A mesoporous Ni3N/NiO composite with a core–shell structure for room temperature, selective and sensitive NO2 gas sensing

RSC Advances ◽  
2016 ◽  
Vol 6 (49) ◽  
pp. 42917-42922 ◽  
Author(s):  
Mingming Zou ◽  
Hu Meng ◽  
Fengdong Qu ◽  
Liang Feng ◽  
Minghui Yang
Keyword(s):  
Shell Structure ◽  
Room Temperature ◽  
Gas Sensing ◽  
Core Shell ◽  
Template Free ◽  
Core Shell Structure

Mesoporous Ni3N/NiO composites with core–shell structure were synthesized by a template free method, demonstrate a significant improvements both in sensitivity and in selectivity for NO2 gas sensing at room temperature.

Au@ZnO core–shell structure for gaseous formaldehyde sensing at room temperature

2014 ◽  
Vol 199 ◽  
pp. 314-319 ◽  
Author(s):  
Feng-Chao Chung ◽  
Zhen Zhu ◽  
Peng-Yi Luo ◽  
Ren-Jang Wu ◽  
Wei Li
Keyword(s):  
Shell Structure ◽  
Room Temperature ◽  
Core Shell ◽  
Formaldehyde Sensing ◽  
Core Shell Structure ◽  
Gaseous Formaldehyde

Indium-implantation-induced enhancement of gas sensing behaviors of SnO2 nanowires by the formation of homo-core–shell structure

2020 ◽  
Vol 321 ◽  
pp. 128475
Author(s):  
Jae-Hun Kim ◽  
Jin-Young Kim ◽  
Jae-Hyoung Lee ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
...  
Keyword(s):  
Shell Structure ◽  
Gas Sensing ◽  
Core Shell ◽  
Sno2 Nanowires ◽  
Core Shell Structure

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 Strengthening of Nanocrystalline Al with Al3Zr Core-Shell Structure

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1144
Author(s):  
Dora Janovszky
Keyword(s):  
Mechanical Properties ◽  
Shell Structure ◽  
Hot Pressing ◽  
Room Temperature ◽  
High Energy ◽  
Core Shell ◽  
Mixed Powder ◽  
Reinforcing Particles ◽  
Core Shell Structure ◽  
Nanocrystalline Phases

High-density Al-based composites reinforced with ten-wt.% recycled nanocrystalline CuZrAgAl particles have been fabricated by mechanical milling, cold- and hot-pressing. The microstructures, phase transformations, and mechanical properties of the mixed powder and sintered samples were investigated. After milling in a ball mill for 30 h, the microhardness of the mixed powder increases to 301 ± 31 HV0.01 and 222 ± 10 HV0.01 without and with ethanol milling, respectively. On account of the interdiffusion, the melting temperature of mixed powder reduces to 574 ± 5.0 °C and 627.5 ± 6.5 °C after 30 h milling. The study showed that the reinforcing particles are homogeneously distributed in the sintered nanocrystalline Al-based composites. During the hot-pressing, a shell zone forms at the interface of reinforcing particles during hot pressing after high energy milling with a minimum of ten hours milling time. This shell zone consists of Al3Zr (D023) phase. The coarsening resistant core-shell structure and grain refinement greatly improve mechanical properties. The compression strength at room temperature varies between 650 and 800 MPa at room temperature and is 380 MPa at 400 °C for the composite containing ten-wt.% of the Cu-Zr-based amorphous-nanocrystalline phases. The Brinell hardness of the sintered composite is 329 HB.

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