Room-temperature ferromagnetism in Ni(ii)-chromia based core–shell nanoparticles: experiment and first principles calculations

2018 ◽  
Vol 20 (15) ◽  
pp. 10396-10406 ◽  
Author(s):  
M. D. Hossain ◽  
R. A. Mayanovic ◽  
S. Dey ◽  
R. Sakidja ◽  
M. Benamara
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Core Shell ◽  
First Principles Calculations ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

We have synthesized bimagnetic core–shell nanoparticles containing a first-of-its-kind Ni(ii)-chromia nanophase shell and a well-defined, epitaxial core–shell interface.

Highly active and stable Au@CuxO core–shell nanoparticles supported on alumina for carbon monoxide oxidation at low temperature

RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75126-75132 ◽  
Author(s):  
Weining Zhang ◽  
Qingguo Zhao ◽  
Xiaohong Wang ◽  
Xiaoxia Yan ◽  
Sheng Han ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Low Temperature ◽  
Co Oxidation ◽  
Room Temperature ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Highly Active ◽  
Co Conversion ◽  
Core Shell Nanoparticles

Au@CuxO core–shell nanoparticles and Au@CuxO/Al2O3 used for CO oxidation at low temperature are prepared. CO conversion on Au@CuxO/Al2O3 can reach to 38% at room temperature and the catalytic activity remains unchanged after 108 hours reaction.

A BIO-INSPIRED POLYDOPAMINE APPROACH TO PREPARATION OF GOLD-COATED Fe3O4 CORE–SHELL NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND MECHANISM

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350061 ◽  
Author(s):  
PENG AN ◽  
FANG ZUO ◽  
XINHUA LI ◽  
YUANPENG WU ◽  
JUNHUA ZHANG ◽  
...  
Keyword(s):  
Shell Structure ◽  
Room Temperature ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Stabilizing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

A biomimetic and facile approach for integrating Fe 3 O 4 and Au with polydopamine (PDA) was proposed to construct gold-coated Fe 3 O 4 nanoparticles ( Fe 3 O 4@ Au – PDA ) with a core–shell structure by coupling in situ reduction with a seed-mediated method in aqueous solution at room temperature. The morphology, structure and composition of the core–shell structured Fe 3 O 4@ Au – PDA nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The formation process of Au shell was assessed using a UV-Vis spectrophotometer. More importantly, according to investigating changes in PDA molecules by Fourier transform infrared spectroscopy (FTIR) and in preparation process of the zeta-potential data of nanoparticles, the mechanism of core–shell structure formation was proposed. Firstly, PDA-coated Fe 3 O 4 are obtained using dopamine (DA) self-polymerization to form thin and surface-adherent PDA films onto the surface of a Fe 3 O 4 "core". Then, Au seeds are attached on the surface of PDA-coated Fe 3 O 4 via electrostatic interaction in order to serve as nucleation centers catalyzing the reduction of Au 3+ to Au 0 by the catechol groups in PDA. Accompanied by the deposition of Au , PDA films transfer from the surface of Fe 3 O 4 to that of Au as stabilizing agent. In order to confirm the reasonableness of this mechanism, two verification experiments were conducted. The presence of PDA on the surface of Fe 3 O 4@ Au – PDA nanoparticles was confirmed by the finding that glycine or ethylenediamine could be grafted onto Fe 3 O 4@ Au – PDA nanoparticles through Schiff base reaction. In addition, Fe 3 O 4@ Au – DA nanoparticles, in which DA was substituted for PDA, were prepared using the same method as that for Fe 3 O 4@ Au – PDA nanoparticles and characterized by UV-Vis, TEM and FTIR. The results validated that DA possesses multiple functions of attaching Au seeds as well as acting as both reductant and stabilizing agent, the same functions as those of PDA.

scholarly journals First-principles calculations of GaN:Gd nanowires: Carbon-dopants-induced room-temperature ferromagnetism

AIP Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 115003 ◽  
Author(s):  
Ruikuan Xie ◽  
Huaizhong Xing ◽  
Yijie Zeng ◽  
Yuan Liang ◽  
Yan Huang ◽  
...  
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
First Principles Calculations

scholarly journals Seed-mediated growth of MOF-encapsulated Pd@Ag core–shell nanoparticles: toward advanced room temperature nanocatalysts

2016 ◽  
Vol 7 (1) ◽  
pp. 228-233 ◽  
Author(s):  
Liyu Chen ◽  
Binbin Huang ◽  
Xuan Qiu ◽  
Xi Wang ◽  
Rafael Luque ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Room Temperature ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Growth Strategy ◽  
Core Shell ◽  
Hydrogen Atoms ◽  
Shell Nanoparticles ◽  
Seed Mediated ◽  
Core Shell Nanoparticles

Core–shell Pd@Ag nanoparticles are formed within the pores of MOFs via a seed mediated growth strategy with activated hydrogen atoms as the reducing agent, leading to a family of bimetallic core–shell MOF nanomaterials with excelling catalytic performance in room temperature reactions.

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