JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2020
·
IF 6.155
Daquan Liu,Yanxia Wang,Xue Jiang,Huijun Kang,Xiong Yang,Xiaoying Zhang,Tongmin Wang
Microstructural modifications and appropriate element doping are necessary to simultaneously enhance the electrical conductivities and reduce the lattice thermal conductivities of thermoelectric materials . Herein, we propose a strategy of multielement doping combined with a burial sintering process to promote thermoelectric properties. Three-element doped Sr 0.9 La 0.05 Dy 0.05 Ti 1− x Nb x O 3 ( x = 0, 0.05, 0.10, 0.15, and 0.20) powders were synthesized by high-energy ball milling, and corresponding bulk samples were prepared by carbon burial sintering. In the bulk samples, we obtained the desired microstructures composed of shell-vesicular architectures with dense dislocations and second phase particles. These materials had ultrahigh electrical conductivities (∼5300 S cm −1 at 300 K), low lattice thermal conductivities (∼1.6 W m −1 K −1 from 700 to 1100 K when x = 0.2) and low total thermal conductivities (minimum value of 2.95 W m −1 K −1 when x = 0.05 at 1100 K). The maximum zT values were 0.28 when x = 0.05 and 0.27 when x = 0.2 at 1100 K. This strategy provides a possible direction for improving the thermoelectric properties of SrTiO 3 based materials.
研究领域:
材料科学
·
热电材料
·
陶瓷
·
固体物理
·
能源材料
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DOI
高影响因子
Energy & Environmental Materials
·
2026
·
IF 13.8
Guomeng Xie,Ziqin Xu,Delai Qian,Ruiwu Li,Qingsong Hua,Shun Lu,Haitao Fang
Single-crystalline Ni-rich cathodes are promising candidates for high-energy density lithium-ion batteries due to their grain-boundary-free structures, which effectively reduce structural degradation associated with intergranular microcracks often seen in polycrystalline materials. However, these single-crystalline cathodes face challenges such as slow Li + diffusion kinetics, significant parasitic interface reactions, and irreversible phase transitions at elevated cut-off voltages, which can lead to the formation of intragranular cracks and impede their practical usage. In this study, the single-crystalline LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) was synthesized by stripping grain boundaries from polycrystalline NCA through Mo/Nb dual doping. The Mo doping near the grain surface significantly reduces parasitic interface reactions, while Nb doping within the bulk of grains helps to improve harmful irreversible phase transitions. The synergistic effect of Mo/Nb dual doping in single-crystalline NCA effectively suppresses intragranular crack formation during prolonged cycling at high cut-off voltages. Therefore, the Mo/Nb co-doped cathode demonstrates enhanced structural stability and electrochemical activity, achieving an impressive capacity retention of 82.4% after 500 cycles at 1 C between 2.8 and 4.7 V, surpassing both polycrystalline and single-crystalline NCA doped only with Mo or Nb. This work provides a new strategy to synthesize single-crystalline NCA combined with effective dual doping, advancing the development of high-energy density lithium-ion batteries.
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Jiaxin Li,Qunwei Guo,Jiangtao Feng,Yinwen Gu,Bo Chi,Jian Pu
Accurate and real-time detection of SO 2 at industrial emission sources is important for emission control, yet reliable sensing under high-temperature and relatively high-concentration conditions remains challenging. In this study, a YSZ-based mixed-potential SO 2 sensor was developed by regulating Nb nonstoichiometry in MnNb 2-x O 6 sensing electrodes and YSZ compositing. Nb deficiency altered particle coarsening, the apparent pore architecture of the electrode layer, and the defect chemistry. Among the single-phase sensing electrodes, MnNb 1.9 O 6 exhibited larger pore sizes and the highest oxygen-vacancy concentration, achieving a sensitivity of −14.76 mV/decade over 50-500 ppm SO 2 at 400 °C. Further compositing with YSZ produced more uniformed pore structure and increased the electrochemically active triple-phase-boundary (TPB) region, with MnNb 1.8 O 6 /20 wt% YSZ achieved the highest sensitivity of −18.74 mV/decade. A comparison of the composition series and YSZ-composite electrodes indicates that electrode microstructure and accessible TPB sites are the primary determinants of the electrochemical response, which enhance SO 2 diffusion and increase the number of active sites. Additionally, the increased oxygen vacancies also provide a synergistic contribution by promoting oxygen ion transport, further enhancing the overall reaction rate. The optimized sensor also showed good repeatability and 15-day stability, highlighting its potential for high-concentration SO 2 monitoring under industrially relevant dynamic-flow conditions.
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Materials Horizons
·
2025
·
IF 10.7
Menglong Gao,Yao Guo,Shiding Zhang,Yinghui Xue,Jianxin Li,Shuaishuai Hu,Haixiang Song,Kaidi Wu,Miaomiao Li,Huihui Zhao,Zhongyuan Zhou,Qing Shen
We study the interface properties of CsPbBr3/Nb2O5 and CsPbBr3/Ta2O5 heterojunctions for structural, electronic, and optical characteristics. First-principles calculations were performed to analyze interfacial binding energy, electronic local function (ELF), charge density difference, and electrostatic potential. Four interface configurations were constructed based on CsPbBr3 (100) and M2O5 (001) terminations, revealing that the PbBr/TaO interface exhibits the highest binding energy (0.0073 eV Å−2), indicating superior stability. Charge transfer calculations demonstrate electron migration from CsPbBr3 to M2O5, forming an internal electric field that promotes charge separation. ELF and charge density difference maps highlight strong covalent interactions at the interfaces, particularly in the PbBr/TaO interface. Experimental characterization via XRD, SEM, TEM and XPS confirms successful heterojunction formation with preserved crystallinity. These findings provide theoretical and experimental insights into optimizing M2O5-based electron transport layers to enhance PSC efficiency and stability.
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Mengyuan Qiu,Yongzhi Xiong,Wei Zhao,Dong Ouyang,Zongxuan Wu,Tangtianxiang Liang,Changzhou Chen,Shengchun Hu,Hao Sun
Designing low-cost, high-performance electrocatalysts for the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to produce 2,5-furandicarboxylic acid (FDCA) remains a significant challenge. Herein, we report a novel post-pyrolysis phosphidation method for preparing Nb- and Fe-doped CoP-based catalysts. Nb-CoP@NC delivers a current density of 91.79 mA cm⁻² at a potential of only 1.50 V vs. RHE, achieving nearly 100 % HMF conversion, 98.3 % FDCA selectivity, and 95.6 % Faradaic efficiency (FE). Structural and surface analyses via XRD and XPS reveal that Nb doping significantly modulates the electronic structure of CoP, generating Nb 5+δ active species, which show superior catalytic activity for HMFOR compared to Fe 3+δ . This work not only highlights the pivotal role of Nb doping in enhancing catalytic performance but also provides a general and facile strategy for constructing efficient bimetallic CoP-based catalysts for biomass-derived HMF oxidation.
研究领域:
催化
·
电化学
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生物质转化
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材料科学
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绿色化学
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xin Tang,Ruipeng Mao,Fan Zhang,Yongzhong Jin,Wei Su,Wu Jiang,Junhao Wang
Cemented carbides play a pivotal role in diverse industrial sectors, and controlling abnormal grain growth and regulating the homogeneity of the Co binder phase are the key challenges to improve their properties. In this study, WC-10Co alloy was prepared for the first time by low-pressure sintering technique using (Ti, Cr, V, Nb, Mo)(C, N) high entropy powder as an inhibitor, focusing on the effect of trace additions of (Ti, Cr, V, Nb, Mo)(C, N) on the microstructure and mechanical properties of the alloy as well as friction and wear properties. The results show that under the conditions of sintering at 1420 ℃, a pressure of 3 MPa, and a holding time of 1 hour, the alloy with 0.2 wt.% high-entropy inhibitor exhibited the best comprehensive properties, with a flexural strength of 3752 MPa, a Vickers hardness of 1679 HV 30 , and a fracture toughness of 13.07 MPa·m 1/2 . During the stable stage of tribological testing, the average friction coefficient reached 0.6195, and the wear rate was as low as 1.34×10 -7 mm 3 /(N·m). The toughening and strengthening mechanism of the (Ti, Cr, V, Nb, Mo)(C, N) - modified alloy is mainly attributed to the significant refinement of WC grains, WC lattice contraction, and the formation of Co-based solid solutions by the high-entropy inhibitor. However, excessive addition deteriorates the overall performance. This study provides experimental data and technical insights for the development of a new generation of cemented carbides with high strength, high toughness, and excellent wear resistance.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
ACS Omega
·
2026
·
IF 5.2
Panpan Xu,Xiaole Qiu,Bing Sun,Li Sun,Ensi Cao,Wentao Hao
Abstract Colossal permittivity (In,Nb) codoped TiO2 ceramics are promising for microelectronic applications but suffer from high low-frequency dielectric loss primarily due to leakage currents across grain boundaries. This work demonstrates that Zr4+ doping at Ti-sites in (In0.5Nb0.5)0.05Ti0.95O2 effectively mitigates this issue. A series of (In0.5Nb0.5)0.05Ti0.95-xZrxO2 (x = 0–0.20) ceramics were synthesized via solid-state reaction. Zr4+ incorporation refines grain size from ∼56.1 μm (undoped) to ∼2.5 μm (x = 0.20) and promotes the precipitation of an insulating ZrTiO4 secondary phase at grain boundaries for compositions with x ≥ 0.10. These microstructural modifications synergistically enhance the grain boundary resistance, which peaks at 10.50 × 106 Ω·cm for the x = 0.10 composition, nearly an order of magnitude higher than the undoped ceramic. Consequently, the low-frequency dielectric loss is significantly reduced, with the x = 0.10 composition sintered at 1450 °C exhibiting a minimal loss tangent. Complex impedance analysis reveals the introduction of a new interfacial polarization associated with the ZrTiO4/INTO phase boundaries. XPS analysis confirms that Zr doping suppresses oxygen vacancy concentration without altering the Ti3+/Ti4+ ratio crucial for electron-pinned defect dipoles. The optimized composition (x = 0.10) also shows improved nonlinear coefficient (α = 2.8) and breakdown field (Eb = 530 V/cm), alongside stable low loss (tanδ < 0.05) over a broad temperature range at 1 kHz. This study presents a viable defect-engineering strategy utilizing Zr4+ doping to achieve low-loss colossal permittivity in (In,Nb) codoped TiO2-based ceramics for practical applications.
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高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yang Yu,Yu Zhao,Tian-Dong Zhang,Rui-Xuan Song,Yu-Lei Zhang,Yu-Long Qiao,Wei-Li Li,Wei-Dong Fei
Colossal dielectric properties in donor-acceptor co-doped rutile TiO 2 ceramics have attracted increased interest in recent years. However, dielectric loss (tan δ) of (Nb+Al) co-doped TiO 2 ceramics are quite scattered in the previous studies. Here, we show the dielectric properties of (Nb+Al) co-doped rutile TiO 2 ceramics are sensitive to sintering and ageing technologies, which is related to the coupling behavior of acceptor-donor ions. Both permittivity and dielectric loss of as-sintered (Nb+Al) co-doped TiO 2 ceramics are very large, and increase with the sintering time increasing. After ageing treatment at 900 °C, the dielectric loss of co-doped ceramics reduces from 139 to 0.15 in a wide frequency range. Based on the X-ray diffraction and complex impedance analyses, it can conclude that Nb 5+ -Al 3+ pair formation during ageing treatment reduces the concentration of oxygen vacancy , resulting in the decreases of the conductivity and dielectric loss. The changes in dielectric response of (Nb+Al) co-doped TiO 2 ceramics clearly suggest that ageing process is an effective way for the Nb 5+ and Al 3+ ions to form the Nb 5+ -Al 3+ pairs. We believe that the coupling effect of donor-acceptor ions is a practical and feasible route to reduce the dielectric loss of (Nb+Al) co-doped TiO 2 ceramics for high-energy-density storage applications.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
Small Methods
·
2023
·Vol. 7
·期 8
·2300054
·
IF 12.4
Lu Chen,Youbing Li,Kun Liang,Ke Chen,Mian Li,Shiyu Du,Zhifang Chai,Michael Naguib,Qing Huang
Two-dimensional (2D) transition metal carbides and/or nitrides, MXenes, are prepared by selective etching of the A-site atomically thin metal layers from their MAX phase precursors. High entropy MXenes, the most recent subfamily of MXenes, are in their infancy and have attracted great interest recently. They are currently synthesized mainly through wet chemical etching of Al-containing MAX phases, while various MAX phases with A-sites elements other than Al have not been explored. It is important to embody non-Al MAX phases as precursors for the high entropy MXenes synthesis to allow for new compositions. In this work, it is reported on the design and synthesis of Ga-containing medium/high entropy MAX phases and then their corresponding medium/high entropy MXenes. Gallium atomic layer etching is carried out using a Lewis acid molten salt (CuCl2). The as-prepared (Ti 1/4 V 1/4 Nb 1/4 Ta 1/4 ) 2 CT x exhibits a Li + specific capacity of ≈400 mAh g −1 . For (Ti 1/5 V 1/5 Nb 1/5 Ta 1/5 Mo 1/5 ) 2 CT x a specific capacity of 302 mAh g −1 is achieved after 300 cycles, and high cycling stability is observed at high current densities. This work is of great significance for expanding the family members of MXenes with tunable chemistries and structures.
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PubMed
高影响因子
Processes
·
2021
·Vol. 9
·期 9
·1487
·
IF 2.847
Muhammad Faizan,Kifayat Ullah Khan Niazi,Hasnain Nawaz,Niaz Muhammad,Hao Li,Fei Dai,Ruirui Zhang,Ruixia Liu,Suojiang Zhang
In recent work, deep eutectic solvents (DESs) as ionic liquid analogues have been abundantly used in catalysis. Herein, vanadium phosphorus oxide (VPO) catalysts were synthesized from mono-, bi-, and tri- metallic DES of Nb, Zr, and Mo metal dopants as structure-directing agents and electronic promoters for n-butane selective oxidation towards maleic anhydride. Higher MA selectivity and larger n-butane conversion was successfully obtained using the newly developed catalysts, while oxidation by-product COx(CO, CO2) was minimized. Characterization techniques including FTIR, DSC, XRD, TEM, SEM, EDS, Raman spectroscopy, TGA, XPS, and NH3-TPD were employed to fully characterize the DESs, precursors and catalysts. This work led to an increase of 7.8% in MA mass yield with 16% more n-butane conversion as compared to an unpromoted VPO catalyst. Moreover, the utilization of a low-carbon alkane brought in a green impact on the chemical plant as well as the environment.Keywords:deep eutectic solvent;vanadium phosphorus oxide;n-butane selective oxidation;structure directing agent;electronic promoter
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Ting Wang,S.-H. Song,Qing Ma,M.-L. Tan,J.-J. Chen
Multiferroic BiFeO 3 and Bi 1- x Sm x Fe 0.95 Nb 0.05 O 3 ceramics are successfully fabricated by spark plasma sintering combined with sol-gel powders. The effects of Sm and Nb co-doping on the structural, dielectric, ferroelectric and magnetic properties of the samples are investigated. With the Sm-Nb co-doping, the crystal structure of as-prepared samples transforms from R 3 c to Pnma and the grain size, loss tangent and leakage current density are reduced. The leakage current density of the co-doped samples can be reduced by approximately three orders of magnitude compared with the undoped sample. The dielectric, ferroelectric and magnetic properties are apparently enhanced due to the Sm-Nb co-doping. The optimal values of remanent polarization ( P r ) and magnetization ( M r ) of the created Bi 0.85 Sm 0.15 Fe 0.95 Nb 0.05 O 3 ceramic are approaching up to 5.853 μC/cm 2 and 0.187 emu/g, respectively. This enhancement of the multiferroic properties could be attributed to the co-doping-induced structural distortion, grain size reduction, oxygen vacancy decrease, space-modulated spin structure collapse as well as increased magnetic ions.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
ACTA MATERIALIA
·
2026
·
IF 9.3
Sai Liu,Xiaopeng Hu,Guangsheng Chen,Shenxiang Luo,Yu Zou,Jinwei Guo,Wang Zhu
Despite their promise as candidates for thermal barrier coatings (TBCs), the engineering application of A 6 B 2 O 17 ( A = Hf, Zr; B = Ta, Nb) ceramics is currently limited by a lack of comprehensive understanding regarding their CMAS corrosion behavior and underlying mechanisms. This paper addresses this gap by elucidating the governing effects of compositional modulation and corrosion conditions on the CMAS corrosion performance of these ceramics, integrating experimental and first-principles theoretical approaches. The results demonstrate that while all compositions exhibit similar corrosion products and resistance mechanisms, A 6 Ta 2 O 17 (particularly Hf 6 Ta 2 O 17 ) displays superior corrosion resistance. This enhanced performance is attributed to a combination of factors, including its exceptional thermodynamic stability, reduced Ca 2+ diffusivity, the significant barrier effect of its dense corrosion product layer, and stronger interfacial bonding strength. Corrosion-induced spallation in Zr 6 B 2 O 17 primarily stems from two factors: the phase transformation of ZrO 2 and an inherently weak interfacial bonding strength. Moreover, while an elevated Ca/Si ratio increases the aggressiveness of CMAS melts, the formation of a dense corrosion product layer on the ceramic surface effectively mitigates this detrimental effect.
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高影响因子
危险品化学品经营许可证（带存储）