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107 results on '"Lai, Xuefei"'

15. Coral-Like NiFe2O4/C Composite as the High-Performance Anode Material for Lithium-Ion Batteries

Author

Bao, Shanshan, Xiao, Yifei, Li, Junfeng, Yue, Bo, Li, Yanjun, Sun, Wenxian, Liu, Lei, Huang, Yi, Wang, Li, Zhang, Peicong, and Lai, Xuefei

Abstract

Abstract: In this work, we fabricated NiFe2O4/C composite with a coral-like structure through co-precipitation approach followed by thermal decomposition. The composite with a large surface area of 162.1 m2g−1and an average pore size of 11.8 nm was obtained. The porous structure in the composite derived from oxalate can effectively accommodate the volume changes of NiFe2O4during the cycling processes. When used as anode materials, the initial charge and discharge capacities of the composite were 926.7 and 1277.7 mAh g−1at 100 mA g−1. After 50 cycles, the reversible capacity of NiFe2O4/C could still remain at 892.4 mAh g−1. Even at a current density of 2000 mA g−1, the reversible capacity still reached 523.3 mAh g−1. The results showed that the synergy between NiFe2O4and carbon improved the electrochemical performance, and the porous composite could stabilize the structure of the electrode. Graphic Abstract:

Published
2024
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24. Mesoporous MnO/C composite synthesised from the precursor of Mn 3 (C 6 H 5 O 7 ) 2 and the application in Li‐ion batteries

Author

Lai Xuefei, Sun Wenxian, Li Junfeng, Li Yanjun, Gao Yang, Bao Shanshan, Yue Bo, and Li Ping

Subjects
chemistry.chemical_classification, Nanocomposite, Materials science, Annealing (metallurgy), Composite number, Biomedical Engineering, Bioengineering, 02 engineering and technology, Electrolyte, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Anode, chemistry, Chemical engineering, General Materials Science, Compounds of carbon, 0210 nano-technology, Porosity, Mesoporous material
Abstract

A facile and scalable route for the in-situ synthesis of porous MnO/C nanocomposite by annealing Mn3(C6H5O7)2 precursor has been developed. MnO particles were encapsulated inside the carbon matrix to form a skeletal architecture. Such a mesoporous structure provided more active sites and effective channels for Li+ and electrolyte, and act as the supporting structure for MnO particles during the cycling process. As an anode material for lithium ion batteries, the porous MnO/C composite had a specific capacity of 831.7 mAh g−1 at 100 mA g−1 and delivered a stable cycling capacity of 564.1 mAh g−1 after 59 cycles, indicating that the porous MnO/C nanocomposite could significantly improve the structural stability and might be a suitable electrode material for lithium-ion batteries.

Published
2019

25. The preparation of a difunctional porous β-tricalcium phosphate scaffold with excellent compressive strength and antibacterial properties

Author

Xie Ke-nan, Xie Lu, Lai Xuefei, Jiang Yi, Long Qin, and Liao Li

Subjects
Scaffold, Materials science, Biocompatibility, Graphene, General Chemical Engineering, General Chemistry, Phosphate, Silver nanoparticle, law.invention, chemistry.chemical_compound, Compressive strength, Chemical engineering, chemistry, law, Cytotoxicity, Porosity
Abstract

Porous β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP) scaffolds are widely applied in the field of bone tissue engineering due to their nontoxicity, degradability, biocompatibility, and osteoinductivity. However, poor compressive strength and a lack of antibacterial properties have hindered their clinical application. In order to address these disadvantages, graphene (G) and silver nanoparticles were introduced into β-TCP through a two-step method. In the synthesis process, G-β-TCP was prepared via an in situ synthesis method, and then silver nanoparticles and HAp particles were coated on the surface of the G-β-TCP scaffold in an orderly fashion using dopamine as a binder. From the results of characterization, when the content of graphene was 1 wt% of β-TCP, the G-β-TCP scaffold had the highest compression strength (127.25 MPa). And core–shell G-β-TCP-Ag-HAp not only had reduced cytotoxicity via the continuous release of Ag+, but it also achieved long-term antibacterial properties. Besides, the material still showed good cell activity and proliferation.

Published
2020

26. Synthesis and characterization of Eu3+-doped C12H18Ca3O18 phosphor

Author

Xianfei Chen, Peicong Zhang, He Huan, Junfeng Li, Liu Lei, Lai Xuefei, Wentao Zhang, and Bao Shanshan

Subjects
Photoluminescence, Materials science, Scanning electron microscope, Process Chemistry and Technology, Analytical chemistry, chemistry.chemical_element, Phosphor, 02 engineering and technology, Crystal structure, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Fluorescence, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Materials Chemistry, Ceramics and Composites, 0210 nano-technology, Luminescence, Europium, Diffractometer
Abstract

A series of Eu3+-doped C12H18Ca3O18 phosphors were synthesized through a facile hydrothermal method and the properties of as-prepared phosphors were explored by X-ray diffractometer (XRD), scanning electron microscope (SEM), and photoluminescence (PL) spectrometer. The exploration results indicated that the C12H18Ca3O18:Eu3+ had been successfully synthesized. The morphology of C12H18Ca3O18:Eu3+ was a strip with the size of 100–4000 nm × 50–400 nm × 50–200 nm and the ratio of length to width of 2–80. The strongest emission peak of C12H18Ca3O18:Eu3+ around 620 nm was ascribed to 5Do→7F2 transition of Eu3+, and the peaks centered at 590, 653 and 694 nm respectively corresponded to 5Do →7F1, 7F3, and 7F4 transitions. C12H18Ca3O18: Eu3+ gave the red light emission, as indicated by color coordinate analysis. The photoluminescence intensity of the phosphors prepared under the Eu3+ concentration of 6% was the highest. The crystal structure of C12H18Ca3O18:Eu3+ was changed after europium ions occupied the lattice position of calcium ions. Europium ion could displace calcium arbitrarily. As a new kind of matrix, calcium citrate possesses the properties of both organic and inorganic compounds and the luminescent C12H18Ca3O18: x Eu3+ particles may be applied in biological fluorescent tags and luminescent materials.

Published
2018

34. Porous composite calcium citrate/polylactic acid materials with high mineralization activity and biodegradability for bone repair tissue engineering.

Author

Xiao, Yifei, Yang, Yanan, Li, Junfeng, Ma, Yue, Wang, Hao, Wang, Li, Huang, Yi, Zhang, Peicong, Zou, Qin, and Lai, Xuefei

Subjects
POLYLACTIC acid, POROUS materials, PORE size distribution, TISSUE engineering, CITRATES, COMPOSITE materials, MINERALIZATION
Abstract

In this study, porous composite materials were prepared from calcium citrate (CC) and polylactic acid (PLA). Scanning electron microscopy (SEM) showed that the prepared composite materials had the uniformly pore distribution and suitable pore size for bone tissue engineering and displayed proper mechanical properties. As confirmed in X-ray diffraction (XRD), SEM and thermal analysis, the lipophilic property of CC had the improved compatibility and uniform dispersion in the PLA matrix. In addition, the prepared materials showed the high mineralization activity and the ability to guide the formation of apatite since the hydrophilicity of CC improved the wettability of the composite materials. In vivo animal experiments showed that the material was nontoxic and had good biocompatibility. Furthermore, the synergic degradation of CC and PLA effectively neutralized the acidic environment, thus preventing partial inflammation caused by acidic products. CC/PLA composite materials provide a promising new bone repair material for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Published
2021
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35. Luminescence properties of self‐activated Ca5Mg3Zn(VO4)6 and Ca5Mg3Zn(VO4)6:xEu3+ phosphors.

Author

He, Huan, Yang, Yanan, Wang, Li, Li, Junfeng, Cao, Wenqiang, Zhang, Wentao, Huang, Yi, Zhang, Peicong, and Lai, Xuefei

Abstract

Self‐activated Ca5Mg3Zn(VO4)6 and Ca5Mg3Zn(VO4)6:xEu3+ phosphors were synthesized via a high‐temperature solid‐state reaction route. The crystalline structure and luminescence properties of the phosphors were analyzed using an X‐ray diffractometer and a photoluminescence spectrometer. The explored results indicated that by varying calcination temperature and the raw material ratio of Ca2+/Mg2+/Zn2+, the phosphors could be developed with different phases, crystallinity, and various fluorescence performances. The fluorescence spectrum of Ca5Mg3Zn(VO4)6 showed a broad emission band over the range 400–650 nm under an excitation wavelength of 330 nm, as well as green light emission. Furthermore, after introduction of Eu3+ ions in Eu(VO4)4, the luminescence intensity of the Eu3+ ions greatly increased as the Eu3+ ion concentration increased at the 393 nm excitation wavelength, showing green–yellow light emission simultaneously. Therefore, the obtained phosphors could be used as a potential green–yellow‐emitting luminescent material in a white light‐emitting diode device. [ABSTRACT FROM AUTHOR]

Published
2021
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38. Preparation of a Fe3O4@C magnetic materials with high adsorption capacity of methylene blue.

Author

Shen, Yuansheng, Guan, Chen, Huang, Yi, Zhang, Peicong, Lai, Xuefei, Du, Haiying, Xu, Xiangjun, Li, Junfeng, Zhang, Wentao, Qiu, Kehui, Ju, Li, Luo, Xiaoling, and Yang, Kangkang

Subjects
MAGNETIC materials, ADSORPTION capacity, FERRIC chloride, MAGNETIC properties, IRON chlorides, METHYLENE blue, BAGASSE, SORBENTS
Abstract

With sugarcane bagasse as the carrier and iron chloride hexahydrate (FeCl3·6H2O) as the iron source, Fe3O4@C materials were prepared in this study. Then the adsorption properties of the prepared adsorbents were characterized by XRD, SEM and VSM analysis. The effects of adsorption time, initial pH value and initial methylene blue concentration on methylene blue adsorption performance were studied and the adsorption mechanism was discussed. The Fe3O4@C materials synergistically exerted the good adsorption capacity and magnetic properties. The adsorption process of methylene blue on Fe3O4@C adsorbent was in accordance with Freundlich isothermal equation and quasi-second-order kinetic model. The saturated adsorption capacity in the experiment of Fe3O4@C material was 270.51 mg/g. The adsorption capacity was high in both acidic and alkaline environments, especially the alkaline environment. [ABSTRACT FROM AUTHOR]

Published
2020
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39. Preparation and characterisation of calcium citrate wires

Author

Peicong Zhang, Li Junfeng, Yang Gao, Lai Xuefei, Cao Wenqiang, and Zhong Liangzhao

Subjects
Supersaturation, Materials science, Precipitation (chemistry), Biomedical Engineering, Bioengineering, Crystal structure, Condensed Matter Physics, Crystal, Crystallinity, Crystallography, Chemical engineering, X-ray crystallography, General Materials Science, Texture (crystalline), Dissolution
Abstract

Long calcium citrate wires were successfully prepared using a convenient and effective soft chemical method that involved heating the sheet precursor at an appropriate temperature in a mixture of alcohol and water for a sufficient amount of time. The X-ray diffraction patterns showed that the crystallinity degree increased with heating time. Moreover, the (200) crystal plane was the preferential growth face that was influenced by alcohol. Such influence was ascribed to alcohol being able to change the free energy and the supersaturation state of the solution. In addition, alcohol might adsorb onto the surface of the crystal and change the growth velocity of each crystal plane. The sheet precursor progressively turned into consecutive long wires by growing along the preferential growth orientation during the dissolution–reprecipitation process. The thickness of the wires was ∼8–30 nm. Long calcium citrate wires were produced to reinforce and strengthen biomaterials or for other purposes.

Published
2015

45. Mesoporous MnO/C composite synthesised from the precursor of Mn3(C6 H5O7 )2 and the application in Li-ion batteries.

Author

Shanshan, Bao, Li Junfeng, Gao Yang, Li Ping, Yue Bo, Li Yanjun, Sun Wenxian, and Lai Xuefei

Subjects
MANGANESE oxides, LITHIUM-ion batteries, NANOCOMPOSITE materials, STRUCTURAL stability, ELECTRODES
Abstract

A facile and scalable route for the in-situ synthesis of porous MnO/C nanocomposite by annealing Mn3(C6H5O7)2 precursor has been developed. MnO particles were encapsulated inside the carbon matrix to form a skeletal architecture. Such a mesoporous structure provided more active sites and effective channels for Li+ and electrolyte, and act as the supporting structure for MnO particles during the cycling process. As an anode material for lithium ion batteries, the porous MnO/C composite had a specific capacity of 831.7 mAh g-1 at 100 mA g-1 and delivered a stable cycling capacity of 564.1 mAh g-1 after 59 cycles, indicating that the porous MnO/C nanocomposite could significantly improve the structural stability and might be a suitable electrode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Published
2019
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49. Luminescence properties of Dy , Eu co-doped Ca 7 Si 2 P 2 O 16 single host phosphor.

Author

Li, Junfeng, Liu, Yuqing, Cao, Wenqiang, Gao, Yang, Zhang, Wentao, and Lai, Xuefei

Subjects
PHOSPHORUS, SOL-gel processes
Abstract

Dy3+/Eu3+ions co-doped Ca7Si2P2O16phosphors were successfully prepared by the sol-gel method. The characterization results confirmed that the rare earth ions occupied Ca2+sites in Ca7Si2P2O16crystal. Meanwhile, the luminescent properties of Ca7Si2P2O16:Eu3+, Dy3+upon excitation at 361 nm were discussed and its sharp emissions were in blue and red spectral regions, respectively. The luminescence intensity and CIE varied with the doping ratio of Dy3+, Eu3+and the emission region is close to the white light. All the results showed that Ca7Si2P2O16: Dy3+, Eu3+as a single host phosphor could be applied in the field of UV-excited white LEDs. [ABSTRACT FROM PUBLISHER]

Published
2017
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50. Structural and electrochemical characterization of Li2O–V2O5–Fe2O3amorphous cathode material for lithium-ion batteries

Author

Wang, Hao, Li, Junfeng, Yin, Yue, Wang, Li, Zhang, Peicong, Lai, Xuefei, Yue, Bo, Li, Yanjun, Hu, Xiaoyu, and He, Donglin

Abstract

In order to explore novel vanadium-based amorphous materials, a series of Li2O–V2O5–Fe2O3amorphous materials were prepared with the low-cost melting-quenching method in this report. As the main framework of amorphous materials, VO4is connected with FeO4and FeO6to form a disordered network structure. 20Li2O–60V2O5–20Fe2O3amorphous material had a stable structure and Li-ion migration channel. In the electrochemical performance test, the second cycle discharge capacity was 150.7 mAh/g at a current density of 100 mA/g and the capacity retention rate was still 80% after 100 cycles because the redox reaction between vanadium and iron ions promoted the electrochemical performance. Li2O–V2O5–Fe2O3amorphous materials are promising lithium-ion battery cathode materials.

Published
2022
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