AuCu, AgCu and AuAg Bimetallic Nanoparticles: Synthesis, Characterization and Water Remediation

MRS Advances ◽  
2016 ◽  
Vol 1 (36) ◽  
pp. 2525-2530
Author(s):  
Judith Tanori ◽  
Diana Vargas-Hernández ◽  
Elisa Martínez-Barbosa ◽  
Raúl Borja-Urby ◽  
Arturo García-Bórquez ◽  
...  
Keyword(s):  
Composite Material ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Water Remediation ◽  
Natural Systems ◽  
Self Assembling ◽  
Transmission Electron ◽  
Gold Silver ◽  
Vis Spectroscopy

ABSTRACTSelf-assembling systems of amphiphilic molecules display structures similar to those of biomineralization natural systems. This allows to somehow mimic nature to synthesize nanomaterials with low polidispersity and with diverse morphologies. In this work we describe the synthesis and characterization of gold-copper, silver-copper, and gold-silver bimetallic nanoparticles by chemical reduction in self-assembling systems of two surfactants. The nanoparticles were characterized by Transmission Electron Microscopy and UV-Vis spectroscopy. We have prepared a composite material using mesoporous silica as support of the AuAg bimetallic nanoparticles. The system was used in photocatalysis experiments for water remediation applications. Our results show that the AuAg/SBA15 composite material degrades methyl orange in water from 17 ppm to 4 ppm in 30 minutes.

scholarly journals Core-Shell Au@Ag Nanoparticles Synthesized with Polyphenols as Antimicrobial Agents

2021 ◽  
Author(s):  
Jesús Mauro Adolfo Villalobos-Noriega ◽  
Ericka Rodríguez Leon ◽  
César Rodríguez-Beas ◽  
Eduardo Larios-Rodríguez ◽  
Maribel Plascencia-Jatomea ◽  
...  
Keyword(s):  
Growth Kinetic ◽  
Antimicrobial Agents ◽  
Bimetallic Nanoparticles ◽  
Kinetic Curve ◽  
Core Shell ◽  
Root Extract ◽  
X Ray ◽  
Transmission Electron ◽  
Gold Silver ◽  
Vis Spectroscopy

Abstract In this work, we used a sequential method of synthesis for gold-silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) give a diameter mean of 36 nm for Au@AgNPs, and 24 nm for gold nanoparticles (AuNPs). The geometrical shapes of NPs were principally quasi-spherical. The thickness of silver shell over AuNPs are around 6 nm and covered by active biomolecules onto surface. Microstructural characterization included high angle annular dark field images (HAADF) recorded with a scanning transmission electron microscope (STEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-Ray Diffraction (XRD), UV-Vis Spectroscopy, and Zeta Potential. Also, a growth kinetic curve analysis using the Gompertz model for Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Candida albicans (yeast) were carried out for Au@AgNPs and monometallic AuNPs and AgNPs. Interestingly, Gompertz analysis indicates that Au@AgNPs present a higher effect on the growth kinetic of microorganisms than shown by monometallic nanoparticles.

Synthesis and Characterization of Novel Au(core)-Au/Pt Alloy(shell) Nanostructure

2004 ◽  
Vol 818 ◽  
Author(s):  
Ru-Shi Liu ◽  
Hau-Ming Chen ◽  
Shu-Fen Hu
Keyword(s):  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Energy Dispersive Spectrometer ◽  
Average Diameter ◽  
Shell Layer ◽  
Plasmon Band ◽  
Transmission Electron ◽  
Pt Alloy ◽  
Different Thickness

AbstractA systematic study is reported about the amount-dependent morphology change in a series of Au-Pt bimetallic nanoparticles synthesized using chemical reduction. The amount of Au precursor is kept constant throughout whole series of compounds to obtain fixed Au core size (∼7.5 nm). The Au/Pt ratio is varied from 1/1 to 1/4 in order to synthesize Pt shell layer of different thickness. We observed a remarkable shift of surface plasmon band around 410 nm. With the aid of high resolution transmission electron microscope (HRTEM) and energy-dispersive spectrometer (EDS), the composition of shell layer is found to be Pt enriched Au-Pt alloy. As the amount of Pt increases, the Pt clusters formed a string-like shape on the surface of nanoparticles. The average diameter of these Pt clusters is about 2 nm. This special structure may exhibit unique catalytic property.

scholarly journals Au@Ag Core@Shell Nanoparticles Synthesized with Rumex hymenosepalus as Antimicrobial Agent

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jesús Mauro Adolfo Villalobos-Noriega ◽  
Ericka Rodríguez-León ◽  
César Rodríguez-Beas ◽  
Eduardo Larios-Rodríguez ◽  
Maribel Plascencia-Jatomea ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Lag Phase ◽  
Core Shell ◽  
Root Extract ◽  
Dependent Manner ◽  
X Ray ◽  
Transmission Electron ◽  
Gold Silver ◽  
Vis Spectroscopy

AbstractIn this work, we used a sequential method of synthesis for gold–silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) gives a mean diameter of 36 ± 11 nm for Au@AgNPs, 24 ± 4 nm for gold nanoparticles (AuNPs), and 13 ± 3 nm for silver nanoparticles (AgNPs). The geometrical shapes of NPs were principally quasi-spherical. The thickness of the silver shell over AuNPs is around 6 nm and covered by active biomolecules onto the surface. Nanoparticles characterization included high angle annular dark field images (HAADF) recorded with a scanning transmission electron microscope (STEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-Ray Diffraction (XRD), UV–Vis Spectroscopy, Zeta Potential, and Dynamic Light Scattering (DLS). Fourier Transform Infrared Spectrometer (FTIR), and X-ray Photoelectron Spectroscopy (XPS) show that nanoparticles are stabilized by extract molecules. A growth kinetics study was performed using the Gompertz model for microorganisms exposed to nanomaterials. The results indicate that AgNPs and Au@AgNPs affect the lag phase and growth rate of Escherichia coli and Candida albicans in a dose-dependent manner, with a better response for Au@AgNPs

Structural Characterization of Iron Nanoparticles Synthesized by Chemical -Methods

2012 ◽  
Vol 1372 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
Claudia López ◽  
R. Pérez ◽  
G. Rosas
Keyword(s):  
Iron Nanoparticles ◽  
Chemical Reduction ◽  
Vinyl Pyrrolidone ◽  
Synthesis Methods ◽  
Transmission Electron ◽  
Metallic Salt ◽  
Vis Spectroscopy ◽  
Chloride Hexahydrate ◽  
Poly Vinyl Pyrrolidone

ABSTRACTDifferent synthesis methods has been employed to produce nanoparticles, however, chemical reduction method offer a effective route to obtained sizes nanoparticles controlled and morphologies very well defined. Iron nanoparticles were synthesized by chemical reduction using sodium borohydride (SB) NaBH4, Fe (III) Chloride hexahydrate (FeCl3·6H2O) as starting metallic salt (MS) and Poly-vinyl pyrrolidone (PVP) as surfactant agent. The nanoparticles have been characterized by transmission electron microscopy (TEM) and UV-Vis spectroscopy.

scholarly journals Synthesis and Characterization of Bifunctionalα-Fe2O3-Ag Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Alvaro Ruíz-Baltazar ◽  
Simón Yobanny Reyes-López ◽  
Rodrigo Esparza ◽  
Miriam Estévez ◽  
Ángel Hernández-Martínez ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Theoretical Models ◽  
Hybrid Nanoparticles ◽  
Chemical Reduction Method ◽  
Transmission Electron ◽  
Chloride Hexahydrate ◽  
The Individual

The synthesis ofα-Fe2O3-Ag bimetallic nanoparticles using a novel and simplified route is presented in this work. These hybrid nanoparticles were produced using a modification of the chemical reduction method by sodium borohydride (NaBH4). Fe(III) chloride hexahydrate (FeCl3·6H2O) and silver nitrate (AgNO3) as precursors were employed. Particles with semispherical morphology and dumbbell configuration were observed. High-resolution transmission electron microscopy (HRTEM) technique reveals the structure of the dumbbell-likeα-Fe2O3-Ag nanoparticles. Some theoretical models further confirm the formation of theα-Fe2O3-Ag structures. Analysis by cyclic voltammetry reveals an interesting catalytic behavior which is associated with the combination of the individual properties of the Ag andα-Fe2O3nanoparticles.

scholarly journals Synthesis and characterization of Fe, Co, and Ni colloids in 2-mercaptoethanol

2020 ◽  
Vol 10 ◽  
pp. 184798042096688
Author(s):  
Galo Cárdenas-Triviño ◽  
Sergio Triviño-Matus
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Colloidal Dispersions ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Chemical Liquid Deposition ◽  
Liquid Deposition

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4.

A novel electrochemical comparative sensing interface of MgO nanoparticles synthesized by different methods

2017 ◽  
Vol 233 (3) ◽  
pp. 753-762 ◽  
Author(s):  
Utkarsh Jain ◽  
CS Pundir ◽  
Shaivya Gupta ◽  
Nidhi Chauhan
Keyword(s):  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Cost Effective ◽  
Green Technology ◽  
Mgo Nanoparticles ◽  
Transmission Electron ◽  
Impedance Spectroscopy Study ◽  
Vis Spectroscopy ◽  
Reduction Methods ◽  
Average Size

Recent advancements in nanotechnology, for the biosynthesis of metal nanoparticles through enormous techniques, showed multidimensional developments. One among many facets of nanotechnology is to procure and adopt new advancements for green technology over chemical reduction synthesis. This adaptation for acquiring green nanotechnology leads us to a new dimension of nanobiotechnology. In order to imply one such efforts, in this study the emphasis is being laid on the synthesis of MgO nanoparticles using green technology and eliminating chemical reduction methods. Different characterization techniques such as UV–Vis spectroscopy, transmission electron microscopy, and dynamic light scattering were used to carry out the experiments. The average size of MgO nanoparticles were obtained in the range of 85–95 nm, when synthesized by various sources. The extracts of plants were capable of producing MgO nanoparticles efficiently and exhibited good results during cyclic voltammetry and electrochemical impedance spectroscopy study. The electrode modified with MgO nanoparticles (plant extract) showed good stability (90 days) and high conductivity. This study reports cost-effective and environment-friendly method for synthesis of MgO nanoparticles using plant extracts. The process is rapid, simple, and convenient and can be used as an alternative to chemical method.

Study on Dispersion and Characterization of Functionalized MWCNTs Prepared by Wet Oxidation

2014 ◽  
Vol 661 ◽  
pp. 8-13 ◽  
Author(s):  
Intan Syaffinazzilla Zaine ◽  
N.A.M. Napiah ◽  
Azmi Mohamad Yusof ◽  
A.N. Alias ◽  
A.M.M. Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Relative Intensity ◽  
Colloidal Stability ◽  
Structural Defects ◽  
Wet Oxidation ◽  
Defect Level ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Functionalized Mwcnts

The MWCNTs was functionalized by refluxing commercial MWCNTs (a-MWCNTs) in concentrated HNO3/H2SO4 (3:1 v/v) at 100°C for 6 hours. The dispersion of a-MWCNTs and functionalized MWCNTs (f-MWCNTs) were observed after 1 hour sonication in ethanol. Both samples were characterized by UV-vis spectroscopy for dispersion behavior. The dried f-MWCNTs and a-MWCNTs were characterized by Raman spectroscopy to estimate the defect level. The morphology of the samples were analyzed by Transmission Electron Microscopy (TEM). The f-MWCNTs was well dispersed in ethanol within 2 weeks of observations period. The colloidal stability of a-MWCNTs was low as it was easily sediment after 24 hours. The UV-vis spectra of f-MWCNTs show maximum absorbance at 250 nm meanwhile no absorbance was observed for a-MWCNTs. Analysis from Raman spectrum shows that the f-MWCNTs have relative intensity of 1.101 which is higher than a-MWCNTs that have relative intensity of 0.935. The image from TEM revealed that the f-MWCNTs have structural defects and the absence of amorphous carbon on sidewall meanwhile the a-MWCNTs indicate otherwise.

scholarly journals Detection Limits of DLS and UV-Vis Spectroscopy in Characterization of Polydisperse Nanoparticles Colloids

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Emilia Tomaszewska ◽  
Katarzyna Soliwoda ◽  
Kinga Kadziola ◽  
Beata Tkacz-Szczesna ◽  
Grzegorz Celichowski ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Point Of View ◽  
Spectroscopy Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The One

Dynamic light scattering is a method that depends on the interaction of light with particles. This method can be used for measurements of narrow particle size distributions especially in the range of 2–500 nm. Sample polydispersity can distort the results, and we could not see the real populations of particles because big particles presented in the sample can screen smaller ones. Although the theory and mathematical basics of DLS technique are already well known, little has been done to determine its limits experimentally. The size and size distribution of artificially prepared polydisperse silver nanoparticles (NPs) colloids were studied using dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) spectroscopy. Polydisperse colloids were prepared based on the mixture of chemically synthesized monodisperse colloids well characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), DLS, and UV-Vis spectroscopy. Analysis of the DLS results obtained for polydisperse colloids reveals that several percent of the volume content of bigger NPs could screen completely the presence of smaller ones. The presented results could be extremely important from nanoparticles metrology point of view and should help to understand experimental data especially for the one who works with DLS and/or UV-Vis only.

scholarly journals Highly Sensitive and Selective Colorimetric Sensor of Mercury (II) Based on Layer–by–Layer Deposition of Gold/Silver Bimetallic Nanoparticles

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4443
Author(s):  
Arjnarong Mathaweesansurn ◽  
Naratip Vittayakorn ◽  
Ekarat Detsri
Keyword(s):  
Bimetallic Nanoparticles ◽  
Limit Of Detection ◽  
Chemical Reduction ◽  
Colorimetric Sensor ◽  
Layer By Layer ◽  
Linear Relationships ◽  
Layer Deposition ◽  
Gold Silver ◽  
Ft Ir ◽  
Uv Visible

A new colorimetric sensor based on gold/silver bimetallic nanoparticles (Au–Ag BNPs) for the sensitive and selective detection of mercury (II) was developed. Gold nanoparticles (AuNPs) were synthesized by Turkevich method. The surface modification of AuNPs was modified by the layer–by–layer technique using poly(diallyl dimethylammonium chloride) which provided positively charged of AuNPs. Negatively charged silver nanoparticles (AgNPs) were synthesized by chemical reduction using poly(4–styrenesulfonic acid–co–maleic acid) as the stabilizing agent. The layer–by–layer assembly deposition technique was used to prepare Au–Ag BNPs of positively and negatively charged of AuNPs and AgNPs, respectively. The synthesized Au–Ag BNPs were characterized by a UV-visible spectrophotometer, zeta potential analyzer, FT–IR, TEM, XRD, and EDX. The Au–Ag BNPs sensor was able to detect mercury (II) in aqueous solution, visibly changing from brownish–orange to purple. The linear relationships of the UV-visible spectrometry demonstrate that the Au–Ag BNPs-based colorimetric sensor can be used for the quantitative analysis of mercury (II) in the range of 0.5–80 mg L−1, with the correlation coefficient, r2 = 0.9818. The limit of detection (LOD) of mercury (II) was found to be 0.526 + 0.001 mg L−1. The BNPs is also verified to have a good practical applicability for mercury (II) detection in the real samples.

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