JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2023
·Vol. 106
·期 9
·5476-5486
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IF 3.9
Shan Peng,Ranran Yang,Binglong Lei,Renhua Chen,Yun Gao,Xiaohong Xia,Kevin P. Homewood
It is of particular significance to unveil the authentic coloration mechanism of the multivalent praseodymium colored ZrSiO 4 yellow pigments for advanced decoration applications. We herein adopted a facile strategy to modulate the fluorine-assisted zircon crystallization and thereby obtained ultrafine Pr-ZrSiO 4 yellow pigments, which have a remarkably narrow size distribution and average diameters within 250–400 nm. By virtue of some cogent combinative spectra of reflection, absorption, excitation, and emission from three types of elaborately-designed H 2 -, air-, and O 2 -based pigments, the coloration mechanism for the Pr-colored zircon was systematically unveiled: both Pr 4+ and Pr 3+ coexist invariably in the pigments, while the former contributes primarily to the ligand-to-metal charge transfer from O 2p to Pr(IV) 4f for the blue–violet absorption to generate the yellow hue, and the latter is inclined to discolor the pigments. Therefore, an oxidizing atmosphere is preferable to produce brilliant Pr-ZrSiO 4 pigments with enhanced chromatic properties. The stark spectroscopic distinctions between the wide-band absorption from the nonluminescent tetravalency and the narrow-band absorption from the luminescent trivalency can expand our understanding to the rare-earth-based inorganic pigments.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 6
·8577-8592
·
IF 5.164
Wei Han,Wei Wang,Yongqiang Zhang,Yijie Wang,Mei Li,Yang Sun
Summary To recover Pr from molten chlorides, the electrode reactions of Pr 3+ on Sn-coated W and liquid Sn electrodes were studied by a group of electrochemical techniques. CV and SWV results exhibited that the electrochemical signals pertaining to the formation of Pr-Sn alloy compounds and solid solution appeared at less negative potentials than that of Pr 3+ on W electrode. The thermodynamic data of Pr-Sn alloy compounds and the kinetic parameters for PrSn 3 /Pr 3+ pair were determined employing OCP, LP, and Tafel methods, separately. The measured diffusion coefficient ( D ) of Pr in liquid Sn metal was 9.40 × 10 −6 cm 2 s −1 . Furthermore, the electrochemical recovering Pr from molten salt was performed using liquid Sn as a working electrode, and the formed Pr-Sn samples characterized by XRD and SEM-EDS were composed of Sn and PrSn 3 phases.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2024
·
IF 2.4
Li Mei,Du Rui,Wei Hedi,Chen Jiayi,Liu Rugeng,Zhang Meng,Han Wei
In order to investigate the influences of the additive (KF) on electrochemistry and deposit morphology of Pr, various electrochemical techniques were used to comparative investigate the electroreduction potential and diffusion coefficient of Pr 3+ and kinetic properties of Pr 3+ /Pr in LiCl–KCl-PrCl 3 before and after the addition of KF at different molar concentration ratios of F − to Pr 3+ ( k ). Cyclic voltammetry, square wave voltammetry, and reverse chronopotentiometry results showed that the value of k ( k = 0, 1, 2, 3, and 4) had no effect on reduction mechanism of Pr 3+ . With the increase of k , the reduction peak potential moved in the negative direction, the diffusion coefficient decreased, and diffusion activate energy increased. Meanwhile, the exchanged current densities ( j 0 ), charge transfer resistances ( R ct ), and activate energies ( E a ) were measured at different k by linear polarization technique, which illustrated that with the increase of k , j 0 gradually decreased, and E a and R ct increased. Furthermore, the electrochemical preparation of Pr aided by KF was explored by potentiostatic electrolysis at different k , and the products were characterized by XRD, SEM, and EDS, which indicated that with the increase of k , the morphology of metallic Pr changed from slender needles to granular. Graphical abstract
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yang Wu,Ying Dai,Yijun Liu,Wen Chen,Xinmei Pei,Fanfeng Xie
Novel eco-friendly green pigments, Pr x Ca 2 -x Al 2 SiO 7 (0 < x ≤ 0.1) were synthesized via a solid-state method using Pr 6 O 11 as the coloring oxide and Ca 2 Al 2 SiO 7 as the base material. The results reveal that praseodymium (Pr) ions dissolved into the Ca 2 Al 2 SiO 7 lattice, with the green coloration primarily attributed to Pr 3+ in the lattice. The solid solution was influenced by both temperature and the amount of Pr 6 O 11 introduced. A bright green pigment with composition Pr x Ca 2 -x Al 2 SiO 7 ( x = 0.08) was obtained by maintaining the material at 1350°C for 1.5 h, yielding chromatic parameters L*: 78.29, a*: -18.37 and b*: 27.51. Pr 3+ , responsible for coloration, are retained in an octahedral coordination environment by substituting Ca 2+ in the Ca 2 Al 2 SiO 7 lattice, while Pr 4+ are converted to Pr 3+ when the temperature exceeds 1323K. The newly synthesized pigment is non-toxic, harmless, and exhibits remarkable thermal stability, its successful application to biscuit ceramics highlights its potential as a sustainable and eco-friendly pigment for the ceramics industry.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2012
·Vol. 95
·期 10
·3214-3219
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IF 2.272
Haoyi Wu,Yihua Hu,Fengwen Kang,Nana Li,Guifang Ju,Zhongfei Mu,Zhongfu Yang
Praseodymium (Pr 3+ ) with rich f energy levels can generate various visible emissions, but the luminescence of Pr 3+ in a CaWO 4 matrix has not yet been studied. In this article, the phosphors of Pr 3+ -doped CaWO 4 were synthesized via a high temperature solid-state reaction, and the photoluminescence (PL) and afterglow properties of Pr 3+ in the CaWO 4 matrix were investigated. The phase identifications of the samples show that an impure monoclinic phase appears when the Pr 3+ concentration is high. The results of PL exhibit the usual Pr 3+ characteristic emissions as well as an emission that is produced by the charge transfer from 5 d of W 6+ to 2 p of O 2− under a shortwave ultraviolet excitation. An intermediate energy transfer occurs during the charge transfer which induces the afterglow. The quenching point of Pr 3+ in CaWO 4 is 2 mol%, corresponding to the critical energy transfer distance of ~20 Å. The quenching mechanism in the Pr 3+ -doped CaWO 4 is the dipole-dipole interaction. The Ca 2+ vacancies ( V Ca ) are the defects that induce the traps and capture holes from O 2− . The thermal energy of holes liberation from V Ca to O 2− results in the charge transfer accompanied by an energy transfer to Pr 3+ , and consequently generates the afterglow. The experimental results also show that the afterglow characteristics of Pr 3+ are prolonged by incorporating Pr 3+ in the CaWO 4 matrix.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
MOLECULAR CRYSTALS AND LIQUID CRYSTALS
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2023
·
IF 0.7
Zhongli Zou,Kun Liu,Yang Li
AZ31B has the advantages of high specific strength, low melting point and good toughness, but one of the significant disadvantages is poor corrosion resistance. This topic designed and prepared a corrosion-resistant composite coating of organic polymer phytic acid and rare earth praseodymium salt based on this characteristic. The test results show that the corrosion resistance of the PA/Pr composite coating is more potent than that of a single phytic acid conversion coating, and the surface of the composite layer is clustered particles with good compactness. The conversion coating mainly consists of praseodymium hydroxide, oxide and some phytate compounds. In addition, density functional theory (DFT) was used to analyze the inhibition mechanism of phytic acid; Molecular dynamics (MD) was used to evaluate the adsorption characteristics of phytic acid on metal substrates and rare earth metal oxides.
研究领域:
材料科学
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电化学
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理论化学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2022
·
IF 4.632
Yandi Cai,Peng Yang,Qinglong Liu,Kaili Ma,Wenxin Ma,Wang Song,Qiuhui Qian,Fei Gao,Wei Tan,Lin Dong
Sulfation treatment has been widely used to promote the catalytic performance of ceria (CeO 2 ) based catalysts for the selective catalytic reduction of NO by NH 3 (NH 3 -SCR of NO). Praseodymium oxide (PrO x ), another commonly used rare earth material with similar structural properties as CeO 2 , also shows satisfactory redox properties due to the facile redox cycle of Pr 3+ ↔ Pr 4+ . In this work, gas phase sulfation treatment with varied duration was performed on PrO x at 200 °C, and the NH 3 -SCR activity of sulfated PrO x was evaluated. Based on the results of systematic characterizations (e.g., N 2 -physisorption, NH 3 oxidation , NO oxidation, in situ diffuse Fourier transform infrared spectroscopy), it is revealed that the catalytic performance of sulfated PrO x is highly dependent on the sulfation time (or the amount of sulfate species deposited on PrO x ), which has a significant impact on the competitive reaction between NH 3 oxidation and NH 3 -SCR of NO, thus determining the NH 3 -SCR activity of PrO x . This work provides new insight into tuning the interaction between PrO x surface and reactants (NO, NH 3 ) via sulfation treatment, which cam guide the design and application of PrO x based catalysts for NH 3 -SCR of NO in the future.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2022
·
IF 5.479
Wenjie Zhang,Yunpeng Du,Xiong Tong,Xian Xie,Dongxia Feng,Qiang Song
As the most important method for the separation and purification of rare earth elements, solvent extraction is widely used in industry. HDEHP (Di(2-ethylhexyl) phosphoric acid) has become the most commonly used organic extractant because of its high separation factor for rare earth elements and large processing capacity. However, the large amount of ammonia nitrogen wastewater generated during the extraction process creates huge pressure on the environment. The tartaric acid complexing agent has been added to the aqueous phase to improve the extraction performance of HDEHP without saponification. This can effectively avoid the generation of ammonia nitrogen wastewater, which is more in line with the concept of green production. In this study, the effect of tartaric acid on the separation of Pr and Nd by HDEHP in hydrochloric acid and the corresponding mechanism are investigated. This study showed that the addition of tartaric acid could significantly increase the separation coefficient of HDEHP for Pr and Nd. When the tartaric acid concentration was 0.4 mol/L and the solution pH was 2.5, the separation coefficient reached β Nd/Pr = 1.85, which was higher than the separation coefficient of HDEHP for Pr and Nd in the saponification system. Combining Fourier-transform infrared spectroscopy, nuclear magnetic spectroscopy other analysis and detection methods, and in-depth exploration of the extraction mechanism, the final extraction of the compound structures was determined.
研究领域:
化学工程
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环境科学
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稀土分离技术
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·Vol. 26
·期 46
·28971-28979
·
IF 2.9
Yuhan Fan,Yongze Cao,Meiling Li,Sai Xu,Yichao Wang,Xizhen Zhang,Jinsu Zhang,Baojiu Chen
A series of Tb3+, Pr3+ and Dy3+ monodoped CaTa4O11(CTO) persistent luminescence (PersL) phosphors have been successfully synthesized using the molten salt method with KCl flux. The PersL color is green and orange for Tb3+ and Pr3+ or Dy3+ doped samples, respectively. The trap depth of Tb3+, Pr3+ and Dy3+ monodoped CTO is 0.33, 0.31 and 0.30 eV, respectively. The PersL time of 3 mol% Tb3+, 1 mol% Pr3+ and 1 mol% Dy3+ monodoped samples is 52.20, 35.00 and 59.46 s, respectively. Tb3+, Pr3+ and Dy3+ monodoped CTO phosphors can be used in luminescence displays and anti-counterfeit labels under commercial 254 nm UV light.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Zhuoyi Zhang,Yunshuo Wu,Yuxin Sun,Haiqiang Wang,Zhongbiao Wu,Xuanhao Wu
Nitrous oxide (N2O) is a potent greenhouse gas with a high global warming potential. The N2O direct decomposition (deN2O) is currently the most widely used technique due to its operational simplicity and lack of secondary pollution. The presence of impurity gases in industrial exhaust increases the challenge of eliminating N2O, urging the development of highly active and stable catalysts for its degradation. In this study, a series of praseodymium (Pr)-doped nickel oxide (NiO) catalysts were synthesized for N2O degradation. These catalysts showed higher N2O decomposition activity (T100 = 400–440 °C) than pure NiO (T100 = 480 °C) and also demonstrated high resistance to impurity gases in simulated industrial nitric acid tail gas. In the catalyst with a Pr to Ni ratio of 0.002, the highly dispersed Pr on the NiO surface regulated its particle size and increased specific surface area and pore volume. DFT calculations revealed that Pr significantly enhanced the electron-donating ability of Ni2+, facilitating the dissociative adsorption of N2O on the catalyst surface, where O existed in the form of Ni3+-O*. Additionally, Pr reduced the desorption energy of O2, the rate-determining step. During the reaction, Pr3+ transferred electrons to Ni3+ via f-d electron hopping, stabilizing the active Ni2+ sites and enabling an efficient catalytic reaction. These findings demonstrate the practical potential of this catalyst and provide new insights into the degradation of N2O in industrial exhaust gases, offering a promising avenue for application.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
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 Superconductivity and Novel Magnetism
·
2022
·Vol. 36
·期 1
·327-341
·
IF 1.675
Li Pengwei,Li Jie,Wang Yonglun,Yao Kai,Shan Shuo,Suo Xing,Ma Saisai
Praseodymium (Pr)–aluminum (Al)-co-doped M-type barium ferrite with Ba 0.85 Pr 0.15 Fe 12-x Al x O 19 ( x = 0.0–1.0) was prepared by combining solid-phase sintering with high-energy ball milling. The samples were characterized using a thermogravimetric analyzer, X-ray diffractometer, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. Thermogravimetric analysis indicated that M-type barium ferrite was formed at 1250 °C. X-ray diffraction patterns showed that Al doping did not destroy the crystal structure of barium ferrite. Field emission scanning electron microscopy showed that the samples had a hexagonal crystal structure. The wave numbers of Fourier transform infrared spectroscopy in the 597–607 and 452–459 cm −1 bands represent tetrahedral and octahedral clusters, respectively. With the increase in the amount of Al doping ( x ) from 0.0 to 1.0, the saturation magnetization ( M s ) and residual magnetization ( M r ) decreased continuously, and the magnetic anisotropy field ( H a ) and coercivity ( H c ) increased significantly.
研究领域:
材料科学
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无机化学
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磁性材料
·
固体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）