CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Renjie Li,Yiran Pu,Jian Xu,Qingfeng Fu,Guisheng Liang,Xiangzhen Zhu,Lijie Luo,Yongjun Chen,Chunfu Lin
To meet the demand of high power and energy densities of Li-ion batteries, M-Nb-O compounds are of significance due to not only the intercalation pseudocapacitance but also the high theoretical capacities and excellent cycling stability. However, the exploration of M-Nb-O is very limited. Herein, we firstly report GaNb 49 O 124 as a novel intercalation-type M-Nb-O anode material . GaNb 49 O 124 microspheres (GaNbO-S) with an average diameter of ∼2 μm are fabricated through a hydrothermal method . Benefiting from the nanosized architecture, GaNbO-S delivers superior electrochemical performance in Li-ion batteries. A large reversible specific capacity of 294 mAh g −1 is obtained at 50 mA g −1 , while 205 mAh g −1 is reached at 4000 mA g −1 . Furthermore, GaNbO-S delivers long-term cycling life with a 72.0% capacity retention over 1800 cycles at 2000 mA g −1 . Thus, GaNb 49 O 124 microspheres could be developed as an efficient anode material for Li-ion batteries.
研究领域:
材料科学
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电化学
·
能源存储
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DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 39
·22559-22566
·
IF 3.049
Hao Chen,Changteng Zhang,Ya Pang,Qianhong Shen,Yang Yu,Yuxuan Su,Jiabang Wang,Fang Zhang,Hui Yang
Novel Nb-doped Bi2WO6 nanosheets have been successfully synthesized by a simple hydrothermal method. XRD, Raman spectra, XPS and SEM were adopted to analyze the structure and morphology of the samples, then the structure-dependent optical properties, photoelectric behavior and photocatalytic activities were investigated, and the structure–property relationship was also discussed. The results show that doping Nb5+ can increase the oxygen vacancies in the Bi2WO6 lattice and reduce the optical band gap of Bi2WO6. The oxygen vacancies also act as electron traps, which promote the separation of photogenerated carriers. Hence, compared with the pure Bi2WO6, the as-prepared Nb-doped Bi2WO6 nanosheets exhibit enhanced visible-light photocatalytic activity for removing contaminants in water such as rhodamine B and tetracycline.
研究领域:
材料科学
·
环境科学
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DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 105
·期 3
·2020-2028
·
IF 3.784
Yuanyuan Wang,Hongbo Liu,Tingnan Yan,Jianwei Zhao,Shifeng Guo,Rong Sun,Zhilun Lu,Dawei Wang
In this work, Nb-doped 0.75SrTiO 3 -0.25BiFeO 3 (ST-BF) lead-free ceramics are designed and synthesized using a conventional solid-state reaction method. The influence of Nb doping on the microstructure, dielectric, and electrical properties are systematically investigated. With the increase of Nb concentration, the crystal structure of ST-BF remains pseudo-cubic as exhibited in the X-ray diffraction patterns. The grain size is found to increase from 0.33 to 6.23 μm, and then decrease to 1.88 μm by Nb doping, along with a clear heterogeneous core–shell microstructure. A relatively low dielectric loss (∼0.1, at 1 kHz) and a stable dielectric constant (∼700, at 1 kHz) are obtained for the 0.03 Nb-doped ST-BF composition at room temperature. Impedance spectroscopy analysis shows that Nb doping in ST-BF increases the total resistivity, forming an electrically conductive core and a nonconductive shell, with enhanced activation energy. The results may provide a feasible approach to develop novel ST-based lead-free dielectric ceramics for capacitor applications.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2026
·Vol. 47
·期 1
·118781
·
IF 6.3
Leichao Cao,Yizhou Xiao,Yutang Liu,Chunchun Li,Guangzu Zhang,Fei Li
In this study, a compositional optimization strategy was formulated within the 85BaTiO 3 -15Na 0.5 Bi 0.5 TiO 3 (85BT-15NBT) system to attain X9R-type stability while maintaining a comparatively high dielectric response. Nb/Y co-doping was introduced to adjust the phase structure and dielectric behavior of the parent 85BT-15NBT. Rietveld refinement revealed a structural evolution from a tetragonal P 4 mm symmetry to pseudocubic Pm 3 ˉ m symmetry. X9R requirement, with a room-temperature permittivity of 1496 and a dielectric loss of 1.82%, was achieved. CaZrO 3 modification increased the relative permittivity to 1679 along with a dielectric loss of 1.50% without compromising the temperature stability. High-temperature impedance and Arrhenius analyses revealed improved high-temperature insulation and CZ-induced changes in the local defect and chemical environment. These findings illustrate that compositional optimization is effective for designing lead-free X9R dielectric ceramics for high-temperature MLCC applications.
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2026
·
IF 9.2
Yuqin Zheng,Haoyuan Zheng,Jiangping Tu,Xin Zhang,Lingchao Zhang,Changdong Gu
Magnesium hydride (MgH 2 ) for hydrogen storage suffers from high thermodynamic stability and slow kinetics. Vacancy engineering has emerged as an effective strategy to improve its performance. Herein, vanadium-deficient VSe 2 nanoflowers assembled from nanosheets were fabricated via Nb doping, which introduced cation vacancies acting as efficient catalysts for MgH 2 . MgH 2 +10 wt% Nb-doped VSe 2 exhibits greatly enhanced kinetics compared with pure MgH 2 and undoped VSe 2 -added MgH 2 . At 275 °C, it releases ∼6.11 wt% H 2 within 300 s and retains 5.66 wt% after 60 cycles. The improved performance stems from three synergistic effects: electron-rich interfaces boosting H 2 dissociation, multivalent V 4+ /Nb 5+ accelerating electron transfer, and active phases (V, MgSe) providing more active sites and diffusion pathways. This study offers a valuable defect-engineering route for high-performance hydrogen storage catalysts.
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高影响因子
Journal of Energy Storage
·
2026
·
IF 10.7
Jia Lin,Zhiju Cai,Laiwen Hu,Hongwei Huang,Jiawen Luo,Hongwei Li,Jianping Long,Genpin Lv,Wei Xiang
Lithium manganese iron phosphate (LiMn x Fe 1- x PO 4 , 0 < x < 1) is regarded as an upgraded cathode material compared to lithium iron phosphate (LiFePO 4 ), owing to its higher voltage plateau and superior energy density. However, its commercial application has been hindered by inherent poor electronic conductivity, abysmal Jahn–Teller effect and manganese dissolution associated with the Mn 3+ , which simultaneously degrades the rate capability and cycling performance. In this study, a dual-doping modification strategy based on a co-precipitation and high-temperature solid-state reaction method is proposed, successfully yielding magnesium and niobium dual-doped LiMn 0.7 Fe 0.3 PO 4 /C composites. The results demonstrate that an appropriate amount of Mg and Nb dual-doping can effectively enhance the electronic/ionic conductivity, improve structural stability, and accelerate lithium-ion migration kinetics of the manganese-enriched lithium manganese iron phosphate. The as-prepared LMFP-Mg2Nb2 sample exhibits optimal rate performance and cycling stability. It maintains a reversible capacity of 145.27 mAh g −1 even at a high current rate of 4C. Furthermore, after 100 cycles at 1C, it demonstrates an excellent discharge capacity of 149.97 mAh g −1 with a high-capacity retention of 98.29%. The synthetic strategy by co-precipitation and solid-state method involved in this work is analogous to the mainstream commercial technical approach for LiFePO 4 -based cathode material and compatibility with commercial LiFePO 4 -production equipment, thereby laying a significant foundation for the industrial application of high-energy-density lithium manganese iron phosphate.
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高影响因子
Microsystems & Nanoengineering
·
2024
·Vol. 10
·期 1
·1-10
·
IF 7.3
Guan Kejie,Li Yinxiao,Liu Lin,Sun Fuqin,Wang Yingyi,Zheng Zhuo,Zhou Weifan,Zhang Cheng,Cai Zhengyang,Wang Xiaowei,Feng Simin,Zhang Ting
Owing to the controllable growth and large-area synthesis for high-density integration, interest in employing atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDCs) for synaptic transistors is increasing. In particular, substitutional doping of 2D materials allows flexible modulation of material physical properties, facilitating precise control in defect engineering for eventual synaptic plasticity. In this study, to increase the switch ratio of synaptic transistors, we selectively performed experiments on WS 2 and introduced niobium (Nb) atoms to serve as the channel material. The Nb atoms were substitutionally doped at the W sites, forming a uniform distribution across the entire flakes. The synaptic transistor devices exhibited an improved switch ratio of 10 3 , 100 times larger than that of devices prepared with undoped WS 2 . The Nb atoms in WS 2 play crucial roles in trapping and detrapping electrons. The modulation of channel conductivity achieved through the gate effectively simulates synaptic potentiation, inhibition, and repetitive learning processes. The Nb-WS 2 synaptic transistor achieves 92.30% recognition accuracy on the Modified National Institute of Standards and Technology (MNIST) handwritten digit dataset after 125 training iterations. This study’s contribution extends to a pragmatic and accessible atomic doping methodology, elucidating the strategies underlying doping techniques for channel materials in synaptic transistors.
研究领域:
材料科学
·
神经网络
·
电子工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Yang Ren,Tong Fang,Haiyan He,Yajuan Hu,Yonggui Shi,Jiqiang Jia,Gaoyang Zhao
Herein, microfabrication of a novel Nb-doped titanium dioxide (TNO) transparent conductive film is proposed using a photosensitive sol-gel method. The method employs a chemical modifier to coordinate Ti 4+ in sol, followed by gel film preparation. The obtained Ti-coordinated chelate has a characteristic absorption peak at ca. 360 nm, which disappears after sufficient exposure to UV radiation. This feature is much similar to that of photoresist. Upon irradiated by UV light through a mask, the film can be dissolved in ethanol in order to obtain a fine-patterned surface. Finally, after annealing treatment at 450 °C Nb 5+ -doped TiO 2 fine-patterned transparent conducting film is obtained. This photochemical lithographic technique integrates photochemical etching and filming process into one step, whilst effectively avoiding damage caused by conventional lithographic techniques (such as dry etching and wet etching) on the photoelectric properties of TNO film. Our methodology eliminates the need for photoresist, creating a simple process that is expected to be performed on large film area.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2021
·
IF 4.076
Lei Wang,Xudong Liu,Xiaoguo Bi,Zhixin Ma,Jinsheng Li,Xudong Sun
(Ln + Nb) co-doped TiO2 polycrystalline ceramics possess remarkable dielectric behaviors, but their origin is still not fully understood. Compared to ceramic materials, a single crystal could keep most of the original material’s properties and eliminate interference due to grain boundaries and pores, thereby useful for exploring the origin of the material’s properties. Here, Ga3+ with a radius close to that of the Ti4+ ion was selected as an acceptor ion to study the properties. To this end, rutile single crystals and (Nb + Ga) co-doped rutile single crystals were prepared by the Verneuil method. The permittivity of the doped single crystal at frequencies from 20 Hz to 2 MHz was found to be greater than 15,000, and the dielectric loss was kept below 0.08. The latter value was much smaller than the reported values of rutile single crystal samples. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy indicated significantly enhanced dielectric properties, mainly attributed to the highly localized electron-pinned defect dipoles rather than the surface barrier layer capacitor effect. The electrons tightly bounded by the local electric dipole defect clusters can only range over a very small distance, which made the doped crystal have a large dielectric constant over a wide frequency range and maintain a low dielectric loss. In sum, the use of single crystals as a research object greatly provided insights into the origin and optimization of giant dielectric properties of TiO2-based materials.
研究领域:
材料科学
·
介电与电磁材料
·
固态物理
·
晶体生长
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高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2023
·Vol. 37
·期 6
·1180-1184
·
IF 1.6
Song Xuyan,He Yunlu,Peng Sanwen,Wang Bo,Dong Ping,Tang Haolin,Yu Jun
We reported sol-gel-derived Nb-doped SnO 2 which is an effective catalyst carrier for deposition of IrO 2 , and the electrocatalytic activity of the synthesized catalysts for OER was investigated. It is found that the doping of Nb can refine the SnO 2 crystal grains and improve the electrical conductivity of SnO 2 . When the doping amount of Nb is 7%, the electrical conductivity of Nb-SnO 2 reaches a maximum value of 3.54 S/cm. With the increase in the loading amount of IrO 2 , the electrocatalytic activity towards OER of the thus-synthesized catalysts is improved, reaching a comparable OER activity with pristine IrO 2 with the loading content of about 44wt%.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Dan Xu,Wenjie Zhao,Wenping Cao,Weili Li,Weidong Fei
The lead-free BiFe 1- x (Li 0·5 Nb 0.5 ) x O 3 ceramics with x = 0.00, 0.01, 0.02, 0.04, 0.06, and 0.08 were modified by Li/Nb co-doping. X-ray diffraction measurements indicated that all the ceramics had a rhombohedral distorted perovskite structure and secondary phases appeared when x = 0.00, 0.04, and 0.06. The BiFeO 3 ceramics with a small amount of Li/Nb co-doping exhibited improvements in the remnant polarization (2 P r ) and ferroelectric P - E loop shape compared with the results of pure BiFeO 3 (BFO). The decreased dielectric loss and leakage current indicated that proper Li/Nb co-doping for the Fe-site in BFO was a promising route to improve the leakage behavior and enhance the resistivity. These improved electrical properties were related to the reduction of oxygen vacancies and suppression of the formation of Fe 2+ . The leakage mechanism was also discussed and analyzed.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Qiang Gao,Xiaomei Wu,Xiangsheng Ma
Series of novel energy-saving window coatings based on F–Nb–TiO 2 /SiO 2 nanocomposites with superhydrophobic self-cleaning performance were successfully prepared. Surface modification of F–Nb–TiO 2 and SiO 2 nanoparticles by aminopropyl triethoxy silane and perfluorooctyltriethoxysilane produced hydrophobic powders. With the help of the hierarchical structures of F–Nb–TiO 2 /SiO 2 nanocomposites, superhydrophobic surfaces were obtained. The water contact angle of the composite coatings reached 155.6°. The prepared superhydrophobic coatings shown superior anti-fouling property and good mechanical performance. Furthermore, the composite coating can shield most of solar radiation. The composite coating lowed the air temperature of the simulate house by 11 °C in the outdoor thermal experiments. The integration of good solar filtration and exceptional anti-fouling performance makes F–Nb–TiO 2 /SiO 2 coatings suitable candidates for energy-saving window coatings.
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高影响因子
危险品化学品经营许可证（带存储）