scholarly journals Temperature-controlled synthesis of hollow, porous gold nanoparticles with wide range light absorption

2020 ◽  
Vol 55 (12) ◽  
pp. 5257-5267 ◽  
Author(s):  
J. Depciuch ◽  
M. Stec ◽  
A. Maximenko ◽  
J. Baran ◽  
M. Parlinska-Wojtan
Keyword(s):  
Gold Nanoparticles ◽  
Near Field ◽  
Synthesis Method ◽  
Synthesis Temperature ◽  
Porous Gold ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Light Absorbance

AbstractAn easy synthesis method of hollow, porous gold nanoparticles (AuHP NPs) with controlled diameter and pores sizes and with a wide range of light absorbance (continuous between 500 and 900 nm) is presented together with the explanation of the nanoparticle formation mechanism. The NPs were investigated using transmission electron microscopy (TEM) combined with the selected area electron diffraction patterns, X-ray diffraction and ultraviolet–visible spectroscopy. TEM images showed that changing the synthesis temperature allows to obtain AuHP NPs with sizes from 35 ± 4 nm at 60 °C to 76 ± 8 nm at 90 °C. The effects of nanoscale porosity on the far- and near-field optical properties of the nanoparticles, as well as on effective conversion of electromagnetic energy into thermal energy, were applied in simulated photothermal cancer therapy. The latter one was simulated by irradiation of two cancer cell lines SW480 and SW620 with lasers operating at 650 nm and 808 nm wavelengths. The mortality of cells after using the synthesized AuHP NPs as photosensitizers is between 20 and 50% and increases with the decrease in the diameter of the AuHP NPs. All these attractive properties of the AuHP NPs make them find application in many biomedical studies.

scholarly journals Chitosan Molecular Weight Effects on The Synthesis of Gold Nanoparticles and Catalytic Degradation of Environmental Pollutants

2018 ◽  
Vol 14 (2) ◽  
pp. 5388-5405
Author(s):  
Hosam Salaheldin Ibrahim
Keyword(s):  
Molecular Weight ◽  
Gold Nanoparticles ◽  
Environmental Pollutants ◽  
Localized Surface Plasmon ◽  
Au Nps ◽  
X Ray ◽  
Heating Source ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns

Gold nanoparticles (Au NPs) was synthesized with Chitosan different molecular weight (MW) using  a microwave as a heating source. Since, Chitosan acts as a reducing and stabilizing agent. The as-synthesized Au NPs were characterized by transmission electron microscopy (TEM) images and selected area electron diffraction patterns (SAED). Furthermore, the Au NPs fabrication was ascertained by UV–Visible spectroscopy (UV–Vis) through the detection of the localized surface plasmon resonance (LSPR) characteristic peak, X-ray powder diffraction (XRD), and energy dispersive X-Ray Spectroscopy (EDS). The formation of the Au NPs was confirmed by the detection of a LSPR peak at 518–527 nm in the UV–Vis spectrum. In addition, the XRD studies depicted that the obtained Au NPs were highly crystalline with ‘face-centered’ cubic geometry. Moreover, TEM micrographs showed that the most Monodispersed AuNPs was synthesized with low molecular weight (LMW) Chitosan with particle size 4.48±0.09 nm. The synthesized Chitosan-Au nanocomposite exhibited an efficient catalytic property in the reduction of  two organic environmental pollutants which are, 4-nitrophenol (4-NP) and methyl orange (MO) dye in the presence of sodium borohydride (NaBH4).

scholarly journals Green Synthesis of Gold Nanoparticles using Aqueous Garlic (Allium sativum L.) Extract, and Its Interaction Study with Melamine

2017 ◽  
Vol 12 (2) ◽  
pp. 212 ◽  
Author(s):  
Yoki Yulizar ◽  
Harits Atika Ariyanta ◽  
Lingga Abduracman
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Allium Sativum ◽  
Synthesis Method ◽  
Spherical Shape ◽  
Phytochemical Analysis ◽  
Interaction Study ◽  
Stabilizing Agents ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

Gold nanoparticles (AuNPs) have been successfully prepared by green synthesis method using aqueous extract of garlic with the Latin name of Allium sativum L. (ASL) as a reducing and stabilizing agents. Identification of active compounds in aqueous ASL extract was conducted by phytochemical analysis and Fourier transform infrared (FTIR) spectroscopy, while the synthesized AuNPs were characterized using UV-Vis spectrophotometer and transmission electron microscopy-selected area electron diffraction (TEM-SAED). The AuNPs formation was optimized at aqueous ASL extract concentration of 0.05%, HAuCl4 concentration of 2.0×10-4 M, and pH of 3.6. The optimized AuNPs was characterized   using TEM, and has a spherical shape with particle size of 15±3 nm. The particles were also stable up until one month. The synthesized AuNPs has been studied its interaction with melamine, and showed the optimum pH of interaction at 3.6. Copyright © 2017 BCREC GROUP. All rights reservedReceived: 13rd November 2016; Revised: 3rd January 2017; Accepted: 10th February 2017How to Cite: Yulizar, Y., Ariyanta, H.A., Abdurrachman, L. (2017). Green Synthesis of Gold Nanoparticles using Aqueous Garlic (Allium sativum L.) Extract, and Its Interaction Study with Melamine. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 212-218 (doi:10.9767/bcrec.12.2.770.212-218)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.770.212-218 

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

scholarly journals Green Synthesis of Silver and Gold Nanoparticles via Sargassum serratifolium Extract for Catalytic Reduction of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sargassum Serratifolium

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.

A novel additive-free oxides–hydrothermal approach for monazite-type LaPO4nanomaterials with controllable morphologies

2010 ◽  
Vol 43 (5) ◽  
pp. 990-997 ◽  
Author(s):  
Jie Ma ◽  
Qingsheng Wu
Keyword(s):  
Electron Microscopy ◽  
Treatment Time ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
Hydrothermal Conditions ◽  
Typical Sample ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Hydrothermal Approach

A facile oxides–hydrothermal (O–HT) method is demonstrated to prepare high-purity monazite-type LaPO4nanomaterials. In this approach, La2O3and P2O5powder are first directly used as precursors under additive-free hydrothermal conditions. The as-prepared samples are characterized with X-ray diffraction, Fourier transform IR spectroscopy, thermogravimetry, scanning electron microscopy, transmission electron microscopy (high-resolution TEM, energy dispersive spectroscopy) and selected-area electron diffraction. The typical sample obtained at 433 K in 24 h comprises uniform single-crystal nanofibres with a diameter of ∼15–28 nm and an aspect ratio of 30–50. The influences of treatment time, synthesis temperature and P/La molar ratio are investigated. The phase transition from hexagonal hydrate to monoclinic anhydrous lanthanum phosphate and the growth process of nanofibres are revealed by the experimental results. The formation mechanism of the monoclinic LaPO4is discussed. The result indicates that the P/La ratio does not influence the composition and crystal phase but changes the morphology of the product in the O–HT system.

scholarly journals Nano-Scale Rare Earth Distribution in Fly Ash Derived from the Combustion of the Fire Clay Coal, Kentucky

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 206 ◽  
Author(s):  
James Hower ◽  
Dali Qian ◽  
Nicolas Briot ◽  
Eduardo Santillan-Jimenez ◽  
Madison Hood ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Fly Ash ◽  
Electron Diffraction ◽  
Eastern Kentucky ◽  
Nano Scale ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Fire Clay

Fly ash from the combustion of eastern Kentucky Fire Clay coal in a southeastern United States pulverized-coal power plant was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). TEM combined with elemental analysis via energy dispersive X-ray spectroscopy (EDS) showed that rare earth elements (REE; specifically, La, Ce, Nd, Pr, and Sm) were distributed within glassy particles. In certain cases, the REE were accompanied by phosphorous, suggesting a monazite or similar mineral form. However, the electron diffraction patterns of apparent phosphate minerals were not definitive, and P-lean regions of the glass consisted of amorphous phases. Therefore, the distribution of the REE in the fly ash seemed to be in the form of TEM-visible nano-scale crystalline minerals, with additional distributions corresponding to overlapping ultra-fine minerals and even true atomic dispersion within the fly ash glass.

A Chemical Solution Route to Rapid Synthesis of Homogeneous Bi100−xSbx Alloys Nanoparticles at Room Temperature

2007 ◽  
Vol 7 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Bo Zhou ◽  
Jun-Jie Zhu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Solution Route ◽  
Diffraction Patterns ◽  
Co Reduction ◽  
Chemical Solution Route

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.

scholarly journals Continuous tuning of the plasmon resonance frequency of porous gold nanoparticles by mixed oxide layers

2020 ◽  
Vol 27 (6) ◽  
pp. 1583-1588
Author(s):  
Laura Juhász ◽  
Bence Parditka ◽  
Péter Petrik ◽  
Csaba Cserháti ◽  
Zoltán Erdélyi
Keyword(s):  
Gold Nanoparticles ◽  
Resonance Frequency ◽  
Mixed Oxide ◽  
High Surface ◽  
Volume Ratio ◽  
Mixture Ratio ◽  
Optical Extinction ◽  
Oxide Layers ◽  
Porous Gold ◽  
Wide Range

Abstract Porous gold nanoparticles (PGNs) are very popular due to their high surface/volume ratio, moreover they have stronger plasmonic properties than their solid counterparts. These properties make the porous gold nanoparticles very useful for lots of applications, for instance chemical sensors, cancer therapy applications. For applications, however, it is indispensable that the resonance frequency (RF) of a plasmonic structure to be tuneable. In this work we show that the RF can be set in a wide range as desired by coating the PGNs by mixed oxide layers. By changing the composition of the coating layer, that is the mixture ratio, the RF can be shifted practically continuously in a wide range determined by the refractive index of the used oxides. As a demonstration, PGNs were coated with mixed alumina-titania oxide layers (5–7 nm) using plasma-enhanced atomic layer deposition method. The oxide layer, beside as a tuning tool, also stabilises the structure of the PGNs when are exposed to elevated temperature. This is shown by the influence of the temperature (from $$350\, ^{\circ }\hbox {C}$$ 350 ∘ C up to $$900\, ^{\circ }\hbox {C}$$ 900 ∘ C ) on the morphology, and as a consequence the optical extinction spectra, of the oxide coated PGNs.

Bulk Synthesis of Fe3Al Intermetallic Compound Nanoparticles by Flow-Levitation Method

NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550002 ◽  
Author(s):  
Shan-Jun Chen ◽  
Yan Chen ◽  
Song Li ◽  
Yang-En Wang ◽  
Hui Zeng ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Phase Measurement ◽  
Energy Dispersive Spectrometer ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
Al Nanoparticles ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Levitated Droplet ◽  
Fe3al Intermetallic

Metallic nanopowders have an increasing application in magnetic materials, catalysts and chemical and metallic industries. In this research, a novel bulk synthesis method for preparing high pure intermetallic Fe 3 Al nanoparticles was developed by flow-levitation (FL) method. The Fe and Al vapors ascending from the high-temperature levitated droplet were condensed by cryogenic argon gas under atmospheric pressure. X-ray diffraction (XRD) and selected-area electron diffraction (SAED) were used to identify and characterize the prepared nanopowders exhibiting a Fe 3 Al phase. Measurement of transmission electron microscopy (TEM) indicated that the Fe 3 Al particles are nearly spherical, and the particle size of the compound ranges from 10 nm to 200 nm in diameter. The chemical composition of the nanoparticles were determined with energy dispersive spectrometer. The magnetic properties of the nanopowder indicate that Fe 3 Al intermetallic compound is a soft magnet at room temperature, with coercivity of 24.2 Oe and saturation magnetization of 173.2 emu/g. The production rate of Fe 3 Al nanoparticles was estimated to be about 4 g/h in a continuous manner, by using the FL method. This method has great potential in mass production of Fe 3 Al nanoparticles.

Predeformation Effects on Shear Response and Microstructure in Pure Titanium-TA2

2007 ◽  
Vol 546-549 ◽  
pp. 1409-1412
Author(s):  
Shu Hua Li ◽  
Fu Chi Wang ◽  
Cheng Wen Tan ◽  
Zhi Yong Chen ◽  
Zhi Sun
Keyword(s):  
Shear Bands ◽  
Pure Titanium ◽  
Adiabatic Shear ◽  
Transmission Electron Micrograph ◽  
Adiabatic Shear Bands ◽  
Hopkinson Pressure Bar ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Pressure Bar

Adiabatic shear properties of pure titanium-TA2 have been investigated using specially designed specimen in a Hopkinson pressure bar at high strain rate of 103s- 1. Microstructural characteristics was investigated using scanning electrion microscopy as well as transmission and high resolution transmission electrion microscopy .The results showed that the shear stress and adiabatic sensitivity for rolled 45% TA2 are higher than forged TA2. Comparing the adiabatic shear bands (ASB) both in the forged and rolled TA2, no evidence in morphology alteration was found except to shear band widths. The transmission electron micrograph of the ASB in forged and rolled TA2 showed the grain size reduction from ~20μm to 200nm. No deformation twins have been observed in ASB. The selected area electron diffraction patterns of the ASB showed reflections of multiple grains, forming discontinuous rings which can be indexed as h.c.p. structure of α-Ti. This indicates that the ASB consists of fine grains of α-Ti and the α-Ti→ β-Ti transformation did not occur.

Sign in / Sign up

Export Citation Format

Share Document