CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Bin Xiao,Gang Wu,Tongde Wang,Zhengang Wei,Yanwei Sui,Baolong Shen,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yaojian Ren,Xiaolan Xue,Junchao Zheng,Jing Mao,Kehua Dai
High entropy oxides (HEOs) have attracted the attention of researchers due to their high theoretical specific capacity and structural stability. However, the effect of elements in HEOs on material properties is unknown. In this work, HEOs (FeNiCrMnZn) 3 O 4 and (FeNiCrMnMg) 3 O 4 were successfully synthesized and used as anode materials for lithium ion batteries . The effects of Zn and Mg on the properties of HEOs were studied from the aspects of crystal structure, micro morphology, and surface valence. Results show that Zn enhances the lithium storage performance of HEOs theoretically, which is verified in the later electrochemical performance tests. (FeNiCrMnZn) 3 O 4 is better than (FeNiCrMnMg) 3 O 4 in all aspects of rate properties, cycle performance, and electrochemical impedance spectroscopy . Therefore, the introduction of electrochemically active metals, such as Zn, can improve the performance of HEOs, thereby providing ideas for the subsequent design and application of HEOs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Liang Xu,Lei Su,Hongjie Wang,Hongfei Gao,Pengfei Guo,Min Niu,Kang Peng,Lei Zhuang,Zhiwei Dai
Materials with ultralow thermal conductivity and good thermal stability are of great interest in numerous applications such as energy storage and conversion devices, and thermal insulation components. In this work, a family of high-entropy Sm 2 B 2 O 7 (B=Ti, Zr, Sn, Hf, Y, Yb, Nb, and Ta) oxides with highly disordered cations on the B-site has been synthesized by introducing large atomic-size mismatch, mass and charge disorder. Through tuning the composition, the high-entropy Sm 2 B 2 O 7 oxides can be engineered from pyrochlore to fluorite structure, accompanied with an order-disorder transition. The pyrochlore Sm 2 (Nb 0.2 Sn 0.2 Ti 0.2 Y 0.2 Zr 0.2 ) 2 O 7 and fluorite Sm 2 (Nb 0.2 Ta 0.2 Y 0.2 Yb 0.2 Zr 0.2 ) 2 O 7 exhibit low thermal conductivities of 1.35 W·m −1 ·K −1 and 1.23 W·m −1 ·K −1 , respectively, indicating their good thermal insulation. In addition, the high-entropy fluorite Sm 2 (Nb 0.2 Ta 0.2 Y 0.2 Yb 0.2 Zr 0.2 ) 2 O 7 also shows average thermal expansion coefficient of 10.2 × 10 −6 °C −1 and high-temperature stability even after thermal exposure at 1600 °C in air for 30 h. These results indicate that the high-entropy Sm 2 B 2 O 7 (B=Ti, Zr, Sn, Hf, Y, Yb, Nb, and Ta) can be promising candidates for thermal barrier coatings and thermally insulators.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Bo Ma,Zhiqin Wen,Jiedong Qin,Zhenyu Wu,Junxiao Liu,Yunming Lv,Junjie Yu,Yuhong Zhao
In this work, single-phase (Ce 0.2 Zr 0.2 La 0.2 Sm 0.2 Nd 0.2 )O 2-δ high-entropy fluorite oxides (HEFOs) were successfully prepared by conventional solid-phase reaction method and crystal structure and microstructure were studied in-depth. Single-phase (Ce 0.2 Zr 0.2 La 0.2 Sm 0.2 Nd 0.2 )O 2-δ is formed at 1600 °C for 12 h, and five cationic elements are uniformly distributed without any segregation at the micrometer and nanometer scales. And the XRD patterns with Rietveld refinement reveal the formation of single-phase fluorite structure of (Ce 0.2 Zr 0.2 La 0.2 Sm 0.2 Nd 0.2 )O 2-δ . The SAED patterns on the [0 1 ‾ 1] band axes are similar to the diffraction patterns of face-centered cubic fluorite structure, and the standard deviation of the cation radius (coordination VIII) distribution of the specimens is 0.1277, which is again identified as forming a single-phase fluorite structure. The bulk specimens are solid compacts free of obvious cracks with randomly distribution porosity at a rare level, and the powder specimens are irregular fragmented shapes with an average particles size of 5.41 μm. The average cation radius and interplanar spacings becomes larger compared with standard fluorite structure of CeO 2 due to the cation radius of La 3+ , Sm 3+ and Nd 3+ are larger than that of Ce 4+ , leading to an increase in lattice parameters of the HEFOs. In addition, the concentration of Ce 3+ in the Ce cation is only 8.1 %, and the δ -value is calculated to be 0.3081 based on the content of all cations per mole of the substance, which indicates that the composition of the prepared specimen is (Ce 0.2 Zr 0.2 La 0.2 Sm 0.2 Nd 0.2 )O 1.6919 .
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Huimin Mao,Xinyue Qu,Hongsheng Ma,Jingqi Chi,Zhenyu Xiao,Yongming Chai,Zexing Wu,Xiaobin Liu,Lei Wang
Seawater electrolysis is undoubtedly a more sustainable alternative to pure water electrolysis at present. However, it is hindered by the relatively slow kinetics of the oxygen evolution reaction and the detrimental effects of chloride ions in seawater that require resolution. In this study, we developed a straightforward synthesis method and successfully prepared FeNiCoMnCr high-entropy oxide (HEO). The strong coupling among multiple 3d orbitals of the transition metals allows for significant regulation of the catalyst’s electronic structure, enabling oxidation and reduction processes at the active site to spontaneously approach an equilibrium state. Additionally, Lewis acid Cr 6+ selectively adsorbs OH − , further enhancing both activity and stability of the catalyst in alkaline seawater. This research provides valuable insights into utilizing HEOs for seawater electrolysis and elucidates the roles of metals within HEOs.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Min Zhu,Jiacheng Cao,Xiaonan Chen,Dandan Ma,Yanjiao Meng
Extensive investigations have been conducted on high-entropy oxides (HEOs) as promising materials for heat conversion. In this study, a novel high-entropy ferrite (Mn 0.2 Co 0.2 Cu 0.2 Zn 0.2 Mo 0.2 )Fe 2 O 4 with a spinel structure was synthesized via the solid-state method at elevated temperatures, and its thermoelectric properties were subsequently evaluated. The XRD, SEM, and TEM-EDS measurements demonstrate the successful incorporation of multi-component cations into a single site, leading to the formation of a homogeneous material phase. Furthermore, TEM analysis reveals the presence of various defects and lattice distortions such as dislocations in this high-entropy ceramic. At 1073K, the high-entropy ceramic exhibits a low thermal conductivity (κ = 1.74 W/m/K) and a high Seebeck coefficient (|S| = 180.5 μV/K). The results suggest that high entropy engineering has the potential to enhance the thermoelectric properties of spinel structured ferrites, thereby creating exciting prospects for utilizing this spinel ferrite as a novel thermoelectric material in high-temperature applications.
研究领域:
材料科学
·
热电材料研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Chufei Cheng,Ruixin Hao,Jiadong Hou,Fengnian Zhang,Fuhao Cheng,Ziqian Meng,Bei Ren,Yang Miao,Libiao Xin,Xiaomin Wang
In the thermal protection system of spacecraft, the bolts connecting the ceramic to the internal superalloy need to have low thermal conductivity and high strength . Two dense high entropy fluorite oxides (Zr 1/7 Hf 1/7 Ce 1/7 Y 2/7 La 2/7 )O 2-δ (ZHCYL) and (Zr 1/8 Hf 1/8 Ce 1/8 Y 1/4 La 1/4 Pr 1/8 )O 2-δ (ZHCYLP) were designed and synthesized by using the synergistic effect of plasma-assisted ball milling and spark plasma sintering(SPS). Through the synergistic effect of lattice distortion and oxygen vacancy guided by entropy regulation, ZHCYLP synthesized in this study has lower thermal conductivity(1.13 W·m −1 ·K −1 ), higher high temperature strength(192 MPa at 1000 °C) and high temperature phase stability up to 1600 °C than 8YSZ ceramics. The thermo-mechanical coupling finite element analysis results of high temperature bending test show that the variation trend of the maximum stress value of the sample is consistent with the experimental results. This shows that the mechanical and thermal properties of high entropy oxides can predict the variation trend of the maximum stress value in high temperature bending tests. It opens up a new way for designing and synthesizing high entropy oxide materials with low thermal conductivity and high strength which can be applied in the field of heat protection and load bearing.
研究领域:
材料科学
·
航天工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Weihua Ji,Jiadong Hou,Yang Miao,Chao Ma
High-entropy fluorite oxides exhibit application potential in thermal barrier coatings. The introduction of pyrochlore phase provides more exploration space for improving thermal properties. However, the phase stability and properties of dual-phase high-entropy oxides (HEOs) need to be further explored. In this paper, high-entropy fluorite single phase and fluorite-pyrochlore dual phase of (ZrHfPrLaSm)O 2-δ were synthesized, both of which exhibit excellent high-temperature phase stability at 1600 °C. The dual-phase HEOs have lower thermal conductivity and higher thermal expansion than single-phase. The thermal conductivity of dual-phase (Zr 0.195 Hf 0.195 Pr 0.195 La 0.195 Sm 0.22 )O 2-δ at 1100 °C is 1.36W·m −1 ·K −1 , which is 18.1 % lower than single-phase. The thermal expansion coefficient of dual-phase HEOs is increased to 11.8 × 10 −6 K −1 . Compared with single-phase structure, the coexistence of pyrochlore-fluorite structure increases oxygen defect content and lattice distortion degree, resulting in the enhancement of phonon scattering which reduces the thermal conductivity. This study provides guidance for the design and development of high-performance high-entropy ceramics.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Kewei Wang,Baisheng Ma,Tao Li,Chunxiao Xie,Zhenzhong Sun,Dianguang Liu,Jinling Liu,Linan An
In this study, powder mixtures at atomic ratios suitable for formation of Sr(Ti 0.2 Y 0.2 Zr 0.2 Sn 0.2 Hf 0.2 )O 3-x were flash sintered at 1000 °C and 40 mA/mm 2 . X-ray diffraction and energy-dispersive spectroscopy analyses revealed the formation of single-phase oxides after sintering for 1 min. This rapid formation of single-phase oxide was attributed to flash sintering characteristics, which not only enhanced the diffusion rate, but also softened the lattice. Compared to conventional heat treatment sintering, the sintering time was shortened to 1 min from 10 h, while the sample temperature was reduced to 1314 from 1500 °C. Therefore, flash sintering is a promising technique for rapid synthesis of high-entropy oxides.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Mengyuan Zhang,Xiaolan Duan,Ying Gao,Shuangshuang Zhang,Xiaoyan Lu,Kongliang Luo,Jian Ye,Xiaopeng Wang,Qiang Niu,Pengfei Zhang,Sheng Dai
Tuning surface oxygen vacancies is important for oxide catalysts. Doping elements with different chemical valence states or different atomic radii into host oxides is a common method to create oxygen vacancies. However, the concentration of oxygen vacancies in oxide catalysts is still limited to the amount of foreign dopants that can be tolerated (generally less than 10% atoms). Herein, a principle of engineering the configurational entropy to tune oxygen vacancies was proposed. First, the positive relationship between the configuration entropy and the formation energy of oxygen vacancies (Eov) in 16 model oxides was estimated by a DFT calculation. To verify this, single binary oxides and high-entropy quinary oxides (HEOs) were prepared. Indeed, the concentration of oxygen vacancies in HEOs (Oβ/α = 3.66) was higher compared to those of single or binary oxides (Oβ/α = 0.22–0.75) by O1s XPS, O2-TPD, and EPR. Interestingly, the reduction temperatures of transition metal ions in HEOs were generally lower than that in single-metal oxides by H2-TPR. The lower Eov of HEOs may contribute to this feature, which was confirmed by in situ XPS and in situ XRD. Moreover, with catalytic CO/C3H6 oxidation as a model, the high-entropy (MnCuCo3NiFe)xOy catalyst showed higher catalytic activity than single and binary oxides, which experimentally verified the hypothesis of the DFT calculation. This work may inspire more oxide catalysts with preferred oxygen vacancies.
研究领域:
材料科学
·
催化化学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
·
2023
·
IF 8.3
Fuhao Cheng,Ziqian Meng,Chufei Cheng,Jiadong Hou,Yufeng Liu,Bei Ren,Haiyan Hu,Feng Gao,Yang Miao,Xiaomin Wang
As gas turbine inlet temperatures continue to rise, new thermal barrier coating (TBC) materials must be developed urgently. This work investigated molten silicate corrosion, thermal conductivity , and high-temperature phase stability of a new class of high-entropy oxides (HEO) as potential protective coating materials. With composition tuning, high-entropy RE 2 B 2 O 7 (RE= Gd, Sm, Y, Pr, La; B Ce, Zr) can be transformed from pyrochlore to fluorite structures. They all exhibited phase stability when annealed at 1600 ℃ for 10 h and very low thermal conductivity (1.21–1.39 W·m −1 ·K −1 ) compared to conventional materials with better thermal protection. In addition, the CMAS corrosion resistance behavior of all samples at 1300 °C and 1500 °C was investigated, and it was found that the infiltration thickness decreased with increasing Ce content (down to ∼10 µm for 5 h at 1500 °C). The RE 2 Ce 2 O 7 had the most substantial CMAS resistance, forming a dense barrier layer composed of uniformly fine crystal grains during the reaction. The results of this study establish the foundation for future applications of RE 2 B 2 O 7 in thermal protection systems.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
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
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
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
·
催化科学
✓ 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）