International Journal of Applied Ceramic Technology
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2022
·Vol. 20
·期 3
·1953-1962
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IF 2.328
Quansheng Wu,Shanshan Ye,Xufeng Zhou,Jianyan Ding
Developing narrowband red phosphors has always been a frontier topic in the phosphor community. In this study, a novel hafnium germanate red phosphor, BaHfGe 3 O 9 :Eu 3+ , was successfully synthesized by solid-state reaction method. The phase and crystal structure of BaHfGe 3 O 9 were investigated by the Rietveld refinement of powder X-ray powder diffraction. The band structure was analyzed by density functional theory calculations. Most importantly, the luminescence behavior of phosphors under near-ultraviolet (n-UV) light and cathode rays sources was studied in detail to explore the possibility of their applications in white light-emitting diodes and field emission display. The BaHfGe 3 O 9 :Eu 3+ phosphor exhibits strong f–f excitation and excellent thermal robustness due to Eu 3+ localization in the rigid lattice and asymmetric Ba 2+ sites. Under cathode rays and n-UV light excitation, BaHfGe 3 O 9 :Eu 3+ exhibits narrowband red light emission peaked at 610 nm. Moreover, BaHfGe 3 O 9 :Eu 3+ shows excellent saturation resistance and aging resistance. The performance of the LED lamp encapsulated by the BaHfGe 3 O 9 :Eu 3+ phosphor was studied. The results show that BaHfGe 3 O 9 :Eu 3+ is a potential red phosphor for multifunctional applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 21
·7535-7544
·
IF 6.1
Hangren Li,Jie Tu,Guoqiang Xi,Xiuqiao Liu,Xudong Liu,Siyuan Du,Dongfei Lu,Da Zu,Yuxuan Zhang,Qingxiao Wang,Dongxing Zheng,Xixiang Zhang,Jianjun Tian,Linxing Zhang
The discovery of ferroelectricity in HfO2-based thin films has strongly energized the field of integrated semiconductor devices. To expand the physical applications of HfO2-based thin films, it is essential to urgently enhance their ferroelectric polarization. In this work, we have synthesized Hf0.85Ce0.15O2−δ thin films with a large remanent polarization of 2Pr ∼ 69 μC cm−2, which is the maximum of all HfO2-based polycrystal thin films. The strong increase of the remanent polarization is caused by the significant lattice expansion triggered by the increase of Ce3+ content, which is controlled by temperature. Due to the increase of the lattice constant in the c-axis, the unit-cell volume expands from 132.16 Å3 to 137.66 Å3, inducing an increase in the distortion of ions along the direction of the polarization axis and leading to an increase in polarization. This finding is of significant practical importance for promoting HfO2-based materials and their development in physical fields.
研究领域:
凝聚态物理
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材料科学
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半导体器件
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功能薄膜
·
铁电材料
✓ 已验证
DOI
高影响因子
BIOMATERIALS
·
2020
·
IF 10.317
Ya Su,Shi Liu,Yuyao Guan,Zhigang Xie,Min Zheng,Xiabin Jing
Carbon dots (CDs) are emerging as powerful nanoprobes for multiple-model bioimaging. Nowadays, orthotopic xenograft models attract increasing attention because of their superiorities of duplicating the tumor microenvironment . However, compared with the extensive study of subcutaneous xenograft tumors , less attention has been paid to CDs for in vivo orthotopic tumor imaging . Furthermore, it is very desirable for a nanoprobe to achieve preferential accumulation at the tumor site and efficient renal clearance . In this work, a novel kind of Hafnium-doped CDs (HfCDs) were successfully prepared via a simple one-pot pyrolysis method. The significant advantages including robust stability, good biocompatibility , excellent water solubility, remarkable computed tomography (CT) contrast performance and preferential tumor accumulation capability endow HfCDs with particular functions of CT/fluorescence imaging of orthotopic liver cancer initially. More importantly, HfCDs could locate at the tumor site and achieve the rapid imaging within 1 min. The findings of the current study represent a facile and universal approach to fabricate outstanding renal clearable multimodal imaging nanoprobes with great potential for clinical diagnosis.
研究领域:
医学影像学
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纳米医学
·
肿瘤学
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Jingyu Lin,Xiaohan Wu,Yifan Xia,Lingzhi Nie,Peiyuan Zuo,Puke Mi,Qixin Zhuang
Polyetherimide (PEI) has great potential as a dielectric because of its high-temperature resistance, but its low energy storage density limits practical applications. Incorporating hafnium dioxide (HfO 2 ) with a moderate dielectric constant ( k ) and wide bandgap can simultaneously enhance the polarization intensity of PEI and potential barriers for charge injection . Nevertheless, the poor compatibility between HfO 2 and PEI inevitably introduces defects, thereby weakening the inhibitory effect on dielectric loss . To tackle this issue, an organic double interface layer is introduced to enhance dielectric performance, where the polar poly(arylene ether urea) (PEEU) containing hydrogen bonds can ensure the layer's compactness. Notably, its non-bonding urea groups serve as deep traps to capture migrating carriers, and the gradient k values of HfO 2 , PEEU, and PEI help mitigate electric field distortions at the interface, therefore enhancing the suppression of conduction loss . The polarity of PEEU and the introduction of multiple interfaces significantly contribute to an increased k (maximum 9.7, at 1 kHz). At 300 kV mm −1 , 5 vol% PEEU@HfO 2 /PEI achieves a discharged energy density of 3.3 J cm −3 and a high charge-discharge efficiency of 83 %, surpassing 5 vol% HfO 2 /PEI by 1.95 and 2.44 times, respectively. The further COMSOL simulation verifies and proves this work as a novel design strategy for nanocomposite dielectrics.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Bohan Sun,Cuiyan Li,Haibo Ouyang,Ruinan Gao,Tianzhan Shen,Yanlei Li
The synthesis of hafnium carbide nanowires (HfC NWs ) on carbon fibers was successfully achieved by employing HfCl 4 and furfuryl alcohol as precursor materials, facilitated by Ni-assisted catalytic pyrolysis . In the polymerization and cross-linking processes of furfuryl alcohol, hafnium cations play a crucial role, leading to the atomic-level amalgamation and effectively enhancing the reactivity of the Hf-O-C system. The nucleation of HfC NWs takes place at 1300 °C, followed by growth through a solid-liquid-solid (SLS) mechanism. Carbon fibers were uniformly coated with tens micrometer-long HfC NWs having an approximate diameter of 500 nm. Notably, the tips of these HfC NWs exhibited clean surfaces free of Ni catalyst particles, indicating their root growth model. This novel catalyst-assisted pyrolysis method holds great potential for enabling cost-effective large-scale production of transition metal carbide nanowires.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Hu Li,Yan Li,Zhen Fang,Richard L. Smith
An acid-base bifunctional nanohybrid phenylphosphonic acid (PhP) - hafnium (1:1.5) was synthesized through assembly of PhP with HfCl 4 for catalytic transfer hydrogenation of furfural (FUR) to furfuryl alcohol (FFA) using 2-propanol as both reaction solvent and hydrogen donor source. An FFA yield of 97.6 % with formation rate of 9760 μmol g −1 h −1 at 99.2 % FUR conversion was obtained with the reaction system at 120 °C for 2 h reaction time. Activation energy (Ea) was estimated to be 60.8 kJ/mol with respect to FUR concentration, which is comparable with or even lower than Ea values attained over metal catalysts. The pronounced catalytic activity of PhP-Hf (1:1.5) is attributed to its moderate acidity and relatively strong basicity. The PhP-Hf (1:1.5) catalyst was demonstrated to maintain its activity for five consecutive reuse cycles.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
IONICS
·
2022
·Vol. 28
·期 9
·4273-4282
·
IF 2.961
Gao Jiayi,Yang Yujie,Ren Yujie,Zhu Wenjie,Li Jin,Liu Yongguang,Dai Lei,Wang Ling,He Zhangxing
Vanadium redox flow batteries have the advantages of long life, flexible design, safety, and reliability, so they have broad development prospects in the field of energy storage. Borides are extensively used in electrochemistry due to their excellent electrical conductivity. In this program, HfB 2 was used as catalyst for the V 3+ /V 2+ pair. The catalytic effect was verified by electrochemical impedance spectroscopy and cyclic voltammetry. The result shows that the cell using HfB 2 as negative catalyst can exhibit excellent rate capability when the current density is 50 ~ 125 mA cm −2 . At 125 mA cm −2 , the discharge capacity of the modified cell is 68.7 mA h, which is much higher than pristine cell (22.8 mA h). And the energy efficiency of pristine cells is 11.2% lower than that of modified cells. These consequences suggest that HfB 2 is a catalyst with promising prospects to enhance electrochemical activity of V 3+ /V 2+ redox reaction in VRFB.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2024
·
IF 4.8
Shuai Ma,Di Dong,Mengyao Zhang,Ye Gao,Zhuangzhi Wu,Dezhi Wang
W-Re-HfC alloys have been extensively applied in the field of high-temperature structural parts. To ensure high temperature reliability, it is essential to enhance creep resistance ability. In this study, the microstructures of forged W-Re-HfC alloys were adjusted using different heat treatment processes . The corresponding tensile creep properties were also measured at 2000 °C with 40 MPa. Furthermore, a possible creep fracture mechanism was also explored. The forged W-Re-HfC sample annealed for 2 h exhibited the best creep performances with a steady-state creep rate of 3.28 × 10 −6 and a creep life of 5.6 h. Generally, a larger grain size indicates a lower steady-state creep rate; however, the precipitation of carbides at the grain boundaries (GBs) deteriorates the bonding strength of interfaces, thus reversing the former trend. The dominant creep mechanism is diffusion creep , in which the voids nucleate perpendicular to the GBs, grow and connect into cracks, ultimately leading to fractures.
研究领域:
材料科学
·
金属学与热处理
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高温结构材料
·
固态物理
·
力学性能
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Luyao Yang,Rong Liu,Meiying Xie,Fan Yang
Metal–organic framework materials (MOFs) have potential for practical applications in solid-phase separation technology. However, no studies of the separation of hafnium and zirconium using MOFs have been performed. This work synthesized MIL-101-DGA solid-phase adsorbent material, which was synthesized using amino-containing MIL-101-NH2 as a matrix material by introducing diglycolic acid (DGA) functional groups through a one-step ring-opening reaction. Betaine hydrochloride was selected as the complexing agent to establish the MIL-101-DGA coupling betaine hydrochloride push–pull system; this system could act as an alternative to the traditional MIBK-HSCN separation system. We are the first to report that this MIL-101-DGA coupling betaine hydrochloride system could obtain separation coefficients (βZr/Hf) of 19.7 at pH 0.50 and 8.2 at pH 1.46. Furthermore, the highest adsorption capacity of MIL-101-DGA for Zr was 63.7 mg/g. These results demonstrated that MIL-101-DGA had excellent separation performance for zirconium and hafnium in the betaine hydrochloride medium. This system also exhibited an outstanding cycling performance and immersion stability. After multiple adsorption/desorption cycles and 1 week of immersion in various solutions, the structure and adsorption capability essentially remained unchanged. The adsorption mechanism was thoroughly examined using a suite of analysis and detection methods, including the slope method, FT-IR, XPS, and DFT. In conclusion, we propose that the MIL-101-DGA coupling betaine hydrochloride system, which is an efficient and green separation system, could replace the traditional MIBK-HSCN separation system; our study provides a concept for the industrialization of zirconium and hafnium separation from key mineral resources.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jingyu Lin,Junhao Jiang,Yukang Zhou,Qianqian Fan,Qixin Zhuang,Puke Mi,Wei Yin,Peiyuan Zuo
Mixing fillers featured with wide band gaps in polymers can effectively meet the requirement of higher energy storage densities. However, the fundamental relationship between the crystal structures of fillers and the dielectric properties of the corresponding nanocomposites is still unclear. Accordingly, we introduced ultralow contents of the synthesized cubic Hafnium dioxide (c-HfO2) or monoclinic Hafnium dioxide (m-HfO2) as deep traps into poly(ether imide) (PEI) to explore their effects on dielectric properties and the charge-blocking mechanism. m-HfO2/PEI showed better charge trapping due to the higher electron affinity and deeper trap energy. At room temperature, the 0.4 vol % m-HfO2/PEI maintains an ultralow dielectric loss of 0.008 while obtaining a dielectric constant twice that of pure PEI at 1 kHz, simultaneously outperforming in terms of leakage current density, breakdown strength (452 kV mm–1), discharge energy density (Ud, 5.03 J cm–3), charge–discharge efficiency (η, 92%), and dielectric thermal stability. At 125 °C, it exhibits a considerable Ud of 2.48 J cm–3 and a high η of 85% at 300 kV mm–1, surpassing the properties of pure PEI. This promising work opens up a new path for studying HfO2-derived dielectrics with unique crystal structures.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Junlian Wang,Xiumin Yang,Chengqiang Hu,Ruiyi Sun,Guodong Xu
A novel extractive resin grafting (2-methylpropyl)(2,4,4-trimethylpentyl)phosphinic acid groups through N atoms (marked as Mer-N-POOH-272), which is superior to most of the reported resins for hafnium(Hf) selective separation from zirconium (Zr), was synthesized and structurally characterized by FT-IR, SEM-EDS and XPS. The adsorption and separation behaviors of Mer-N-POOH-272 for Zr and Hf in sulphate media were investigated. The desorption behaviors of the adsorbed Zr and Hf by HCl, H 2 SO 4 , NaOH and Na 2 CO 3 solutions were studied. Density functional theory (DFT) calculations were conducted to reveal the adsorption mechanism. Mer-N-POOH-272 preferentially adsorbs Hf over Zr in H 2 SO 4 media, and the maximum Zr/Hf separation factor ( β Hf/Zr ) reached to 6.5 ± 0.3. The Zr and Hf adsorption by Mer-N-POOH-272 fit pseudo-first kinetic model and Langmuir isothermal adsorptionc model. It is the intraparticle diffusion that probably determines the adsorption rate. The Zr and Hf adsorptions onto Mer-N-POOH-272 belong to monolayer adsorption, and their experimental maximum adsorption amounts were 16.8 ± 0.8 mg/g and 29.2 ± 1.0 mg/g, respectively. Sulfuric acid solution of 4.5 mol/L selectively desorbed the adsorbed Zr, and NaOH and Na 2 CO 3 solutions of ≥ 1.0 mol/L efficiently desorbed the left Hf. The DFT calculations show it is the two O atoms of -POOH in Mer-N-POOH-272 that probably interact with Zr or Hf ions during adsorption in H 2 SO 4 media, and Hf has lower adsorption energy than Zr, which explains the selectivity of Mer-N-POOH-272.
研究领域:
化学工程
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材料科学
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 17
·7718-7725
·
IF 2.7
Yanping Luo,Chengjin Xu,Jianhui Su,Xiujing Peng,Xiangfeng Kong,Shuo Wang,Jiahui Sun,Yu Cui,Yong Nie,Xuchuan Jiang,Guoxin Sun
Nuclear-grade zirconium and hafnium play an essential role in the nuclear industry. It is difficult to separate and purify zirconium and hafnium because of the similar properties caused by lanthanide shrinkage and the preferential extraction of hafnium is challenging. In this work, a new extractant, di(p-tert-butylphenyl)phosphate (DTBPPA), was synthesized, and its separation performance of zirconium and hafnium in the sulfuric acid system was evaluated. Under identical extraction conditions, DTBPPA shows excellent preferential extraction properties for hafnium compared to current commercial extractants, such as D2EHPA and PC88A. The highest SFHf/Zr value is up to 16.3. A crystal of the hafnium extracted species was grown to study the extraction mechanism and the principle of preferential extraction of hafnium. It was found that the crystal growth of zirconium-extracted species was difficult under the same conditions. Hafnium extracted species crystals reveal a six-coordinated hafnium ion bound to six extractant molecules. The electron withdrawing effect of the aromatic substituents results in a low electron density of O atoms in the P–O group of the new extractant, and the extractant coordination group shows the characteristics of a soft base. This matches the soft acid properties of hafnium ions. DTBPPA shows a solid ability to identify hafnium ions, thus achieving preferential separation of hafnium from zirconium and hafnium mixtures.
研究领域:
核化学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）