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 ◽  
...  

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.

2004 ◽  
Vol 818 ◽  
Author(s):  
Ru-Shi Liu ◽  
Hau-Ming Chen ◽  
Shu-Fen Hu

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.


2016 ◽  
Vol 1816 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
R. Esparza ◽  
J.L López-Miranda ◽  
G. Rosas ◽  
R. Pérez

ABSTRACTThe synthesis of Fe3O4-Ag bimetallic nanoparticles by chemical reduction was carried out. Fe nanoparticles were obtained using Fe (III) Chloride hexahydrate (FeCl3•6H2O) as precursor and sodium borohydride (NaBH4) as reducing agent, subsequently, a solution of silver nitrate (AgNO3) was added to the reaction. The synthesis methodology employed in this case, is a modification of chemical reduction method. Through this procedure has been possible simplify the synthesis route used to obtain bimetallic systems such as Fe3O4-Ag. Particles with semi-spherical morphology were observed. High-resolution transmission electron microscopy (HREM), ultraviolet visible spectroscopy (UV-is) and quasi-elastic light scattering (QELS) techniques were employed for the structural characterization of Fe3O4-Ag nanostructures. Some models presented describe and prove the formation of the Fe3O4-Ag alloy type structures.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Marta Paszkiewicz ◽  
Anna Gołąbiewska ◽  
Łukasz Rajski ◽  
Ewelina Kowal ◽  
Agnieszka Sajdak ◽  
...  

In this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs). We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) data, UV-Vis spectra, particle size distribution, and zeta potential. This work presents a comprehensive overview of experimental studies of the most stable colloidal solutions to impregnate fabrics that will exhibit a bactericidal and fungicidal activity againstCandida albicans,Escherichia coli, andStaphylococcus aureus.


2012 ◽  
Vol 1372 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
Claudia López ◽  
R. Pérez ◽  
G. Rosas

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.


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 ◽  
...  

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.


2006 ◽  
Vol 71 (11) ◽  
pp. 1153-1160 ◽  
Author(s):  
Chang Hu-Yuan ◽  
Feng Li ◽  
Li. Hua ◽  
Bin Zhang

As prepared carbon nanotubes were pretreated with nitric acid (CNTs-HNO3) or ammonia (CNTs-NH3). Fourier transform infrared spectroscopy (FTIR) measurements showed that the surface of the nanotubes was functionalized with carboxylic and hydroxyl functional groups after the acid treatment and that basic groups containing nitrogen, such as N-H and C-N, were introduced to the surface of the nanotubes after the ammonia treatment. X-Ray diffraction analysis implied that the nickel residue in the CNTs was effectively removed by acid treatment. However, the nickel residue was only partially eliminated by ammonia pretreatment. NiB amorphous catalysts supported on CNTs-HNO3 and CNTs-NH3 were prepared by the impregnation-chemical reduction method and characterized by transmission electron microscopy (TEM), as well as inductively coupled plasma (ICP) spectroscopy and studied in the selective hydrogenation of acetylene. TEM measurements showed that a high density NiB particles of about 9 nm were homogeneously dispersed on the CNTs-NH3. However, NiB particles (13-23 nm)with amean size of 16 nm were scattered on the CNTs-HNO3.As a result, the activity and selectivity of NiB/CNTs-NH3 were higher than those of NiB/CNTs-HNO3 in the selective hydrogenation of acetylene.


2011 ◽  
Vol 82 (2) ◽  
pp. 513-517 ◽  
Author(s):  
Zaheer Khan ◽  
Shaeel Ahmed Al-Thabaiti ◽  
Abdullah Yousif Obaid ◽  
A.O. Al-Youbi

2013 ◽  
Vol 755 ◽  
pp. 97-103 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
R. Esparza ◽  
R. Pérez ◽  
G. Rosas

In this study, a natural zeolite clinoptilolite-type was impregnated through homogeneous and heterogeneous nucleation with silver nanoparticles. The synthesis of Ag nanoparticles was carried out by chemical reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4). In the case of homogeneous nucleation, colloidal solution of Ag nanoparticles at concentrations of 1, 2 and 4 parts per million was added and magnetically mixed with the porous material. With respect to heterogeneous nucleation, a solution of clinoptilolite and silver nitrate (0.01 M) was prepared and stirred; subsequently, the reduction of Ag was possible due to the addition of an aqueous solution of sodium borohydride. For the structural characterization, transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopy (IR) techniques were carried out. The results were compared and discussed in both types of nucleation.


2013 ◽  
Vol 313-314 ◽  
pp. 232-236
Author(s):  
Dan Zhang

Activated carbon supported gold nanoparticles (Au/C) were prepared by a chemical reduction process using NaBH4as a reducing agent. The characterization of transmission electron microscope indicated that the Au nanoparticles (AuNPs) in the Au/C catalyst were highly well dispersed on the carbon support. The catalytic activity of the Au/C catalyst for the methanol electrooxidation (MEO) was investigated by the cyclic voltammetry (CV). The results displayed that the Au/C catalyst exhibited a favorable catalytic activity towards the MEO in alkaline solution. Moreover, the competitive adsorption between OH-and CH3OH on the surface of the AuNPs in the Au/C catalyst existed in the course of the MEO. Based on this competitive adsorption, the mechanism of the MEO on the Au/C catalyst was further investigated.


2008 ◽  
Vol 40 (10) ◽  
pp. 3183-3186 ◽  
Author(s):  
M.A.S. Sadjadi ◽  
Babak Sadeghi ◽  
M. Meskinfam ◽  
K. Zare ◽  
J. Azizian

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