scholarly journals Synthesis, Characterization and Dye Removal Behavior of Core–Shell–Shell Fe3O4/Ag/Polyoxometalates Ternary Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1255 ◽  
Author(s):  
Shixia Zhan ◽  
Chunyan Li ◽  
Heyun Tian ◽  
Chenguang Ma ◽  
Hongling Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Removal Efficiency ◽  
Dye Removal ◽  
Physical Property Measurement System ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Vis Spectroscopy

The ternary nanocomposites Fe3O4/Ag/polyoxometalates (Fe3O4/Ag/POMs) with core–shell–core nanostructure were synthesized by coating [Cu(C6H6N2O)2(H2O)]H2[Cu(C6H6N2O)2(P2Mo5O23)]·4H2O polyoxometalates on the surface of Fe3O4/Ag (core–shell) nanoparticles. The transmission electron microscopy/high resolution transmission electron microscopy (HR-TEM) and X-ray powder diffraction (XRD) analyses show that the Fe3O4/Ag/POMs ternary nanocomposites reveal a core–shell–core nanostructure, good dispersibility, and high crystallinity. The vibrating sample magnetometer (VSM) and physical property measurement system (PPMS) demonstrated the good magnetic properties and superparamagnetic behavior of the nanocomposites at 300 K. The UV–vis spectroscopy displayed the broadband absorption of the Fe3O4/Ag/POMs with the maximum surface plasmon resonance of Ag nanostructure around 420 nm. The dye removal capacity of Fe3O4/Ag/POMs was investigated using methylene blue (MB) as a probe. Through adsorption and photocatalysis, the nanocomposites could quickly remove MB with a removal efficiency of 98.7% under the irradiation of visible light at room temperature. The removal efficiency was still as high as 97.5% even after six runs by magnetic separation of photocatalytic adsorbents after processing, indicating the reusability and high stability of the nanocomposites. These Fe3O4/Ag/POMs photocatalytic adsorbents with magnetic properties will hopefully become a functional material for wastewater treatment in the future.

Formation of bismuth iron oxide based core–shell structures and their dielectric, ferroelectric and magnetic properties

2019 ◽  
Vol 7 (5) ◽  
pp. 1280-1291 ◽  
Author(s):  
Alaka Panda ◽  
R. Govindaraj ◽  
R. Mythili ◽  
G. Amarendra
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Shell Structures ◽  
Core Shell ◽  
Bismuth Iron Oxide ◽  
The Core ◽  
Shell Nanostructures ◽  
Transmission Electron

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.

A Novel Approach of Core-Shell Ag@Pt Nanoparticles Production

2017 ◽  
Vol 886 ◽  
pp. 48-52
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gas Sensors ◽  
Pt Nanoparticles ◽  
Core Shell ◽  
New Approach ◽  
Novel Approach ◽  
Transmission Electron ◽  
Car Exhaust ◽  
Vis Spectroscopy

Pt-based nanoparticles (NPs) have numerous applications, such as, as catalyst, in car exhaust systems, gas sensors, biosensors and cancer therapy. One of the Pt based NPs which has been successfully produced is core-shell Ag@Pt NPs. Numerous methods for the synthesis of this material have been reported. This paper reports a fully new approach of chemical mediated synthesis for core-shell Ag@Pt NPs. Characterization process for the synthesized Ag@Pt NPs, carried out by the UV-vis Spectroscopy, Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM) showed that the core AgNPs have approximate sizes of 18 nm in diameter are shelled with Pt and the sizes of core-shell Ag@Pt NPs were estimated to be around 29 nm in diameter.

Facile Fabrication of Antibacterial Core–Shell Nanoparticles Based on PHMG Oligomers and PAA Networks via Template Polymerization

2014 ◽  
Vol 67 (1) ◽  
pp. 142 ◽  
Author(s):  
You Wei Zhang ◽  
Yan Chen ◽  
Jiong Xin Zhao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Acrylic Acid ◽  
Electrostatic Interactions ◽  
Minimum Size ◽  
Core Shell ◽  
Nanoparticle Dispersion ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Antibacterial core–shell nanoparticles based on poly(hexamethylene guanidine hydrochloride) (PHMG) oligomers and poly(acrylic acid) (PAA) networks are efficiently fabricated via a facile one-step co-polymerization of acrylic acid and N,N′-methylenebisacrylamide on PHMG templates in aqueous solution. Dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy observations were used to characterize the size, morphology, and structure of the nanoparticles, as well as the interactions between the components. Also, the stability of the nanoparticle dispersion against storage, pH value, salt, and temperature was investigated. The results show that the crosslinked PAA/PHMG nanoparticles are stabilized by electrostatic interactions. The core–shell structure of the nanoparticles was confirmed by transmission electron microscopy observation. The size of the nanoparticles increases substantially with extension of storage or with increase of the salt concentration. The nanoparticle dispersion is stable in a pH range of 2.0–4.0. The size change of the nanoparticles with pH of the medium is parabolic, and the minimum size is reached at pH 3.0. A rise of temperature leads to a slight and recoverable size increase of the nanoparticles. Antibacterial efficiency was evaluated quantitatively against Escherichia coli and Staphylococcus aureus by the plating method according to Standard JC/T 897–2002. The antibacterial activity against these two bacteria are both above 99.0 % at a nanoparticle concentration of 5 mg mL–1. This makes the nanoparticle dispersion a good candidate for the application of antibacterial water-based coatings and textiles coating.

Synthesis and Characterization of WO3/S Core/Shell Nanoparticles by Thermal Evaporation

2014 ◽  
Vol 602-603 ◽  
pp. 51-54 ◽  
Author(s):  
Jing Wen Qian ◽  
Zhi Jian Peng ◽  
Dian Zhong Wu ◽  
Xiu Li Fu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Large Scale ◽  
Thermal Evaporation ◽  
Nano Particles ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Core Shell Nanoparticles

WO3 has been widely applied in many fields such as electrochromic window, photocatalyst, and gas-senor. In this paper, WO3/S core/shell nanoparticles were synthesized in high density and large scale on silicon substrates via simple thermal evaporation of WO3 and S powders at 950 °C in a tube furnace. The morphology, composition and structure of the nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results indicate that the nano-particles have a uniform morphology with a diameter in the range of 150-250 nm and well crystalline structure. The growth mechanism of the nanoparticles was also proposed.

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