A1 Journal article (refereed)
Support work function as a descriptor and predictor for the charge and morphology of deposited Au nanoparticles (2020)

Ghosh, S., Mammen, N., & Narasimhan, S. (2020). Support work function as a descriptor and predictor for the charge and morphology of deposited Au nanoparticles. Journal of Chemical Physics, 152(14), Article 144704. https://doi.org/10.1063/1.5143642

JYU authors or editors

Publication details

All authors or editors: Ghosh, Sukanya; Mammen, Nisha; Narasimhan, Shobhana

Journal or series: Journal of Chemical Physics

ISSN: 0021-9606

eISSN: 1089-7690

Publication year: 2020

Volume: 152

Issue number: 14

Article number: 144704

Publisher: American Institute of Physics

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1063/1.5143642

Publication open access:

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/68554

Abstract

We show, using density functional theory calculations, that the charge, magnetic moment, and morphology of deposited Au nanoclusters can be tuned widely by doping the oxide support with aliovalent cations and anions. As model systems, we have considered Aun (n = 1, 2, or 20) deposited on doped MgO and MgO/Mo supports. The supports have been substitutionally doped with varying concentrations θ of F, Al, N, Na, or Li. At θ = 2.78%, by varying the dopant species, we are able to tune the charge of the Au monomer between −0.84e and +0.21e, the Au dimer between −0.87e and −0.16e, and, most interestingly, Au20 between −3.97e and +0.49e. These ranges can be further extended by varying θ. These changes in charge are correlated with changes in adsorption and/or cluster geometry and magnetic moment. We find that the work function Φ of the bare support is a good predictor and descriptor of both the geometry and charge of the deposited Au cluster; it can, therefore, be used to quickly estimate which dopant species and concentration can result in a desired cluster morphology and charge state. This is of interest as these parameters are known to significantly impact cluster reactivity, with positively or negatively charged clusters being preferred as catalysts for different chemical reactions. It is particularly noteworthy that the Na-doped and Li-doped supports succeed in making Au20 positively charged, given the high electronegativity of Au.

Keywords: nanoparticles; gold; density functional theory

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 1