Fabrication of Gold Nanoparticles of Different Sizes and its Interaction in Aquatic Phase

MRS Advances ◽  
2019 ◽  
Vol 4 (38-39) ◽  
pp. 2109-2117
Author(s):  
Rossymar Rivera Colón ◽  
Wilfred Fonseca Ferrer ◽  
Sonia J. Bailón-Ruiz
Keyword(s):  
Gold Nanoparticles ◽  
Color Change ◽  
Gold Nanostructures ◽  
Localized Surface Plasmon ◽  
Molar Ratio ◽  
Face Centered Cubic ◽  
Spherical Form ◽  
Microscopy Technique ◽  
Transmission Electron ◽  
Face Centered

ABSTRACTThe generation of AuNPs was realized in presence of gold chloride (Au3+), and citrate solution as reducing agent. The production of AuNPs was proved by the color change in the solution; from yellow to red wine. Purified nanostructures synthesized at citrate/Au3+ molar ratio of 1.0/10.0 evidenced an absorption peak at 526 nm attributed to the localized surface Plasmon Resonance (LSPR) which suggested the formation of small gold nanoparticles (NPs). The decrease of citrate/Au3+ molar ratio at 1.0/3.0 provoked a growing of gold nanostructures, which was evidenced by a red shift in the SPR at 546nm. High Resolution Transmission Electron Microscopy technique evidenced the spherical form and sizes for both nanoparticles at the range 10-15 nm (small NPs) and 20-25 nm (big NPs), respectively. Electron Diffraction (ED) patterns for both sizes evidenced the (111), (200), (220), (311), and (222) reflections of face centered cubic (FCC) gold nanostructures. Studies of energy-dispersive X-ray Spectroscopy indicated peaks at 1.65, 2.12, 9.71, 11.58 and 13.38 keV for both nanostructures, which suggests the presence of gold into the crystalline structure of the nanoparticles. Interaction tests were carried out in presence of marine crustaceans and different concentrations of gold nanoparticles; including a control test. Both sizes evidenced to be toxic when the concentration and exposure time were increased.

scholarly journals Exploration of the Antimicrobial and Catalytic Properties of Gold Nanoparticles Greenly Synthesized by Cryptolepis buchanani Roem. and Schult Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kamonpan Wongyai ◽  
Phitchayapak Wintachai ◽  
Rasimate Maungchang ◽  
Parawee Rattanakit
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Nanoparticles ◽  
Analytical Techniques ◽  
Average Diameter ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Face Centered

A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.

Ethylene-bridged Mesoporous Organosilicas with Hexagonal and Cubic Symmetry

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1289-1304 ◽  
Author(s):  
Yucang Liang ◽  
Egil Sev. Erichsen ◽  
Marianne Hanzlik ◽  
Reiner Anwander
Keyword(s):  
Electron Microscopy ◽  
Molar Ratio ◽  
Face Centered Cubic ◽  
Surfactant Mixtures ◽  
Cubic Symmetry ◽  
Surface Areas ◽  
Transmission Electron ◽  
Face Centered ◽  
Long Range Ordering ◽  
Mesoporous Organosilicas

A series of ordered periodic mesoporous organosilicas (PMOs) with cubic and hexagonal symmetries were fabricated by using divalent surfactants [CH3(CH2)15NMe2(CH2)3NMe3]2+ 2Br− (C16-3-1) or binary surfactant mixtures [CH3(CH2)15NMe3]+ Br− (C16TABr) and C16-3-1 as structure-directing agents (SDAs) and 1,2-bis(triethoxysilyl)ethane (BTEE) as an organosilica source under various basic conditions. The shape/structure of surfactant, molar ratio of binary surfactant mixtures, and base concentration crucially affect the formation of distinct mesophases. Face-centered cubic Fm3̄̅m mesoporous organosilicas can be obtained by using various concentrations of divalent surfactant C16-3-1 or equimolar mixtures of divalent and monocationic surfactants as SDAs under basic conditions. Cubic Pm3̄̅n or 2D hexagonal p6mm mesophases can be synthesized by changing the molar ratio of the binary surfactant mixtures or the amount of the base NaOH. Use of monocationic C16TABr instead of C16-3-1 as template produced the hexagonal p6mm mesophase exclusively independent of the amount of the surfactant and the base. In addition, use of trimethylbenzene as expander molecule in the aforementioned binary surfactant template system caused a mesophase transformation from cubic Pm3̄̅n to p6mm symmetry. All samples were characterized by powder X-ray diffraction (PXRD) analysis and N2 physisorption. The formation of face-centered cubic Fm¯3m, primary cubic Pm3̄̅n, and hexagonal p6mm PMOs was also confirmed by transmission electron microscopy (TEM), revealing a good long-range ordering with regular arrays.Moreover, variation of the synthesis parameters resulted in a variety of different PMO morphologies, as ascertained by scanning electron microscopy (SEM). FT-IR and solid-state 13C and 29Si NMR spectroscopy further revealed that the organic groups were uniformly incorporated into the framework. The various BET surface areas of the PMOs range from 470 to 780 m2 g−1, while the pore diameters lie within a 26 to 30 °A range, as derived from N2 physisorption

scholarly journals Green Synthesis of Gold Nanoparticles from Coprinus comatus, Agaricaceae, and the Effect of Ultraviolet Irradiation on Their Characteristics

2021 ◽  
Vol 18 (8) ◽  
Author(s):  
Ghassan Adnan NAEEM ◽  
Ahmed Saadoun JALOOT ◽  
Mustafa Nadhim OWAID ◽  
Rasim Farraj MUSLIM
Keyword(s):  
Gold Nanoparticles ◽  
Uv Irradiation ◽  
Color Change ◽  
Visible Spectrum ◽  
Face Centered Cubic ◽  
Coprinus Comatus ◽  
Light Yellow ◽  
Uv Visible ◽  
Face Centered ◽  
Nanoscale Range

The present research aims to produce gold nanoparticles (AuNPs) from the aqueous extract of locally isolated mushroom Coprinus comatus from Hit city, Iraq. Its properties were studied using the optical vision, UV-Vis, EDX, XRD, FTIR, AFM, and Zetasizer analyses. The exposure of the colloidal solution of AuNPs to UV radiation was investigated for 1, 2, and 3 h. The results showed the color change of the interaction mixture from light yellow to purple after 25 min. The lambda max of the absorbance reached 530 nm using UV-Visible spectrum as evident in the formation of AuNPs. FTIR spectra revealed the presence of functional groups related to peptides, proteins, flavonoids, monosaccharides, and phenolic compounds, which reduced gold ions. The EDX technique showed that the formed nanoparticles were AuNPs. XRD results showed that AuNPs have a face-centered cubic (fcc) crystal. The UV irradiation at different times led to an increase in the intensity of absorbance and sizes of AuNPs from 17.39 nm before the irradiation and switched to 58.16, 59.13, and 47.35 nm after 1, 2, and 3 h, respectively, but their sizes remained within the nanoscale range (less than 100 nm). In conclusion, the best result was observed after about an hour on the effects of UV irradiation on sizes of AuNPs, which reached smaller nanoparticles compared with times 2 and 3 h.

Faceted antiphase boundaries in GaAs grown on Ge

1987 ◽  
Vol 45 ◽  
pp. 314-315
Author(s):  
N.-H. Cho ◽  
S. McKernan ◽  
C.B. Carter ◽  
K. Wagner
Keyword(s):  
Cross Section ◽  
Atomic Resolution ◽  
Face Centered Cubic ◽  
Electrical Behavior ◽  
Sphalerite Structure ◽  
Antiphase Boundaries ◽  
Transmission Electron ◽  
Face Centered ◽  
Quality Material ◽  
Simulated Images

Interest has recently increased in the possibility of growing III-V compounds epitactically on non-polar substrates to produce device quality material. Antiphase boundaries (APBs) may then develop in the GaAs epilayer because it has sphalerite structure (face-centered cubic with a two-atom basis). This planar defect may then influence the electrical behavior of the GaAs epilayer. The orientation of APBs and their propagation into GaAs epilayers have been investigated experimentally using both flat-on and cross-section transmission electron microscope techniques. APBs parallel to (110) plane have been viewed at the atomic resolution and compared to simulated images.Antiphase boundaries were observed in GaAs epilayers grown on (001) Ge substrates. In the image shown in Fig.1, which was obtained from a flat-on sample, the (110) APB planes can be seen end-on; the faceted APB is visible because of the stacking fault-like fringes arising from a lattice translation at this interface.

Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Hydrothermal Method ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

scholarly journals Enhanced sunlight photocatalytic activity and biosafety of marine-driven synthesized cerium oxide nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Somayeh Safat ◽  
Foad Buazar ◽  
Salim Albukhaty ◽  
Soheila Matroodi
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Color Change ◽  
Removal Rate ◽  
Average Crystallite Size ◽  
Face Centered Cubic ◽  
One Pot ◽  
Stabilizing Agents ◽  
Face Centered ◽  
Living Organisms

AbstractThis contribution presents the biosynthesis, physiochemical properties, toxicity and photocatalytic activity of biogenic CeO2 NPs using, for the first time, marine oyster extract as an effective and rich source of bioreducing and capping/stabilizing agents in a one-pot recipe. CeO2 NPs formation was initially confirmed through the color change from light green to pale yellow and subsequently, their corresponding absorption peak was spectroscopically determined at 310 nm with an optical band-gap of 4.67 eV using the DR-UV technique. Further, XRD and Raman analyses indicated that nanoceria possessed face-centered cubic arrangements without any impurities, having an average crystallite size of 10 nm. TEM and SEM results revealed that biogenic CeO2 NPs was approximately spherical in shape with a median particle size of 15 ± 1 nm. The presence of various bioorganic substances on the surface of nanoparticles was deduced by FTIR and TGA results. It is found that marine-based nanoceria shows no cytotoxic effect on the normal cell, thus indicating their enhanced biocompatibility and biosafety to living organisms. Environmentally, due to energy band gap, visible light-activated CeO2 nanocatalyst revealed superior photocatalytic performance on degradation of methylene blue pollutant with removal rate of 99%. Owing to the simplicity, cost-effectiveness, and environmentally friendly nature, this novel marine biosynthetic route paves the way for prospective applications of nanoparticles in various areas.

scholarly journals In-Situ TEM Annealing Observation of Helium Bubble Evolution in Pre-Irradiated FeCoNiCrTi0.2 Alloys

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3727
Author(s):  
Huanhuan He ◽  
Zhiwei Lin ◽  
Shengming Jiang ◽  
Xiaotian Hu ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Vacuum Arc ◽  
In Situ Tem ◽  
Face Centered Cubic ◽  
Helium Bubble ◽  
High Entropy ◽  
Helium Bubbles ◽  
Transmission Electron ◽  
Bubble Evolution ◽  
Face Centered

The FeCoNiCrTi0.2 high-entropy alloys fabricated by vacuum arc melting method, and the annealed pristine material, are face centered cubic structures with coherent γ’ precipitation. Samples were irradiated with 50 keV He+ ions to a fluence of 2 × 1016 ions/cm2 at 723 K, and an in situ annealing experiment was carried out to monitor the evolution of helium bubbles during heating to 823 and 923 K. The pristine structure of FeCoNiCrTi0.2 samples and the evolution of helium bubbles during in situ annealing were both characterized by transmission electron microscopy. The annealing temperature and annealing time affect the process of helium bubbles evolution and formation. Meanwhile, the grain boundaries act as sinks to accumulate helium bubbles. However, the precipitation phase seems have few effects on the helium bubble evolution, which may be due to the coherent interface and same structure of γ’ precipitation and matrix.

scholarly journals The Examination of Calcium ion Implanted Alumina with Energy Filtered Transmission Electron Microscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 413-414
Author(s):  
E.M. Hunt ◽  
J.M. Hampikian ◽  
N.D. Evans
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pure Aluminum ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Knoop Microhardness ◽  
Aluminum Nanocrystals ◽  
Face Centered

Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.

Self-Organized Lead(II) Sulfide Quantum Dots Superlattice

MRS Advances ◽  
2017 ◽  
Vol 2 (15) ◽  
pp. 841-846 ◽  
Author(s):  
José Maria C. da Silva Filho ◽  
Victor A. Ermakov ◽  
Luiz G. Bonato ◽  
Ana F. Nogueira ◽  
Francisco C. Marques
Keyword(s):  
Quantum Dots ◽  
Interplanar Spacing ◽  
Face Centered Cubic ◽  
X Ray ◽  
Self Organized ◽  
Transmission Electron ◽  
The Mean ◽  
Face Centered ◽  
Pbs Quantum Dots ◽  
Deposited Films

ABSTRACTWe show that superlattice (SL) of PbS quantum dots (QD) can be easily prepared by drop casting of colloidal QD solution onto glass substrate and the ordering level can be controlled by the substrate temperature. A QD solution was dropped on glass and dried at 25, 40, 70 and 100°C resulting in formation of different SL structures. X-ray diffractograms (XRD) of deposited films show a set of sharp and intense peaks that are higher order satellites of a unique peak at 1.8 degrees (two theta), which corresponds, using the Bragg’s Law, to an interplanar spacing of 5.3 nm. The mean particles diameter, calculated through the broadening of the (111) peak of PbS using the Scherrer’s formula, were in agreement with the interplanar spacing. Transmission electron microscopy (TEM) measurements were also used to study the SL structure, which showed mainly a face centered cubic (FCC) arrangement of the QD. The photoluminescence (PL) spectrum of QD in the SL showed a shift toward lower energy compared to one in solution. It can be attributed to the fluorescence resonant energy transfer (FRET) between neighbors QD´s. Moreover, we observed greater redshift of PL peak for film with lower drying temperature, suggesting that it has a more organized structure.

Green Formation of Nano-Hexagon from Nano-Triangle of Gold Nanoparticles Using Palm Oil Fronds Extracts

2019 ◽  
Vol 290 ◽  
pp. 87-92
Author(s):  
Adamu Ibrahim Usman ◽  
Azlan Abdul Aziz ◽  
Osama Abu Noqta
Keyword(s):  
Gold Nanoparticles ◽  
Palm Oil ◽  
Good Control ◽  
Soft Template ◽  
Face Centered Cubic ◽  
Simple Method ◽  
Vis Spectroscopy ◽  
Production Techniques ◽  
Face Centered ◽  
Xrd Patterns

A simple method to synthesized nanoparticles was satisfied by reduction of tetrachloroauric acid in the presence of palm oil fronds extracts as capping and reduced agents. The as-synthesized gold nanoparticles structures have a triangular and hexagonal shape that are of tens of nanometre in size. It was realized that good control shape of nano-hexagonal gold nanoparticles were obtained from nano-triangular gold nanoparticles in the absence of any soft template. The production techniques of the gold nanoparticles were examined by using UV-vis spectroscopy, EFTEM and XRD patterns, which showed peaks at (111), (200), (220), (311) and (222), that described the preferential structure of the AuNPs as face-centered cubic crystal

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