Author, as appears in the article.: Poblet, JM; Lopez, X; Clotet, A; Zhongling Lang; Isabel Maicas Gabas; Jesús M. de la Fuente; Scott G. Mitchell

Department: Química Física i Inorgànica

URV's Author/s: POBLET RIUS, JOSEP MARIA; LÓPEZ FERNÁNDEZ, JAVIER; CLOTET ROMEU, ANNA MARIA; Zhongling Lang; Isabel Maicas Gabas; Jesús M. de la Fuente; Scott G. Mitchell

Abstract: Polyoxometalate (POM)-mediated reduction and nucleation mechanisms in nanoparticle (NP) syntheses are still largely unknown. We carried out comprehensive theoretical analysis using density functional theory (DFT) to gain insight into the molecular and electronic changes that occur during the reduction of HAuIIICl4 with the Kabanos-type polyoxomolybdate, [Na{(MoV2 O4)3(m2-O)3(m2-SO3)3(m6-SO3)}2]15. In the system presented herein the electrons are supplied by the POM, making the computational thermodynamic analysis more feasible. Our results reveal that this particular POM is a multi-electron source and the proton-coupled electron transfer (PCET) greatly promotes the reduction process. Based on the energy and molecular orbital studies of the intermediate species the reduction of AuIII to AuI is shown to be thermodynamically favourable, and a low HOMO–LUMO gap of the POM–Au superstructure is advantageous for electron transfer. By modelling the reduction of three couples of AuIII - AuI by the same POM unit, it is proposed that the reduced polyoxomolybdate is finally fully oxidised. The subjacent idea of using the Kabanos POM was confirmed by comprehensive experimental characterisation of POMstabilised gold nanoparticles (AuNPs@POM). Present theoretical analysis suggests that protons have a significant influence on the final AuI to Au0 reduction step that ultimately leads to colloidal AuNPs@POM.

Research group: Química Quàntica

Thematic Areas: Química Química Chemistry

licence for use: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 1144-0546

Author identifier: 0000-0002-4533-0623; 0000-0003-0322-6796; 0000-0003-0543-6607; ; ; ;

Record's date: 2019-01-14

Last page: 1038

Journal volume: 40

Papper version: info:eu-repo/semantics/publishedVersion

Link to the original source: https://pubs.rsc.org/en/content/articlelanding/2016/NJ/C5NJ02773J#!divAbstract

Article's DOI: 10.1039/c5nj02773j

Entity: Universitat Rovira i Virgili

Journal publication year: 2016

First page: 1029

Publication Type: Article Artículo Article