Positive Thinking: Countercation Effects in Colloidal Syntheses of Gold Nanoparticles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41071761.
- Also identified by DOI 10.1021/acs.nanolett.5c04815 and PMC identifier 12550839.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Gold nanoparticles (Au NPs) are intensively studied and widely applicable to catalysis, sensing, medical applications, and many more. In particular, citrate- and borohydride- mediated colloidal syntheses of Au NPs are extremely popular. While it can be reasonably expected that countercations have a role to play, there is surprisingly almost no study on the effect of countercations in citrate- and borohydride-mediated colloidal syntheses of Au NPs. It is here shown that the countercation (Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>) from citrate, borohydride, but also from hydroxide species, plays an overlooked role in the stabilization of gold colloidal dispersions. The stability, size, and degree of shape control over the NP decrease in the order Li<sup>+</sup> > Na<sup>+</sup> > K<sup>+</sup>, due to a stronger interaction between the smaller cations and metal surfaces. The findings are directly relevant for further fundamental studies, an improved control of the syntheses and scale-up.