| Full text | |
| Author(s): |
Lanza, Gustavo
;
Jimenez, Mawin J. Martinez
;
Alvarez, Fernando
;
Perez-Taborda, Jaime Andres
;
Avila, Alba
Total Authors: 5
|
| Document type: | Journal article |
| Source: | ACS OMEGA; v. N/A, p. 7-pg., 2022-09-15. |
| Abstract | |
Gold nanoparticles (AuNPs) are commonly synthesized using the citrate reduction method, reducing Au3+ into Au1+ ions and facilitating the disproportionation of aurous species to Au atoms (Au-0). This method results on citrate-capped AuNPs with valence single states Au-0. Here, we report a methodology that allows obtaining AuNPs by the dewetting process with three different valence states (Au3+, Au1+, and Au-0), which can be fine-tuned with ion bombardment. The chemical surface changes and binding state of the NPs were investigated using core-level X-ray photoelectron spectroscopy (XPS). This is achieved by recording high-resolution Au 4f XPS spectra as a function of ion dose exposure. The results obtained show a time-dependent tuning effect on the Au valence states using low-energy 200 V acceleration voltage Ar+ ion bombardment, and the valence state conversion kinetics involves the reduction from Au3+ and Au1+ to Au-0. Proper control of the reduction in the valence states is critical in surface engineering for controlling catalytic reactions. (AU) | |
| FAPESP's process: | 12/10127-5 - Research and development of nanostructured materials for electronic and surface physics applications |
| Grantee: | Fernando Alvarez |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 19/18460-4 - Synthesis, thermo-mechanical and tribological properties of advanced multicomponent materials of high entropy |
| Grantee: | Fernando Alvarez |
| Support Opportunities: | Regular Research Grants |