CERAMICS INTERNATIONAL
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2021
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IF 4.527
Bin Xiao,Gang Wu,Tongde Wang,Zhengang Wei,Yanwei Sui,Baolong Shen,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yaojian Ren,Xiaolan Xue,Junchao Zheng,Jing Mao,Kehua Dai
High entropy oxides (HEOs) have attracted the attention of researchers due to their high theoretical specific capacity and structural stability. However, the effect of elements in HEOs on material properties is unknown. In this work, HEOs (FeNiCrMnZn) 3 O 4 and (FeNiCrMnMg) 3 O 4 were successfully synthesized and used as anode materials for lithium ion batteries . The effects of Zn and Mg on the properties of HEOs were studied from the aspects of crystal structure, micro morphology, and surface valence. Results show that Zn enhances the lithium storage performance of HEOs theoretically, which is verified in the later electrochemical performance tests. (FeNiCrMnZn) 3 O 4 is better than (FeNiCrMnMg) 3 O 4 in all aspects of rate properties, cycle performance, and electrochemical impedance spectroscopy . Therefore, the introduction of electrochemically active metals, such as Zn, can improve the performance of HEOs, thereby providing ideas for the subsequent design and application of HEOs.
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高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 24
·14629-14637
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IF 10.733
Chong Lu,Yanling Ma,Fan Li,Hong Zhu,Xiaoqin Zeng,Wenjiang Ding,Tao Deng,Jianbo Wu,Jianxin Zou
A core–shell nanostructured Mg@Pt composite, consisting many of icosahedral Mg particles as the core with nano-sized Pt particles distributed homogeneously on different surfaces, was synthesized through an arc plasma method followed by the generic solid-state method. The microstructures and hydrogen sorption properties of the Mg@Pt composite were carefully investigated and compared to that of pure Mg powder. In particular, the dehydrogenation behaviors of the hydrogenated Mg@Pt composite were observed in situ via high-resolution transmission electron microscopy (HRTEM). The results revealed that the Pt on Mg particles showed a “spillover” effect to improve the hydrogen absorption kinetics in the early stage. It then transformed into H-stabilized Mg3Pt, followed by the formation of MgH2. DFT calculation and in situ TEM observations demonstrated that the H-stabilized Mg3Pt acted as a “hydrogen pump” for the dehydrogenation of MgH2 and then transformed into Pt after desorption. Through this effect, the dehydriding kinetics of the hydrogenated Mg@Pt composite was improved and the onset dehydrogenation temperature was reduced compared to that of the pure MgH2 powder.
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高影响因子
APPLIED SURFACE SCIENCE
·
2018
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IF 4.439
Zhiqiang Qian,Shidong Wang,Xiushen Ye,Zhong Liu,Zhijian Wu
A spraying method has been employed to prepare silica-based superhydrophobic coatings on AZ31B Mg alloy surfaces. Both nanometer and micrometer silica particles were used to construct the micrometer and nanometer scale binary structures, and 1H, 1H, 2H, 2H-Perfluorooctyltriethoxysilane (PFOTES) was used as the fluorine silane coupling agent. The coatings were characterized using the techniques of Field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectra. The corrosion resistance properties of the prepared superhydrophobic surfaces were checked based on polarization curves. And their wetting properties were studied for aqueous solutions of HCl, NaOH, NaCl, MgCl 2 , NaI, CH 3 COONa, C 2 H 5 OH, C 17 H 33 COONa, and sodium dodecylbenzene sulfonate, respectively, with contact angle and sliding angle as the parameters. In contrast with the bare magnesium alloy AZ31B, after coating, the corrosion current density shows a more than three-order of magnitude smaller value, and the water contact angle increases from ∼32° to over 155°. Solution pH and coexisted NaCl, MgCl 2 , NaI, and CH 3 COONa salts have little effect on the wetting properties of the prepared superhydrophobic surfaces. On the contrary, coexisted C 2 H 5 OH, C 17 H 33 COONa, or sodium dodecylbenzene sulfonate has an obvious effect on the wetting properties. The differences in the wetting properties were explained by considering the interactions between the superhydrophobic surfaces and the surfaces of the solution droplets. In addition, the superhydrophobicity coating also exhibited good mechanical, chemical and environment stability in the abrasion test, immersion test, salt spray test, etc.
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高影响因子
MATERIALS LETTERS
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2015
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IF 2.489
Zhang Leilei,Li Hejun,Li Kezhi,Liu Shoujie,Zhang Yulei,Yao Pei,Zhang Wenqi,Chen Guanzheng
A multi-layer coating composed of SiC inner-layer and Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer for carbon fibers has been synthesized using a combination method of chemical vapor deposition , electrochemical deposition and ion exchange method. The morphology, microstructure and in-vitro bioactivity of the multi-layer coating are analyzed. The results show that the SiC inner-layer exhibits a squamous shape. Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer covers the SiC inner-layer coated carbon fiber entirely and uniformly with a flat structure. The multi-layer coating could induce the precipitation of particle-shaped apatite crystals with Ca/P molar ratios of 1.34–1.51 on its surface in simulated body fluid. The multi-layer SiC/Mg and F co-substituted hydroxyapatite/chitosan coated carbon fibers should have potential application for tissue engineering.
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高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2014
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IF 2.063
Ran-ran Shan,Liang-guo Yan,Yan-ming Yang,Kun Yang,Shu-jun Yu,Hai-qin Yu,Bao-cun Zhu,Bin Du
The Mg–Al-CO 3 -LDH with Mg 2+ /Al 3+ molar ratio of 2 was prepared via coprecipitation method at constant pH of 9–10 and used to remove three red dyes by batch adsorption method. The results showed the Mg–Al-LDH were well crystallized and can adsorb the red dyes effectively. The optimal adsorbent dosage and contact time were 1.0 g and 60 min, respectively. Adsorbed amount hardly changed when pH < 10. The adsorption kinetics fit the pseudo-second order kinetic models well and isotherms correspond to Langmuir model strictly. All the relevant mechanisms were studied and manifested as anion exchange and also electrostatic attraction for CR.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2013
·Vol. 51
·期 16
·3328-3332
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IF 3.543
Hou Chen,Gaojian Lv,Ying Liang,Jinming Sun
High performance polyacrylonitrile (PAN) was prepared with Mg powder as both reducing agent (RA) and supplemental activator (SA) by single electron transfer-living radical polymerization (RASA SET-LRP). First-order kinetics of polymerization with respect to monomer concentration, linear increase of molecular weight, and narrow polydispersity with monomer conversion, and the obtained high isotacticity PAN indicate that RASA SET-LRP in the presence of Mg powder could simultaneously control molecular weight and tacticity of PAN. compared with that obtained with ascorbic acid (VC) as RA, an obvious increase in isotacticity of PAN was observed. the block copolymer pan- b -pAN with molecular weight at 112,460, polydispersity at 1.33, and isotacticity at 0.314 was successfully prepared. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51 , 3328–3332
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高影响因子
ACS Omega
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2016
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IF 0
Zhiyi Wu,Qiangqiang Zhu,Chun Shen,Tianwei Tan
Aimed at the green synthesis of supported noble metal nanoparticles without any additional reducing agents or stabilizers at room temperature, a new strategy in which monodispersed Pd nanoparticles were successfully immobilized on Mg–Al mixed metal oxides derived from layered double hydroxides was developed, and the reduction mechanism was also proposed. It allowed the in situ immobilization of monodispersed Pd nanoparticles with a face-centered cubic structure, using only alcohols with α-hydrogen atom as the solvent and reducing agent. Control over the mean particle size and content of Pd nanoparticles was realized by adjusting the temperature, initial concentration, and type of alcohol. With the content of Pd varied from 6.4 to 42.3 mg/g, the mean particle size of Pd increased from 1.1 to 4.9 nm. The as-prepared catalyst showed high catalytic activity for oxidation of benzyl alcohol: when the Pd content was 6.4 mg/g, conversion of 60.3% and selectivity of 99.2% were obtained with a turnover frequency of 4807 h–1. Similarly, on the basis of the high stand electrode potentials, immobilized Ag (5.6 nm) and Au (4.7 nm) nanoparticles were also prepared through this methodology. Moreover, the choice of supports was extended to other powder supports that would react with the byproduced acid. Overall, this facile method opens up new opportunities for controllable synthesis of supported nanoparticle catalysts in a green way.
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PubMed
Progress in Natural Science-Materials International
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2017
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IF 2.038
Xuezhang Xiao,Teng Qin,Yiqun Jiang,Fulei Jiang,Meng Li,Xiulin Fan,Shouquan Li,Hongwei Ge,Qidong Wang,Lixin Chen
Mg(AlH 4 ) 2 nanoparticles with a particle size less than 10 nm have been successfully synthesized by mechanochemical method using LiAlH 4 and MgCl 2 as raw materials together with LiCl buffering additive. In comparison to Mg(AlH 4 ) 2 microparticles, Mg(AlH 4 ) 2 nanoparticles exhibit a faster hydrogen desorption kinetics and lower desorption temperature. The hydrogen desorption temperatures of the first and second dehydrogenation steps are 80 and 220 °C for the Mg(AlH 4 ) 2 nanoparticles, which are about 65 and 60 °C, respectively, lower than those of Mg(AlH 4 ) 2 microparticles. The decomposition activation energy is reduced from 135 kJ/mol for Mg(AlH 4 ) 2 microparticles to 105.3 kJ/mol for Mg(AlH 4 ) 2 nanoparticles. It is proposed that the shortened diffusion distance and enhanced diffusivity of Mg(AlH 4 ) 2 /MgH 2 nanoparticles provide an energy destabilization for lowering the dehydrogenation temperature, and thus being the key factor for promoting the hydrogen desorption kinetics. More importantly, it is demonstrated that the dehydrided nano MgH 2 hydride with a particle size below 10 nm can be formed after rehydrogenation process, resulting in the good cycling hydrogen desorption performance of nano MgH 2 .
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高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2024
·Vol. 149
·期 22
·12697-12708
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IF 3
Sun Mengxia,Liao Xueqin,Liu Jianzhong
Using Al–Mg alloy instead of pure aluminum can improve the agglomeration and combustion characteristics of composite propellants. In this experiment, the effects of oxygen concentration and pressure on the ignition and combustion performance of Al–Mg binary alloy (with a magnesium mass content of 20%) and Al–Mg alloy mixed with ammonium perchlorate (AP) were investigated using a laser ignition test bench. The thermogravimetric results showed that the melting of aluminum, magnesium and intermetallic phases in the alloy powder occurred under argon, producing four heat absorption peaks. Magnesium evaporates at about 580 °C. In air, only one endothermic peak was observed, with oxidation occurring at approximately 510 °C. During the oxidation process, the intermetallic phase decomposes. Laser ignition tests showed that the alloy mainly undergoes gas-phase combustion, exhibiting phenomena such as gas emission, particle fragmentation, and micro-explosions. The introduction of AP promotes ignition and combustion of the alloy, resulting in more intense gas-phase reactions. Both increased pressure and oxygen concentration will promote alloy combustion. There are two reaction zones in the particles during combustion. Filamentary solids were observed in the combustion products of the AP-AM samples, which were primarily the products of the reaction of magnesium with O and Cl.
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高影响因子
ENERGY & FUELS
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2024
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IF 5.2
Congwen Duan,Jinhui Wu,Poqian Liang,Haimei Wang,Ting Qu,Yuchen Fan,Yaohua Su,Zhaohua Su,Lianxi Hu,Ying Wu
The hydrogen storage potential and cost-effectiveness of MgH2 have rendered it a desirable material for hydrogen storage. However, its application has been hindered by limitations in thermal stability and dehydrogenation kinetics. In this study, the carbon nanotube-Pd bifunctional catalyst was prepared by using hydrothermal and calcination technology, significantly improving the kinetics of Mg/MgH2 during hydrogen adsorption/desorption. The activation energy for the Mg@ CNTs-Pd was reduced to 42.73 kJ/mol, as determined by fitting the Avrami–Erofeev model with the Arrhenius equation. Additionally, the activation energy during dehydrogenation was found to be 73.98 kJ/mol based on the Johnson–Mehl–Avrami–Kolmogorov equation and the Arrhenius equation. It is worth noting that the dynamic enhancement persists even after 10 cycles. This groundbreaking research has paved the way for potential applications of MgH2 as a hydrogen storage material, providing it with broader development opportunities.
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高影响因子
Defence Technology
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2024
·
IF 5
Zhanjun Yang,Hao Liu,Li Mi,Xiaoqian Wang,Oisik Das,Zhong xuan Han,Lin Jiang
To investigate the differences in combustion and energy release characteristics of metastable intermolecular composite materials composed of aluminum alloys and polyvinylidene fluoride (PVDF) with different compositions, two types of alloys were selected: Al-Mg and Al-Si. Pure aluminum powder of the same size was also chosen for comparison. The PVDF-coated metal particle composites and the mixtures of PVDF with metal particles were prepared using electrospray (ES) and physical blending methods (PM), respectively. A systematic study was conducted on the morphology, compositional structure, combustion performance, energy release characteristics, and thermal reactivity of the fabricated composites and their combustion products through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), combustion performance experiments, closed vessel pressure tests, and simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC). The experimental results indicated that the PVDF-coated metal particles prepared by the electrospray method exhibited a distinct core-shell structure, with the metal particles in close contact with the PVDF matrix. Compared to the PM blended materials, the ES composites demonstrated superior combustion performance and energy release characteristics during combustion. Analysis of different metal fuel systems under identical preparation conditions revealed that Al-Mg and Al-Si fuels modulate the combustion and energy release properties of aluminum alloy-PVDF MICs through two distinct pathways.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2025
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IF 7.7
Jie Yao,Hao Liu,Wei Liu,Jianxin Nie,Shi Yan,Xueyong Guo
Metal fuels are widely used in energetic materials to improve their energy release. Al Si alloy fuel is an aluminum-based alloy fuel, and its slow reaction rate limits its potential application in energy material systems. Herein, Al-Si-Mg AlSi9Mgx alloy fuel had been designed and successfully prepared by gas atomization to achieve excellent reactivity characteristics. The reaction characteristics of the fuel were systematically measured by thermal analysis (TG-DSC), bomb calorimeter, volumetric explosion vessel system and laser ignition measurement. Due to the addition of highly active magnesium, the activation energy of alloy fuel was reduced, and the combustion efficiency was increased to more than 99 %, and the ignition delay time was reduced by 6.7 ms and 33.6 ms respectively. Combustion of potassium perchlorate (KP) mixtures shows that AlSi9Mgx alloy fuels had a faster flame propagation rate, 22.814 mm/s and 42.543 mm/s. The superior reaction properties of AlSi9Mgx alloy fuel are due to the presence of internal solid solution Mg or low melting point alloy compound. This work and design provide a reliable method for optimizing the energy output of alloy fuels.
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危险品化学品经营许可证（带存储）