scholarly journals Photocatalytic Property of Fe3O4/SiO2/TiO2Core-Shell Nanoparticle with Different Functional Layer Thicknesses

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Junyang Li ◽  
Libo Gao ◽  
Qiang Zhang ◽  
Ruiting Feng ◽  
Hongyan Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Order Kinetic ◽  
Shell Nanoparticles ◽  
Functional Layer ◽  
Carbon Reduction ◽  
Core Shell Nanoparticles

This study examined the different properties of Fe3O4/SiO2/TiO2(FST) core-shell nanoparticles encapsulated for one to five different times, represented as FST1 to FST5, respectively. These FST nanoparticles were obtained using the carbon reduction and sol-gel methods, and their properties were characterized by various tools, such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, vibratory sample magnetometer, laser granularity apparatus, and specific surface area analyzer. The relationship between irradiation time and decoloration ratio indicates that FST2 demonstrated significant efficiency in the decolorization of methyl orange (MO) under UV light. Further study on recycle activity showed that FST2 had a high decoloration rate after four cycles of photocatalysis, and its degradation of MO was well aligned with the apparent first-order kinetic equation. Furthermore, FST2 exhibited the highest apparent rate in the first cycle. All these results demonstrate that the recoverable FST2 possessed excellent photocatalytic activity while maintaining outstanding stability for further applications, such as managing environmental pollution.

scholarly journals Fabrication of Magnetite/Silica/Titania Core-Shell Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suh Cem Pang ◽  
Sze Yun Kho ◽  
Suk Fun Chin
Keyword(s):  
Methylene Blue ◽  
Uv Light ◽  
Sol Gel ◽  
Core Shell ◽  
Silica Nanospheres ◽  
Shell Nanoparticles ◽  
Gel Method ◽  
Uv Light Irradiation ◽  
Silica Nanosphere ◽  
Core Shell Nanoparticles

Fe3O4/SiO2/TiO2core-shell nanoparticles were synthesized via a sol-gel method with the aid of sonication. Fe3O4nanoparticles were being encapsulated within discrete silica nanospheres, and a layer of TiO2shell was then coated directly onto each silica nanosphere. As-synthesized Fe3O4/SiO2/TiO2core-shell nanoparticles showed enhanced photocatalytic properties as evidenced by the enhanced photodegradation of methylene blue under UV light irradiation.

scholarly journals Removal of Zinc from Aqueous Solutions by Magnetite Silica Core-Shell Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Masoomeh Emadi ◽  
Esmaeil Shams ◽  
Mohammad Kazem Amini
Keyword(s):  
Aqueous Solutions ◽  
Sol Gel ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Core Shell ◽  
Order Kinetic ◽  
Shell Nanoparticles ◽  
Silica Core ◽  
Core Shell Nanoparticles

Magnetite silica core-shell nanoparticles (Fe3O4-SiO2) were synthesized and evaluated as a nanoadsorbent for removing Zn(II) from aqueous solutions. The core-shell nanoparticles were prepared by combining coprecipitation and sol-gel methods. Nanoparticles were characterized by X-ray diffraction, transmission electron microscopy (TEM), and FT-IR. The magnetization values of nanoparticles were measured with vibrating sample magnetometer (VSM). The adsorption of Zn(II) ions was examined by batch equilibrium technique. The effects of pH, initial Zn(II) concentration, and contact time on the efficiency of Zn(II) removal were studied. The equilibrium data, analyzed by using Langmuir and Freundlich isotherm models, showed better agreement with the former model. Using the Langmuir isotherm model, maximum capacity of the nanoadsorbent for Zn(II) was found to be 119 mg g−1at room temperature. Kinetic studies were conducted and the resulting data were analyzed using first- and second-order equations; pseudo-second-order kinetic equation was found to provide the best correlation. The adsorption and sedimentation times were very low. The nanoadsorbent can be easily separated from aqueous solution by a magnet. Repeated adsorption acid regeneration cycles were performed to examine the stability and reusability of the nanoadsorbent. The result of this study proved high stability and reusability of Fe3O4-SiO2as an adsorbent for Zn(II) ions.

scholarly journals Development of coating formulation with silica–titania core–shell nanoparticles against pathogenic fungus

2018 ◽  
Vol 5 (8) ◽  
pp. 180633 ◽  
Author(s):  
Jaya Verma ◽  
Arpita Bhattacharya
Keyword(s):  
Electron Microscopy ◽  
Pathogenic Fungus ◽  
Antimicrobial Property ◽  
Sol Gel ◽  
Core Shell ◽  
Good Growth ◽  
Growth Reduction ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
Coating Formulation

In the present study, we developed an antifungal coating formulation using silica, titania and silica–titania core–shell nanoparticles individually. The idea behind the synthesis of core–shell nanoparticles was to use the mechanical strength of silica and the antimicrobial property of TiO 2 together. These nanoparticles were characterized by dynamic light scattering, transmission electron microscopy, scanning electron microscopy, EDX, FTIR and X-ray diffraction. Silica nanoparticles of 92 nm were prepared by the sol–gel process, while TiO 2 nanoparticles and nano-core–shells were prepared through the peptization process with a size of 77 and 144 nm separately. The antifungal effect of the prepared nanoparticles was observed in potato dextrose agar media using the concentration of nanoparticles at 1 wt%. These nanoparticles were incorporated in two types of binder, polyurethane and polyacrylic, with the same concentration of nanoparticles. Coatings were applied on tiles, dried and tested against pathogenic fungus, and fungus growth reduction was observed up to 7–10 days. Coatings developed with TiO 2 nanoparticles have shown good growth reduction of pathogenic fungus, but coatings formulated with silica–titania core–shell nanoparticles killed the fungus fusarium completely and have shown around 90% growth reduction for acremonium species also.

PHOTOCATALYTIC PROPERTIES OF TiO2/CNTs FILMS WITH DIFFERENT MORPHOLOGY ON STAINLESS STEEL SUBSTRATES

NANO ◽  
2014 ◽  
Vol 09 (01) ◽  
pp. 1450003 ◽  
Author(s):  
S. G. WANG ◽  
Z. R. DU ◽  
C. X. KONG ◽  
P. F. LI ◽  
J. L. XU ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Electrochemical Impedance ◽  
Uv Light ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Chemical Vapor ◽  
Photocatalytic Properties ◽  
Sol Gel Process ◽  
Steel Substrates

CNTs– TiO 2 films with different morphology were fabricated on stainless steel substrates through chemical vapor hydrolysis deposition (CVHD) process and sol–gel process, respectively. Their morphology was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic properties of the films were tested in the degradation of methyl orange by UV light irradiation. The results revealed that TiO 2 nanoparticles could form a continuous layer on the surface of CNTs through CVHD process. While for sol–gel process, most TiO 2 nanoparticles were isolated and only a small amount of TiO 2 nanoparticles attached on the surface of CNTs. And the photocatalytic property of TiO 2/CNTs film synthesized through CVHD process was better than that of TiO 2/CNTs films synthesized through sol–gel process. Electrochemical impedance spectroscopy (EIS) analysis illuminated that TiO 2/CNTs synthesized through CVHD process displayed a smaller resistance than the sample which was synthesized through sol–gel process and certified that the close combination between TiO 2 and CNTs could minimize recombination of photogenerated electrons and holes, and thus promote the photocatalytic property.

scholarly journals Structural and chemical characterization of MoO2/MoS2 triple-hybrid materials using electron microscopy in up to three dimensions

2021 ◽  
Author(s):  
Anna Frank ◽  
Thomas Gänsler ◽  
Stefan Hieke ◽  
Simon Fleischmann ◽  
Samantha Husmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Characterization ◽  
Three Dimensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Carbon Nanotube Network ◽  
Core Shell Nanoparticles

This work presents the synthesis of MoO2/MoS2 core/shell nanoparticles within a carbon nanotube network and their detailed electron microscopy investigation in up to three dimensions. The triple-hybrid core/shell material was...

Immobilization of Nano-TiO2 on Expanded Perlite for Photocatalytic Degradation of Rhodamine B

2011 ◽  
Vol 110-116 ◽  
pp. 3795-3800 ◽  
Author(s):  
Xiao Zhi Wang ◽  
Wei Wei Yong ◽  
Wei Qin Yin ◽  
Ke Feng ◽  
Rong Guo
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Sol Gel ◽  
Polluted Water ◽  
Order Kinetic ◽  
Expanded Perlite ◽  
Initial Concentration

Expanded perlite (EP) modified titanium dioxide (TiO2) with different loading times were prepared by Sol-Gel method. Photocatalytic degradation kinetics of Rhodamine B (RhB) in polluted water by the materials (EP-nanoTiO2), as well as the effects of different loading times and the initial concentration of RhB on photocatalysis rate were examined. The catalytic activity of the regenerated photocatalyst was also tested. The results showed that photocatalyst modified three times with TiO2had the highest catalytic activity. Degradation ratio of RhB by EP-nanoTiO2(modified three times) under irradiation for 6 h were 98.0%, 75.6% and 63.2% for 10 mg/L, 20 mg/L and 30 mg/L, respectively.The photocatalyst activity has little change after the five times recycling, and the degradation rate of RhB decreased less than 8%. The reaction of photocatalysis for RhB with irradiation time can be expressed as first-order kinetic mode within the initial concentration range of RhB between 10mg/L and 30 mg/L. EP-nanoTiO2photocatalyst has a higher activity and stability to degrade RhB in aqueous solution.

scholarly journals Cu-Ag core-shell nanoparticles: A direct correlation between micro-Raman and electron microscopy

2006 ◽  
Vol 73 (11) ◽  
Author(s):  
M. Cazayous ◽  
C. Langlois ◽  
T. Oikawa ◽  
C. Ricolleau ◽  
A. Sacuto
Keyword(s):  
Electron Microscopy ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

scholarly journals Characterization of silver-polymer core–shell nanoparticles using electron microscopy

Nanoscale ◽  
2018 ◽  
Vol 10 (19) ◽  
pp. 9186-9191 ◽  
Author(s):  
Nathalie Claes ◽  
Ramesh Asapu ◽  
Natan Blommaerts ◽  
Sammy W. Verbruggen ◽  
Silvia Lenaerts ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Using electron microscopy, polymer encapsulated silver nanoparticles were visualized and their coverage, molecular structure and plasmonic properties could be investigated.

Sol-gel synthesis, characterisation, and photocatalytic activity of porous spinel Co3O4 nanosheets

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Uv Light ◽  
Average Pore Size ◽  
Sol Gel ◽  
Spherical Particles ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Oriented Growth

AbstractMesoporous spinel Co3O4 nanosheets were synthesised via a simple sol-gel route using the Pluronic P123 triblock copolymer as the stabilising agent. Their structural, morphological, and textural properties were characterised. FTIR spectrum revealed the formation of cobalt oxide without any surface adsorbed impurities. Face centered cubic phase of spinel Co3O4 with the mean crystalline size of 26 nm was assigned by the X-ray diffraction analysis without the formation of other phases. Porous nanosheets and cave-like morphologies were identified from the scanning electron microscopy (SEM) images. Highly agglomerated more or less spherical particles with well separated lattice fringes, representing the oriented growth of nanocrystals, were noticed on the transmission electron microscopy photographs. Surface area analysis revealed that the spinel has high surface area of about 25 m2 g−1 with monomodal mesoporosity. The average pore size distribution was found to be about 15.8 nm. The as-prepared spinel photocatalyst showed a mild photocatalytic activity in the degradation of methylene blue (2.5 mg L−1) under UV light irradiation with air as the oxidising agent. Photocatalytic activity of the as-prepared reusable Co3O4 was found to be higher than that of the commercial spinel powder.

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.

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