JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2025
·
IF 14.3
Yao Li,Yongheng Jin,Hassan Raza,Yuping Wang,Qingkui Chen,Xingjian Zou,Zhengyang Ren,Junjie Guo,Guangping Zheng,Junye Cheng
Recently, the strategy of tuning the dielectric parameters of absorbers for their excellent electromagnetic wave absorption (EMA) performance has attracted much attention. Among those candidates used for EMA application, high-entropy oxides (HEOs) can be implemented with this strategy due to their rich composition modulability. In this work, a series of implementation approaches varying from elemental design to structural modulation are employed to modulate the dielectric parameters of HEOs, resulting in their excellent EMA performance. The addition of Ti element optimizes the dipole distribution at the microscopic scales, improving the dielectric polarization of the materials. Moreover, a composite material is constructed by physically blending HEO with acetylene black (ACET), which significantly improves the macroscopic conduction loss of the material. The optimization of the dielectric genes of HEO/ACET is achieved with the blending effect and excellent EMA performance could be obtained. Among them, HEO with 17.5% ACET addition exhibits dual-band absorption, while Ti-HEO containing Ti element exhibits not only low-frequency absorption with reflection loss (RL) up to −29.81 dB at C-band but broadband absorption over 6 GHz as well as an optimal RL value up to −52.31 dB. In addition to the development of innovative EMA materials, this study offers a new perspective on how the EMA characteristics can be effectively regulated.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Yuanxi Guo,Xinxin Zhang,Hehe Wei,Hai-tao Yu,Ying Xie
High-entropy oxides (HEOs) exhibit excellent structural stability, and the synergistic effects among their constituent elements contribute to performance enhancement, providing vast opportunities for designing novel and efficient electrocatalysts. Utilizing four common transition metals such as Fe, Co, Ni, and Cr as the base and introducing a fifth metal, M (M = Mg, Mn, Zn, and Cu), with different outer electron shells, relevant high-entropy oxides with varying sizes were successfully synthesized via the hydrothermal method. Among all considered samples, FCNCMg, with the smallest particle size, possessed a much larger specific surface area, leading to the exposure of more active sites and thus favoring an improvement of the OER performance. The introduction of the fifth metal induced a redistribution of charges among Fe, Co, Ni, and Cr within the catalyst, resulting in different oxidation states for these metals. Mg addition led the XPS peaks of Fe/Ni and Cr/Co elements to shift towards lower and higher binding energies, respectively. This dynamic compensation effect between metal ions synergistically promoted their OER performance. In alkaline environments, FCNCMg exhibited the best OER performance, with an overpotential of 278 mV at 10 mA cm −2 and a Tafel slope of 49.90 mV dec −1 . Moreover, it demonstrated excellent stability, achieving 50 h at 10 mA cm −2 and 20 h at 50 mA cm −2 . This study, by controlling the composition of HEOs, explored the impact of particle size and synergistic effects on their performance, offering new insights for design and optimization of relevant high-performance HEOs.
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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2025
·Vol. 36
·期 5
·1-12
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IF 2.8
Chen Zheng,Hou Junxin,Jin Xiangwei,Zheng Lingxia,Liu Fenghua,Li Zhixiang
The utilization of the high-entropy effect and the cocktail effect in high-entropy oxides has significantly expanded the horizon for material design and performance enhancement. Consequently, the fabrication of high-entropy oxides has emerged as a focal point of recent research. High-entropy oxides that serve as cathode materials for battery electrodes must exhibit high electrical conductivity. In this study, a high-entropy oxide (La 0.2 Ba 0.2 Cu 0.2 Sn 0.2 Ni 0.2 ) 3 O 4 was synthesized using the high-temperature solid-state reaction method. A systematic investigation was conducted to analyze the impact of varying sintering temperatures on the phase structure and electrical properties of the material. The findings indicate that the high-entropy oxide under study possesses commendable electrical conductivity. The electrical conductivity of the material was observed to increase initially and then decrease with the elevation of sintering temperature. Optimal electrical conductivity was achieved at a sintering temperature of 1280 °C. The temperature-dependent electrical conductivity of the sample was found to increase initially and then decrease, with a nominal conductivity of 20.062 S·cm −1 at 25 °C, and a stepwise increase to 30.06 S·cm −1 at 250 °C. This material holds promising potential for applications in energy, electronics, and catalysis sectors.
研究领域:
材料科学
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能源科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
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2024
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IF 5.2
Jipeng Wang,Xinli Tong,Chen Guo,Yahui Wei
The high entropy oxides are widely studied as the potential catalytic materials owing to their unique structure and excellent properties. In this work, a new high entropy oxide catalyst MnFeCoNiCuO x was successfully prepared and used for the oxidative condensation reaction of furfural (FUR) and aliphatic alcohol , where the carbon-chain length can be selectively increased under the mild conditions. For the selective oxidative transformation of FUR with n-butanol, a more than 99.0 % conversion of FUR and 91.5 % selectivity of 2-(furanyl-2-methylene) butanal was obtained at 80 ºC for 2 h. In addition, the oxidative condensation of FUR with ethanol, n-propanol, n-pentanol, n-hexanol and n-heptanol was also carried out with the MnFeCoNiCuO x - LiOH as catalyst system in the presence of molecular oxygen , where a moderate to high product yields were acquired. Furthermore, the characterizations of catalyst showed that the existence of abundant oxygen vacancy and high specific area was greatly important to the catalytic reactions .
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2024
·
IF 5.8
Qifa Wan,Faming Zhang,Yifeng Xiong
For the first time, we adopted the in-situ formed alumina , which resulted from the thermal decomposition of cheap and accessible potassium alum, as the source of aluminum cation to synthesize (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 spinel-structured high-entropy oxide powder after the solid state reaction process, showing the advantages of lower synthesis temperature and scalable fabrication. To investigate the effect of aluminum cation insertion on the mechanical properties of (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 , the (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 and (Co 1/5 Mn 1/5 Fe 1/5 Cr 1/5 Ni 1/5 ) 3 O 4 ceramics were first fabricated and reported. Owing to significant lattice distortion induced by the aluminum cation, the (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 possessed higher compressive strength , hardness, and elastic modulus , which were 139.3 MPa, 11.3 GPa, and 167.5 GPa, respectively. Moreover, the average grain size of (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 only increased from 2.63 µm to 10.11 µm, while that of (Co 1/5 Mn 1/5 Fe 1/5 Cr 1/5 Ni 1/5 ) 3 O 4 increased from 1.77 µm to 15.61 µm. The slower grain growth rate of (Co 1/6 Mn 1/6 Fe 1/6 Cr 1/6 Ni 1/6 Al 1/6 ) 3 O 4 after aluminum cation insertion was attributed to the sluggish diffusion effect.
研究领域:
材料科学
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固体力学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Hongchen Guo,Jianxing Shen,Tailin Wang,Chuanbing Cheng,Hongyan Yao,Xiujun Han,Qiuju Zheng
The rock salt structure of high entropy oxide (HEO) (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O has promising prospects for energy materials. Here, we prepare HEO and calculate the entropy value S m i x ≥ 1.5R (R represents the gas constant), thus proving that HEO is obtained. In addition, we design and obtain HEO@G (HEO@Graphene) through the surface modification of HEO with graphene, which is analysed by X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy to reveal the rock salt structure of HEO@G and the formation of a planar layer architecture on the surface of HEO by graphene. The electrode well design with HEO@G as the anode material for lithium-ion batteries provides a high capacity of 1225 mA h g −1 in the first discharge at 100 mA g −1 and maintains a discharge capacity of ∼950 mA h g −1 after 200 cycles. A reversible cycling capacity of 460 mA h g −1 is obtained under the condition of multiple cycles at high speed. In terms of expansion, electrochemical impedance spectrometry and pseudocapacitance investigations deeply demonstrate that the addition of graphene enhances the diffusion dissemination coefficient of lithium ions in the composite electrode and changes the electrochemical kinetic properties of the composite anode. Such a modification approach for HEO will provide a reference in energy storage applications.
研究领域:
材料科学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 35
·2205325
·
IF 19.924
Guohao Dai,Ruixiang Deng,Tao Zhang,Yun Yu,Lixin Song
High-entropy oxides (HEO) with high stability and designability are potential microwave absorbers that serve in harsh environments. However, loss design is critical for the absorption performance of HEO due to its weak intrinsic loss capability. Inadequate loss ability results in considerable secondary reflection. Here, an in situ conductive heterogeneous phase is constructed in (Fe 0.2x Co 0.2 Ni 0.2 Cr 0.2 Mn 0.2 ) 3 O 4 ( x = 1–5) using a reductive circumstance, to form a dual-phase composite. Both the ohmic and dielectric loss are enhanced as the conductive phase is introduced, while great impedance matching condition is well maintained. Hence, the composites can achieve substantial absorption across the whole X or Ku band with a thin thickness. Furthermore, key efforts are made to reveal the relationship between the absorbing performance and loss capability of an absorber. The analytical expression of the theoretical threshold of attenuation constant is derived. Based on the statistics of experimental data, the broad feasibility and practicability of the proposed theoretical threshold of attenuation constant are confirmed and discussed. Combined with both the theoretical and experimental studies, the mechanism by which the conductive phase contributes to increased absorption is also disclosed, providing an effective basis for the loss design of broadband microwave absorbers.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 105
·期 8
·5490-5500
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IF 4.186
Liang Xu,Lei Su,Hongjie Wang,Min Niu,Lei Zhuang,Kang Peng,Xingyu Fan,Hongfei Gao,De Lu
Pursuing novel thermal barrier–coating materials with lower thermal conductivity and high-temperature stability can simultaneously improve the working efficiency and service temperature of a gas turbine. In this study, a series of high-entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 (RE = La, Nd, Sm, Gd, Dy, and Er) oxides were prepared though solid-state reaction. Through tuning the rare-earth cations, an order–disorder transition occurs from certain partially ordered weberite structure ( C 222 1 ) to disordered defective fluorite structure ( Fm 3 ¯ $\bar{3}$ m ). All the high-entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides possess low thermal conductivity in the range of 0.91–1.34 W m −1 K −1 at room temperature, which can be attributed to increased lattice anharmonicity and disorder, resulting in additional phonon scattering. Herein, we proved that the incorporation of heterovalent cations at B-sites in high-entropy A 2 B 2 O 7 crystals is an effective strategy to reduce the thermal conductivity without compromising the decrease of oxygen vacancy. Moreover, the high-entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides show the relatively higher thermal expansion coefficients of 10.3–10.7 × 10 −6 °C −1 and excellent phase stability at elevated temperatures.
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhezhe Deng,Ying Peng,W.W. Qin,Benxue Liu,Guanghui Zhang,Xinqiang Wang,Yongshuai Xie,Luyi Zhu,Dong Xu
Single-component oxide fibers encounter various issues, including grain transition growth and mechanical property degradation at high temperatures, which restrict their potential usage for high-temperature applications. The unique properties of high-entropy materials, including lattice distortion, sluggish diffusion, and cocktail effects, can effectively maintain small grains and excellent mechanical properties even in extreme conditions. Therefore, developing high-entropy oxide fibers provides a dependable solution to address the issues associated with single-component fibers. This paper successfully obtained the (Zr 0.2 Hf 0.2 Ti 0.2 Gd 0.2 Y 0.2 )O 2-δ (ZHTGY) high-entropy oxide fibers by commencing from molecular design. Compared to other high entropy oxide materials, ZHTGY fibers exhibit a low crystallization temperature of 700 °C and exceptional high-temperature stability with no phase changes observed from RT to 1500 °C. In addition, the ZHTGY fiber membranes exhibit a density of merely 33 mg·cm −3 , a tensile strength of 2.73 MPa@1000 °C, excellent flexibility, knot-free and fold-free properties, as well as the ability to bend freely even in environments with butane flame or liquid nitrogen. The ZHTGY fiber membranes have excellent thermal insulation properties due to their ultra-low density and high-temperature structural stability. With a thermal conductivity of only 25.7 mW·m −1 K −1 , an 8 mm thick sample laminated with these fiber membranes can reduce the temperature of a 1370 °C heat source to just 320 °C. The fiber membranes maintain good flexibility and strength even after heat treatment at 1200 °C for 50 h and 1400 °C for 180 s. This study provides a novel approach for preparing high-entropy oxidation fibers, thereby enabling the development of lightweight high-temperature thermal protection materials.
研究领域:
材料科学
·
高温材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yubin Wen,Yufu Liu
Typical high-entropy fluorite oxides with five metal cations have exhibited improved thermomechanical properties . In this work, we have successfully prepared single-phase high-entropy (Zr 0.2 Ce 0.2 Hf 0.2 Y 0.2 Al 0.2 )O 2-δ fluorite oxides through the combination of sol-gel method and calcination , using metal nitrate/chloride, citric acid and absolute ethanol as the primary raw materials. A series of characterizations were employed for chemical, morphological and structural analysis of the calcined products. The five cationic elements were shown to be uniformly distributed in the nearly pure fluorite oxide without apparent segregation at the micro/nano-meter scales after 1500 °C calcination. Annealing and water quenching within the test temperature range did not witness any appreciable phase transition. It is revealed that the concentration of Ce 3+ in Ce ions reaches 33.84% and δ is equal to 0.234, yielding a nominal composition of (Zr 0.2 Ce 0.2 Hf 0.2 Y 0.2 Al 0.2 )O 1.766 . Cation and anion configurational entropy were found to be 1.609 R and 0.722 R, respectively, where R is the ideal gas constant, for a sum of the total configurational entropy of 2.331 R in the high-entropy system. Line defects inside the crystals and 3 types of crystalline boundary structures have been observed and identified among the mostly atomically sharp grain boundaries.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Mingrun Du,Yuhan Xiao,Xuelian Yang,Yu Ma,Yingdong Han,Zepeng Li,Tong Wei,Yunling Zou
In this work, high-entropy (La 0.2 Dy 0.2 Er 0.2 Yb 0.2 Y 0.2 ) 2 Zr 2 O 7 oxide (RZHEO-1600) has been synthesized by using a simple solid-state reaction method and investigated as a promising thermal barrier coating (TBC) material with potential optical pressure sensing application. Compared to oxide-yttria stabilized zirconium (YSZ) and single component zirconates, RZHEO-1600 exhibits excellent thermal stability at 1600 °C and a larger thermal expand coefficient 13.5 × 10 −6 K −1 due to the high entropy effect. Its thermal conductivity (1.23–1.41 W m −1 K −1 ) and Vickers hardness (10 GPa) are lower than YSZ, while its fracture toughness (2.9 MPa m 1/2 ) is much larger. The photoluminescence (PL) emissions of RZHEO-1600 excited by 514 nm laser are assigned to 4 S 3/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 transitions of Er 3+ ions. The centre positions of emission peaks initially at 560 and 677 nm are sensitive to pressure, which red shift linearly with pressure coefficients of 0.178 nm/GPa (−5.650 cm −1 /GPa) and 0.223 nm/GPa (−4.932 cm −1 /GPa), respectively. Interestingly, the PL intensity ratios I 677 /I 658 and I 560 /I 547 are found to be pressure sensitive, which continuously increase during the compression. The findings of this study could serve as a new guide for the development of novel high-entropy oxide TBC materials with optical sensing applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2023
·
IF 8.3
Liang Xu,Min Niu,Lei Su,Xin He,Haotian Ni,Hongfei Gao,Lei Zhuang,Hongjie Wang
Engineering stoichiometry of materials is an effective strategy to optimize the comprehensive properties. Here we prepare high-entropy Er 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce x ) 2 O δ with single-phase fluorite structure by a solid-state reaction. The effects of stoichiometry of cerium on thermophysical properties and corrosion resistance to calcium−magnesium−alumina−silicate (CMAS) of the high-entropy oxides have been investigated. By engineering the cerium stoichiometry, thermal conductivity increases slightly from 1.21 to 1.36 W·m −1 ·K −1 and thermal expansion coefficients also increases from 10.56 × 10 −6 to 11.61 × 10 −6 °C −1 at 1000 °C. Furthermore, corrosion resistance of the high-entropy Er 2 (Nb 0.2 Ta 0.2 Y 0.2 Yb 0.2 Ce x ) 2 O δ improves with the increase of cerium content. The effects of cerium content on CMAS resistance have been discussed in detail. Our work reveals that engineering stoichiometry of high-entropy oxides is expected to be an effective strategy to broaden the compositional space and optimize the thermophysical properties and CMAS corrosion resistance.
研究领域:
材料科学
·
工程学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）