Electrochemistry at single bimetallic nanoparticles – using nano impacts for sizing and compositional analysis of individual AgAu alloy nanoparticles

Abstract

The increasing interest in producing bimetallic nanoparticles and utilizing them in modern technologies sets the demand for fast and affordable characterization of these materials. To date Scanning Transmission Electron Microscopy (STEM) coupled to energy dispersive X-ray spectroscopy is usually used to determine the size and composition of alloy nanoparticles, which is time-consuming and expensive. Here electrochemical single nanoparticle analysis is presented as an alternative approach to infer the particle size and composition of alloy nanoparticles, directly in a dispersion of these particles. As a proof of concept, 14 nm sized AgAu alloy nanoparticles are analyzed using a combination of chronoamperometric single nanoparticle analysis and cyclic voltammetry ensemble studies. It is demonstrated that the size, the alloying and the composition can all be inferred using this approach. Thus, the electrochemical characterization of single bimetallic alloy nanoparticles is suggested here as a powerful and convenient complement or alternative to TEM characterization of alloy nanoparticles.

Deciphering the Surface Composition and the Internal Structure of Alloyed Silver–Gold Nanoparticles

“…When comparing the bimetallic particles to the pure metal particles, it is notable that the Ag oxidation peak is shifted to higher potentials, indicating an alloy character of the nanoparticles . Furthermore, the Ag oxidation peak becomes broader with lower silver content, which is due to constrained Ag leaching because of the alloy character of the sample.…”

“…For the CVs, all potentials are given against a Ag/AgCl, 3 m KCl reference electrode ( E= 0.207 V vs. SHE). The silver oxidation peak in the pure silver sample occurs at +0.12 V and is associated with the formation of sparingly soluble AgCl, as shown in Equation . The reduction to Ag in the reverse cycle occurs at +0.01 V. …”

Piece by Piece—Electrochemical Synthesis of Individual Nanoparticles and their Performance in ORR Electrocatalysis

“…[1][2][3] Since the size is crucial to their properties,the production of monomodal NP batches with narrow size distribution is highly desired to maximise catalytic activity and selectivity. [1][2][3] Since the size is crucial to their properties,the production of monomodal NP batches with narrow size distribution is highly desired to maximise catalytic activity and selectivity.…”

“…Upon the stochastic impact of each individual micelle at anegatively polarised Pt microdisk electrode (E = À1.09 V vs.Fc/Fc + ,3-electrode setup), the precursor contained in the micelle is electrochemically reduced. (2)], [28] where 1 denotes the density of Au, M the molar mass of Au, z the number of transferred electrons,and F the Faraday constant. This reduction spike in the current-time trace is integrated R Idt to measure the charge Q.…”

Partikel für Partikel – elektrochemische Einschlagsexperimente zur Synthese oberflächenimmobilisierter Goldnanopartikel für die Elektrokatalyse

“…[1][2][3] Weil die Partikelgrçße füri hre Eigenschaften entscheidend ist, ist die Herstellung von monomodalen NP mit mçglichst enger Grçßenverteilung essenziell, um die katalytische Aktivität und Selektivitätz um aximieren. [1][2][3] Weil die Partikelgrçße füri hre Eigenschaften entscheidend ist, ist die Herstellung von monomodalen NP mit mçglichst enger Grçßenverteilung essenziell, um die katalytische Aktivität und Selektivitätz um aximieren.…”