Additive Manufacturing
·
2023
·
IF 11
Shurui Li,Kai Zhang,Zhilong Yan,Tingting Liu,Zhiguang Zhu,Zhiwei Xiong,Zhiyong Zou,Jiansen Li,Wenhe Liao
The Ti 2 AlC MAX-phase ceramic matrix composites were successfully additively manufactured from the Ti, Al, Nb and C elemental powders via laser powder bed fusion (LPBF) plus pressureless sintering (PLS) process. The phase formation, microstructure evolution , and mechanical properties of the as-fabricated samples were systematically analyzed under different Nb contents and sintering temperatures . The Nb content and sintering temperatures can significantly affect the phase formation and microstructure of samples. In the LPBF stage, all the samples are composed of TiC, Ti 3 Al, and TiAl, while adding Nb into the Ti-Al-C system powders can promote Ti 2 AlC MAX-phase. Furthermore, doping of Nb induce the transformation from Ti 2 AlC to Ti 3 AlC during the subsequent PLS. With increasing the sintering temperature from 1200 °C to 1400 °C, the width of Ti 2 AlC lamellar structure increases from 0.36 µm to 1.58 µm. The compressive strength of the Ti 2 AlC MAX-phase ceramic samples ranges between 17.5 MPa and 30.3 MPa. The optimal compressive strength of Ti 2 AlC MAX-phase ceramic matrix ceramic composite (30.3 MPa) was achieved under optimized Nb content (1 wt%) and sintering temperature (1300 °C). This work could shed light on designing Ti 2 AlC MAX-phase ceramic from the microalloying perspective via LPBF and sintering.
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高影响因子
Coatings
·
2022
·Vol. 12
·期 8
·1111
·
IF 3.236
Angang Song,Yiwen Wang,Suxiang Liu,Qinpu Wang,Junhua Hu
In this study, remote plasma sputtering deposition of niobium-doped SnO2transparent conductive oxides on glass substrates was carried out at ambient temperature with no post-deposition annealing. The microstructure, optical, electrical, and surface morphology of the thin films were characterized using a combination of advanced techniques, such as X-ray diffraction (XRD), UV-Vis spectrophotometer, Hall-effect measurements, as well as field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. It was determined that the oxygen defects of the films have a substantial impact on their transparent conductivity. The crystalline films, which were crystallized by annealing at 450 °C, had higher resistivities due to a decreased concentration of oxygen vacancies, which restricted conduction. In comparison, the amorphous films exhibited remarkable conductivity. The best amorphous films (Nb:SnO2) exhibited a resistivity of less than 4.6 × 10−3Ω·cm, with a 3 × 1020cm−3carrier concentration and a 4.4 cm2/(V·S) of Hall mobility. X-ray amorphous Nb:SnO2films can be used to make conductive and transparent protective layers that can be used to shield semiconducting photoelectrodes used in solar water splitting. These layers can also be used with more conductive TCO films (ITO or AZO) when needed.
研究领域:
材料科学
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薄膜技术
·
半导体物理
·
表面化学
·
可再生能源材料
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Zhao Jiang,Taibo Liang,Yu Liu,Shengzhao Zhang,Zhongxu Li,Donghuang Wang,Xiuli Wang,Xinhui Xia,Changdong Gu,Jiangping Tu
It is still a big challenge to simultaneously enhance the ionic conductivity, dendrite suppression capability, and interfacial compatibility of sulfide solid electrolytes. In this work, a novel Li7P2.88Nb0.12S10.7O0.3 solid electrolyte is prepared via Nb and O cosubstitution of glass-ceramic Li7P3S11. This sulfide-based electrolyte possesses a high ionic conductivity (3.59 mS cm–1) at 298 K, improved critical current density (1.16 mA cm–2), and excellent interfacial compatibility between the sulfide electrolyte and Li2S active material. The improved electrochemical stability of the sulfide solid electrolyte against metallic lithium is attributed to the formation of Nb and Li2O at the interface, which can induce uniform Li deposition and prevent further side reaction. The all-solid-state Li/Li2S batteries based on this electrolyte exhibit remarkably enhanced cycling stability and rate performance.
研究领域:
材料科学
·
电化学
·
储能技术
·
固体离子学
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高影响因子
Advanced Science
·
2023
·Vol. 10
·期 10
·2206877
·
IF 15.1
Lu Chen,Youbing Li,Biao Zhao,Shanshan Liu,Huibin Zhang,Ke Chen,Mian Li,Shiyu Du,Faxian Xiu,Renchao Che,Zhifang Chai,Qing Huang
Electromagnetic (EM) wave pollution is harmful to human health and environment, thus it is absolutely important to develop new electromagnetic wave absorbing materials. MAX phases have been attracted more attention as a potential candidate for electromagnetic wave absorbing materials due to their high conductivity and nanolaminated structure. Herein, two new magnetic MAX phases with multiprincipal elements ((Ti 1/3 Nb 1/3 Ta 1/3 ) 2 FeC and (Ti 0.2 V 0.2 Nb 0.2 Ta 0.2 Zr 0.2 ) 2 FeC) in which Fe atoms replace Al atoms in the A sites are successfully synthesized by an isomorphous replacement reaction of multiprincipal (Ti 1/3 Nb 1/3 Ta 1/3 ) 2 AlC and (Ti 0.2 V 0.2 Nb 0.2 Ta 0.2 Zr 0.2 ) 2 AlC MAX phases with Lewis acid salt (FeCl 2 ). (Ti 1/3 Nb 1/3 Ta 1/3 ) 2 FeC and (Ti 0.2 V 0.2 Nb 0.2 Ta 0.2 Zr 0.2 ) 2 FeC exhibit ferromagnetic behavior, and the Curie temperature ( T c ) are 302 and 235 K, respectively. The dual electromagnetic absorption mechanisms that include dielectric and magnetic loss, which is realized in these multiprincipal MAX phases. The minimum reflection loss (RL) of (Ti 1/3 Nb 1/3 Ta 1/3 ) 2 FeC is −44.4 dB at 6.56 GHz with 3 mm thickness, and the effective bandwidth is 2.48 GHz. Additionally, the electromagnetic wave absorption properties of the magnetic MAX phases indicate that magnetic loss also plays an important role besides dielectric loss. This work shows a promising composition-design strategy to develop MAX phases with good EM wave absorption performance via simultaneously regulating dielectric and magnetic loss together.
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DOI
PubMed
高影响因子
Scientific Reports
·
2020
·Vol. 10
·期 1
·1-11
·
IF 3.998
Chen Minjian,Yang Jing,Li Lei,Hu Yanhui,Lu Xiaomei,Sun Rongli,Wang Yubang,Wang Xinru,Zhang Xiaoling
Recently, celastrol has shown great potential for inducing apoptosis in acute myeloid leukemia cells, especially acute promyelocytic leukaemia cells. However, the mechanism is poorly understood. Metabolomics provides an overall understanding of metabolic mechanisms to illustrate celastrol's mechanism of action. We treated both nude mice bearing HL-60 cell xenografts in vivo and HL-60 cells as well as NB-4 cells in vitro with celastrol. Ultra-performance liquid chromatography coupled with mass spectrometry was used for metabolomics analysis of HL-60 cells in vivo and for targeted L-cysteine analysis in HL-60 and NB-4 cells in vitro . Flow cytometric analysis was performed to assess mitochondrial membrane potential, reactive oxygen species and apoptosis. Western blotting was conducted to detect the p53, Bax, cleaved caspase 9 and cleaved caspase 3 proteins. Celastrol inhibited tumour growth, induced apoptosis, and upregulated pro-apoptotic proteins in the xenograft tumour mouse model. Metabolomics showed that cysteine metabolism was the key metabolic alteration after celastrol treatment in HL-60 cells in vivo . Celastrol decreased L-cysteine in HL-60 cells. Acetylcysteine supplementation reversed reactive oxygen species accumulation and apoptosis induced by celastrol and reversed the dramatic decrease in the mitochondrial membrane potential and upregulation of pro-apoptotic proteins in HL-60 cells. In NB-4 cells, celastrol decreased L-cysteine, and acetylcysteine reversed celastrol-induced reactive oxygen species accumulation and apoptosis. We are the first to identify the involvement of a cysteine metabolism/reactive oxygen species/p53/Bax/caspase 9/caspase 3 pathway in celastrol-triggered mitochondrial apoptosis in HL-60 and NB-4 cells, providing a novel underlying mechanism through which celastrol could be used to treat acute myeloid leukaemia, especially acute promyelocytic leukaemia.
研究领域:
肿瘤学
·
药理学
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代谢组学
·
细胞生物学
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DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Zhiwei Li,Zhengxiang Bian,Yurong Ren,Zhihui Chen,Jiujun Xu
(1-x)(0.9Ba 1.003 Ti 0.97 Ca 0.03 O 3 –0.1(Bi 0.51 Na 0.47 ) 0.94 Ba 0.06 TiO 3 )-xNa(Nb 0.85 Ta 0.15 )O 3 ( x = 0.03–0.15) ceramics were designed and fabricated through a bidirectional optimization strategy using traditional solid reaction method. The results revealed that the introduction of Na(Nb 0.85 Ta 0.15 )O 3 increased the vacancy concentration at the A site , conducing to improved polarization and reduced grain size. The substitution at the B site disrupted the long-range ordered ferroelectric domains and generated polar nanodomains, leading to enhanced relaxation behavior. The optimum energy storage density of 3.57 J/cm 3 and efficiency of 87.5% were simultaneously achieved under the electric field of 220 kV/cm in the sample with x = 0.09. Moreover, it also exhibits extremely high-power density (∼57 MW/cm 3 ), ultrafast discharge time (∼103 ns), high discharge density (1.35 J/cm 3 ), along with excellent temperature (30‒120 °C) and frequency stability (1‒100 Hz) under the equivalent electric field of 120 kV/cm. This novel design strategy provides theoretical guidance for the development of advanced electrical energy storage devices.
研究领域:
材料科学
·
能源存储
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高影响因子
RSC Advances
·
2016
·Vol. 6
·期 32
·27094-27101
·
IF 3.289
Xiao Yu,Ling Xin,Yong Liu,Wenxia Zhao,Baojun Li,Xiang Zhou,Hui Shen
One of the main drawbacks with applying the most promising electrode materials in lithium-ion batteries is their intrinsic poor electronic conductivity. Many approaches which include mixing them with good electrical conductors have been developed to solve this problem, yet they do not improve the lattice electronic conductivity within the crystal. Here we present a one-step hydrothermal route for fabricating the core–shell heterostructures through sequential growth of the core and shell materials. The cores are Nb-doped TiO2 rods with improved conductivity that can deliver high capacity, yet the Nb2O5 nanosheets shells can act as a protective layer to prevent electrode dissolution and maintain the electrode integrity over long term cycles and contribute additional lithium storage capacity. When employed as an anode material in lithium-ion batteries, it exhibits an outstanding cycle stability of 189 mA h g−1 at 170 mA g−1 for more than 700 cycles. This work provides an important strategy to improve the conductivity of the host and construct a protective layer by simply adding a guest ion in reaction.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机化学
·
固态化学
·
电池技术
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DOI
高影响因子
Journal of Energy Chemistry
·
2023
·
IF 13.1
Bayu Admasu Beshiwork,Xinyu Wan,Min Xu,Haoran Guo,Birkneh Sirak Teketel,Yu Chen,Jun Song Chen,Tingshuai Li,Enrico Traversa
The sluggish kinetics of the electrochemical oxygen reduction reaction (ORR) in intermediate-temperature solid oxide fuel cells (IT-SOFCs) greatly limits the overall cell performance. In this study, an efficient and durable cathode material for IT-SOFCs is designed based on density functional theory (DFT) calculations by co-doping with Nb and Ta the B-site of the SrFeO 3− δ perovskite oxide. The DFT calculations suggest that Nb/Ta co-doping can regulate the energy band of the parent SrFeO 3− δ and help electron transfer. In symmetrical cells, such cathode with a SrFe 0.8 Nb 0.1 Ta 0.1 O 3− δ (SFNT) detailed formula achieves a low cathode polarization resistance of 0.147 Ω cm 2 at 650 °C. Electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) analysis confirm that the co-doping of Nb/Ta in SrFeO 3− δ B-site increases the balanced concentration of oxygen vacancies, enhancing the electrochemical performance when compared to 20 mol% Nb single-doped perovskite oxide. The cathode button cell with Ni-SDC|SDC|SFNT configuration achieves an outstanding peak power density of 1.3 W cm −2 at 650 °C. Moreover, the button cell shows durability for 110 h under 0.65 V at 600 °C using wet H 2 as fuel.
研究领域:
材料科学
·
电化学
·
能源工程
·
无机非金属材料
·
催化化学
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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2026
·
IF 7.7
Shangpeng Pan,Kaiwen Yun,Rui Shan,Shuxiao Wang,Taoli Huhe,Xiang Ling,Haoran Yuan,Yong Chen
For the high-value resource recovery of waste epoxy resin, this study prepared Nb and Ga modified ZSM-5 zeolite catalysts and systematically evaluated their performance in the catalytic pyrolysis of epoxy resin for aromatic hydrocarbon production. The results indicate that the bimetallic catalyst 8Nb4Ga (with 8% Nb and 4% Ga loading) exhibited the optimal catalytic activity, achieving the highest aromatic hydrocarbon yield of 68.6% under the conditions of 650 °C and a feedstock-to-catalyst mass ratio of 1:1. Characterization analyses confirmed that the metal species were well-dispersed on the ZSM-5 support without destroying the zeolite framework structure, though they induced changes in the pore structure. The introduction of Ga contributed to the formation of more mesoporous structures. Kinetic analysis revealed that the 8Nb4Ga catalyst significantly increased the apparent activation energy of the pyrolysis process, indicating that it guides the reactants through a higher-energy-barrier yet more selective pathway for aromatic hydrocarbon formation. This research provides theoretical support for the targeted catalytic conversion of waste epoxy resins into high-value aromatics.
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高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2026
·
IF 5.7
Adila Abulimiti,Yudong Zhang,Yiyuan Hua,Yanjun Miu,Tong Zhou,Xuejing Zhang,Can Cui,Weiji Dai,Cuijiao Zhao,Saifang Huang
Mg/Zr/Nb tri-doping jointly stabilizes Ni-rich layered cathodes under harsh operating conditions. • Tri-doping reduces Li + /Ni 2+ mixing and stabilizes the transition-metal layer and oxygen framework. • MZN-NCM delivers excellent cycling stability at room temperature, high temperature, and high cutoff voltage. • Mg/Zr/Nb co-doping improves charge transfer and Li + diffusion, enhancing the durability of Ni-rich cathodes. Ni-rich layered cathode materials (LiNi x M 1-x O 2 , x ≥ 0.8) offer high capacity and high energy density, but their cycling stability severely suffers from Li + /Ni 2+ cation mixing, H2-H3 phase-transition strain, interfacial side reactions, and sluggish Li + transport, especially under harsh conditions such as elevated temperature and high cutoff voltage. In this work, a Mg/Zr/Nb tri-doping strategy is proposed to construct Li(Ni 0.9 Co 0.05 Mn 0.05 ) 0.97 Zr 0.01 Mg 0.01 Nb 0.01 O 2 (MZN-NCM) cathode for synergistic stabilization under different operating conditions. The results show that Mg/Zr/Nb co-doping regulates the Ni valence distribution, reduces Li + /Ni 2+ cation mixing, enhances the stability of the transition-metal layer and oxygen framework, and suppresses interfacial side reactions and CEI degradation during cycling. MZN-NCM retains 90.1% of its capacity after 100 cycles at 25 °C and 89.8% at 60 °C, compared with only 59.8% and 41.7% for Pristine-NCM, respectively. Under a high cutoff voltage of 4.5 V, MZN-NCM also maintains a higher capacity retention of 87.7% after 100 cycles. Moreover, kinetic and interfacial chemical analyses indicate that multielement doping improves both charge-transfer behavior and Li + diffusion, enabling a synergistic enhancement of structural stability, interfacial stability, and ion transport. This work demonstrates that Mg/Zr/Nb synergistic doping is an effective material-design strategy for extending the applicable operating conditions of Ni-rich cathodes.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Guowei Zhang,Zhanhui Peng,Xiaobin Zhou,Qingqing Li,Junjie Meng,Di Wu,Lingling Wei,Pengfei Liang,Zupei Yang,Xiaolian Chao
Oxygen vacancies in (Al x In 1- x ) 0.0025 Nb 0.0025 Ti 0.995 O 2 ceramics are regulated by tuning the Al 3+ /In 3+ acceptor ratio at a fixed Nb 5+ donor content. • The sample with x = 0.4 achieves optimal dielectric performance: ultrahigh permittivity 2 × 10 4 and low dielectric loss ~0.05 over broad frequency and temperature ranges. • Al 3+ enrichment contracts the rutile lattice, reduces oxygen vacancies, and modulates Ti 3+ states and local lattice distortion. • Impedance, modulus and Arrhenius analyses verify thermally activated Ti 3+ /Ti 4+ carrier hopping and oxygen vacancy related dielectric relaxation in the ceramics. • Oxygen-vacancy dipoles and IBLC/SBLC interfacial polarization synergistically yield colossal permittivity in grain/grain-boundary heterostructures. TiO 2 -based colossal permittivity ceramics show promising potential for energy storage applications and sensing due to their superior dielectric performance and tunable defect structures. (Al x In 1− x ) 0.0025 Nb 0.0025 Ti 0.995 O 2 ceramics were fabricated via a solid-state reaction method, aiming to tailor oxygen vacancy defects through acceptor-ion substitution. With increasing Al content, the E g Raman mode exhibits a pronounced shift, indicating significant modulation of local lattice distortion and oxygen-vacancy concentration. Remarkably, the composition with x = 0.4 an excellent balance between dielectric permittivity and loss, exhibiting a dielectric constant of ~ 2 × 10 4 and a low dielectric loss of ~0.05. Detailed impedance and modulus analyses reveal that the observed dielectric relaxation originates from thermally activated Ti 3+ /Ti 4+ hopping and oxygen vacancy related defect responses. Combined with the electrically heterogeneous microstructure consisting of semiconducting grains and insulating grain boundaries, the colossal permittivity behavior is primarily attributed to an IBLC/SBLC-related polarization mechanism. Overall, a high dielectric constant can be achieved via defect engineering and triple doping modulation, providing a viable strategy for the design of next-generation dielectric capacitors.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2026
·
IF 5.4
Zhiyuan Xu,Jingming Yan,Fengyang Liu,Rui Ma,Chao Yang,Wentao Hu,Wenjie Zou
Imidazolium-based polymer (ImPOP-2) can efficiently enrich low-concentration Nb (V) in sulfuric acid-oxalate solutions. • ImPOP-2 exhibited high capacity and fast kinetics for Nb (Ⅴ) via anion exchange. • ImPOP-2 demonstrated superior selectivity towards Nb (V). • The weak interaction between Nb(V) and ImPOP-2 was revealed. Common solvent extraction methods are uneconomical for large volumes of low-concentration Nb(V) leachate, whereas ion exchange exhibits clear advantages. Nevertheless, studies on ion-exchange materials for the recovery of low-concentration niobium in non-fluoride systems are still limited, particularly in the sulfuric acid-oxalate leaching system. Emerging imidazolium-based cationic porous organic polymers have demonstrated great potential for capturing anions. However, few studies have explored their use for Nb(V) capture. In this study, a cationic organic polymer named ImPOP-2 was synthesized and used for batch adsorption experiments in sulfuric acid-oxalate solutions. ImPOP-2 exhibited a high adsorption capacity (212.20 mg·g⁻¹), rapid kinetics (reaching 79.66% of the equilibrium adsorption capacity within 10 min at an initial concentration of 400 mg·L⁻¹) and good reusability (maintaining 91.62% of the original capacity following five regeneration cycles). Even in the presence of 10 times higher concentrations of Fe(III) and 2 times higher concentrations of Ti(IV), ImPOP-2 exhibited good selectivity for Nb(V) over these competing ions, with selectivity coefficients (adsorbed mass ratio) of 1.27 and 1.67, respectively. ImPOP-2 demonstrated superior adsorption performance compared to existing adsorbents used in non-fluoride systems. The interactions between ImPOP-2 and Nb(V) were analyzed using scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier Transform infrared spectroscopy and independent gradient model based on Hirshfeld partition analysis. The results indicated that the adsorption mechanism was primarily ion exchange driven by electrostatic forces, with van der Waals forces and hydrogen bonding also contributing to the adsorption. This study aims to provide a feasible strategy for the efficient enrichment of low-concentration niobium in the sulfuric acid-oxalate leaching system. Download: Download high-res image (214KB) Download: Download full-size image
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