Synthesis and photoluminescence properties of novel core–shell–shell SiO2@CePO4:Tb@SiO2 submicro-spheres

Spherical submicron SiO2 particles have been coated with luminescent Lu2O3: Eu3+ layers by a Pechini sol-gel process, resulting in the formation of SiO2@Lu2O3: Eu3+ core-shell particles(300, 500 nm). The obtained core–shell phosphors have perfect spherical shape with narrow size distribution, smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (50 nm for four deposition cycles). Under the excitation of ultraviolet, the Eu3+ ion mainly shows its characteristic emissions in the core-shell particles from Lu2O3: Eu3+) shells. The PL intensity of Eu3+ increases with the number of coating cycles.

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Photoluminescence properties study of the Au/Au2S nanoshell

Canadian Journal of Physics ◽

10.1139/p02-047 ◽

2002 ◽

Vol 80 (6) ◽

pp. 707-711

Author(s):

J J Diao ◽

F S Qiu ◽

G D Chen ◽

C Xi ◽

Y Song

Keyword(s):

Size Effect ◽

Quantum Size Effect ◽

Experimental Results ◽

Nanometer Scale ◽

Core Shell ◽

Photoluminescence Properties ◽

The Core ◽

Enhanced Photoluminescence ◽

Quantum Size ◽

Photoluminescence Peak

Photoluminescence experimental results of the Au/Au2S nanoshell (a nanometer-scale Au2S core coated by a thin Au shell) are presented in this note. An enhanced photoluminescence peak of Au coated Au2S is obtained near the bluegreen region, compared with the photoluminescence region of bulk Au2S, which is near the orangered region. The quantum-size effect and the core/shell nanostructure caused the blueshift photoluminescence of the Au2S/Au nanoshell. PACS Nos.: 81.05Ys, 78.55-m

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Synthesis and Microwave Absorption Properties of Core-Shell Structured Co3O4-PANI Nanocomposites

Journal of Nanomaterials ◽

10.1155/2015/845983 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 12

Author(s):

Hongyan Xu ◽

Zhenyin Hai ◽

Jiangtao Diwu ◽

Qiang Zhang ◽

Libo Gao ◽

...

Keyword(s):

Microwave Absorption ◽

Reflection Loss ◽

In Situ Polymerization ◽

Low Cost ◽

Core Shell ◽

Absorption Properties ◽

Microwave Absorption Properties ◽

The Core ◽

High Efficient

The core-shell structured Co3O4-PANI nanocomposites have been successfully prepared using an in situ polymerization method, while the core Co3O4 nanoparticles were synthesized by carbon-assisted method using degreasing cotton as a template. The obtained samples were characterized by XRD, TEM, FTIR, and XPS. The results indicated that the amorphous PANI was well covered on the surface of the spinel Co3O4 and the Co3O4-PANI with core-shell structure was formed with particle size of about 100 nm. The interfacial interaction of the core-shell nanocomposite greatly enhances the microwave absorption properties. The maximum reflection loss of Co3O4-PANI is up to −45.8 dB at 11.7 GHz with a thickness of 2.5 mm and the adsorption bandwidth with the reflection loss below −10 dB reaches 14.1 GHz ranging from 3.9 to 18 GHz when the thickness is between 2 and 5.5 mm. Therefore, the facilely synthesized and low-cost Co3O4-PANI nanocomposite with superior microwave absorption properties can be a promising nanomaterial for high efficient microwave absorption.

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Preparation of CdS/ZnO Core/shell Structured Nanoparticles by Hydrothermal Method

MRS Proceedings ◽

10.1557/proc-692-h9.41.1 ◽

2001 ◽

Vol 692 ◽

Cited By ~ 1

Author(s):

Chunhua Yan ◽

Lingdong Sun ◽

Xuefeng Fu ◽

Chunsheng Liao

Keyword(s):

Hydrothermal Method ◽

Surface Defects ◽

Structure Characterization ◽

Cds Nanoparticles ◽

Core Shell ◽

Photoluminescence Properties ◽

The Core ◽

Core Shell Structure ◽

20 Nm ◽

Zno Semiconductor

AbstractCdS and ZnO capped CdS (CdS/ZnO) semiconductor nanoparticles were synthesized via hydrothermal method by thermal decomposition of the cysteine-cadmium and Zn(OH)42− complex precursors. Both of the photoluminescence properties and structure characterization confirmed the core/shell structure as expected. Compared to CdS nanoparticles, the band-gap emission of CdS/ZnO was greatly improved, that means the capping layer of ZnO modified the surface of CdS and reduced the surface defects effectively. ED and XRD confirmed the formation of hexagon phased CdS and the TEM image indicated the size of CdS/ZnO was about 20 nm.

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Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

Ukrainian Journal of Physics ◽

10.15407/ujpe65.10.904 ◽

2020 ◽

Vol 65 (10) ◽

pp. 904

Author(s):

V. O. Zamorskyi ◽

Ya. M. Lytvynenko ◽

A. M. Pogorily ◽

A. I. Tovstolytkin ◽

S. O. Solopan ◽

...

Keyword(s):

Magnetic Properties ◽

Spinel Ferrite ◽

Composite Nanoparticles ◽

Core Shell ◽

Cofe2o4 Nanoparticles ◽

Core Diameter ◽

The Core ◽

Shell Particles ◽

Interface Parameters ◽

Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

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Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Catalysts ◽

10.3390/catal11010072 ◽

2021 ◽

Vol 11 (1) ◽

pp. 72

Author(s):

Christian Zambrzycki ◽

Runbang Shao ◽

Archismita Misra ◽

Carsten Streb ◽

Ulrich Herr ◽

...

Keyword(s):

Water Purification ◽

Functional Materials ◽

Core Material ◽

Solid Catalyst ◽

Core Shell ◽

Shell Nanoparticles ◽

The Core ◽

Shell Nanostructures ◽

Sio2 Shell ◽

Iron Based

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.

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Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Polymers ◽

10.3390/polym13060888 ◽

2021 ◽

Vol 13 (6) ◽

pp. 888

Author(s):

Nguyen Thi Thanh Hai ◽

Nguyen Duc Cuong ◽

Nguyen Tran Quyen ◽

Nguyen Quoc Hien ◽

Tran Thi Dieu Hien ◽

...

Keyword(s):

Antifungal Activity ◽

Carboxymethyl Cellulose ◽

Chemical Reduction ◽

Low Cost ◽

Phytophthora Capsici ◽

Reduction Process ◽

Spherical Shape ◽

Core Shell ◽

Cu Nanoparticles ◽

Average Size

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

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Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽

10.3390/mi12040359 ◽

2021 ◽

Vol 12 (4) ◽

pp. 359

Author(s):

Francesco Ruffino

Keyword(s):

Optical Properties ◽

Light Scattering ◽

Bimetallic Nanoparticles ◽

Dominant Role ◽

Scattered Light ◽

Specific Interaction ◽

Surface Enhanced Raman Spectroscopy ◽

Localized Surface Plasmon ◽

Core Shell ◽

The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

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Tuning and understanding the electronic effect of Co-Mo-O sties in bifunctional electrocatalysts for ultralong-lasting rechargable zinc-air battery

Journal of Materials Chemistry A ◽

10.1039/d1ta04408g ◽

2021 ◽

Author(s):

Yi Guan ◽

Nan Li ◽

Jiao He ◽

Yongliang Li ◽

Lei Zhang ◽

...

Keyword(s):

Electronic Effect ◽

Metal Organic Frameworks ◽

Core Shell ◽

Zeolitic Imidazolate Frameworks ◽

Assembly Strategy ◽

The Core ◽

Bifunctional Electrocatalysts ◽

Metal Organic ◽

Air Battery

Herein, we report a post-assembly strategy by growing the bimetallic Co/Zn zeolitic imidazolate frameworks (BIMZIF) on the surface of the customized Mo metal-organic frameworks (MOFs) (Mo-MOF) to prepare the core-shell...

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Solubilization of Charged Porphyrins in Interpolyelectrolyte Complexes: A Computer Study

Polymers ◽

10.3390/polym13040502 ◽

2021 ◽

Vol 13 (4) ◽

pp. 502

Author(s):

Karel Šindelka ◽

Zuzana Limpouchová ◽

Karel Procházka

Keyword(s):

Dissipative Particle Dynamics ◽

Water Soluble ◽

Coarse Grained ◽

Core Shell ◽

Computer Study ◽

Interpolyelectrolyte Complex ◽

The Core ◽

Porphyrin Derivatives ◽

Oppositely Charged ◽

Positively Charged

Using coarse-grained dissipative particle dynamics (DPD) with explicit electrostatics, we performed (i) an extensive series of simulations of the electrostatic co-assembly of asymmetric oppositely charged copolymers composed of one (either positively or negatively charged) polyelectrolyte (PE) block A and one water-soluble block B and (ii) studied the solubilization of positively charged porphyrin derivatives (P+) in the interpolyelectrolyte complex (IPEC) cores of co-assembled nanoparticles. We studied the stoichiometric mixtures of 137 A10+B25 and 137 A10−B25 chains with moderately hydrophobic A blocks (DPD interaction parameter aAS=35) and hydrophilic B blocks (aBS=25) with 10 to 120 P+ added (aPS=39). The P+ interactions with other components were set to match literature information on their limited solubility and aggregation behavior. The study shows that the moderately soluble P+ molecules easily solubilize in IPEC cores, where they partly replace PE+ and electrostatically crosslink PE− blocks. As the large P+ rings are apt to aggregate, P+ molecules aggregate in IPEC cores. The aggregation, which starts at very low loadings, is promoted by increasing the number of P+ in the mixture. The positively charged copolymers repelled from the central part of IPEC core partially concentrate at the core-shell interface and partially escape into bulk solvent depending on the amount of P+ in the mixture and on their association number, AS. If AS is lower than the ensemble average ⟨AS⟩n, the copolymer chains released from IPEC preferentially concentrate at the core-shell interface, thus increasing AS, which approaches ⟨AS⟩n. If AS>⟨AS⟩n, they escape into the bulk solvent.

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