| Texto completo | |
| Autor(es): |
Xavier, Ismael P. L.
;
Lemos, Laura L.
;
de Melo, Eduardo C.
;
Campos, Eduardo T.
;
de Souza, Breno L.
;
Faustino, Leandro A.
;
Galante, Douglas
;
de Oliveira, Paulo F. M.
Número total de Autores: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Physical Chemistry Chemical Physics; v. 26, n. 15, p. 9-pg., 2024-03-26. |
| Resumo | |
Bottom-up mechanochemical synthesis (BUMS) has been demonstrated to be an efficient approach for the preparation of metal nanoparticles (NPs), protected by surface agents or anchored on solid supports. However, there are limitations, such as precise size and morphological control, due to a lack of knowledge about the mechanically induced processes of NP formation under milling. In this article, we further investigate the BUMS of AuNPs. Using SiO2 as a solid support, we studied the effect of typical reducing agents, namely NaBH4, l-ascorbic acid, and hydroquinone (HQ), on the conversion of a AuIII source. XANES showed that HQ is the strongest reducing agent under our experimental conditions, leading to the quantitative conversion of gold salt in a few minutes. Interestingly, even when HQ was used in sub-stoichiometric amounts, AuIII could be reduced to ratios higher than 85% after two minutes of milling. Investigations into the byproducts by 1H NMR and GC-FID/MS enabled the identification HQ regeneration and the formation of its derivatives. We mainly focused on benzoquinone (BQ), which is the product of the oxidation of HQ as it reduces the gold salt. We could demonstrate that HQ is regenerated from BQ exclusively under milling and acidic conditions. The regenerated HQ and other HQ-chlorinated molecules could then reduce gold-oxidized species, leading to higher conversions and economy of reactants. Our study highlights the intriguing and complex mechanisms of mechanochemical systems, in addition to fostering the atom and energy economy side of mechanochemical means to produce metal nanoparticles. The hydroquinone reducing agent is regenerated during the mechanochemical reduction of gold salt to form metal nanoparticles, and it remains active in the chemical reduction process even when used in sub-stoichiometric conditions. (AU) | |
| Processo FAPESP: | 23/01223-5 - Mecanoquímica como ferramenta na preparação de nanomateriais multimetálicos |
| Beneficiário: | Ismael Pinheiro Lucas Xavier |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado Direto |
| Processo FAPESP: | 22/04604-7 - Contribuições plasmônicas na co-eletrolise de N2 e CO2 |
| Beneficiário: | Leandro Augusto Faustino |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 20/14955-6 - Desenvolvendo uma nova geração de materiais avançados multicomponentes via síntese mecanoquímica |
| Beneficiário: | Paulo Filho Marques de Oliveira |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |
| Processo FAPESP: | 22/03996-9 - Estudo dos parâmetros de moagem na síntese mecanoquímica de nanopartículas de prata. |
| Beneficiário: | Laura Libório Lemos |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |
| Processo FAPESP: | 19/09341-1 - Baterias de lítio-enxofre: nova geração no desenvolvimento de eletrodos positivos baseados em compósitos de MOFs/enxofre |
| Beneficiário: | Breno Luiz de Souza |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |