Bimetallic nanoparticles: A single step synthesis, stabilization, and characterization of Au–Ag, Au–Pd, and Au–Pt in sol–gel derived silicates

Abstract

Nanobimetallic particles consisting of Au-Pd, Au-Ag, and Au-Pt have been synthesized in a single step by a sol-gel process and stabilized in liquid and solid matrices. Organically modified silicates (Ormosils) that play a dual role of a matrix and of a stabilizer have been used to obtain very stable dispersions in the form of sols, gels, and monoliths. The simultaneous reduction of metal ions leads to either a surface enriched with one component or an alloy type of structure depending on the bimetal combination. The nanometallic dispersions are characterized by absorbance, TEM, XRD, IR, XPS, and CO adsorption studies. The stabilized nanoparticles are found to be good electrocatalysts and the preliminary results on the electrochemical reduction of oxygen are reported.

Study of PtPd Bimetallic Nanoparticles for Fuel Cell Applications

“…Bimetallic nanoparticles (NPs) are of interest since they lead to many interesting electrical, chemical, catalytic, and optical properties 1 . They are particularly important in the field of catalysis since they show superior catalytic properties than their monometallic counterparts 2,3 . The structure of bimetallic NPs depends mainly on the synthesis conditions and the miscibility of the two components 4 .…”

Size‐, Shape‐ and Composition‐Dependent Alloying Ability of Bimetallic Nanoparticles

“…[32] All the solid symbols denote the compositions and sizes for the particles that have been alloyed, while all the open symbols represent that for non-alloyed particles. The referred data are from: solid circles [14] (sizes smaller than 5 nm are estimated from TEM images), solid triangles, [18] solid squares, [17] open circles, [49] open squares [52] and open prisms. [53] tems ascribed to the model.…”

Au-Ag Gradient Alloy Nanoparticles with Extended Surface Plasmon Resonance Wavelength: Synthesis via Microreaction

“…Besides, only one SPR wavelength exhibits in the spectra, illustrating as-obtained Au-Ag NPs are of pure phase. The reason can be assigned to that a mixture of Au and Ag NPs will present two SPR peaks in their UV-Vis absorption spectra [5]. The inset of Fig.…”

“…Especially, their enhanced surface plasmon resonance (SPR) of these materials is useful in many fields, including bioimaging, cancer therapy, drug delivery [2][3][4]. Generally, spherical Au and Ag NPs typically exhibit SPR wavelength around 520 nm and 410 nm, respectively, while the wavelength of Au-Ag alloy varied from 520 nm to 410 nm according to their composition [5]. By varying the shape of the NPs, SPR wavelength out of the above range can be obtained.…”