scholarly journals Formation and Application of Core–Shell of FePt-Au Magnetic–Plasmonic Nanoparticles

2021 ◽  
Vol 9 ◽  
Author(s):  
Da-Hua Wei ◽  
Tei-Kai Lin ◽  
Yuan-Chang Liang ◽  
Huang-Wei Chang
Keyword(s):  
Phase Transfer ◽  
Liquid Solution ◽  
Mercaptoacetic Acid ◽  
Core Shell ◽  
Face Centered Cubic ◽  
Shell Nanoparticles ◽  
Au Nps ◽  
Engineering Research ◽  
Shell Nanostructures ◽  
Research Fields

Monodispersed FePt core and FePt–Au core–shell nanoparticles (NPs) have been chemically synthesized in liquid solution and with controllable surface-functional properties. The NP size was increased from 2.5 nm for FePt to 6.5 nm for FePt–Au, which could be tuned by the initial concentration of gold acetate coated onto FePt seeding NPs via a seed-mediated formation of self-assembled core–shell nanostructures. The analyses of the interplanar spacing obtained from the high-resolution transmission electron microscopy (HRTEM), selective electron diffraction pattern (SAED), and x-ray diffraction (XRD) confirmed that both FePt core and Au shell belong to the face-centered cubic (fcc) structure. FePt–Au NPs have a surface plasmon resonance (SPR) peak at 528 nm in the visible optical band region, indicating the red shift compared with the typical theoretical value of 520 nm of pure Au NPs. The surface modification and ligand exchange of FePt–Au was using mercaptoacetic acid (thiol) as a phase transfer reagent that turned the NPs hydrophilic due to the functional carboxyl group bond on the surface of presented multifunctional magnetic–plasmonic NPs. The water-dispersible FePt-based NPs conjugated with biomolecules could reach the different biocompatibility requirements and also provide enough heating response that acted as a potential agent for magnetic fluid hyperthermia in biomedical engineering research fields.

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

Catalysts ◽  
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.

scholarly journals Core@shell Nanoparticles: Greener Synthesis Using Natural Plant Products

2018 ◽  
Vol 8 (3) ◽  
pp. 411 ◽  
Author(s):  
Mehrdad Khatami ◽  
Hajar Alijani ◽  
Meysam Nejad ◽  
Rajender Varma
Keyword(s):  
Large Scale ◽  
Hybrid Nanoparticles ◽  
Target Cells ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Environmental Friendliness ◽  
Shell Nanostructures ◽  
Greener Synthesis ◽  
Core Shell Nanoparticles ◽  
Synthesis Of Nanostructures

Among an array of hybrid nanoparticles, core-shell nanoparticles comprise of two or more materials, such as metals and biomolecules, wherein one of them forms the core at the center, while the other material/materials that were located around the central core develops a shell. Core-shell nanostructures are useful entities with high thermal and chemical stability, lower toxicity, greater solubility, and higher permeability to specific target cells. Plant or natural products-mediated synthesis of nanostructures refers to the use of plants or its extracts for the synthesis of nanostructures, an emerging field of sustainable nanotechnology. Various physiochemical and greener methods have been advanced for the synthesis of nanostructures, in contrast to conventional approaches that require the use of synthetic compounds for the assembly of nanostructures. Although several biological resources have been exploited for the synthesis of core-shell nanoparticles, but plant-based materials appear to be the ideal candidates for large-scale green synthesis of core-shell nanoparticles. This review summarizes the known strategies for the greener production of core-shell nanoparticles using plants extract or their derivatives and highlights their salient attributes, such as low costs, the lack of dependence on the use of any toxic materials, and the environmental friendliness for the sustainable assembly of stabile nanostructures.

Impact of the capping agent removal from Au NPs@MOF core-shell nanoparticles heterogeneous catalysts

2022 ◽  
Author(s):  
Shan Dai ◽  
Kieu Phung Ngoc ◽  
Laurence Grimaud ◽  
Sanjun Zhang ◽  
Antoine Tissot ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Synergistic Effects ◽  
Core Shell ◽  
Capping Agent ◽  
Shell Nanoparticles ◽  
Au Nps ◽  
Capping Agents ◽  
Core Shell Nanoparticles

Metal nanoparticles encased in a MOF shell have shown remarkable properties in catalysis due to potential synergistic effects. However, capping agents, commonly used to prepare these nanoparticles, lower their reactivity...

scholarly journals Lead-Free BNT–BT0.08/CoFe2O4 Core–Shell Nanostructures with Potential Multifunctional Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 672
Author(s):  
Marin Cernea ◽  
Roxana Radu ◽  
Harvey Amorín ◽  
Simona Gabriela Greculeasa ◽  
Bogdan Stefan Vasile ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
Transmission Electron Microscopy Data ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Two Phase ◽  
X Ray ◽  
Shell Nanostructures

Herein we report on novel multiferroic core–shell nanostructures of cobalt ferrite (CoFe2O4)–bismuth, sodium titanate doped with barium titanate (BNT–BT0.08), prepared by a two–step wet chemical procedure, using the sol–gel technique. The fraction of CoFe2O4 was varied from 1:0.5 to 1:1.5 = BNT–BT0.08/CoFe2O4 (molar ratio). X–ray diffraction confirmed the presence of both the spinel CoFe2O4 and the perovskite Bi0.5Na0.5TiO3 phases. Scanning electron microscopy analysis indicated that the diameter of the core–shell nanoparticles was between 15 and 40 nm. Transmission electron microscopy data showed two–phase composite nanostructures consisting of a BNT–BT0.08 core surrounded by a CoFe2O4 shell with an average thickness of 4–7 nm. Cole-Cole plots reveal the presence of grains and grain boundary effects in the BNT–BT0.08/CoFe2O4 composite. Moreover, the values of the dc conductivity were found to increase with the amount of CoFe2O4 semiconductive phase. Both X-ray photoelectron spectroscopy (XPS) and Mössbauer measurements have shown no change in the valence of the Fe3+, Co2+, Bi3+ and Ti4+ cations. This study provides a detailed insight into the magnetoelectric coupling of the multiferroic BNT–BT0.08/CoFe2O4 core–shell composite potentially suitable for magnetoelectric applications.

scholarly journals [email protected] Core-Shell and Yolk-Shell Nanostructures: Selective Synthesis, Characterization, and Near-Infrared-Mediated Photocatalytic Reduction of Cr(VI)

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Wan-Ni Wang ◽  
Wang Dong ◽  
Chen-Xi Huang ◽  
Bo Liu ◽  
Sheng Cheng ◽  
...  
Keyword(s):  
Near Infrared ◽  
Separation Efficiency ◽  
Solution Process ◽  
Infrared Light ◽  
Core Shell ◽  
Sulfur Source ◽  
Shell Nanoparticles ◽  
Near Infrared Light ◽  
Shell Nanostructures ◽  
Photogenerated Electrons

Constructing near-infrared-light-mediated core-shell nanostructures incorporating upconversion nanoparticles (UCNPs) and semiconductors is of great importance for potential applications in photocatalysis, nano-biomedical engineering, solar cell, etc. In this work, we have demonstrated a two-step solution process to synthesize [email protected] core-shell nanoparticles (CSN). Firstly, a layer of AA-Zn(Cd)[OH]4− composites was coated on UCNPs to form UCNPs@AA-Zn(Cd)[OH]4− composites, which has been converted to [email protected] CSN via sulfidation reaction process using thioacetamide (TAA) as the sulfur source. Moreover, the [email protected] yolk-shell nanoparticles (YSN) have been obtained from the [email protected] CSN after calcination at 400°C, which show significantly photocatalytic activity for reduction of Cr(VI) under near-infrared light. All these can be attributed to the enhanced crystallization degree, resulting in enhanced energy transfer efficiency and separation efficiency of the photogenerated electrons and holes. An alternative strategy is provided in this study for fabrication of UCNP/semiconductor composites for various applications.

Gold coated iron oxide core shell nanostructures for oxidation of indoles and synthesis of uracil-derived spirooxindoles

2022 ◽  
Author(s):  
Shivanee Borpatra Gohain ◽  
Purna K Boruah ◽  
Manash Ranjan Das ◽  
Ashim Jyoti Thakur
Keyword(s):  
Iron Oxide ◽  
Core Shell ◽  
Hydrophilic Surface ◽  
Iron Species ◽  
Au Nps ◽  
Shell Nanostructures ◽  
Iron Oxide Core

Encapsulation of iron oxide (Fe3O4) based nanoparticles (NPs) with Au NPs hold promising scope for catalysis, which overcomes the hindrance of the inherent hydrophilic surface of iron species and facilitates...

Aptamer based surface enhanced Raman scattering detection of adenosine using various core sizes of Au–Ag core–shell nanoparticles

RSC Advances ◽  
2014 ◽  
Vol 4 (50) ◽  
pp. 26251-26257 ◽  
Author(s):  
Fu-Hsiang Ko ◽  
Yu-Cheng Chang
Keyword(s):  
Raman Scattering ◽  
Core Shell ◽  
Silicon Substrates ◽  
Shell Nanoparticles ◽  
Au Nps ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Core Shell Nanoparticles ◽  
Growth Approach

The combination of the varied sizes of Au NPs and seeding growth approach can be exploited to control the sizes of Au–Ag core–shell NPs. The silicon substrates with self-assembled Au–Ag core–shell NPs can be used to detect adenosine by a structures-switch aptamer.

scholarly journals One Pot Synthesis of Au_ZnO Core-Shell Nanoparticles Using a Zn Complex Acting as ZnO Precursor, Capping and Reducing Agent During the Formation of Au NPs

2018 ◽  
Vol 2018 (43) ◽  
pp. 4659-4659 ◽  
Author(s):  
Annalinda Contino ◽  
Giuseppe Maccarrone ◽  
Luca Spitaleri ◽  
Lucia Torrisi ◽  
Giuseppe Nicotra ◽  
...  
Keyword(s):  
Reducing Agent ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
One Pot ◽  
Au Nps ◽  
One Pot Synthesis ◽  
Core Shell Nanoparticles

scholarly journals Tunable Piezophotonic Effect on Core-Shell Nanoparticles Prepared by Laser Ablation in Liquids under External Voltage

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
A. K. Kodeary ◽  
S. M. Hamidi
Keyword(s):  
Laser Ablation ◽  
Lead Zirconate Titanate ◽  
Laser Pulses ◽  
Lead Zirconate ◽  
Core Shell ◽  
Laser Ablation In Liquid ◽  
Shell Nanoparticles ◽  
Nonlinear Properties ◽  
Shell Nanostructures ◽  
Core Shell Nanoparticles

We report an experimental study on the piezophotonic effect of gold and lead zirconate titanate (PbZrTiO3) nanoparticles (NPs) and also their core-shell nanostructures prepared by the laser ablation in liquid method. To obtain these NPs and composite materials, the targets were immersed in deionized water and a polymeric solution of polyvinyl pyrrolidone (PVP) under Nd:YAG laser pulses irradiation. Linear and nonlinear properties of these NPs were studied by optical spectroscopy and the Z-scan technique. Furthermore, tunable nonlinear properties of the NPs were measured under an external electric field under illumination to investigate the piezophotonic effect. Our results show that, at the interface of PZT and Au, due to the Schottky barrier, we have electron/hole recombination prevention, which leads to efficient enhancement in the nonlinear properties.

Microstructure and electronic behavior of PtPd@Pt core-shell nanowires

2010 ◽  
Vol 25 (4) ◽  
pp. 711-717 ◽  
Author(s):  
Wei-Qiang Han ◽  
Dong Su ◽  
Michael Murphy ◽  
Matthew Ward ◽  
Tsun-Kong Sham ◽  
...  
Keyword(s):  
Shell Structure ◽  
Phase Transfer ◽  
Core Shell ◽  
Face Centered Cubic ◽  
Edge Structure ◽  
X Ray ◽  
One Step ◽  
Core Shell Structure ◽  
Face Centered ◽  
X Ray Absorption

PtPd@Pt core-shell ultrathin nanowires were prepared using a one-step phase-transfer approach. The diameters of the nanowires range from 2 to 3 nm, and their lengths are up to hundreds of nanometers. Line scanning electron energy loss spectra showed that PtPd bimetallic nanowires have a core-shell structure, with a PtPd alloy core and a Pt monolayer shell. X-ray absorption near edge structure (XANES) spectra reveal that a strong Pt-Pd interaction exists in this nanowire system in that there is PtPd alloying and/or interfacial interaction. Extended x-ray absorption fine structures (EXAFS) further confirms the PtPd@Pt core-shell structure. The bimetallic nanowires were determined to be face-centered cubic structures. The long-chain organic molecules of n-dodecyl trimethylammonium bromide and octadecylamine, used as surfactants during synthesis, were clearly observed using aberration-corrected TEM operated at 80 KV. The interaction of Pt and surfactants was also revealed by EXAFS.

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