Direct Imaging the Upconversion Nanocrystal Core/Shell Structure at the Subnanometer Level: Shell Thickness Dependence in Upconverting Optical Properties

The core-shell structure NiFe2O4@TiO2 nanoparticles was successfully prepared using a sol-gel method, the influence of shell thickness and calcination temperatures on the composition, microstructure, magnetic properties and visible-light catalytic activity of the nanoparticles was studied by XRD, TEM, Uv–vis, vibrating sample magnetometer, etc. Results showed the main composition of core in NiFe2O4@TiO2 was spinel ferrite, and the shell was anatase TiO2, and theshell thickness increased significantly with the increase of TiO2 content, ranging from 10nm to 50nm. The Ms and Mr of nanoparticles decreased with the increase of TiO2 content, and no obvious reaction between the magnetic core and shell occurred; visible-light degradation percent of NiFe2O4@TiO2 nanoparticles increased along with the increase of TiO2 content, whereas the recovery rate of it decreased. Degradation percent and the recovery percent of NiFe2O4@TiO2-50 still reached 93.7% and 90.5%, even after 10 cycle times, respectively, possessing the excellent long-term stability.

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Stress Distribution in Microregion of Core–Shell Structure Lightweight Aggregate Concrete

Buildings ◽

10.3390/buildings11110540 ◽

2021 ◽

Vol 11 (11) ◽

pp. 540

Author(s):

Meng Zhu ◽

Lihua Zhang ◽

Weilong Wang ◽

Hongping Zhang ◽

Wenjin Xing

Keyword(s):

Stress Distribution ◽

Shell Structure ◽

Shell Thickness ◽

Lightweight Aggregate ◽

Thickness Ratio ◽

Core Shell ◽

Distribution Analysis ◽

Failure Resistance ◽

The Core ◽

Core Shell Structure

An in-depth understanding of the effect of cordierite/belite core–shell structure lightweight aggregate (CSLWA) on the mechanical performance of LWA concrete (LWAC) is critical for improving the failure resistance of LWAC. In this study, the stress distribution of the microregion in CSLWA was systematically investigated via a finite element analysis to explore its effect on the mechanical properties of LWAC. In detail, the material components, core–shell thickness ratio, porosity and width of interfacial transition zone (ITZ), and absence or presence of interfacial bonding zone (IBZ) were considered during the stress distribution analysis of the microregion of LWAC. The results showed that a reduction in the material components, with a high-elastic modulus in the core, a decrease in the core–shell thickness ratio, and the formation of the core–shell IBZ are beneficial for optimizing the stress distribution of the microregion and alleviating the stress concentration phenomenon of LWAC. Moreover, due to the continuous hydration of belite shell, the ITZ of CSLWA becomes increasingly dense, thus the stress distribution is more uniform than that of ordinary LWAC, indicating that CSLWA exhibits the potential to improve the failure resistance of LWAC. This study helps to develop an understanding of the role played by the core–shell structure in improving the toughness of LWAC, and provides a new solution and methodology for improving the brittleness of LWAC.

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Synthesis of Au/SnO2 core–shell structure nanoparticles by a microwave-assisted method and their optical properties

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2010.11.009 ◽

2011 ◽

Vol 184 (2) ◽

pp. 312-316 ◽

Cited By ~ 28

Author(s):

Yeon-Tae Yu ◽

Prabir Dutta

Keyword(s):

Optical Properties ◽

Shell Structure ◽

Core Shell ◽

Microwave Assisted ◽

Core Shell Structure ◽

Microwave Assisted Method

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Direct imaging of core-shell structure in silver-gold bimetallic nanoparticles

Applied Physics Letters ◽

10.1063/1.2139851 ◽

2005 ◽

Vol 87 (24) ◽

pp. 243103 ◽

Cited By ~ 52

Author(s):

Z. Y. Li ◽

J. Yuan ◽

Y. Chen ◽

R. E. Palmer ◽

J. P. Wilcoxon

Keyword(s):

Shell Structure ◽

Bimetallic Nanoparticles ◽

Core Shell ◽

Direct Imaging ◽

Core Shell Structure

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Fine regulation of electron transfer in Ag@Co3O4 nanoparticles for boosting oxygen evolution reaction

Chemical Communications ◽

10.1039/d1cc02189c ◽

2021 ◽

Author(s):

Xiwen Du ◽

Zhe Li ◽

Yi Feng ◽

Xiuyao Lang ◽

Wenjing Kang ◽

...

Keyword(s):

Electron Transfer ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Shell Structure ◽

Shell Thickness ◽

Core Shell ◽

Co3o4 Nanoparticles ◽

Fine Regulation ◽

Core Shell Structure

In this study, a core-shell structure (Ag@Co3O4) was constructed to modify valance state of cobalt cations precisely by continuously adjusting the shell thickness. There exists a volcano relationship between valence...

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