ADVANCED MATERIALS
·
2025
·
IF 26.8
Lei Zhuang,Zihao Wen,Yiwen Liu,Jing Yang,Hulei Yu,Yanhui Chu
Understanding the behavior of high-entropy carbides (HECs) under oxygen-containing environments is of particular importance for their promising applications in structural components, catalysis, and energy-related fields. Herein, the structural evolution of (Ta, Ti, Cr, Nb)C (HEC-1) nanoparticles (NPs) is tracked in situ during the oxidation at the atomic scale by using an open-cell environmental aberration-corrected scanning transmission electron microscope. Three key stages are clearly discerned during the oxidation of HEC-1 NPs at the atomic level below 900 °C: i) increased amorphization of HEC-1 NPs from 300 to 500 °C due to the energetically favorable formation of carbon vacancies and substitution of carbon with oxygen atoms; ii) nucleation and subsequent growth of locally ordered nanocluster intermediates within the generated amorphous oxides from 500 to 800 °C; and iii) final one-step crystallization of non-equimolar MeO 2 and Me 2 O 5 (Me = metallic elements, Ta, Ti, Cr, and Nb) high-entropy oxides above 800 °C, accompanied with the reduction in atomic defects. This result is further confirmed by theoretical calculations that these observed high-entropy oxide phases are thermodynamically preferable to generate above 830 °C. The study provides direct evidence of the ordered–disordered–ordered structural transition of HECs during oxidation.
研究领域:
材料科学
·
纳米技术
·
表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Guangjin Chen,Cuiwei Li,Huaiming Jia,Hao Li,Siyuan Li,Bo Gong,Linan An,Kepi Chen
Five equimolar multicomponent oxides were synthesized by replacing one of five cations in (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 )O 2 with Ca 2+ . The results reveal that except for the one in which Ce 4+ replaced by Ca 2+ , the other four components can form single-phase high-entropy fluorite oxides (HEFOs) at different temperatures, which indicates that Ce 4+ is very important for the formation of single-phase HEFOs. The sintering behavior, lattice parameter and properties containing density, porosity, flexural strength and thermal conductivity of the four single-phase HEFOs were investigated. With the change of substituted ions, grain size, relative density, flexural strength and thermal conductivity of the materials vary greatly, which are correlated to the size disorder and mass disorder of these materials. The results of this paper provide a reference for the composition designing and performance tailoring of equimolar HEFOs.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wenchao Lin,Pengrong Ren,Yuhui Wan,Shu Yang
BaTiO 3 , Ba(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 , SrTiO 3 , Sr(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 , (Sr 0.5 Ba 0.5 )TiO 3 and (Sr 0.5 Ba 0.5 )(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 ceramic samples were prepared using a traditional solid-state reaction method. XRD analysis shows that all the samples are a single-phase perovskite structure. After the addition of B-site high-entropy components Sn 4+ , Zr 4+ , Hf 4+ , and Nb 5+ in BaTiO 3 , the permittivity and dielectric loss decrease significantly, and the temperature stability of the permittivity is remarkably improved. Compared with the undoped sample, the insulation resistance of the high-entropy ceramic sample increases exponentially. The incorporation of high entropy components changes the conduction mechanism, improves the insulation performance, and significantly decreases thermal conductivity, which improves the adiabatic performance of ceramics. These results demonstrate that the high entropy strategy can significantly influence the electrical and thermal properties of BaTiO 3 and SrTiO 3 -based ceramics. Our work provides a new idea for the modification of functional ceramic materials and offers new promising candidates of dielectrics applied for Class-I type ceramic capacitors.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Shixin Zhao,Lei Zhuang,Hulei Yu,Yanhui Chu
High-entropy diboride (HEB) microfibers are in great demand for structural and functional applications in extreme conditions. Here, we synthesize (Hf, Ta, Nb, Mo, Ti)B 2 HEB microfibers through a two-step technique involving thermal decomposition of polymers and subsequent boro/carbothermal reduction for the first time. Specifically, polymer precursor microfibers are first decomposed at a moderate temperature of 773 K, followed by a high-temperature calcination at 2273 K to promote boro/carbothermal reduction. The resulting HEB microfibers, with a diameter of approximately 1 µm, exhibit a polycrystalline structure and high-compositional uniformity from nanoscale to microscale. This work opens up a new way to synthesize innovative HEB microfibers.
研究领域:
材料科学
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陶瓷工程
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纳米技术
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无机合成
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Binghao Lin,Xu Wu,Xuejie He,Jiaxin Ye,Yuqin Song,Ping Jiang,Linxuan Bai,Xiangyue Liao,Yangjie Li,Yu Huo,Qiaoji Zheng,Heng Zhang,Dunmin Lin
Na 3 V 2 (PO 4 ) 3 (NVP) with typical NASICON structure is highly regarded as one of the most appealing cathodes for sodium-ion batteries (SIBs) for their excellent structural stability; however, the poor electronic conductivity and irreversible phase transition at high voltage (∼4 V) for the material result in poor rate capabilities and significant capacity degradation during electrochemical reactions. Herein, the high-entropy doping strategy of introducing six types of metal ions into the V-sites in Na 3 V 2 (PO 4 ) 3 is used to design a high-performance cathode of Na 3 V 1.73 (Mn, Ca, Mg, Al, Zr) 0.05 Nb 0.02 (PO 4 ) 3 (HE-NVP) for SIBs. After the high-entropy doping, a reversible V 4+ /V 5+ redox pair is activated at high voltage of ∼4 V, which significantly contributes to the enhancement of energy density and operating voltage. Moreover, after high entropy doping, the single solid solution phase transition in high voltage range is induced, effectively improving the material’s structural stability and exhibiting very small volume change of 1.1 % during the Na + extraction/insertion. Based on the unique advantages mentioned above, the high-entropy HE-NVP exhibits a superior discharge capacity of 122.1 mAh g −1 at a current rate of 0.5C and maintains a remarkable capacity retention of 90.1 % after 500 cycles at a rate of 5C. This work provides a useful reference for designing advanced cathodes for SIBs by regulating high entropy doping.
研究领域:
材料科学
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电化学
·
储能技术
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电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·Vol. 107
·期 11
·7352-7363
·
IF 3.5
Shengtai Zhang,Zhen Teng,Linzhen Wu,Yongqiang Tan,Chen Chen,Xiaosong Zhou
Designing waste forms using the cocktail effect of high-entropy ceramics can improve the efficiency of ceramic waste forms. In this work, traditional garnet (Y 1.2 Nd 1.8 Fe 5 O 12 , YIG) and high-entropy (HE) garnet (Y 0.6 Gd 0.6 Sm 0.6 Eu 0.6 Dy 0 . 6 Fe 5 O 12 , HEG) are synthesized through ignition and plasma sintering to form dense ceramic waste forms. The chemical stability of YIG and HEG was studied by using static leaching tests at pH = 3, 5, 7, 9, 11. The results indicate that acidic environments can increase the leaching rate of ceramics. Leaching behavior leads to a decrease in lattice volume, but the elements remain uniformly distributed. The leaching mechanism indicates that YIG and HEG are controlled by dissolution and surface effect in the early stage (1–7 days) of leaching. The leaching mechanism in the later stage (14–42 days) is characterized by diffusion control. The diffusion coefficient of long-term leaching indicates that HEG is more suitable as the immobilization substrate for high-level radioactive waste (HLW) than YIG.
研究领域:
材料科学
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核废物管理
✓ 已验证
DOI
高影响因子
Acta Metallurgica Sinica-English Letters
·
2022
·Vol. 35
·期 10
·1653-1664
·
IF 3.024
Xie Shenghui,Liao Xiang,Zeng Xierong,Yang Haipeng,He Liang
High-entropy alloys (HEAs) have attracted widespread attention due to their excellent mechanical properties. However, their functional properties arising from the supersaturated solid solution state can be improved. Advanced oxidation processes (AOPs) are considered to be an effective method for decomposing organic pollutants, and HEAs are proposed as effective candidates for AOP catalysts. Currently, several HEAs used for organic pollutant degradation are prepared through mechanical alloying. In this work, FeAlCoNi and FeAlCoNiB Fenton-like catalysts were prepared by single roll melt spinning and subsequent ball milling techniques. We found that the FeAlCoNiB HEA exhibits highly efficient degradation for p -nitrophenol ( p -NP). The degradation efficiency of FeAlCoNiB is 120 times higher than that of FeAlCoNi, which confirms that boron functions effectively during the degradation process. FeAlCoNiB has a better degradation efficiency than pure iron powder and a degradation efficiency comparable to that of the amorphous Fe 78 Si 11 B 11 alloy. Additionally, the degradation efficiency of FeAlCoNiB X increases ( k values from 0.13 to 0.55 min −1 ) when the boron content increases from an X value of 0.25 to 1.25. We speculate that Fe 2 B favors the degradation process and promotes zero-valent iron to decompose organic pollutants through a galvanic cell effect. Possible p -NP degradation pathways are proposed after LC–MS analysis. This study provides a new series of HEA Fenton-like catalysts, which have the potential to be prepared into bulk devices for industrial applications.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 27
·12670-12677
·
IF 3.3
Weiwen Cao,Xuanyu Yang,Weiji Dai,Bing Wu,Yudong Zhang,Cuijiao Zhao,Yanwei Sui,Saifang Huang
Efficient and robust electrocatalysts towards the oxygen evolution reaction (OER) are highly desirable in electrochemical systems for applications including water splitting and metal-air batteries. Herein, we report the preparation of an amorphous FeCoNiMnCr high-entropy alloy (HEA) on the surface of flower-like 2H-MoS2 (FeCoNiMnCr@MoS2) as a highly efficient electrocatalyst for the OER. The flower-like 2H-MoS2 is prepared on the flexible conductive carbon cloth (MoS2-CC) via a hydrothermal method, and subsequently the amorphous FeCoNiMnCr HEA is loaded on the surface of 2H-MoS2via an electrodeposition method to form FeCoNiMnCr@MoS2-CC electrocatalysts. Owing to the unique microstructure of 2H-MoS2 and abundant active sites of FeCoNiMnCr HEA, the FeCoNiMnCr@MoS2-CC electrocatalysts exhibit significantly improved OER electrocatalytic performances with a low overpotential of 210 mV at a current density of 10 mA cm−2 and a small Tafel slope of 40.3 mV dec−1 in 1.0 M KOH solution. Moreover, it shows excellent stability for OER electrocatalysis with the potential barely increased for at least 50 h. This work sheds light on the development of highly efficient OER electrocatalysts based on HEAs.
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
·
2025
·
IF 5.6
Wenyi Li,Feng Li,Xiaoming Qiu,Chuangchuang Gong,Min Jiang,Zhenxin Zhao,Xiaomin Wang
Owing to the intrinsic dielectric-magnetic coupling loss mechanism, perovskite-type lanthanide-transition metal oxide (LaTMO 3 ) is considered as a promising candidate for electromagnetic wave absorbing material, but unmodified LaTMO 3 suffers from limited polarization processes and weak super-exchange magnetic response. Herein, we manipulate the TM-O bond properties by regulating the configuration entropy of transition metal sites to address such issues within single-phase LaTMO 3 . Elaborate structural characterization and P-V-L bond theory demonstrate quantitatively the optimization of electromagnetic wave absorption performance mainly stems from the synergistic improvement in TM-O bond distortion degree and covalency, as well as the formation of diverse super-exchange pathways. Consequently, the high entropy La(Cr 0.2 Mn 0.2 Fe 0.2 Co 0.2 Ni 0.2 )O 3 exhibits a minimum reflection loss of −50.68 dB, an effective absorption bandwidth covering entire Ku band of 7.6 GHz. The radar cross section of the structure with La(Cr 0.2 Mn 0.2 Fa 0.2 Co 0.2 Ni 0.2 )O 3 coating are less than −10 dBm 2 within the incident angles -60-60°. This study contributes to a deeper understanding of design and preparation of efficient broadband electromagnetic wave absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·
IF 2.5
Tang Yingying,Xia Yongfeng,Yao Dongxu,Zhu Ming,Zhao Jun,Zeng Yu-Ping
Thermal insulation materials must exhibit superior mechanical properties alongside exceptional thermal insulation conductivity. However, traditional porous ceramics often struggle to meet these dual requirements simultaneously. In high-entropy materials, the phonon scattering induced by lattice distortion effects can significantly reduce the thermal conductivity of ceramics, thus opening new avenues for the design of novel thermal insulation materials. Inspired by the high-entropy effect, this study employed solid-state reaction methods to synthesize (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Ca 0.2 )O 2−δ (CZTSC) high-entropy ceramics at various temperatures, investigating their phase constituents, microstructural characteristics, and mechanical properties, while exploring the optimal sintering temperature. Additionally, a pore-forming agent method was utilized to fabricate monophasic CZTSC porous ceramics with different porosities at 1400 °C. Specifically, when the pore-forming agent content was 20 wt%, the sample exhibited an apparent porosity of 42.82%, with a low thermal conductivity of 0.57 W·m − 1 ·K − 1 , a low thermal diffusivity of 0.406 mm 2 ·s − 1 , and a relatively high compressive strength of 32.49 MPa. The current investigation underscores the promising prospects of porous CZTSC ceramics in the field of thermal insulation.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Qi Ni,Congcong Ding,Fuxin Liu,Fen Luo,Xiaoyan Shu,Yulu Fu,Xirui Lu
Multi-component high-entropy pyrochlore (HEP) offers several advantages compared to single-component pyrochlore in solidifying radioactive waste , including the ability to solubilize multiple types of waste and lower leaching rates (LRs) of radionuclides . In this study, we successfully synthesized HEP (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 and immobilized Ce, a simulated nuclide of Pu at 1500 °C for 48 h using a free occupied design approach. The Raman, XRD , and Rietveld refinement results showed that the immobilization limit for Ce fell between 20 wt .% and 30 wt .%. Notably, the ordered pyrochlore phase gradually transformed into the defective fluorite phase with an increase in Ce content. Moreover, the leaching tests demonstrated the excellent stability of the matrix, with the normalized LR for Ce reaching 10 −7 g·m −2 ·L −1 after 42 days at 90 °C. These findings collectively suggest that HEP (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 holds promise as a substrate for immobilizing radioactive waste in the future.
研究领域:
材料科学
·
核能工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL SPRAY TECHNOLOGY
·
2020
·Vol. 29
·期 7
·1827-1837
·
IF 2.522
Zhang Ying,Han Tengfei,Xiao Meng,Shen Yifu
The diamond enhanced (NiCoCrTi 0.5 Nb 0.5 )C x ( x = 3, 6, 12 wt.%) high-entropy alloy coatings were well-prepared by laser cladding, which are denoted as C 3 , C 6 and C 12 , respectively. The macroscopic morphology, phase, microstructure, hardness and wear resistance were investigated. The coatings without pores and cracks, are well-metallurgically bonded with the substrate. The width, melting depth and dilution rate of (NiCoCrTi 0.5 Nb 0.5 )C x coating decrease with the increase of diamond content. The coatings are mainly composed of BCC solid solution, (Ti,Nb)C and Cr 3 C 2 . The increase of diamond content results in the precipitation of (Ti,Nb)C and Cr 3 C 2 , and the coating with x = 12 wt.% retains more diamonds. The hardness of coatings is much higher than that of the substrate. As the diamond content increases, the average hardness of (NiCoCrTi 0.5 Nb 0.5 )C x coating increases first and then decreases. The abrasive wear occurs in each coating. The wear depth, roughness and wear rate decrease first and then increase as the diamond content increases. The C 6 coating with the better wear resistance produces a smooth worn surface, which indicates that C 6 coating can be fully applied to various tools, molds and mechanical parts.
研究领域:
材料科学
·
表面工程
✓ 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）