The structure and atomic ordering of Au-Ag nanoparticles grown in the gas phase are determined by a combination of HAADF-STEM, XPS and Refl-XAFS techniques as a function of composition. It is shown consistently from all the techniques that an inversion of chemical ordering takes place by going from Au-rich to Ag-rich compositions, with the minority element always occupying the nanoparticle core, and the majority element enriching the shell. With the aid of DFT calculations, this composition-tunable chemical arrangement is rationalized in terms of a four-step growth process in which the very first stage of cluster nucleation plays a crucial role. The four-step growth mechanism is based on mechanisms of a general character, likely to be applicable to a variety of binary systems besides Au-Ag.
Unravelling the nucleation mechanism of bimetallic nanoparticles with composition-tunable core-shell arrangement / T. Liao, A. Yadav, K. Hu, J. Van Der Tol, S. Cosentino, F. D'Acapito, R.E. Palmer, C. Lenardi, R. Ferrando, D. Grandjean, P. Lievens. - In: NANOSCALE. - ISSN 2040-3364. - 10:14(2018), pp. 6684-6694.
|Titolo:||Unravelling the nucleation mechanism of bimetallic nanoparticles with composition-tunable core-shell arrangement|
LENARDI, CRISTINA [Writing – Original Draft Preparation]
|Parole Chiave:||Materials Science (all)|
|Settore Scientifico Disciplinare:||Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin)|
|Progetto:||Design of novel high performance catalysts and biosensors based on deposited mass-selected clusters assisted by computataional theoretical screening|
|Data di pubblicazione:||2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1039/c8nr01481g|
|Appare nelle tipologie:||01 - Articolo su periodico|