CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
M. Yousaf,Majid Niaz Akhtar,Baoyuan Wang,Asma Noor
Rare earths RE's (Pr, Y, Gd, Ho, Yb) substituted MnZn spinel ferrites with composition of Mn 0.5 Zn 0.5 M 0.02 Fe 1.98 O 4 (M = Pr, Y, Gd, Ho, Yb) are prepared by sol gel combustion approach. Low sintering temperature (500 °C) is used to sinter the RE's doped MnZn samples. MnZn samples are further characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to measure the cubic crystalline structure, particle size, morphology, porosity and grain size. Cubic crystalline phase of prepared RE's doped MnZn ferrites is confirmed by x-ray diffraction (XRD). The morphology, porosity and grain size are observed using FESEM. The magnetic properties of RE's doped MnZn nanoferrites are analyzed by vibrating sample magnetometer (VSM). Coercivity (H c ), remanence (M r ) and saturation magnetization (M s ) are calculated from the magnetic loops. The saturation and remanence of the nanoferrites are increased by the substitution of RE's metal ions and varies from 14.76 to 26.36 emu/g and 9.98–22.48 emu/g respectively. Bohr magneton and anisotropy constant are calculated from the recorded magnetic data. The conductive analysis of the prepared samples is studied at 40 °C −300 °C temperature, leading to the conductivity measurements from 1.12 × 10 -2 Ω -1 -cm -1 to 9.52 × 10 -2 Ω -1 -cm -1 . UV–Vis spectroscopy is used to determine the semi conducting nature of RE's doped MnZn spinel ferrite samples. The magnetic, conductive and optical study of the RE's doped MnZn nanoferrites sintered at low temperature suggests the use of these materials for microwave absorption, supercapacitor , lithium ion batteries and nanoelectronics industrial applications.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Cheng Wang,Mingxue Deng,Yanfeng Tang,Tongming Sun,Minmin Wang,Jin Wang,Zhenzhen Zhou,Jiacheng Wang
Ultraviolet C (UVC) sterilization has the advantages of high efficiency, broad spectrum, and no secondary pollution. However, the emission wavelength of UVC phosphors still suffers from a large deviation from the golden sterilization wavelength of 265 nm and a low luminescence intensity. Herein, we report UVC emission near the golden sterilization wavelength as well as a long afterglow through crystal field engineering, which can lead to 100% sterilization efficiency. Combined with theoretical calculation and experimental studies, substitution of Ca2+ with large-sized Sr2+ could obtain slight expansion and distortion of cationic sites, resulting in a decrease in crystal field intensity and blue shift of Ca1.5Sr0.5Al2SiO7:1%Pr3+, and produce near golden UVC emission. Ca1.5Sr0.5Al2SiO7:1%Pr3+ phosphor can effectively inactivate Staphylococcus aureus within 10 min, showing more efficiency than the traditional mercury lamp. This work provides an effective solution for the design and preparation of UVC phosphors using crystal field engineering toward near golden UVC emission.
研究领域:
材料科学
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发光材料
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光学工程
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杀菌技术
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固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 94
·期 5
·1576-1584
·
IF 2.659
Weijie Wen,Zhencheng Lou,Yanjin Chen,Dingsheng Chen,Shuanghong Tian,Ya Xiong
BACKGROUND Iron (Fe) 3+ has much a smaller ion radius than cerium (Ce) 4+ but praseodymium (Pr) ions have a similar radius to Ce ions with the same valence. Hence, it is interesting to tune the structural properties, including lattice deformation, band gap and oxygen vacancy (O v ), of CeO 2 by Pr and Fe codoping for enhanced visible-light catalytic activity. RESULTS A series of Ce 1-x-y Pr x Fe y O 2-σ ( x = 0∼0.012, y = 0.003∼0.031) nanoparticles were prepared by a simple one-step sol-gel method. The structural properties of CeO 2 , including crystal deformation (cell lattice from 5.4069 to 5.4195), band gap (from 2.20 to 2.93), oxygen vacancies (O v from 0.15% to 9.03%), and peroxide species (O 2 2− from 0.37% to 1.09%) can be finely tuned by Pr and Fe codoping. Among ten samples, Ce 0.982 Pr 0.003 Fe 0.015 O 2-σ with proper structural properties showed the highest photocatalytic activity towards the degradation of acid orange 7. The first reaction rate constant reaches 0.0687 min −1 , 9.3 and 7.7 times that of Ce 0.994 Pr 0.006 O 2-σ and Ce 0.985 Fe 0.015 O 2-σ , respectively. The mechanism was found to involve ·OH, ·O 2 − and photogenerated holes. CONCLUSION The structural properties of CeO 2 can be finely and easily tuned by Pr and Fe codoping. Thus, the photocatalytic activity of CeO 2 under visible light irradiation was boosted. © 2019 Society of Chemical Industry
研究领域:
材料科学
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光催化
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纳米材料
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环境化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2025
·Vol. 13
·期 31
·16040-16051
·
IF 5.1
Jin Zhou,Tong Shi,Ri-Tao Huang,An-Di Liu,Gao-Shang Gong,Yong-Qiang Wang,Lang-Sheng Ling,Jing-Xin Li,Yu-Yan Han,Wei Tong,Zheng-Cai Xia,Zhao-Ming Tian
The diverse exotic magnetic states realized in one-dimensional (1D) spin-chain systems have motivated the extensive exploration of new materials with a 1D spin-chain motif, while 1D magnets comprising rare-earth (RE) ions are largely unexplored compared with their 3d transition metal (TM)-based counterparts. Herein, we report the synthesis and magnetic properties of a family of RE-based zigzag spin-chain Ba2REV3O11 compounds (RE = Pr, Nd, and Gd–Ho) crystallized into a monoclinic structure with the space group P21/a, wherein spin chains are connected by edge-sharing REO6 octahedra along the b axis and well separated by nonmagnetic VO4 tetrahedra extended within the ac plane. Moreover, the nearest neighbor (NN) intrachain RE–RE distance (dintra, ∼3.856–3.952 Å) is much shorter than the NN interchain separation (dinter, ∼5.191–5.246 Å), supporting quasi-1D characteristics. Magnetic susceptibility and isothermal magnetization measurements revealed that only Ba2DyV3O11 displays a magnetic anomaly at ∼2.9 K and other family members do not order down to 1.8 K. Among them, Ba2GdV3O11 with a spin-only magnetic moment (S) of 7/2 exhibits a long-range magnetic order with TN ∼ 0.67 K and a large magnetocaloric effect with a maximum magnetic entropy change (ΔSM) of 14.3 J K−1 (mol-Gd)−1 under a magnetic field change (Δμ0H) of 4 T at a temperature of ∼1 K, making it a suitable material for magnetic refrigeration in sub-Kelvin temperature regimes.
研究领域:
凝聚态物理
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磁性材料
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固态化学
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低温物理
✓ 已验证
产品关联
DOI
高影响因子
Materials Advances
·
2021
·Vol. 2
·期 12
·3927-3939
·
IF 0
Ya-Fang Zhang,Ben Dai,Dan Zhao,Di-Hui Zhang,Meng-Xing Xu,Xiang-Hua He,Chao Chen
To span the inherent application limitation of state-of-the-art catalysts for the chemical transformation of biomass derivatives, here, we formulate a series of Pr–Ni–P catalysts for the hydrogenation transformation of biomass-derived levulinic-acid, furfural and maleic anhydride. With comprehensive characterizations, Pr–Ni–P samples are verified as (PrPO4)m/Ni2P nanocomposites with a molar ratio (m) in the range of 0.24–11.0. In comparison with the poor catalytic performance of Ni2P, a ten-fold enhancement in TOF up to 0.45 s−1 and at least five-time promotion on the yield of objective products up to 91–98% are achieved by introducing proper amounts of PrPO4 to form reusable (PrPO4)m/Ni2P nanocomposites. Surface chemistry and kinetic mechanism studies further disclose that the cooperative catalytic function of two components, in particular the exclusive capability of PrPO4 to activate hydrogen, is responsible for the promoted hydrogenation transformation of biomass derivatives via a quick Langmuir–Hinshelwood process over (PrPO4)m/Ni2P. These findings imply that an easily obtainable, cost-affordable and robust rare earth phosphate like present PrPO4 could be a potential replacement catalytic component for the traditional metal catalyst in the hydrogenation transformation reactions of biomass derivatives, which was also worth noting as a new kind of basic material for other green mass-transformation techniques involving hydrogen activation processes such as corresponding optical and electrical transformations.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Zhiyong Huang,Lijun Fan,Nianjun Hou,Tian Gan,Juanjuan Gan,Yicheng Zhao,Yongdan Li
Ni–Ce 0.8 Pr x Sm 0.2-x O 2-δ (x = 0–0.15) is studied as an anode of solid oxide fuel cells. The doping of Pr facilitates the chemical oxidation of CH 3 OH on the ceramic phase because the strength of Pr–O bond is weaker than that of Ce–O bond. With the addition of Pr, the electronic conductivity of the ceramic phase increases in an oxidizing atmosphere but decreases in a reducing atmosphere. The electrochemical conductivity relaxation results indicate that Pr improves oxygen surface exchange coefficient and oxygen chemical diffusion coefficient of Ce 0.8 Sm 0.2 O 2-δ simultaneously. The doping of Pr shows negligible influence on the performance of the cell fed with H 2 due to the high reactivity of H 2 . However, the maximum power density of the cell with methanol as the fuel increases significantly with the addition of Pr in the anode, demonstrating the high importance of the oxygen activity of the anode when a less active fuel is used. A Ce 0.8 Sm 0.2 O 2-δ -carbonate electrolyte-supported single cell with Ni–Ce 0.8 Pr 0.1 Sm 0.1 O 2-δ anode shows a maximum power density of 792 mW cm −2 at 650 °C with methanol as the fuel.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Nanotechnology
·
2022
·Vol. 17
·期 5
·524-530
·
IF 40.523
Liang Yusen,Zhu Zhimin,Qiao Shuqian,Guo Xin,Pu Rui,Tang Huan,Liu Haichun,Dong Hao,Peng Tingting,Sun Ling-Dong,Widengren Jerker,Zhan Qiuqiang
A photon avalanche (PA) effect that occurs in lanthanide-doped solids gives rise to a giant nonlinear response in the luminescence intensity to the excitation light intensity. As a result, much weaker lasers are needed to evoke such PAs than for other nonlinear optical processes. Photon avalanches are mostly restricted to bulk materials and conventionally rely on sophisticated excitation schemes, specific for each individual system. Here we show a universal strategy, based on a migrating photon avalanche (MPA) mechanism, to generate huge optical nonlinearities from various lanthanide emitters located in multilayer core/shell nanostructrues. The core of the MPA nanoparticle, composed of Yb 3+ and Pr 3+ ions, activates avalanche looping cycles, where PAs are synchronously achieved for both Yb 3+ and Pr 3+ ions under 852 nm laser excitation. These nanocrystals exhibit a 26th-order nonlinearity and a clear pumping threshold of 60 kW cm −2 . In addition, we demonstrate that the avalanching Yb 3+ ions can migrate their optical nonlinear response to other emitters (for example, Ho 3+ and Tm 3+ ) located in the outer shell layer, resulting in an even higher-order nonlinearity (up to the 46th for Tm 3+ ) due to further cascading multiplicative effects. Our strategy therefore provides a facile route to achieve giant optical nonlinearity in different emitters. Finally, we also demonstrate applicability of MPA emitters to bioimaging, achieving a lateral resolution of ~62 nm using one low-power 852 nm continuous-wave laser beam.
研究领域:
光学
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纳米技术
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材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biotechnology Journal
·
2023
·
IF 4.7
Xia Ke,Zi-Hao Pan,Hong-Fei Du,Yi Shen,Ji-Dong Shen,Zhi-Qiang Liu,Yu-Guo Zheng
Background 7-dehydrocholesterol (7-DHC) can be directly converted to vitamin D 3 by UV irradiation and d e novo synthesis of 7-DHC in engineered Saccharomyces cerevisiae has been recognized as an attractive substitution to traditional chemical synthesis. Introduction of sterol extracellular transport pathway for the secretory production of 7-DHC is a promising approach to achieve higher titer and simplify the downstream purification processing. Methods and results A series of genes involved in ergosterol pathway were combined reinforced and reengineered in S. cerevisiae . A Biphasic fermentation system was introduced and 7-DHC was found to be enriched in oil-phase with an increased titer by 1.5-folds. Quantitative PCR revealed that say1, atf2, pdr5, pry1-3 involved in sterol storage and transport were all significantly induced in sterol overproduced strain. To enhance the secretion capacity, lipid transporters of Pry (Pathogen-related yeast proteins), NPC2(Niemann-Pick disease type C2), ABC(ATP-binding cassette)-family and their homologues were screened. Both individual and synergetic overexpression of Pr-1 (Plant pathogenesis Related protein-1) and St1 (Sterol transport1) largely increased the de novo biosynthesis and secretory productivity of 7-DHC, and the final titer reached 28.2 mg/g with a secretion ratio of 41.4%, which was 26.5-folds higher than the original strain. In addition, the cooperation between Pr-1 and St1 in sterol transport was further confirmed by confocal microscopy, molecular docking and directed site-mutation. Conclusion Selective secretion of different sterol intermediates was characterized in sterol over-produced strain and the extracellular export of 7-DHC developed in present study significantly improved the cell biosynthetic capacity, which offered a novel modification idea for 7-DHC de novo biosynthesis by S. cerevisiae cell factory. This article is protected by copyright. All rights reserved
研究领域:
生物技术
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微生物学
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代谢工程
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RARE EARTHS
·
2020
·
IF 3.104
Wei Li,Shuang Wang,Jinping Li
A series of BaCeO 3 modified with different rare earth elements (La, Y, Pr) were synthesized by co-precipitation and calcination and the effect of rare earth elements for catalytic ammonia synthesis under mild conditions was studied. The ammonia synthesis performance tests show that 2.5% Ru/BaCe 0.9 La 0.1 O 3– δ catalyst (All the percentages of Ru in this article are in mass fraction) exhibits the highest ammonia synthesis rate (34 mmol/(g·h)) at 3 MPa, 450 °C, and no sign of deactivation after 100 h of reaction. H 2 -TPR and XPS analyses indicate that the introduction of La increases the amount of oxygen vacancies of the catalyst, which is beneficial to increasing the electron density of Ru surface. HRTEM analysis shows that the Ru particle size is reduced greatly after La is introduced, which facilitates the catalyst generating more B 5 -type sites (active sites of Ru species for N N dissociation). CO 2 -TPD analysis indicates that BaCe 0.9 La 0.1 O 3– δ has stronger basicity , which promotes electrons transfer from support to Ru. This work provides an effective method for design and synthesis of Ru-based multi-element composite perovskite oxide catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Zhaoyang Wang,Pei Wang,Chunyu Bi,Xinxin Zhang,Haitao Yu,Xudong Xiao,Ying Xie
Wastewater containing organic pollutants poses significant risks to both the natural environment and human health, highlighting the urgent need for developing efficient photocatalytic materials. In this study, Pr-doped Bi 4 Ti 3 O 12 nanoflowers with different doping concentrations were synthesized by a one-step hydrothermal method. Density functional theory (DFT) calculations combined with experimental characterization revealed that the introduction of Pr 4f energy levels creates intermediate states within the bandgap, which act as electron trapping centers and prolong the carrier lifetime. Experimental results demonstrated that the 15.5% Pr/Bi 4 Ti 3 O 12 catalyst exhibited the optimal photocatalytic activity for ciprofloxacin degradation, achieving a removal rate of 89.41% within 60 min. Mechanistic investigations revealed that the coexistence of Pr 4+ and Pr 3+ oxidation states facilitates the conversion of O 2 into superoxide radicals (·O 2 − ), which function as one of the predominant reactive species in the catalytic cycle and are responsible for the enhanced photocatalytic degradation efficiency of the material. As a result, Pr doping significantly improves the photocatalytic performance of the catalyst. This work provides further insight into the underlying mechanism of rare-earth doping in photocatalysts.
✓ 已验证
DOI
高影响因子
Inorganic and Nano-Metal Chemistry
·
2017
·
IF 0
Huimin Li,Shasha Li,Yuanrui Wang,Yafeng Li,Qian Qiao
Two Pr-based coordination polymers, {[Pr(phen)]2·(p-cpoa)3}·0.5H2O (phen = 1,10-phenanthroline, p-cpoa = 4-carboxyphenoxyacetic acid) (1) and {[Pr(phen)]2·L2·bpdc} (L = 4,4′-bis(2-sulfonatostyryl)bi-phenyl and bpdc = biphenyl-4,4′-dicarboxylic acid) (2) have been hydrothermally synthesized. In compound 1, four-connection p-cpoa connects the Pr-dimers to double-strand chain, which is further linked by three-connection p-cpoa to (4,4)-net layer. The 2D→3D framework is set up by the π-π conjugation of interlayer phen. In compound 2, Pr-dimer shows distorted six-connection model containing four L and two bpdc with phen as a pendant. The packing framework displays the flat pcu-topology. The compounds are further characterized by PXRD, TG, and luminescence.
研究领域:
无机化学
·
材料科学
·
配位聚合物化学
·
发光材料
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Zhepeng Zhang,Ruiyun Zhou,Chen Wang,Jiangbo Li,Heera Jayan,Xiaobo Zou,Zhiming Guo
Enhanced R-CDs@Pr-MOF nanocomposite-embedded electrospun film was developed. • A superior hierarchical sensing system through lanthanide MOF medicated R-CDs. • Multifunctional Pr-MOF filler improved physical properties of packaging film. • Smartphone-assisted monitoring platform with self-developed APP was developed. • The S RGB of spinning film showed an excellent correlation with quality parameters. Fluorescent carbon dots (CDs)-based stimuli-responsive materials exhibited considerable promise for real-time monitoring of food quality and safety, but their poor stability and reliance on single-color changes have limited their broader application. Herein, red-emitting CDs (R-CDs) were immobilized onto Pr-based metal-organic framework (Pr-MOF) through electrostatic interactions. The Pr-MOF served as an adsorption scaffold for R-CDs while also contributing to the enhanced fluorescence responsiveness of the composite. Afterward, the R-CDs@Pr-MOF nanomaterial was incorporated into a blended matrix of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) to fabricate spinning film responsive to sulfur-based gases. The incorporation of R-CDs@Pr-MOF into the PVDF/PVP matrix moderately improved the water resistance while enhancing the mechanical properties and thermal stability of the film. Importantly, the film exhibits a clear multicolor evolution in response to analyte, effectively overcoming the single-color limitation. The MOF effectively also mitigates the comprehensive performance deficiencies of R-CDs in the packaging film. Finally, a linear correlation equation between the S RGB -value of the MOFs-based film and the quality parameters of packaged durian was established using a self-developed APP (Optimal group equation: y = (0.101 ± 0.002) x + (32.365 ± 0.753); R 2 = 0.9924; LOD: 0.086–0.836; RSD: 1.91%). Hence, utilizing digital sensing platform in conjunction with dual-channel light response mode, a powerful approach for the rapid assessment of multiple quality parameters of packaged fruits was developed. Moreover, the R-CDs@Pr-MOF material facilitates accurate and non-invasive monitoring of fruit freshness, enhancing the precision and safety of intelligent packaging systems. Download: Download high-res image (569KB) Download: Download full-size image
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）