-temperature catalytic performance and durability of the M-PrCr catalyst for 1,2-dichloroethane (1,2-DCE) oxidation. The M-30PrCr catalyst possess enhanced active oxygen sites and acid sites, thereby exhibiting the highest catalytic activity and stability. This study may provide a novel and promising strategy for practical applications in the elimination of 1,2-DCE.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Chenwei Xiong,Rui Hao,Kewen Tao,Huashan Li,Shaopeng Lin,Decai Ma
This study has demonstrated that lithium niobate doped with praseodymium (LiNbO 3 :Pr), which initially did not exhibit persistent luminescence(PersL), can display significant PersL performance through the modulation of the lithium-to-niobium ratio (R LN ). By adjusting the R LN to 1, LiNbO 3 :Pr achieved enhanced PersL, lasting several minutes, with the afterglow's duration further influenced by the R LN . Thermoluminescence (TL) assays and energy diagram analyses have elucidated that the presence and depth of oxygen vacancy defects are critical for both the emergence and longevity of PersL LiNbO 3 :Pr polycrystals . These insights enhance the understanding of PersL mechanisms in lithium niobate crystals and highlight their potential for application in optical information storage.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yehong Zhang,Xiangyu Li,Zhidong Pan,Shanjun Ke,Yanmin Wang
This paper was to synthesize praseodymium-doped neodymium molybdate allochroic pigments with different molar ratios of molybdenum (Mo), neodymium (Nd) and praseodymium (Pr) through solid-state reactions. The pigments synthesized were investigated by X-ray diffraction (XRD), selected area electron diffraction (SAED), thermogravimetry and differential thermal analysis (TG-DSC), diffuse reflectance spectroscopy , X-ray photoelectron spectroscopy (XPS) and colorimeter. The results show that a pure neodymium molybdate (i.e., Nd 2 MoO 6 ) can be formed after sintering at 1000 °C for 3 h, and praseodymium-doped neodymium molybdate can be synthesized after sintering at 1000 °C for 3 h due to praseodymium ions entering in the lattice of Nd 2 MoO 6 . The crystal structure in the pigment synthesized can transform from cubic to tetragonal depending on the molar ratio of neodymium/molybdenum and sintering procedure. The color properties of pigments were measured in color space CIE L*a*b* under different standard illuminants (i.e., solar-light (D65), incandescent light (A), cool white fluorescent lamp (F2), and three-band fluorescent lamp (F11)). The results show that the colors of the pigments vary under different illuminants. According to the color difference (Δ E ) analysis, neodymium molybdate pigment exhibits a maximum color difference of 10.69, and the maximum color difference of praseodymium-doped neodymium molybdate pigment with doping content of 0.2 increases to 17.63 due to the Pr 3+ ions substitution for Nd 3+ ions in the lattice. In addition, the color difference of the pigments with allochroic effect was discussed based on the colorimetry. The color difference of the pigments is due to a high reflectance region at 540–550 nm and a low reflectance region at 380–500 nm.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 47
·20061-20070
·
IF 2.7
Jiabing Chen,Yibo Tang,Xiaojun Lu,Zijing Lu,Xingmao Jiang
The industrial production of methyl propionate synthesized via methoxycarbonyl esterification of ethylene achieved 100% atom economy. In this study, we synthesized ruthenium-loaded praseodymium–cerium oxide (Pr–CeO2) catalysts by precipitation impregnation and evaluated their performance in the methoxycarbonylation reaction of ethylene. The effect of Pr doping on the reaction results was analyzed by characterization and mechanistic studies. Pr doping increased the concentration of localized oxygen vacancies in the catalysts and thus modulated the catalytic effect of Lewis acid–base pairs. The increase of local oxygen vacancies significantly enhanced the activation and dissociation of CH3OH. At the same time, since the dissociation activation of the other two feedstock molecules, ethylene and CO, occurred at the Ru site, Pr doping facilitated the dispersion of Ru to a certain extent, thus increasing the dissociation activation of CO and ethylene, which, in combination with Pr doping, further increased the content of oxygen vacancies in the active site as methanol, resulting in a substantial enhancement of the dissociation activation of the feedstock molecules, which then increased the catalytic reaction rate through synergistic effects. The results provide a new perspective for the future study of methoxycarbonylation.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Tao Wang,Junling Yu,Jianmin Liu,Feng Jiang,Guo Feng,Jian Liang,Lifeng Miao,Quan Zhang,Qian Wu,Xinbin Lao
A fluorine-free route has been developed to fabricate V/Pr co-doped zircon (ZrSiO 4 ) ceramic pigments with Na 3 VO 4 and Pr(NO 3 ) 3 ·6H 2 O as colourants . The as-prepared pigments were characterized by XRD , Raman, XPS , UV–vis, FE-SEM, TEM and automatic colourimeters . The results show that Na 3 VO 4 can not only act as colourant to produce blue hue, but as mineralizer to accelerate the formation of V/Pr co-doped ZrSiO 4 pigment. A colour tuning between blue, green and yellow can be achieved by increasing the mole ratio of Pr/V, and the most intense yellow hue (L* = 74.55, a* = −0.38, b* = 46.82) is obtained at a mole ratio of Pr/V = 0.5. Both Pr 4+ and Pr 3+ cations are co-existed in the pigments, where Pr 4+ contributes to the generation of yellow hue while Pr 3+ undermines the yellow hue. The good chromatic ability in glaze at high temperature suggest its potential application in ceramic decoration.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Min Li,Wei Zhang,Weifeng Chen,Meiling Li,Weijing Wu,Hua Xu,Jianhua Zou,Hong Tao,Lei Wang,Miao Xu,Junbiao Peng
Praseodymium-doped indium zinc oxide (PrIZO) channel materials have been fabricated by a solution process with conventional chemical precursor. The PrIZO-based thin-film transistors (TFTs) exhibited a field-effect mobility of 10.10 cm2/V s, a subthreshold swing value of 0.25 V/decade, and an Ion/Ioff ratio of 108. The as-fabricated PrIZO-TFTs showed an improved device performance against positive bias temperature stress (PBTS shift of 1.97 V for 7200 s), which was evidently better than the undoped IZO-TFTs (PBTS shift of 9.52 V). This result indicates that the organic residual (−OCH3 and −CH2−) in metal–oxide semiconductor, which is confirmed to be a dominant effect on the performance of PBTS, can be passivated by the rare earth of praseodymium element. The residual is intended to be oxidized with a more stable ester group with the assistant of PrOx, weakening the electron-withdrawing characteristic during the thermal bias stress.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Zi-Jun Wei,Weichao Bao,Shi-Kuan Sun,Lewis R. Blackburn,Sheng-Heng Tan,Laura J. Gardner,Wei-Ming Guo,Fangfang Xu,Neil C. Hyatt,Hua-Tay Lin
Praseodymium-doped zirconolite ceramics targeting nominal composition Ca 1-x Pr x ZrTi 2-5x/3 Al 5x/3 O 7 (x ≤ 0.20, Δx = 0.05) were fabricated by a mixed oxide solid state reaction, at 1350 °C in air for 20 h. Praseodymium (Pr) was employed as a surrogate for neptunium (Np), with Al 3+ co-accommodated to provide charge balance. High-resolution transmission electron microscopy and electron diffraction analyses confirmed that zirconolite crystallised as the 2M monoclinic polytype throughout the phase evolution, with no evidence of transformation to other polytype structures. Phase assemblage and microstructural data were consistent with zirconolite occupying a high fraction of the phase assemblage (> ca . 93 wt.%), alongside a minor secondary perovskite phase at all levels of targeted Pr incorporation. Despite this, it was demonstrated near theoretical density formed through a solid-state fabrication route, and we therefore propose that, through analogy with the corresponding Pr solid solution, zirconolite may be a suitable candidate for the immobilisation of Np-bearing wastes.
研究领域:
材料科学
·
核废料管理
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2018
·
IF 2.32
Qiang Liu,Xiaoying Li,Jiawei Dai,Zhaoxiang Yang,Tengfei Xie,Jiang Li
Praseodymium doped terbium aluminum garnet (Pr:TAG) magneto-optical ceramics with different doping concentrations were fabricated by vacuum pre-sintering and hot isostatic pressing (HIP) post-treatment from the co-precipitated Pr:TAG nanopowders . It is found that all the as-synthesized powders exhibit a pure TAG phase and show good dispersity. The in-line transmittance of Pr:TAG ceramics fabricated by pre-sintering at 1700 °C for 20 h and HIP post-treating at 1700 °C for 3 h decreases from 80.6% to 76.3% at 1064 nm with the Pr 3+ doping concentration increasing from 0 at% to 2.0 at%. The Verdet constant of the 2.0 at% Pr:TAG ceramics at 633 nm is −189.8 rad T -1 m -1 , which is 42% larger than that of the commercial TGG single crystals (−134 rad T -1 m -1 ). The superior characteristics of the Pr:TAG ceramics indicate that they have great potential to meet the increasing requirements for magneto-optical devices used in the visible and near-infrared wavelength.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Zefei Peng,Wei Shi,Song Chen,Hang Shi,Xueling Yan,Zelin Liu,Linfeng Lan,Miao Xu,Min Li,Lan Liu
Although different kinds of one dimensional (1D) metal oxide nanofibers (MO-NFs) based field effect transistors (FETs) have been developed in recent years, their intrinsic deficiency in illumination instability are not addressed yet, which further prevented their application in practical life. In this work, due to the outstanding performance of suppressing oxygen vacancies and the blue light down-conversion with low charge transfer transition energy, praseodymium (Pr) is demonstrated an ideal candidate to dope into In 2 O 3 NFs for both transferring the depletion mode to the enhancement mode and enhancing the illumination stability of the FETs. The optima In 2 O 3 NFs-based FET was achieved by doping with 3 mol% Pr and exhibited an excellent electrical performance with a carrier mobility of 6.92 cm 2 V −1 s −1 , an on/off current ratio of ∼5.4 × 10 7 , threshold voltage of 5.2 V, and subthreshold swing of 0.37 V/dec. Moreover, the FETs exhibited good illumination stability under 3600 s negative gate bias stress test with illumination (NBIS). Finally, the FET was also used as a switch to bright the LED in this work, demonstrating its great promise of Pr-doped In 2 O 3 NFs in future one-dimensional electronic devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Meidan Que,Yabo Wang,Ruochen Shi,Xun Sun,Jun Xu,Peihong Ma,Yanbo Sun,Jing Guan,Shengxia An
MIL-125(Ti) is well known for having stable structure, tunable electron structure, and multiple active sites, which is commonly studied in the field of photocatalysis . In this work, a series of rare earth (RE) doped MIL-125(Ti) (RE=Ce, Pr, Tm, Dy, Eu, and Sm) are prepared via the one-step hydrothermal method . Notably, Pr-MIL-125 displays a significantly enhanced catalytic performance than other RE-doped MIL-125, resulting in a maximal CO and CH 4 yield of 13.30 and 0.87 µmol·g −1 ·h −1 , respectively, which are 2.53-fold and 4.14-fold of the pristine MIL-125. The layered morphology endows Pr-MIL-125 with more active sites and facilitates the reaction of photoreduction CO 2 . Furthermore, the promoted photoactivities attributed to Pr ion dopant can act as electron transfer bridge and suppress charge recombination. This work would provide insight and guidance for designing RE-MOF based photocatalysts and enhancing the performance of photoreduction CO 2 .
研究领域:
材料化学
·
光催化
·
环境科学
·
无机化学
·
能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）