γ-Irradiation route to photoluminescent CdS–CdSe with core–shell nanostructures under ambient conditions

2003 ◽  
Vol 81 (5) ◽  
pp. 381-384 ◽  
Author(s):  
Fen Xu ◽  
Xu Zhang ◽  
Jun Lu ◽  
Wang Xi ◽  
Jie Hong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Exchange Reaction ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Core Shell ◽  
Ambient Conditions ◽  
Γ Irradiation ◽  
X Ray ◽  
Ion Exchange Reaction

Photoluminescent CdS–CdSe nanocomposites with core–shell structures were obtained via a novel two-step γ-irradiation process followed by a simple ion-exchange reaction at room temperature and under ambient pressure. To fully characterize CdS–CdSe nanocomposites, X-ray photoelectron spectroscopy, UV–vis absorption spectra, and photoluminescence spectra were recorded, as well as powder X-ray diffraction, transmission electron microscopy, and high-resolution electron microscopy, to confirm the presence of the core–shell nanostructure.Key words: core–shell nanostructure, γ-irradiation, ion-exchange reaction.

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 Fabrication and Characterization of Porous Core–Shell Graphene/SiO2 Nanocomposites for the Removal of Cationic Neutral Red Dye

2020 ◽  
Vol 10 (23) ◽  
pp. 8529
Author(s):  
Junyi Wang ◽  
Tianlu Chen ◽  
Biao Xu ◽  
Yueqiu Chen
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Neutral Red ◽  
Water Vapor Adsorption ◽  
Core Shell ◽  
X Ray ◽  
Adsorption Sites ◽  
Sio2 Nanocomposites

Porous rGO/SiO2 nanocomposites with a “core-shell” structure were prepared as an efficient adsorbent for the liquid-phase adsorption of cationic neutral red (NR) dye. The samples were characterized with powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and N2 and water vapor adsorption/desorption methods. The NR removal ability and kinetics of the adsorption process of SiO2 and the rGO/SiO2 nanocomposites were investigated at 298 K. The rGO/SiO2 nanocomposite SG 0.30 showed a superior adsorption of NR dye. In regard to NR at pH 5, we measured a superior adsorption capacity of 66.635 mg/g at an initial NR concentration of 50 mg/L. The experimental adsorption capacity of SG 0.30 was 3.791 times higher than that of SiO2. Then, we compared the results with similar materials used for NR removal. Moreover, the water adsorption sites provided by the nitrogen- and oxygen-containing groups might be one of the reasons for the increased adsorption of water vapor. The broad range of properties of the rGO/SiO2 nanocomposite, including its simple synthesis, ability to be mass prepared, and strong adsorption properties, makes it a truly novel adsorbent that can be industrially produced, and shows potential application in the treatment of wastewater-containing dyes.

scholarly journals Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO2 Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2209 ◽  
Author(s):  
Jing Liu ◽  
Xiao-Min Li ◽  
Jing He ◽  
Lu-Ying Wang ◽  
Jian-Du Lei
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Sulfur Removal ◽  
Oxidation Products ◽  
Core Shell ◽  
Adsorptive Desulfurization ◽  
X Ray ◽  
Tio2 Microspheres

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

Characterization of Highly Luminescent LaPO4:Eu3+/LaPO4 One-Dimensional Core/Shell Heterostructures

2008 ◽  
Vol 8 (3) ◽  
pp. 1266-1271 ◽  
Author(s):  
Wenbo Bu ◽  
Jianlin Shi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Trap States ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
X Ray ◽  
Luminescence Efficiency ◽  
Transmission Electron

Highly luminescent LaPO4:Eu3+/LaPO4 one-dimensional (1D) core/shell heterostructures were successfully synthesized by a mild and simple self-aggregation process under refluxing or hydrothermal conditions. The resulting 1D core/shell heterostructures were characterized using a variety of techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray photoelectron spectroscopy (XPS) to demonstrate successful coating by the crystalline LaPO4. In addition, a possible formation mechanism for this core/shell heterostructure was proposed. Finally, the photoluminescence property of the LaPO4:Eu3+/LaPO4 1D core/shell heterostructures was investigated in detail, which illustrates that the core/shell heterostructures remarkably increase the luminescence efficiency because the LaPO4 shells effectively eliminate surface trap-states and suppress the energy quenching in the energy-transfer processes.

Self-Assembly of Perovskite Nanosheet Colloid at Room Temperature

2006 ◽  
Vol 301 ◽  
pp. 227-230
Author(s):  
Kenji Toda ◽  
Hiroki Sato ◽  
Akira Sugawara ◽  
Saori Tokuoka ◽  
Kazuyoshi Uematsu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Self Assembly ◽  
Room Temperature ◽  
Spectroscopic Studies ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Exchange Reaction ◽  
Perovskite Materials

We present a new method for soft chemical synthesis of perovskite materials. Perovskite K1-xLixNbO3 powders are produced by an ion-exchange reaction of layered perovskite precursor, K2NbO3F, with lithium chloride in water at room temperature. X-ray diffraction and X-ray fluorescent spectroscopic studies show that a mechanism of the ion-exchange reaction is a self-assembly between the perovskite nanosheets in aqueous solution.

Rapidly engineering the electronic properties and morphological structure of NiSe nanowires for the oxygen evolution reaction

2017 ◽  
Vol 5 (48) ◽  
pp. 25494-25500 ◽  
Author(s):  
Yunxiao Li ◽  
Dafeng Yan ◽  
Yuqin Zou ◽  
Chao Xie ◽  
Yanyong Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Electronic Properties ◽  
Exchange Reaction ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Morphological Structure ◽  
Core Shell ◽  
Fast Method ◽  
Ion Exchange Reaction

We report an extremely simple and fast method to synthesize a NixFe1−xSe@Ni(Fe)OOH core–shell nanostructure with a nanosheet shell by a facile solvothermal selenization and ion exchange reaction.

scholarly journals Agar Hydrogel Template Synthesis of Mn3O4 Nanoparticles through an Ion Diffusion Method Controlled by Ion Exchange Membrane and Electrochemical Performance

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 503 ◽  
Author(s):  
Qian Xue ◽  
Qiang Zhang
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Photoelectron Spectroscopy ◽  
Ion Exchange Membrane ◽  
Diffusion Method ◽  
Ion Diffusion ◽  
X Ray ◽  
Novel Strategy ◽  
Exchange Membrane ◽  
Mn3o4 Nanoparticles

A novel strategy, ion diffusion method controlled by ion exchange membrane combining with agar hydrogel template, was reported for the synthesis of Mn3O4 nanoparticles without any oxidizing agents. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauere-Emmette-Teller (BET) isotherm were carried out to characterize the structure, morphology, pore size and distribution and specific surface area of the as-prepared nanomaterials. It is shown that the morphology and size of Mn3O4 nanoparticles can be controlled by the concentration of agar hydrogel. All the specific capacitances of the Mn3O4 samples prepared with agar hydrogel template are much higher than that of Mn3O4 prepared without any template agent. The Mn3O4 sample prepared at 1.5 g L−1 of agar hydrogel solution exhibits a highest specific capacitance of 183.0 F g−1 at the current density of 0.5 A g−1, which is increased by 293% compared with that of Mn3O4 synthesized without any template agent. The results indicate that the ion diffusion method controlled by ion exchange membrane combining with agar hydrogel template is a convenient and effective approach for preparing inorganic nanomaterials.

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