Sol–Gel SiO2 Film Contained Au/SiO2/Quantum Dot Core/Shell/Shell Nanostructures with Plasmonic Enhanced Photoluminescence

2012 ◽  
Vol 12 (12) ◽  
pp. 8999-9002 ◽  
Author(s):  
Ping Yang ◽  
Lipeng Zhang ◽  
Yingzi Wang
Keyword(s):  
Quantum Dot ◽  
Sol Gel ◽  
Sio2 Film ◽  
Core Shell ◽  
Enhanced Photoluminescence ◽  
Shell Nanostructures

scholarly journals Magnetite-Silica Core/Shell Nanostructures: From Surface Functionalization towards Biomedical Applications—A Review

2021 ◽  
Vol 11 (22) ◽  
pp. 11075
Author(s):  
Angela Spoială ◽  
Cornelia-Ioana Ilie ◽  
Luminița Narcisa Crăciun ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Biomedical Applications ◽  
Sol Gel ◽  
Magnetic Nanomaterials ◽  
Core Shell ◽  
Synthesis Methods ◽  
Shell Nanostructures ◽  
Silica Core ◽  
Magnetic Resonance Imaging Mri ◽  
Co Precipitation

The interconnection of nanotechnology and medicine could lead to improved materials, offering a better quality of life and new opportunities for biomedical applications, moving from research to clinical applications. Magnetite nanoparticles are interesting magnetic nanomaterials because of the property-depending methods chosen for their synthesis. Magnetite nanoparticles can be coated with various materials, resulting in “core/shell” magnetic structures with tunable properties. To synthesize promising materials with promising implications for biomedical applications, the researchers functionalized magnetite nanoparticles with silica and, thanks to the presence of silanol groups, the functionality, biocompatibility, and hydrophilicity were improved. This review highlights the most important synthesis methods for silica-coated with magnetite nanoparticles. From the presented methods, the most used was the Stöber method; there are also other syntheses presented in the review, such as co-precipitation, sol-gel, thermal decomposition, and the hydrothermal method. The second part of the review presents the main applications of magnetite-silica core/shell nanostructures. Magnetite-silica core/shell nanostructures have promising biomedical applications in magnetic resonance imaging (MRI) as a contrast agent, hyperthermia, drug delivery systems, and selective cancer therapy but also in developing magnetic micro devices.

scholarly journals Lead-Free BNT–BT0.08/CoFe2O4 Core–Shell Nanostructures with Potential Multifunctional Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 672
Author(s):  
Marin Cernea ◽  
Roxana Radu ◽  
Harvey Amorín ◽  
Simona Gabriela Greculeasa ◽  
Bogdan Stefan Vasile ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
Transmission Electron Microscopy Data ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Two Phase ◽  
X Ray ◽  
Shell Nanostructures

Herein we report on novel multiferroic core–shell nanostructures of cobalt ferrite (CoFe2O4)–bismuth, sodium titanate doped with barium titanate (BNT–BT0.08), prepared by a two–step wet chemical procedure, using the sol–gel technique. The fraction of CoFe2O4 was varied from 1:0.5 to 1:1.5 = BNT–BT0.08/CoFe2O4 (molar ratio). X–ray diffraction confirmed the presence of both the spinel CoFe2O4 and the perovskite Bi0.5Na0.5TiO3 phases. Scanning electron microscopy analysis indicated that the diameter of the core–shell nanoparticles was between 15 and 40 nm. Transmission electron microscopy data showed two–phase composite nanostructures consisting of a BNT–BT0.08 core surrounded by a CoFe2O4 shell with an average thickness of 4–7 nm. Cole-Cole plots reveal the presence of grains and grain boundary effects in the BNT–BT0.08/CoFe2O4 composite. Moreover, the values of the dc conductivity were found to increase with the amount of CoFe2O4 semiconductive phase. Both X-ray photoelectron spectroscopy (XPS) and Mössbauer measurements have shown no change in the valence of the Fe3+, Co2+, Bi3+ and Ti4+ cations. This study provides a detailed insight into the magnetoelectric coupling of the multiferroic BNT–BT0.08/CoFe2O4 core–shell composite potentially suitable for magnetoelectric applications.

Magnetic response of hybrid ferromagnetic and antiferromagnetic core–shell nanostructures

Nanoscale ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 6064-6070 ◽  
Author(s):  
U. Khan ◽  
W. J. Li ◽  
N. Adeela ◽  
M. Irfan ◽  
K. Javed ◽  
...  
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Magnetic Response ◽  
Step Method ◽  
Shell Nanostructures

The synthesis of FeTiO3–Ni(Ni80Fe20) core–shell nanostructures by a two-step method (sol–gel and DC electrodeposition) has been demonstrated.

Au/SiO2/QD core/shell/shell nanostructures with plasmonic-enhanced photoluminescence

2012 ◽  
Vol 14 (9) ◽  
Author(s):  
Ping Yang ◽  
Kazunori Kawasaki ◽  
Masanori Ando ◽  
Norio Murase
Keyword(s):  
Core Shell ◽  
Enhanced Photoluminescence ◽  
Shell Nanostructures

scholarly journals Plasmonic Properties of Bimetallic Quantum Dot Ag@Au Core-Shell Nanostructures Embedded in Non-Absorptive Host Medium

2021 ◽  
Author(s):  
Gashaw Beyene Beyene Kassahun
Keyword(s):  
Quantum Dot ◽  
Field Enhancement ◽  
Visible Spectral Region ◽  
Classical Electrodynamics ◽  
Core Shell ◽  
Core Size ◽  
Static Approximation ◽  
Host Medium ◽  
Shell Nanostructures ◽  
Outer Interface

This studies the plasmonic properties of the bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorbent host medium. Local field enhancement factor and coefficient of absorption of Ag-core and Au-shell are primarily studied based on quasi-static approximation of classical electrodynamics for 6-10 nm composite radius. In this quantum dot geometry, two set of plasmonic resonances in visible spectral region are observed: the first resonance associated with inner interface of gold (Ag@Au) and the second resonance associated with outer interface of gold (Au@medium). The two plasmonic resonances are close each other and enhanced when the size of composite decreased for a fixed core size while shifted to in opposite direction and the amplitude of peak decreased when the core size is increased for a fixed composite size. For the optimized size of core/composite or shell thickness and other parameters to the desired values, such type of composites are recommended for various applications like; photocatalysis, biomedical, nano-optoelectronics.

scholarly journals Enhanced photoluminescence of DCJTB with ordered Ag-SiO2 core–shell nanostructures via nanosphere lithography

2020 ◽  
Vol 17 ◽  
pp. 103168
Author(s):  
Yuan-Fong Chou Chau ◽  
Chieh-Jen Lin ◽  
Tsung Sheng Kao ◽  
Ya-Chih Wang ◽  
Chee Ming Lim ◽  
...  
Keyword(s):  
Nanosphere Lithography ◽  
Core Shell ◽  
Enhanced Photoluminescence ◽  
Shell Nanostructures

scholarly journals ZnTe/CdSe type-II core/shell spherical quantum dot under an external electric field

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
A. Chafai ◽  
I. Essaoudi ◽  
A. Ainane ◽  
F. Dujardin ◽  
R. Ahuja
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
External Electric Field ◽  
Function Approximation ◽  
Charge Carriers ◽  
Conduction Band Edge ◽  
Core Shell ◽  
Electron Effective Mass ◽  
Spherical Quantum Dot ◽  
Shell Nanostructures

We have investigated in the framework of the envelope function approximation and taking into account the dependence of the electron effective mass on radius the energy of an electron inside a ZnTe/CdSecore/shell spherical quantum dot. In order to make the problem more realistic, we describe the conduction band-edge alignment between core and shell materials by a finite height barrier. By applying the Ritz variational principle the effect of the electric field on the electronic states was also examined. Our numerical results show the opportunity to control the energy states position of the charge carriers inside our core/shell nanostructures by controlling the size (core radius, shell thickness) of the nanostructure and the strength of the external electric field. #CORE/SHELL MATERIALS #NANOSTRUCTURES #QUANTUM DOTS #ELECTRIC FIELD

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