Ultrasonic synthesis and optical properties of Au/Pd bimetallic nanoparticles in ethylene glycol

Abstract

Au/Pd bimetallic nanoparticles, even with core-shell structure, were synthesized by successive and simultaneous sonochemical irradiation of their metal precursors in ethylene glycol, respectively. In the successive method, Pd clusters or nanoparticles are first obtained by reduction of Pd(NO 3) 2 , followed by adding HAuCl 4 solution. As a result, Au-core/Pd-shell structured particles are formed, instead of Pd-core/Au-shell as usually expected. The successive method is more effective than the simultaneous one in the formation of the core-shell structure. Detailed investigation with optical absorption spectroscopy suggested that the pre-formed Pd atoms or clusters have a reduction effect on Au 3+ ions and the post-formation of Pd-shell can damp the surface plasmon resonance of Au nanoparticles. Theoretical absorption spectra based on Mie-like model for core-shell structured particles yield excellent agreement with the experimental results.

Selective Oxidation of Benzyl-Alcohol over Biomass-Supported Au/Pd Bioinorganic Catalysts

“…A study on the characterisation of the bimetallic catalyst using a combination of surface and bulk probing techniques showed an important degree of metal-metal coordination and indicated the formation of Au/Pd core/shell NPs where surface-exposed Pd atoms decorate a core of Au atoms [23]. Similar results have been reported in studies where the sacrificial hydrogen strategy was used to generate the Pd/Au NPs [24,25]. In these published methods, the construction of core/shell structures is facilitated by the sequential reduction of Pd(II) followed by Au(III).…”

Anodic stripping voltammetric determination of arsenic(III) using a glassy carbon electrode modified with gold-palladium bimetallic nanoparticles

“…However, the intensities of surface Plasmon resonance peak of gold nanoparticles gradually disappeared with the increase of concentration of Pd shell thickness, indicating the formation of the core-shell structure. The formation of Pd shell on the Au core leads to the gradual damping of the Plasmon of Au core and the ever-increasing adsorption in the low wavelength region [25]. It also can be seen that the absorption peak of gold shift owing to the increase of the electron density on gold nanoparticles [26].…”

Surface Composition and Catalytic Evolution of Au x Pd1−x (x = 0.25, 0.50 and 0.75) Nanoparticles Under CO/O2 Reaction in Torr Pressure Regime and at 200 °C

“…Additionally, our AP-XPS studies revealed no significant changes in the surface composition for the Pd-rich Au 0. 25 We have employed a modified polyol reduction reaction method using 1,4-butandiol as the reducing solvent and PVP as the capping agent [26][27][28][29]. As investigated in vacuum at ambient temperature by synchrotron XPS, the topmost surface layers mainly consist of Pd atoms.…”