scholarly journals Laser-Assisted Synthesis of Composite Nanoparticles of Perovskite BaTiO3 in Aqueous Solutions and Their Optical Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4086
Author(s):  
Ekaterina V. Barmina ◽  
Bulat A. Mukhametyanov ◽  
Oleg V. Uvarov ◽  
Igor I. Vlasov ◽  
Oleg S. Kudryavtsev ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Composite Nanoparticles ◽  
Visible Range ◽  
Laser Exposure ◽  
Colloidal Solutions ◽  
Gold Target ◽  
X Ray ◽  
Near Ir ◽  
Ir Laser ◽  
Transmission Electron

Experimental results are presented on laser-assisted synthesis of composite nanoparticles of perovskite BaTiO3 with gold nanoparticles using the technique of laser ablation in water and aqueous solution of hydrogen peroxide. Nanoparticles of BaTiO3 are generated by near IR laser radiation with pulse durations of 170 fs, 1 ps, and 200 ns. Nanoparticles of barium titanate BaTiO3 (BTO) have tetragonal structure for all used pulse durations. Two ways of synthesis are tested. In the first one a gold target is ablated in the colloidal solution of BaTiO3 nanoparticles. The second way consists of laser exposure of the mixture of colloidal solutions of nanoparticles of BaTiO3 and Au. Synthesized composite nanoparticles are characterized by optical spectroscopy, Raman spectroscopy, X-Ray diffractometry, and Transmission Electron Microscopy. Composite BaTiO3‑Au nanoparticles have the absorption band in the visible range of spectrum and demonstrate plasmonic luminescence.

Preparation and Characterization of γ-Fe2O3-ZnFe2O4 Composite Nanoparticles

2013 ◽  
Vol 873 ◽  
pp. 152-157
Author(s):  
Long Long Chen ◽  
Jun Ming Li ◽  
Xiao Min Gong ◽  
Jian Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Species ◽  
Composite Nanoparticles ◽  
X Ray Diffraction ◽  
Ferrite Core ◽  
Phase Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Chemically Induced

Using a chemically induced transition in an FeCl2 solution, γ-Fe2O3 nanoparticles can be prepared from an amorphous precursor composed of FeOOH and Mg (OH)2. Surface modification by adding ZnCl2 during liquid-phase synthesis was attempted. The magnetization, morphology, crystal structure, and chemical species of as-prepared samples were characterized by vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy-dispersive spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the surface of the γ-Fe2O3 nanoparticles can be modified by adding ZnCl2 to form composite nanoparticles with a γ-Fe2O3/ZnFe2O4 ferrite core coated with Zn (OH)2 and absorbed FeCl36H2O; this modification can be enhanced by additional NaOH.

Aquatic Fern (AzollaSp.) Assisted Synthesis of Gold Nanoparticles

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650008 ◽  
Author(s):  
Anal K. Jha ◽  
K. Prasad
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Au Nanoparticles ◽  
X Ray ◽  
Aquatic Fern ◽  
Transmission Electron ◽  
Anthraquinone Glycosides ◽  
Uv Visible

Aquatic pteridophyte (Azolla sp.) was taken to assess its potential to synthesize the metal (Au) nanoparticles. The synthesized particles were characterized using X-ray, UV-visible, scanning and transmission electron microscopy analyses. Nanoparticles almost spherical in shape having the sizes of 5–17[Formula: see text]nm are found. UV-visible study revealed the surface plasmon resonance at 538[Formula: see text]nm. Responsible phytochemicals for the transformation were principally phenolics, tannins, anthraquinone glycosides and sugars present abundantly in the plant thereby bestowing it adaptive prodigality. Also, the use of Azolla sp. for the synthesis of gold nanoparticles offers the benefit of eco-friendliness.

scholarly journals Photocatalytic Activity of Monosized AuZnO Composite Nanoparticles

2018 ◽  
Vol 9 (1) ◽  
pp. 111 ◽  
Author(s):  
Chenguang Ma ◽  
Xianhong Wang ◽  
Shixia Zhan ◽  
Xuemei Li ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ethylene Glycol ◽  
Visible Light ◽  
Composite Nanoparticles ◽  
Narrow Particle Size Distribution ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Suitable Amount ◽  
Copolymer Poly

Photocatalytic activity of monosized AuZnO composite nanoparticles with different compositions were synthesized by the one-pot polyol procedure, using the triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-blockpoly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The structure and morphology of the composite nanoparticles were analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), selected area electron diffraction (SAED), a transmission electron microscope (TEM) and high resolution transmission electron microscopy (HRTEM). The characterization showed that the AuZnO composite nanoparticles were spherical, with narrow particle size distribution and high crystallinity. The Fourier transform infrared spectroscopy (FTIR) study confirms the PEO-PPO-PEO molecules on the surface of the composite nanoparticles. The investigations by ultraviolet-visible light absorbance spectrometer (UV-Vis) and photoluminescence spectrophotometer (PL) demonstrate well the dispersibility and excellent optical performance of the AuZnO composite nanoparticles. Photocatalytic activity and reusability of the AuZnO nanoparticles in UV and visible light regions was evaluated by the photocatalytic degradation of Rhodamine B (RhB). The experimental results show that the AuZnO composite nanoparticles with a suitable amount of Au loading have stability and improved photocatalytic activity. AuZnO composite nanoparticles are effective and stable for the degradation of organic pollutants in aqueous solution.

Effect of Au on the Performance of Porous Silicon/V2O5 Nanorods Heterojunctions to NO2 Gas

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Analytical Techniques ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.

Synthesis of Au-SiO2 Composite Nanospheres and Their Catalytic Activity

2016 ◽  
Vol 16 (4) ◽  
pp. 3821-3826 ◽  
Author(s):  
Wang Dexuan ◽  
Li Guian ◽  
Han Qingyan ◽  
Wang Ziqiang ◽  
Pan Liping ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Photoelectron Spectroscopy ◽  
Au Nanoparticles ◽  
Catalytic Properties ◽  
Organic Dyes ◽  
Chemical Elements ◽  
X Ray ◽  
Transmission Electron ◽  
Environmentally Friendly Approach

We report a simple and environmentally friendly approach to the synthesis of Au-SiO2 composite nanospheres. Our method presents a route for the decoration of preformed amine functionalized SiO2 nanospheres by in situ formation of Au nanoparticles at three different concentrations of Au precursor (HAuCl4). Herein, the silane coupling agent (KH-550) is used as an intermediary to connect the Au nanoparticles to the surfaces of the SiO2 nanospheres, which helps avoid the aggregation of Au nanoparticles. The crystal structure, chemical elements, morphology and catalytic properties of the Au-SiO2 composite nanospheres were analyzed by transmission electron microscopy (TEM), X-Ray powder diffraction (XRD), UV-vis-spectrophotometer (UV-vis) and X-ray photoelectron spectroscopy (XPS). The analytical results demonstrate that the Au nanoparticles (4–9 nm) were homogeneously distributed on the surface of the SiO2 nanospheres, which had a good FCC crystal structure. Moreover, the Au-SiO2 composite nanospheres exhibited good catalytic properties, measured by their ability to reduce organic dyes. The Au-SiO2 composite nanospheres are promising candidates for applications in catalysis and wastewater treatment.

scholarly journals Photoluminescence Enhancement of Titanate Nanotubes by Insertion of Rare Earth Ions in Their Interlayer Spaces

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Thalles M. F. Marques ◽  
Cleanio Luz-Lima ◽  
Marco Sacilloti ◽  
Kazunori Fujisawa ◽  
Nestor Perea-Lopez ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Strong Dependence ◽  
Sodium Titanate ◽  
Rare Earth Ions ◽  
Titanate Nanotubes ◽  
Visible Range ◽  
Exchange Reactions ◽  
X Ray ◽  
Transmission Electron

The optical properties of titanate nanotubes (TiNts) intercalated with rare earths (RE) ions were intensively investigated in this study. To prepare the nanomaterials, sodium titanate nanotubes (Na-TiNts) were submitted to ion exchange reactions with different rare earth elements (RE: Pr3+, Er3+, Nd3+, and Yb3+). To the best of our knowledge, it is the first time that these RE-TiNts were synthesized. All samples were characterized by Raman spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Furthermore, the optical properties were examined using photoluminescence spectroscopy (PL) and UV-Vis-NIR absorption spectroscopy. The PL intensity (visible range) of the RE-TiNt samples showed a strong dependence when the temperature was decreased down to 20 K. This PL enhancement probably was promoted by electronic modifications in titanate layer band gap and/or interface charge transfers due to RE ions intercalation.

Preparation and Wide Tunable Band-Gap Energies of PbTe Nanocrystals Using Glycerin as a Capping Ligand

2014 ◽  
Vol 904 ◽  
pp. 81-85
Author(s):  
Xing Li Ren ◽  
Xing Rong Jiang
Keyword(s):  
Band Gap ◽  
Blue Shift ◽  
Visible Range ◽  
X Ray Diffraction ◽  
Size Dependent ◽  
Near Ir ◽  
Transmission Electron ◽  
Novel Method ◽  
Uv Visible ◽  
Tunable Band Gap

PbTe nanocrystals (NCs) have been synthesized by a novel method at low temperature. Pb acetate being solved in glycerol and Te in TOP solution were used as the precursors for the preparation of PbTe nanocrystals. The as-prepared products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UVvis absorption, Fourier transform infrared spectroscopy (FTIR). These data, together with analysis of the absorption spectra, allowed us to observe the size dependence of the peaks in the absorption spectrum. The size-dependent optical spectra of the PbTe nanocrystals exhibits wide tunable band gap energies varying from UV visible range to near IR region, which corresponds to a huge blue shift of 3.0 eV in comparison to the bulk counterpart. Keywords: 1. PbTe nanocrystals, 2. optical properties, 3. wide tunable band gap, 4. microstructure

scholarly journals Synthesis of Dandelion-like Porous Au Nanoparticles for Catalytic Reduction of Nitrophenol

2020 ◽  
Vol 01 ◽  
Author(s):  
Huiying Wu ◽  
Feng Liang
Keyword(s):  
Active Sites ◽  
Au Nanoparticles ◽  
Catalytic Reduction ◽  
Molar Ratio ◽  
Void Space ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
Templating Method ◽  
X Ray ◽  
Transmission Electron

Background: Porous Au nanomaterials show great potential in the fields of biomedicine, drug delivery and catalysis for the merits of low density, large void space and large specific surface area. The preparation of porous Au nanomaterials is usually carried out by using a hard-templating method which is cumbersome. Methods: Dandelion-like porous Au nanoparticles were synthesized through a soft-templating method in our work. The synthesized porous Au nanoparticles were characterized via transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and cyclic voltammetry (CV). The reduction of nitrophenol was carried out to evaluate the catalytic behavior of porous Au nanoparticles. Results: Porous Au nanoparticles prepared were in uniform size (47.9±6.4 nm) and the morphology could be regulated by adjusting the molar ratio of reactants. The apparent rate constant (kapp) value of reducing nitrophenol catalyzed by porous Au nanoparticles was higher than Au nanospheres and nanobranches in similar size. It could be attributed to the large amount of active sites and high proportion of high-order crystal faces proved by CV and XRD. Conclusion: We developed a facile and reproducible method for synthesizing porous Au nanoparticles. The morphology of porous Au nanoparticles can be ajusted by changing the molar ratio of reactants. Porous Au nanoparticles we prepared behaved better in catalysis compared with Au nanospheres and Au nanobranches.

Plasmon Enhanced Emission of Perovskite Quantum Dot Films

MRS Advances ◽  
2018 ◽  
Vol 3 (14) ◽  
pp. 733-739 ◽  
Author(s):  
Seyma Dadı ◽  
Yemliha Altıntas ◽  
Emre Beskazak ◽  
Evren Mutlugun
Keyword(s):  
Quantum Dot ◽  
Au Nanoparticles ◽  
Au Nanoparticle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Transmission Electron ◽  
Coating Method ◽  
Photoluminescence Enhancement ◽  
Time Resolved Photoluminescence

ABSTRACTWe propose and demonstrate the photoluminescence enhancement of CsPbBr3 perovskite quantum dot films in the presence of Au nanoparticles. Embedded into a polymer matrix, Au nanoparticle- quantum dot film assemble prepared by an easy spin coating method enabled the photoluminescence enhancement of perovskite quantum dot films up to 78%. The properties of the synthesized perovskite QDs and gold nanoparticles have been analysed using high resolution transmission electron microscopy, X-ray diffraction, energy dispersive X- ray spectroscopy, UV-Vis absorption spectrophotometer, steady state and time-resolved photoluminescence spectrometer.

scholarly journals EFFECT OF Ag NANOPARTICLE ON THE PHOTOCATALYTIC ACTIVITY OF TIO2 NANOTUBES

2018 ◽  
Vol 54 (1A) ◽  
pp. 42
Author(s):  
Le Thi Ngoc Tu
Keyword(s):  
Photocatalytic Activity ◽  
Tio2 Nanotubes ◽  
Visible Range ◽  
Ag Nanoparticle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ag Particles ◽  
Structure Morphology ◽  
Uv Range

The TiO2 nanotubes were fabricated by the hydrothermal method. Then, Ag nanoparticles with the varying ratio were attached on the TiO2 nanotubes by photoreduction. The characteristics of structure, morphology, chemical composition and of TiO2 nanotubes modified Ag (Ag-TNTs) was investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and the absorption spectral of Methylene blue (MB) solution. The results showed that Ag-TNTs have fairly uniform length with Ag particles immobilized on the tube. The photocatalysis TiO2 nanotubes (TNTs) is higher than Ag-TNTs in UV range and lower than Ag-TNTs in the visible light. And the photocatalytic activity of Ag-TNTs with 5 wt.% Ag is highest in the visible range.

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