Geoscience Frontiers
·
2020
·Vol. 12
·期 2
·957-963
·
IF 4.202
Ruijing Fu,Yaping Chen,Lingrui Wang,Zhiwei Ma,Pengfei Lv,Ying Song,Songrui Yang,Guanjun Xiao,Bo Zou
SiO 2 is the major mineral substance in the upper mantle of the earth. Therefore, studies of the silica-coated materials under high-pressure are essential to explore the physical and chemical properties of the upper mantle. The silica-confined CsPbBr 3 nanocrystals (NCs) have recently attracted much attention because of the improved photoluminescence (PL) quantum yield, owing to the protection of silica shell. However, it remains considerable interest to further explore the relationship between optical properties and the structure of CsPbBr 3 @SiO 2 NCs. We systemically studied the structural and optical properties of the CsPbBr 3 @SiO 2 NCs under high pressure by using diamond anvil cell (DAC). The discontinuous changes of PL and absorption spectra occurred at ∼1.40 GPa. Synchrotron X-ray diffraction (XRD) studies of CsPbBr 3 @SiO 2 NCs under high pressure indicated an isostructural phase transformation at about 1.36 GPa, owing to the pressure-induced tilting of the Pb-Br octahedra. The isothermal bulk moduli for two phases are estimated about 60.0 GPa and 19.2 GPa by fitting the equation of state. Besides, the transition pressure point of CsPbBr 3 @SiO 2 NCs is slightly higher than that of pristine CsPbBr 3 NCs, which attributed to the buffer effect of coating silica shell. The results indicate that silica shell is able to enhance the stabilization without changing the relationship between optical properties and structure of CsPbBr 3 NCs. Our results were fascinated to model the rock metasomatism in the upper mantle and provided a new ‘lithoprobe’ for detecting the upper mantle.
研究领域:
材料科学
·
高压物理
·
纳米材料
·
光学性质
·
地球物理学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Erying Zhao,Zonglei Guo,Jie Liu,Qian Zhang,Ziyang Guo,Yu Yang,Hui Wang,Lei Wang
High-energy-density Li-ion batteries are urgently demanded in the development of electric vehicles and smart power grids. Owing to the high theoretical capacity, silicon (Si) has been considered as one of the most promising anode materials for next-generation Li-ion batteries. However, Si anode materials undergo huge volume change during charge and discharge processes, which severely impairs the cycle stability of Si anodes. Herein, to stabilize the Si anodes, a low-cost and eco-friendly network binder coupling hardness with softness was designed through in-situ cross-linking of guar gum (GG) and carboxylated acrylonitrile-butadiene rubber (XNBR). The rigid and high-viscosity GG functions as a skeleton to withstand the expansion of Si active materials, and the elastic XNBR can effectively buffer the residual stress. The mass ratio of GG and XNBR was systematically studied to achieve superior cycling stability of Si anodes. Especially, the Si@X4G6 electrode shows excellent cycle stability, remaining a capacity of 1929 mAh g − 1 at 1000 mA g − 1 after 100 cycles. Interestingly, such an effective strategy not only works well in Si anodes but also does well in Si/C anodes and LiFePO 4 cathodes.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米材料
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Zhao Li,Baorang Li,Xiaoze Du,Hongwei Wu
It is recognized that the thermal performances of the molten salt based nanocomposite can be significantly enhanced. However, there were rare investigations regarding its stability under practical operating thermal environments . In this study, both of the specific heat capacity and thermal diffusivity of the molten salt based nanocomposite were experimentally evaluated under various operating conditions, including that of exposure to constant high temperature and low-high temperature circulation. The typical solar salt based nanofluid was prepared via the modified two-step method. The selected nanoparticle was SiO 2 with an average diameter of 30 nm. Experimental results indicated that both the heat treatments could significantly decrease the thermophysical properties , which would result in poor thermal stability. In comparison with the samples exposing to constant high temperature, the thermal cycled samples showed a more stable thermal property. Further investigations on the SiO 2 particle morphology transition in the process of the heat treatments revealed that the impact of both temperature field and natural convection on particle agglomeration should be responsible for the decrease in thermophysical properties of nanofluid.
研究领域:
材料科学
·
热物理学
·
能源工程
·
纳米科技
·
化学工程
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2019
·
IF 3.683
Yunfei Chang,Yuze Li,Chen Zhang,Tongyao Zhao,Xiaohang Tuo,Jing Guo,Yumei Gong
We developed a facile one-pot method to synthesize multishelled hollow mesoporous SiO2 microspheres (HMSs) with controllable interior structures including one-shell, double-shell, and yolk–shell. Single reagent formaldehyde could fully control the morphology of HMSs, in that formaldehyde was crucial to the SiO2 precursor’s hydrolysis rate and the template pore size.
研究领域:
材料科学
·
纳米医学
·
药物递送
·
生物材料
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2012
·
IF 2.159
Yuxin Wang,Kaituo Liu,Tao He,Jinhu Wu,Yunming Fang
Zeolite with trimodal porosity can be synthesized by desilication of zeolite nanocrystal aggregate. In the desilication process, the originally existed intercrystalline mesopores of zeolite nanocrystal aggregate were enlarged into large mesopore, and the new small intracrystalline mesopore channel was created, thus the Zeolite with trimodal porosity was formed. The structure of resulted zeolite, both on aggregate and mesopore level can be fine tuned by the desilication degree.
研究领域:
材料科学
·
多孔材料
·
纳米材料
·
催化化学
·
无机合成
✓ 已验证
DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2018
·
IF 4.66
Fanyu Kong,Xiaodong He,Qianqian Liu,Xinxin Qi,Dongdong Sun,Yongting Zheng,Rongguo Wang,Yuelei Bai
The Si@Ti 3 C 2 MXene nanocomposite was prepared in this paper by simply ultrasonic mixing of commercially available nanosized Si and Ti 3 C 2 MXene. The introduction of Ti 3 C 2 makes the aggregation of silicon nanoparticles relieved. Electrochemical measurements show that the nanocomposite maintains a reversible capacity of 188 mAh·g −1 at 0.2 A·g −1 after 150 cycles and exhibits improved capacity retention, which are significantly better than those of pure Si. The enhanced cycling stability and rate capability are attributed to the good electrical connection between silicon and Ti 3 C 2 . This study provides a new available matrix and guidance for the applications of MXenes in Si-based anode LIBs.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2015
·Vol. 19
·期 12
·3595-3604
·
IF 2.446
Hou Xianhua,Zhang Miao,Wang Jiyun,Hu Shejun,Liu Xiang
A silicon/silver/carbon (Si/Ag/C) composite with a core-core-shell structure has been synthesized via a simple method based on pyrolysis of an organic carbon source and silver mirror reaction. The Si and Ag nanoparticles are served as cores, while the porous amorphous carbon layer formed from pyrolysis of citric acid is served as shell. The porous amorphous carbon layer and highly conductive Ag nanoparticles can effectively alleviate the volume change of Si nanoparticles during lithiation/delithiation process and provide sufficient electrical conductivity for Si nanoparticles. As an anode material, the obtained Si/Ag/C composite exhibits excellent electrochemical performances, including high initial coulombic efficiency (85.6 % at 200 mA g −1 ), stable cycling performance (a discharge capacity of 2006.3 mA g −1 at 200 mA g −1 after 100 cycles), and excellent rate performance (a discharge capacity of 826.4 mA h g −1 at 3 A g −1 ). This simple method may open up an effective way to make other anode and cathode materials for commercial lithium-ion battery.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
·
复合材料
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2014
·Vol. 72
·期 1
·122-129
·
IF 1.547
Liu Yanghua,Zhou Yifeng,Nie Wangyan,Song Linyong,Chen Pengpeng
In this work, silica particles were firstly modified with poly(methyl methacrylate) and then converted to poly(methacrylic acid) (PMAA). The PMAA brushes with different molecular weight were used to modify the seed particles and learn the formation process of the raspberry-like particles. Silica particles with core–shell structure were obtained when the silica seed particles were modified only with carboxyl functional groups. With the increase of the molecular weight of PMAA brushes, uniform raspberry-like silica particles appeared gradually. But when the molecular weight of PMAA brushes was above 136,100, the morphologies became complicated. The electric charge of the polymer brushes was also found to have influence on the final morphologies of the particles. The contact angle (CA) tests showed that films composed of nanoparticles with uniform raspberry-like structures had an average CA of 157.2°, which indicated great prospects in the super-hydrophobic applications.
研究领域:
材料科学
·
表面工程
·
纳米技术
·
高分子化学
·
胶体与界面科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 13
·20810-20818
·
IF 3.83
Mengjing Liu,Sun-Wai Chiang,Xiaodong Chu,Jia Li,Lin Gan,Yanbing He,Baohua Li,Feiyu Kang,Hongda Du
Herein, oriented boron nitride (BN)/alumina (Al 2 O 3 )/polydimethylsiloxane (PDMS) composites were obtained by filler orientation due to the shear-inducing effect via 3-D printing. The oriented BN platelets acted as a rapid highway for heat transfer in the matrix and resulted in a significant increase in the thermal conductivity along the orientation direction. Extra addition of spherical Al 2 O 3 enhanced the fillers networks and resulted in the dramatic growth of slurry viscosity. This, together with filler orientation induced the synergism and provided large increases in the thermal conductivity . A high orientation degree of 90.65% and in-plane thermal conductivity of 3.64 W/(m∙K) were realized in the composites with oriented 35 wt% BN and 30 wt% Al 2 O 3 hybrid fillers. We attributed the influence of filler orientation and hybrid fillers on the thermal conductivity to the decrease of thermal interface resistance of composites and proposed possible theoretical models for the thermal conductivity enhancement mechanisms.
研究领域:
材料科学
·
高分子化学
·
热管理材料
·
先进制造
·
复合材料工程
✓ 已验证
DOI
高影响因子
BIOLOGICAL TRACE ELEMENT RESEARCH
·
2016
·Vol. 174
·期 1
·208-217
·
IF 1.798
Gao Jianyong,Wang Ming,Shi Chao,Wang Liping,Wang Dalin,Zhu Yingchun
The main inorganic minerals in natural bones are non-stoichiometric hydroxyapatite (HA, Ca 10 [PO 4 ] 6 [OH] 2 ) doped with various trace elements, which may possess important biochemical effects. To investigate the functions of Sr and Si elements in human hard tissues, non-doped HA, trace Si doped HA, Si and Sr codoped HA with the concentration of natural bones are synthesized by hydrothermal method in this study. The samples are characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The biological activities are evaluated via cytotoxicity study, adhesion and proliferation of osteoblast measurement, and alkaline phosphatase (ALP) assay. All the synthesized materials are HA phase, which have hierarchical structures with oriented HA nanorods assembled into the platy particles. These materials are non-cytotoxic against L929 cells line even at 400 μg/ml powder suspension. The results clearly indicate that the proliferation of L929 cells increases with trace elements doping from trace Si-HA to Si + Sr-HA. The adhesion and proliferation of osteoblast measurement illustrates that proliferation of osteoblasts advances about 1.3 times for Si-HA and about 1.8 times for Si + Sr-HA compared with undoped HA. In general, Si-HA with trace Si element shows enhanced cell differentiation, and Si + Sr-HA dual-doped with Si and Sr elements presents increased biological activity compared with Si-HA.
研究领域:
生物材料学
·
骨组织工程
·
无机非金属材料
·
生物医学工程
·
细胞生物学
✓ 已验证
DOI
高影响因子
Nano Energy
·
2014
·
IF 10.211
Xiaolei Jiang,Huayun Xu,Jing Liu,Jian Yang,Hongzhi Mao,Yitai Qian
Hierarchical mesoporous Li 2 Mn 0.5 Fe 0.5 SiO 4 consisted of nanoparticles or nanoplates has been successfully synthesized for the first time by a hydrothermal method . Their carbon-coated composites are obtained by a heat treatment in the presence of citric acid. These composites were characterized by powder X-ray diffractometry, scanning and transmission electron microscopy , Raman spectroscopy , and thermogravimetric analysis . The lithium storage capacity and cycling performance of the optimized Li 2 Mn 0.5 Fe 0.5 SiO 4 /C composite are greatly enhanced when tested as a cathode material in lithium-ion batteries (LIBs). It exhibits a discharge capacity of 125 mAh g −1 after 60 cycles at a rate of 0.1 C. This superior electrochemical property could be ascribed to high purity and mesoporous structure of Li 2 Mn 0.5 Fe 0.5 SiO 4 , which greatly enhances the electronic conductivity as well as the diffusion coefficient of lithium ions .
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 31
·17682-17693
·
IF 4.22
Liu Bei,Huang Peng,Liu Minqi,Xie Zhiyong
Impurities and carbon defects generally hinder practical application of microcrystalline graphite as anode material for lithium-ion batteries. However, the impurities and carbon defects of the natural microcrystalline graphite are found to be the active sites to catalyze silicon deposition during the chemical vapor deposition process. In this work, the impurities and carbon defects of prepared anode material are wrapped by double coatings that are combined by the silicon nanowires and the carbon layer. The composite anode material exhibits a high capacity of 640 mA h g −1 at a current density of 186 mA g −1 after 250 cycles. The results of the density functional theory calculation reveal that the existence of impurities and carbon defects on graphite surface enhances the absorption energy of graphite to silicon during chemical vapor deposition process at 900 °C. By utilizing the impurities and carbon defects, the natural microcrystalline graphite can be employed as a new and low-cost anode material to fabricate the high-performance lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
计算材料学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）