A Phase-Transfer Identification of Core−Shell Structures in Ag−Pt Nanoparticles

2005 ◽  
Vol 109 (12) ◽  
pp. 5468-5472 ◽  
Author(s):  
J. Yang ◽  
Jim Yang Lee ◽  
L. X. Chen ◽  
Heng-Phon Too
Keyword(s):  
Phase Transfer ◽  
Pt Nanoparticles ◽  
Shell Structures ◽  
Core Shell

Phase Transfer Identification of Core–Shell Structures in Ag–Au Bimetallic Nanoparticles

2005 ◽  
Vol 5 (7) ◽  
pp. 1095-1100 ◽  
Author(s):  
J. Yang ◽  
Jim Yang Lee ◽  
L. X. Chen ◽  
Heng-Phon Too
Keyword(s):  
Bimetallic Nanoparticles ◽  
Phase Transfer ◽  
Shell Structures ◽  
Core Shell

Phase-Transfer Identification of Core-Shell Structures in Bimetallic Nanoparticles

Plasmonics ◽  
2006 ◽  
Vol 1 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Jun Yang ◽  
Jim Yang Lee ◽  
Heng-Phon Too
Keyword(s):  
Bimetallic Nanoparticles ◽  
Phase Transfer ◽  
Shell Structures ◽  
Core Shell

A phase transfer identification of core–shell structures in Au–Ru nanoparticles

2005 ◽  
Vol 537 (1-2) ◽  
pp. 279-284 ◽  
Author(s):  
J. Yang ◽  
Jim Yang Lee ◽  
Heng-Phon Too
Keyword(s):  
Phase Transfer ◽  
Shell Structures ◽  
Core Shell ◽  
Ru Nanoparticles

Magnetic Pt single and double core-shell structures for the catalytic selective hydrogenation of cinnmaladehyde

2020 ◽  
Vol 92 (3) ◽  
pp. 413-427 ◽  
Author(s):  
Robinson B. Dinamarca ◽  
Rodrigo Espinoza-González ◽  
Cristian H. Campos ◽  
Gina Pecchi
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Pt Nanoparticles ◽  
Magnetic Core ◽  
Shell Structures ◽  
Pt Catalyst ◽  
Core Shell ◽  
Average Particle ◽  
Cinnamyl Alcohol ◽  
Metal Support Interaction

AbstractThis study reports the catalytic preparation, characterization, and evaluation of nanoscale core-shell structures with a γ-Fe2O3 core covered by a SiO2 monoshell or by a SiO2@TiO2 multishell as a support for Pt nanoparticles (NPs) to synthesize active and operationally stable catalysts for selective liquid-phase cinnamaldehyde hydrogenation. The structures were designed with a magnetic core so they could be easily recovered from the catalytic bed by simple magnetization and with a SiO2 monoshell or a SiO2@TiO2 multishell to protect the magnetic core. At the same time, this study details the effect of the shell on the catalytic performance. Moreover, the effect of particle size on the selective production of cinnamyl alcohol was studied by preparing two families of catalysts with metal loadings of 1 wt% and 5 wt% Pt with respect to the core-shell. The particle size effect enabled the Fe2O3@SiO2-5%Pt system, with an average particle size of 5.6 nm, to reach 100 % conversion of cinnamaldehyde at 300 min of reaction, producing cinnamyl alcohol with 90 % selectivity; this result differed greatly from that of the Fe2O3@SiO2-1%Pt (dPt = 3.5 nm) system, which reached a maximum conversion at 600 min with 49 % selectivity for the product of interest. However, the Fe2O3@SiO2@TiO2-x%Pt systems showed lower levels of conversion and selectivity compared to those of the Fe2O3@SiO2-x%Pt catalysts, which is attributed to the fact that average metal particle sizes below 5.0 nm were obtained in both cases. After reduction in H2 at 773 K, the Fe2O3@SiO2@TiO2-1%Pt catalyst showed deactivation, reaching 10 % conversion at 600 min of reaction and 60 % selectivity for the product of interest. However, the reduced Fe2O3@SiO2@TiO2-5%Pt system showed 98 % conversion with 95 % selectivity for cinnamyl alcohol at 24 h of operation; the increase in selectivity is attributed to the combined effects of the increase in average particle size (~7.5 nm) and the presence of strong metal-support interaction – SMSI – effects after reduction. Finally, the most selective systems were tested for operational stability, where the Fe2O3@SiO2@-5%Pt catalyst could be reused in three consecutive operating cycles while maintaining its activity and selectivity for cinnamyl alcohol – unlike the Fe2O3@SiO2@TiO2-5%Pt reduced system, which was deactivated after the third reaction cycle due to active phase leaching.

Designing active mats based on cellulose acetate/polycaprolactone core/shell structures with different release kinetics

2021 ◽  
Vol 261 ◽  
pp. 117849 ◽  
Author(s):  
Adrián Rojas ◽  
Eliezer Velásquez ◽  
Constanza Piña ◽  
María José Galotto ◽  
Carol López de Dicastillo
Keyword(s):  
Cellulose Acetate ◽  
Release Kinetics ◽  
Shell Structures ◽  
Core Shell

scholarly journals A SERS Study of Charge Transfer Process in Au Nanorod–MBA@Cu2O Assemblies: Effect of Length to Diameter Ratio of Au Nanorods

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Shell Structure ◽  
Shell Structures ◽  
Core Shell ◽  
Absorption Bands ◽  
Au Nanorods ◽  
The Core ◽  
Band Position ◽  
Surface Enhanced Raman ◽  
Core Shell Structure

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.

Template-free synthesis of ordered ZnO@ZnS core–shell arrays for high performance supercapacitors

2016 ◽  
Vol 45 (44) ◽  
pp. 17980-17986 ◽  
Author(s):  
Hailong Yan ◽  
Tong Li ◽  
Yang Lu ◽  
Jinbing Cheng ◽  
Tao Peng ◽  
...  
Keyword(s):  
High Performance ◽  
Shell Structures ◽  
Core Shell ◽  
Template Free

In this article, ordered ZnO@ZnS core–shell structures have been produced on a stainless mesh by a two-step approach without using a template.

Synthesis and characterisation of core–shell structures for orthopaedic surgery

2007 ◽  
Vol 40 (15) ◽  
pp. 3349-3353 ◽  
Author(s):  
Edina Rusen ◽  
Cătălin Zaharia ◽  
Teodora Zecheru ◽  
Bogdan Mărculescu ◽  
Robert Filmon ◽  
...  
Keyword(s):  
Orthopaedic Surgery ◽  
Shell Structures ◽  
Core Shell
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