scholarly journals Recent progress on synthesis of ceramics core/shell nanostructures

2013 ◽  
Vol 7 (2) ◽  
pp. 45-62 ◽  
Author(s):  
Vladimir Srdic ◽  
Bojana Mojic ◽  
Milan Nikolic ◽  
Stevan Ognjanovic

Thin surface layers on fine particles were found to substantially change their functionalities and properties, such as chemical reactivity, thermal stability, catalytic activity, dispersibility, or optical, magnetic and electronic properties. Because of that, the core/shell nanostructures have opened up research opportunities in almost all areas of science and engineering, including medicine, catalysis, biotechnology, chemistry, optics, electronics, energy storage, etc. Immense efforts have been implied to produce and investigate different core/ shell systems, and thereby, various synthesis techniques have been developed. In this review, we report a detailed overview of different synthesis techniques used for preparation of various ceramics core/shell nanostructures with tunable size and tailored structure.

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  

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.


Nanoscale ◽  
2021 ◽  
Author(s):  
Qing Xu ◽  
Danyang Li ◽  
Haijun Zhou ◽  
Biaoqi Chen ◽  
Junlei Wang ◽  
...  

We describe the synthesis of MnO2-coated porous Pt@CeO2 core–shell nanostructures (Pt@CeO2@MnO2) as a new theranostic nano-platform. The porous Pt cores endow the core–shell nanostructures with high photothermal conversion efficiency (80%)...


2019 ◽  
Vol 7 (5) ◽  
pp. 1280-1291 ◽  
Author(s):  
Alaka Panda ◽  
R. Govindaraj ◽  
R. Mythili ◽  
G. Amarendra

Bismuth and iron oxides subjected to ball milling followed by controlled annealing treatments showed the formation of core–shell nanostructures with Bi2Fe4O9 as the core and a shell of BiFeO3 and Bi25FeO40 phases as deduced based on the analysis of transmission electron microscopy results.


2019 ◽  
Vol 34 (07) ◽  
pp. 1138-1153 ◽  
Author(s):  
Mengkun Tian ◽  
Chenze Liu ◽  
Jingxuan Ge ◽  
David Geohegan ◽  
Gerd Duscher ◽  
...  

Abstract


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dipti Rawat ◽  
P. B. Barman ◽  
Ragini Raj Singh

Abstract The selected and controlled preparation of core@shell nanostructures, which unite the multiple functions of ferromagnetic Ni-Zn ferrite core and CdS shell in a single material with tuneable fluorescence and magnetic properties, have been proposed by the seed mediated aqueous growth process. The shell particle thickness and core of nanostructures were precisely tuned. Current work exhibits the comparative study of core@shell multifunctional nanostructures where core being annealed at two different temperatures. The core@shell nanostructure formation was confirmed by complementary structural, elemental, optical, magnetic and IR measurements. Optical and magnetic characterizations were performed to study elaborative effects of different structural combinations of core@shell nanostructures to achieve best configuration with high-luminescence and magnetic outcomes. The interface of magnetic/nonmagnetic NiZnFe2O4/CdS nanostructures was inspected. Unexpectedly, in some of the core@shell nanostructures presence of substantial exchange-bias was observed in spite of the non-magnetic nature of CdS QDs which is clearly an “optically-active” and “magnetically-inactive” material. Presence of “exchange-bias” was confirmed by the change in “magnetic-anisotropy” as well as shift in susceptibility derivative. Finally, successful formulation of stable and efficient core@shell nanostructures achieved, which shows no exchange-bias and shift. Current findings suggest that these magneto-fluorescent nanostructures can be used in spintronics; and drug delivery-diagnosis-imaging applications in nanomedicine field.


2020 ◽  
Vol 11 ◽  
pp. 1834-1846
Author(s):  
Bridget K Mutuma ◽  
Xiluva Mathebula ◽  
Isaac Nongwe ◽  
Bonakele P Mtolo ◽  
Boitumelo J Matsoso ◽  
...  

Core–shell based nanostructures are attractive candidates for photocatalysis owing to their tunable physicochemical properties, their interfacial contact effects, and their efficacy in charge-carrier separation. This study reports, for the first time, on the synthesis of mesoporous silica@nickel phyllosilicate/titania (mSiO2@NiPS/TiO2) core–shell nanostructures. The TEM results showed that the mSiO2@NiPS composite has a core–shell nanostructure with a unique flake-like shell morphology. XPS analysis revealed the successful formation of 1:1 nickel phyllosilicate on the SiO2 surface. The addition of TiO2 to the mSiO2@NiPS yielded the mSiO2@NiPS/TiO2 composite. The bandgap energy of mSiO2@NiPS and of mSiO2@NiPS/TiO2 were estimated to be 2.05 and 2.68 eV, respectively, indicating the role of titania in tuning the optoelectronic properties of the SiO2@nickel phyllosilicate. As a proof of concept, the core–shell nanostructures were used as photocatalysts for the degradation of methyl violet dye and the degradation efficiencies were found to be 72% and 99% for the mSiO2@NiPS and the mSiO2@NiPS/TiO2 nanostructures, respectively. Furthermore, a recyclability test revealed good stability and recyclability of the mSiO2@NiPS/TiO2 photocatalyst with a degradation efficacy of 93% after three cycles. The porous flake-like morphology of the nickel phyllosilicate acted as a suitable support for the TiO2 nanoparticles. Further, a coating of TiO2 on the mSiO2@NiPS surface greatly affected the surface features and optoelectronic properties of the core–shell nanostructure and yielded superior photocatalytic properties.


2019 ◽  
Vol 7 (8) ◽  
pp. 3516-3530 ◽  
Author(s):  
Kuo-Chuan Ho ◽  
Lu-Yin Lin

This review article outlines the most commonly used methods for making the core/shell structures as the active materials for supercapacitors over the past decade (2007–2018), and points out the most efficient combination of the material categories and morphologies for the core/shell structure.


2012 ◽  
Vol 15 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Nora Mayté Sánchez-Padilla ◽  
Sagrario M. Montemayor ◽  
F.J. Rodríguez Varela

In this work, the effect of changing the stirring method and temperature on the physicochemical properties of metallic nanoparticles and core-shell nanostructures is shown. Magnetic (MS), mechanical (UT) and ultrasonic (USS) stirring are the methods of synthesis. The effect that, temperatures between 0 and 50 °C, has on the structure and particle size of Fe3O4 nanoparticles is evaluated. The results indicate that Fe3O4 prepared by the three methods presents a spinel-type crystalline structure. An increase in the synthesis temperature leads to highly crystalline powders. Afterwards, Pt is deposited by the UT method on Fe3O4 to form Fe3O4@Pt core-shell nanostructures. It is important to mention that the time used for the synthesis of the nanoparticles and the core-shell nanostructures is only one minute. The presence of Fe3O4 and Pt is confirmed by XRD and XPS. The metallic Pt phase is confirmed because the binding energy of Pt 4f 7/2 is associated to platinum in the zero-valent state. We evaluated the electrochemical activity of the Fe3O4@Pt core-shell nanostructures for the oxygen reduction reaction (ORR). The novel materials show a high electrocatalytic activity and the Koutecky-Levich analysis indicates that the reaction follows a 4 electron transfer mechanism on the Fe3O4@Pt nanostructures prepared by the three stirring processes. Moreover, the mass specific activity of the core-shell materials is as high as that obtained from the Pt-alone catalysts, suggesting that the amount of Pt in these electrodes can be reduced without decreasing the performance.


2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
K. Santhosh Kumar ◽  
Vijay Bhooshan Kumar ◽  
Pradip Paik

This paper covers the core-shell nanomaterials, mainly, polymer-core polymer shell, polymer-core metal shell, and polymer-core nonmetal shells. Herein, various synthesis techniques, properties, and applications of these materials have been discussed. The detailed discussion of the properties with experimental parameters has been carried out. The various characterization techniques for the core-shell nanostructure have also been discussed. Their physical and chemical properties have been addressed. The future aspects of such core-shell nanostructures for biomedical and various other applications have been discussed with a special emphasis on their properties.


2017 ◽  
Vol 5 (7) ◽  
pp. 1204-1229 ◽  
Author(s):  
Rahila Batul ◽  
Tasnuva Tamanna ◽  
Abdul Khaliq ◽  
Aimin Yu

An overview of polydopamine derived nanostructures; PDA NPs, capsules, core-shell nanostructures and PDA coatings as well as their application in various biomedical fields.


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