Multidimensional thermally-induced transformation of nest-structured complex Au-Fe nanoalloys towards equilibrium
Jacob Johny,Oleg Prymak,Marius Kamp,Florent Calvo,Se-Ho Kim,Anna Tymoczko,Ayman A. El-Zoka,Christoph Rehbock,Ulrich Schürmann,Baptiste Gault,Baptiste Gault,Lorenz Kienle,Stephan Barcikowski +12 more
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In this article, the in situ temporal evolution of the crystalline ordering in Au-Fe nanoparticles, obtained from a modern laser ablation in liquids synthesis, is investigated, and a detailed structural characterization by X-ray diffraction and transmission electron microscopy as well as atom probe tomography is presented.Abstract:
Bimetallic nanoparticles are often superior candidates for a wide range of technological and biomedical applications owing to their enhanced catalytic, optical, and magnetic properties, which are often better than their monometallic counterparts. Most of their properties strongly depend on their chemical composition, crystallographic structure, and phase distribution. However, little is known of how their crystal structure, on the nanoscale, transforms over time at elevated temperatures, even though this knowledge is highly relevant in case nanoparticles are used in, e.g., high-temperature catalysis. Au-Fe is a promising bimetallic system where the low-cost and magnetic Fe is combined with catalytically active and plasmonic Au. Here, we report on the in situ temporal evolution of the crystalline ordering in Au-Fe nanoparticles, obtained from a modern laser ablation in liquids synthesis. Our in-depth analysis, complemented by dedicated atomistic simulations, includes a detailed structural characterization by X-ray diffraction and transmission electron microscopy as well as atom probe tomography to reveal elemental distributions down to a single atom resolution. We show that the Au-Fe nanoparticles initially exhibit highly complex internal nested nanostructures with a wide range of compositions, phase distributions, and size-depended microstrains. The elevated temperature induces a diffusion-controlled recrystallization and phase merging, resulting in the formation of a single face-centered-cubic ultrastructure in contact with a body-centered cubic phase, which demonstrates the metastability of these structures. Uncovering these unique nanostructures with nested features could be highly attractive from a fundamental viewpoint as they could give further insights into the nanoparticle formation mechanism under non-equilibrium conditions. Furthermore, the in situ evaluation of the crystal structure changes upon heating is potentially relevant for high-temperature process utilization of bimetallic nanoparticles, e.g., during catalysis.read more
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Recent Developments in Plasmonic Alloy Nanoparticles: Synthesis, Modelling, Properties and Applications
TL;DR: An overview of the most recent results and developments in the field, organized according to synthetic strategies, modelling approaches, dominant properties and reported applications, can be found in this paper , where several plasmonic nanoalloys under development as well as the large number of those still awaiting synthesis, modelling, properties assessment and technological exploitation.
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Controlled Doping of Electrocatalysts through Engineering Impurities
Se-Ho Kim,Su-Hyun Yoo,Sangyong Shin,Ayman A. El-Zoka,Olga Kasian,Joo Ann Lim,Jiwon Jeong,Christina Scheu,Joerg Neugebauer,Hyunjoo Lee,Mira Todorova,Baptiste Gault +11 more
TL;DR: In this article , the authors observe an unexpected ingress of B into Pd nanocatalysts synthesized by wet chemistry, and report on its influence on the hydrogenoxidation reaction in alkaline conditions.
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Structural relaxation in Ag-Ni nanoparticles: atomistic modeling away from equilibrium
TL;DR: In this article , the out-of-equilibrium structural relaxation of Ag-Ni nanoparticles containing about 1000-3000 atoms was investigated by means of molecular dynamics trajectories in which the temperature is decreased gradually over hundreds of nanoseconds.
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Structural evolution under physical and chemical stimuli of metastable Au-Fe nanoalloys obtained by laser ablation in liquid.
Andrea Basagni,Veronica Torresan,Pasquina Marzola,M. B. Fernández van Raap,Luca Nodari,Vincenzo Amendola +5 more
TL;DR: In this article , a metastable Au-Fe alloy nanoparticles were produced by laser ablation in liquid, an emerging versatile synthetic approach for freezing multielement nanosystems in non-equilibrium conditions.
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Impact of Sterilization on the Colloidal Stability of Ligand-Free Gold Nanoparticles for Biomedical Applications.
Jacob Johny,Charlotte E R van Halteren,S. Zwiehoff,Carina Behrends,Christian Bäumer,Beate Timmermann,Christoph Rehbock,Stephan Barcikowski +7 more
TL;DR: The physicochemical characteristics of laser-generated ligand-free colloidal AuNPs exposed to steam sterilization and sterile filtration as a function of particle size and mass concentration are examined and physicochemical insight into particle growth processes is obtained.
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