JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Chong Lu,Jianxin Zou,Xiaoqin Zeng,Wenjiang Ding,Huaiyu Shao
To improve the hydrogen sorption properties of Mg, an arc plasma method with a vacuum vapor deposition technique was used to synthesize a core-shell like structured Mg@NaBH 4 composite. Homogeneously distributed nanoscale NaBH 4 particles can be observed on the surface of Mg matrix according to bright-field scanning transmission electron microscope (BF-STEM) and high-resolution transmission electron microscopy (HRTEM) techniques. A solid solution of Na in Mg might form according to the results of XRD and energy dispersive X-Ray analysis (EDX)-STEM technique. The hydrogenation activation energy ( E a = 60.1 kJ/mol H 2 ) of the Mg in the composite and the onset dehydrogenation temperature for the hydrogenated composite measured from temperature programmed desorption (TPD) (245 °C) were lower than those of pure MgH 2 . The improvement can be ascribed to the core-shell like structure which induces more sufficient contacts between catalysts and Mg, thus providing more nucleation sites for hydrogen sorption. In addition, the formation of MgB 2 and the substitution of Na atoms might support more grain boundaries and cause the changes of electronic structure of Mg/MgH 2 , which can significantly improve the hydrogen sorption properties of Mg. This study implies a novel structure design approach for development of future hydrogen absorption materials.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2014
·
IF 2.93
Wei Yuan Pan,Bin Hong Liu,Zhou Peng Li
In this study, we synthesized ZrO 2 nanorods through a hydrothermal process as a catalyst precursor for the reversible hydrogen storage reaction between 2LiH + MgB 2 and 2LiBH 4 + MgH 2. The 2LiH + MgB 2 composites doped with the ZrO 2 nanorods demonstrated superior and stable hydriding/dehydriding kinetics upon cycling. The XRD , SEM and HRTEM results revealed that the doped ZrO 2 nanorods were transformed into ZrB 2 nanoparticles with a size of a few nanometers during the first hydrogenation. The initial nanosize of the ZrO 2 catalyst precursor accounted for the formation of extremely fine ZrB 2 nanoparticles , which acted as heterogeneous nuclei of MgB 2 . The present study provides a new route for performance enhancement of complex hydride composites through manipulating the nanostructure of catalysts.
研究领域:
材料科学
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能源存储
✓ 已验证
DOI
高影响因子
Crystals
·
2021
·Vol. 11
·期 3
·278
·
IF 2.589
Liangqun Yang,Hongli Suo,Lin Ma,Min Liu,Wanli Zhao,Jianhua Liu,Lei Wang,Zili Zhang,Qiuliang Wang
In this study, boron powder with different particle sizes was purified by both chemical and heat treatment methods. The reduction in the particle size can improve the chemical purification with no effort on the heat treatment. The superconducting properties of the powder drastically changed even with only a partial elimination of oxygen. On the one hand, less oxygen content resulted in highTcandJcvalues under the low magnetic field, and most importantly, a significant improvement in the superconducting connectivity (Afvalue). On the other hand, the degradation ofJcunder a high field and a change in the pinning mechanism were also found, along with decreasing oxygen. This result indicated that oxygen, probably MgO, might act as the pinning center and as an obstacle for the supercurrent in MgB2at the same time. This work paves the way for obtaining pure oxygen-free MgB2and understanding the real effect of oxygen in MgB2.Keywords:boron powder;purification;particle size;MgB2;superconducting connectivity
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
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2024
·
IF 1.3
Wenbin Jin,Nan Liu,Fang Cheng,Zongqing Ma,Yongchang Liu,Pingzhan Si,Hongliang Ge
We report the C substitution effects in MgB 2 bulks on the lattice parameters, FWHM, and critical current density ( J c ) as a function of doping level. It is shown that using carbon-coated boron powder can effectively control the grain growth of MgB 2 during the whole sintering process. Accompanied by the rapid cooling process, the final average grain size can be restrained within merely 50 nm, and the J c value of the sample can be significantly improved at high field. On top of that, adding Cu is also considered a key factor in improving the current carrying property of the graphene-doped sample throughout the whole field, which can be attributed to the formation of the MgCu 2 alloy phase.
研究领域:
材料科学
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超导体研究
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Liang Zheng,Wenjie Zhang,Qi Wang,Hong Zhang,Zhou Yu,Cuihua Cheng,Yong Zhang,Ming Lei,Yong Zhao
MgB 2 bulks with NaCl doping amount ranging from 0–30 at% have been prepared by hot pressed sintering process . With the increase of NaCl doping amount, the c axis lattice parameter of MgB 2 monotonously increases, indicating the substitution of Mg atoms by larger Na atoms. Meanwhile, the intensity of diffraction peaks of both NaCl and impurity phase of MgO increases. More compact morphology was found in the NaCl doped MgB 2 samples. The critical transition temperature ( T c ) decreases from 38.2 K to 36.8 K with the increase of NaCl doping amount from 0 to 30 at%, and the corresponding transition width of T c (Δ T c ) increases from 0.5 K to 1.8 K. When the doping amount of NaCl is not exceeding 10 at%, the J c value is about 10 6 A/cm 2 at 4.2 K, 3 T, and 5 × 10 5 A/cm 2 at 10 K, 3T. J c performance of the 5 at% NaCl doped MgB 2 sample (NC05) reaches 6.8 × 10 5 A/cm 2 at 20 K, 2T, which improves approximately 20% compared to the pure one, attributing to the better grain connectivity of MgB 2 and enhancement of flux pinning force by NaCl doping.
研究领域:
凝聚态物理
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材料科学
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超导材料
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无机固体化学
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功能陶瓷
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 35
·10184-10192
·
IF 0
Jie Shao,Xuezhang Xiao,Lixin Chen,Xiulin Fan,Leyuan Han,Shouquan Li,Hongwei Ge,Qidong Wang
A system of 2LiH–MgB2 and its hydrogenated 2LiBH4–MgH2 is an attractive candidate for hydrogen storage. However, its hydriding–dehydriding kinetics have to be further improved for practical application. In the present work, three kinds of Ni–B nanoparticles with different crystalline states and particle sizes were prepared by wet-chemical reduction and mechanochemical methods, and then introduced into a 2LiH–MgB2 composite for catalytic enhancement. The catalytic roles of Ni–B nanoparticles on the hydriding–dehydriding properties were investigated systematically. The results show that all of the Ni–B nanoparticles can significantly enhance the hydriding–dehydriding kinetics of the 2LiH–MgB2 composite, resulting in no incubation period for the formation of MgB2 during dehydrogenation. The more disordered the amorphous structure and the smaller sized the Ni–B particles are, the better the catalytic effect that is obtained. Microstructure analyses clearly reveal the formation of the MgNi3B2 phase in the dehydriding process, which acts as the nucleation agent for MgB2 formation determined by an edge-to-edge model. Directly doping with Ni–B nanoparticles in the 2LiH–MgB2 system shows a higher hydrogen desorption capacity of 9.4 wt% and obtains a better catalytic efficiency than doping with NiCl2.
研究领域:
材料科学
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储能材料
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无机化学
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纳米催化
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氢储存
✓ 已验证
DOI
ACS Nano
·
2025
·
IF 16
Yaoyu Hu,Pengfei Zhu,Junwei Deng,Yi Yu,Qian Chen,Haitao Wu,Zhengbao Zha,Hua Wang,Yan Ma
Individuals diagnosed with inflammatory bowel disease (IBD) frequently encounter dysbiosis of the intestinal microbiota and are predisposed to psychiatric comorbidities, such as depression and anxiety. The development of oral therapeutics that concurrently attenuate intestinal inflammation, modulate gut microbiota, and ameliorate psychiatric symptoms is imperative for effective IBD management. This study introduced an orally administered Inulin gel incorporating magnesium diboride nanosheets (MgB2@Inulin gel). The hydrolysis of MgB2 nanosheets could generate reductive hydrogen gas (H2), which is critical for scavenging excess reactive oxygen/nitrogen species (RONS), and boron ions that neutralize harmful lipopolysaccharides (LPS). Prebiotic Inulin could effectively protect MgB2 nanosheets from gastric acid degradation, ensuring their persistence in the intestinal tract, where it modulated the gut microbiota and preserved intestinal barrier integrity. Notably, MgB2@Inulin gel markedly alleviated anxiety and depressive behaviors in the model of colitis by regulating the gut–brain axis. Thus, this work underscores the pivotal role of the gut–brain axis in the therapeutic approach to IBD and its associated psychiatric manifestations, proposing a straightforward, safe, and efficacious oral hydrogen treatment strategy for IBD and concurrent mental health disorders.
研究领域:
纳米医学
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胃肠病学
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神经科学
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微生物学
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药理学
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材料科学
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免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RARE METALS
·
2025
·
IF 11
Liu Yu-Kun,Pang Yu-Chen,Li Chao-Qun,Zhang Xiao-Yue,Hu Xue-Chun,Chen Wei,Yu Xue-Bin,Xia Guang-Lin
As a typical reactive composite hydrogen storage system, 2LiBH 4 –MgH 2 holds an ultrahigh hydrogen storage capacity of 11.5 wt%. However, it suffers from sluggish hydrogen storage kinetics due to the difficult nucleation of MgB 2 . Herein, amorphous VB 2 nanoparticles with an average size of approximately 32 nm are synthesized to enhance the hydrogen storage performance of 2LiBH 4 –MgH 2 composite. VB 2 , sharing the same hexagonal structure with MgB 2 with a d -value mismatch ratio of only 2.28%, could serve as effective nucleation sites for promoting the formation of MgB 2 . Theoretical calculations reveal that the introduction of VB 2 significantly reduces the binding energies of B and Mg, facilitating in situ nucleation of MgB 2 . As a result, after the introduction of VB 2 nanoparticles, complete hydrogen desorption of 9.23 wt% is achieved for 2LiBH 4 -MgH 2 within 2 h at 400 °C, which is 4 times shorter than the time required for pure 2LiBH 4 -MgH 2 , and no nucleation incubation period for hydrogen desorption is observed even at a low temperature of 380 °C. More importantly, a reversible capacity of 9.3 wt%, corresponding to a capacity retention of 100%, could be preserved after 10 cycles of hydrogen storage, demonstrating stable reversible hydrogen storage performance. This study provides a novel technological pathway for improving the reversible hydrogen storage performance of composite metal hydrides and offers significant insights into the development of high-performance hydrogen storage materials. Graphical
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Fang Cheng,Yongchang Liu,Zongqing Ma,Huijun Li,M. Shahriar Al Hossain
The un-doped Mg 11 B 2 and Cu-doped Mg 11 B 2 bulks using 11 B as a boron precursor were fabricated by solid-state reaction and sintered at different temperature in present work. By analyzing the sintering process, it was found that 11 B original powder is more reactive and can react with Mg severely even at low temperature before Mg melting, which leads to the formation of refined Mg 11 B 2 grains. Consequently, the critical current density of Mg 11 B 2 sample prepared in this work is higher than that of natural MgB 2 . Furthermore, it was found that proper Cu addition could obviously accelerate the reaction between Mg and 11 B and promote the formation of Mg 11 B 2 due to the appearance of Mg–Cu liquid at low sintering temperature before Mg melting. On the other hand, Cu addition also introduced more MgCu 2 impurity, leading to a relatively lower critical current density on the whole. Interestingly, the critical current density of the Cu doped sample sintered at 800 °C is surprisingly enhanced at the low field, compared with that of the corresponding un-doped one. This is due to the peritectic reaction which generated small-sized MgCu 2 occurred that at 800 °C, providing MgCu 2 pinning centers well-distributed in the MgB 2 matrix.
研究领域:
材料科学
·
超导体研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yong-Chao Zhang,Yan-Wei Li,Caidi Han,Yingtai Qin,Jinhao Zhang,Jinting Wu,Jian Gao,Xiao-Dong Zhu
The separator is an important component in lithium-sulfur (Li-S) batteries. However, the conventional polypropylene (PP) separators have the problem of easy shuttling of lithium polysulfide (LiPSs). Herein, ultrathin magnesium boride (MgB 2 ) nanosheets were prepared by ultrasonic-assisted exfoliation technology, and were suction-filtered onto a separator to serve as a separator modification layer. The introduction of a microporous structure into MgB 2 nanosheets after ultrasonic peeling increases the specific surface area and pore volume, with more adsorption sites, which can fully utilize the surface adsorption/catalytic performance of MgB 2 for LiPSs and accommodate the volume expansion of lithium sulfide (Li 2 S). Therefore, MgB 2 @PP as a separator significantly improves the sulfur utilization and cycle stability in Li-S batteries. When the MgB 2 @PP separator is used, the reversible specific capacity of the assembled Li-S battery at 0.1 C (current rate) is 1184 mAh/g, and the specific capacity at 2 C is 732 mAh/g. After 500 cycles at 2 C, it remains at 497 mAh/g.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Qian Zhao,Jiabo Zhang,Guoqing Xia,Shilong Ma,Shaofeng Fan,Xuecheng Ping,Liang Hao,Yaran Zhang
This study investigates the effect of Cu 2 Se doping on the morphology, structure, and reaction process of MgB 2 superconductors . Polycrystalline MgB 2 samples with different Cu 2 Se doping levels were synthesized using the conventional solid-state sintering method. A comprehensive analysis of the phase formation, microstructure, and sintering mechanisms was investigated. The results indicated that Cu 2 Se reacted with Mg at temperatures below 650 °C, forming Mg 2 Cu and MgSe phases, which leads to a reduction in the Mg content during the solid-state reaction process. This reaction pathway promotes the regeneration of the MgB 2 phase through the interaction between Mg 2 Cu and B. The novel approach not only eliminates the high porosity caused by Mg evaporation above 650 °C but also enhances the critical current density of MgB 2 by introducing secondary phase such as MgSe and MgCu 2 nanoparticles . The results suggest that Cu 2 Se doping provides a promising way for optimizing the unique microstructure and highly density of MgB 2 superconductor.
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Wanli Zhao,HongLi Suo,Shuo Wang,Lin Ma,Lei Wang,Qiuliang Wang,Zili Zhang
MgB 2 superconductor pellets were synthesized through Mg gas infiltration method using nanosized- and microsized B powders. There was a marked difference in the superconducting properties of the two samples, particularly in the pinning force and dominant pinning mechanism. The microstructures of the samples were observed using HR-TEM and STEM-HAADF, and the results showed that the primary reason for the difference in the superconducting properties is the distribution of the nanosized second-phase particle MgO. Additionally, a feasible reaction model for the Mg gas infiltration method was established. Compared to the Mg liquid infiltration method, the gas infiltration showed better penetrability ability with a small amount of residual Mg. This study presents a novel synthesis process to fabricate an MgB 2 pellet with superior density and superconducting properties. This method can be used in multiple applications such as superconducting bearings, compact superconductor magnets, and magnetic shielding.
研究领域:
超导物理
·
材料科学
·
陶瓷工艺
·
应用物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）