ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yaoyu Ren,Yang Shen,Yuanhua Lin,Ce-Wen Nan
Al-contained Li7–xLa3Zr2–xTaxO12 (xTa-LLZO) powder was synthesized via solid-state reaction, where increasing the Ta doping level was found to reduce the average particle size and facilitate a higher relative density in the sintered pellet. 0.8Ta-LLZO pellets sintered at 1150 °C achieved a relative density of 96.2 ± 0.2% and survived the Li striping/plating test under a unidirectional current polarization of 0.5 mA/cm2 for more than 8 h without short-circuiting. In contrast, other xTa-LLZO sintered pellets with lower Ta doping levels were short-circuited by lithium dendrites after polarization for much shorter time periods. The microstructure of the sintered body played a more essential role in lithium dendrite prevention compared to relative density alone. By characterizing the microstructure of xTa-LLZO sintered pellets, we proposed a formation mechanism of the pathways for lithium dendrite growth.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Crystals
·
2018
·Vol. 8
·期 3
·113
·
IF 2.144
Hui Wang,Qin Li,Chaoyue Wang,Huan He,Jianding Yu,Jiayue Xu
High-quality Ta-doped La2Ti2O7(Ta-LTO) single crystal of about 40 mm in length and 5 mm in diameter was successfully prepared by the optical floating zone method. An X-ray rocking curve reveals that the crystal of LTO has excellent crystalline quality. As-grown crystals were transparent after annealing in air and the transmittance is up to 76% in the visible and near-infrared region. X-ray diffraction showed that this compound possessed a monoclinic structure with P21space group. The dielectric properties were investigated as functions of temperature (0~300 °C) and frequency (102Hz~105Hz). Dielectric spectra indicated an increase in the room-temperature dielectric constant accompanied by a drop in the loss tangent as a result of the Ta doping. One relaxation was observed in the spectra of electric modulus, which was ascribed to be related to the oxygen vacancy. The dielectric relaxation with activation energy of 1.16 eV is found to be the polaron hopping caused by the oxygen vacancies.Keywords:Ta-LTO single crystal;floating zone method;dielectric properties;oxygen vacancy
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 12
·983
·
IF 3.504
Shiman He,Yuying Meng,Yangfei Cao,Senchuan Huang,Jingling Yang,Shengfu Tong,Mingmei Wu
TiO2is one of the most attractive semiconductors for use as a photoanode for photoelectrochemical (PEC) water oxidation. However, the large-scale application of TiO2photoanodes is restricted due to a short hole diffusion length and low electron mobility, which can be addressed by metal doping and surface decorating. In this paper we report the successful synthesis of hierarchical Ta doped TiO2nanorod arrays, with nanoparticles on the top (Ta:TiO2), on F-doped tin oxide (FTO) glass by a hydrothermal method, and its application as photoanodes for photoelectrochemical water oxidation. It has been found that the incorporation of Ta5+in the TiO2lattice can decrease the diameter of surface TiO2nanoparticles. Ta:TiO2-140, obtained with a moderate Ta concentration, yields a photocurrent of ∼1.36 mA cm−2at 1.23 V vs. a reversible hydrogen electrode (RHE) under FTO side illumination. The large photocurrent is attributed to the large interface area of the surface TiO2nanoparticles and the good electron conductivity due to Ta doping. Besides, the electron trap-free model illustrates that Ta:TiO2affords higher transport speed and lower electron resistance when under FTO side illumination.Keywords:hierarchical TiO2;Ta doping;charge separation;photoelectrochemical water oxidation
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2015
·
IF 0
Gang Chen,Chun Wei Gong,Chun Lin Fu,Xiao Dong Peng,Wei Cai,Rong Li Gao,Xiao Ling Deng
(Sr1-xBax) 2(Nb0.9Ta0.1) 2O7 (SBNT) ceramics were prepared by solid state reaction. The crystal structure of SBNT ceramics, surface morphology and dielectric properties were studied using XRD, SEM and LCR instrument analyzer, respectively. The results show that the grain size decreases with increasing Ba concentration, and all samples show single phase, no second phase can been observed. Addition of Ba ion can improve the dielectric properties of SBN ceramics. The dielectric constant increases first, then decreases; the maximum value (εr=97) can be obtained at x=0.1, the dielectric constant changes slightly with increasing wide frequency.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
FERROELECTRICS
·
2014
·
IF 0.433
Lian Xiang,Gang Chen,Chunlin Fu,Wei Cai,Wei Wang,Kaihua Liu
Sr2(TaxNb1-x)2O7 (x = 0.0, 0.1, 0.2, 0.4) (STNO) ceramics were prepared by the conventional solid-state reaction method. The microstructure, dielectric and ferroelectric properties of the samples were investigated. The results show single phase STNO with perovskite-like layered structure and that Ta5+ ion can diffuses into the crystal lattice. The addition of Ta5+ dopant decreases the grain size of the material. The dielectric constant increases with increased x, and the sample with x = 0.2 exhibits enhanced dielectric properties (ϵr ≈ 56, tanδ ≈ 0.01%). The remnant polarization (2Pr) and coercive electric field (2EC) of STNO ceramics increase with increasing Ta content, and reach the maximum value (2Pr = 0.11μC/cm2 and 2EC = 5.75 kV/cm) at x = 0.4. Our results indicate that Ta doping can effectively improve the dielectric and ferroelectric properties of Sr2Nb2O7 ceramics.
研究领域:
材料科学
·
电子材料
✓ 已验证
DOI
高影响因子
IONICS
·
2025
·
IF 2.6
Yang Yue,Zhang Zheng,Ma Tianhui,Jia Shaoting,Huang Chao
To achieve high density and high Li-ion conductivity in the garnet LLZO (Li 7 La 3 Zr 2 O 12 ), an effective strategy is to dope it with high-valence elements to stabilize the cubic phase and to lower the sintering temperature. As well known, flash sintering (FS) is characterized by short sintering times and low furnace temperature. Herein, the doping modification of Ta-LLZO by flash sintering at 700 °C for the higher conductivity of LLZO was investigated in the present study. The results indicate that the addition of an appropriate amount of Ta 5+ can enhance the ionic conductivity. The relative density of the sintered cubic Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 is 94.72%, with a corresponding total ion conductivity of 9.8 × 10 –4 S cm −1 , demonstrating good electrical performance. A solid-state lithium metal battery with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 electrolyte was assembled, and its electrical performance was tested at 50 °C. The results showed that an initial discharge specific capacity of 126.5 mAh g −1 at a 0.1C rate could be reached.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 28
·期 4
·3768-3773
·
IF 1.798
Shen Zhengbo,Wang Xiaohui,Li Longtu
Ta-doped 0.90BaTiO 3 –0.10(Bi 0.5 Na 0.5 )TiO 3 ceramics were successfully prepared by conventional solid-state reaction method and studied to satisfy super-broad temperature stability. The effects of Ta 2 O 5 doping on the dielectric properties and microstructures were thoroughly investigated. Ta plays an important role in the formation of core–shell structure because of chemical inhomogeneity, which gives rise to the weak temperature dependence of dielectric properties. The samples with the additon of 1.5 mol% Ta 2 O 5 satisfy the X9R specification, exhibiting an optimum dielectric behavior of ε
r
~ 2100, tanδ ~ 1.6% at room temperature, which is a promising candidate material for X9R MLCC applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Sanjiang Pan,Zishuo Xie,Hang Li,Shenao Wang,Yang Fu,Desong Wang
Considering the regional distribution of freshwater resources, acquiring hydrogen by seawater electrolysis has lower cost and feasibility. NiCoFe-based materials have been widely studied due to their excellent catalytic oxidation performance in freshwater. However, the large amount of chloride ions in seawater will severely erode the catalytic site and greatly reduce the catalyst's lifetime. In this paper, a two-dimensional nanosheet quaternary metal hydroxide electrode composed of Ni, Co, Fe, and Ta elements was synthesized via a facile one-step hydrothermal method for efficient oxygen evolution reaction (OER) in seawater electrolysis. Structural characterization and in-situ test revealed that the incorporation of Ta not only optimized the electronic structure of the catalyst but also accelerated the formation of the γ-NiOOH phase, making the active phase is protected from being attacked by Cl - ions during the formation process, enhancing its OER activity while achieving extended durability. The catalyst was operated at an ampere-level of 1 A cm -2 for over one month (800 h), and no significant degradation was observed. This work provides a promising strategy for developing cost-effective, efficient, and stable catalysts for challenging applications in seawater electrolysis.
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 Physical Chemistry C
·
2025
·
IF 3.2
Xiaoyu Shen,Zhaozhu Qu,Shuai Ding,Congkai Guo,Yao Liu,Xiaoyu Yao,Wenjuan Xia,Guohua Wu,Yaohong Zhang
Tungsten oxide (WO3), as a typical electrochromic material, is well-known for its high coloration efficiency, wide optical modulation range, and excellent cyclic stability. In this study, tantalum (Ta)-doped WO3 films were fabricated by using the sol–gel method. The effects of Ta doping on the morphology and oxygen vacancy concentration of WO3 films were systematically investigated, along with how these factors influence their electrochromic performance. The results demonstrate that Ta doping significantly enhances the optical modulation (82.9% at 750 nm), accelerates the response time (5.0 s for coloring and 4.5 s for bleaching), and improves the optical reversibility of WO3 films compared to undoped WO3 films. Remarkably, the Ta-doped WO3 films exhibit substantial optical modulation in both the visible and the near-infrared regions, achieving outstanding dual-band electrochromism.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Hui Ye,Yixuan Feng,Pengkai Shan,Bin Qian,Lin Ge,Han Chen,Yifeng Zheng
Reversible solid oxide cells (RSOCs) have attracted considerable interest due to their efficient energy conversion. However, the low catalytic activity of air electrodes limits the application of RSOCs. Bi 0.5 Sr 0.5 Fe 0.9 Ta 0.1 O 3-δ developed in our previous work exhibits a comparatively desirable performance and is expected to be further optimized. Herein, a novel strategy of anionic F and cationic Ta co-doped Bi 0.5 Sr 0.5 Fe 0.9 Ta 0.1 O 3-δ-x F x (x = 0, 0.05, 0.10, 0.15, denoted as, BSFTF0, BSFTF5, BSFTF10, BSFTF15) materials are obtained to enhance the oxygen transport property of Bi 0.5 Sr 0.5 FeO 3-δ for RSOCs. The polarization resistance (Rp) of BSFTF10 (0.017 Ω cm 2 ) decreases by 66 % compared with that of BSFTF0 (0.051 Ω cm 2 ) at 800 °C. In fuel cell mode, the single cell with BSTF10 reaches the maximum power density of 908 mW cm −2 , which is approximately 72 % higher than the only Ta-doped BSFTF0 (527 mW cm −2 ) at 800 °C. In electrolysis mode, the single cell with BSFTF10 exhibits a high electrolysis current density of 1679 mA cm −2 , indicating an approximately 90 % increase compared to that of BSFTF0 at 800 °C and 1.5 V with 70 % CO 2 -30 % CO feed gas. The bulk chemical diffusion (D chem ) of BSFTF10 is up to 5.12 × 10 −4 cm 2 s −1 , which is 4.3 times higher than that of BSFTF0. The superior oxygen transport property of BSFTF10 is attributed to the high electronegativity of F − (4.0) and low electronegativity of Ta 5+ (1.8), which may weaken the chemical bonding between B-site ions and O 2− , generating more oxygen vacancies and accelerating the rate of oxygen transfer. The results indicate that F and Ta co-doping is an effective strategy to develop a highly catalytically active air electrode for RSOCs featuring oxygen transport properties.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 9
·1-10
·
IF 2.8
Dong Shijun,Li Runqiu,Wu Junpeng,Zhong Wenxia,Zhao Ye,Ji Xinran,Zheng Hui,Zheng Peng,He Hong,Zheng Liang
With the development of 5G electronic products, solving electromagnetic pollution becomes an urgent issue for human health. In this work, the electromagnetic performance of W-type hexagonal barium ferrite (BaZn 2 Fe 16−x Ta x O 27 ) was improved by doping with high-valence Tantalum (Ta 5+ ) ions. The dependence of the concentrations of Ta 5+ ions on the microstructure, crystal structure and electromagnetic properties was studied in detail. Structural characterizations confirm that the doping Ta 5+ prefers the 4f2 site, increasing the lattice values and grain size, promoting more Fe 3+ translation into Fe 2+ , which effectively improves the electromagnetic properties including saturation magnetization, complex permittivity and permeability. However, some Ta 2 O 5 was also formed at the doping concentration of x = 0.2 which deteriorates the electromagnetic properties. The BaZn 2 Fe 16−x Ta x O 27 ferrite at x = 0.15 obtains the highest value of saturation magnetization of 92 emu/g, the highest intensity of complex permittivity and permeability, showing a potential application in absorbing material.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Tianhang Zhang,Timothy Daniel Christopher,Saifang Huang,Yan’gai Liu,Wei Gao,Tilo Sӧhnel,Peng Cao
In this work, pressureless sintering (PLS) method was used to prepare Li 7 La 3 Zr 2 O 12 based Al-free garnet electrolytes with the substitution of tantalum (Ta). A series of Ta-doped lithium garnets Li 7- x La 3 Zr 2- x Ta x O 12 (LLZTO, x = 0, 0.25, 0.5, 0.75 and 1.0) were prepared, and the effect of Ta on the structure, densification and ionic conductivity was investigated. Both relative density and ionic conductivity of the LLZTO pellets are dependent on the content of Ta substitution, with the maximum values being reached at x = 0.5. We also studied the stability and degradation mechanism of lithium garnets (Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 ) in humid air with relative humidity of above 70%. It is revealed that after exposure in the humid air for 4 weeks, a layer of LiOH∙H 2 O was observed on the grain boundaries, which lowered its ionic conductivity considerably. In comparison, the pellet stored in a desiccator had clear surface with negligible change in the ionic conductivity.
研究领域:
材料科学
·
能源存储与转换
✓ 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）