Version 2 2024-03-20, 13:45Version 2 2024-03-20, 13:45
Version 1 2024-02-15, 08:05Version 1 2024-02-15, 08:05
journal contribution
posted on 2024-03-20, 13:45authored byGuillermo González-Rubio, Pablo Llombart, Jian Zhou, Henry Geiss, Ovidio Peña-Rodríguez, Huiyu Gai, Bing Ni, Rose Rosenberg, Helmut Cölfen
Despite the advances achieved in the past decade in the seed-mediated
synthesis of colloidal single-crystal gold nanorods (Au NRs), the
seed size role in the Au NR formation is not fully understood. Moreover,
although the anisotropic growth of single-crystal seeds typically
occurs at sizes between 4 and 6 nm, synthesizing high-quality Au NRs
with sub-10 nm lengths remains challenging. We investigated herein
the effect of seed dimensions on the silver-assisted seed-mediated
growth of single-crystal Au NRs with lengths below 10 nm in the presence
of hexadecyltrimethylammonium bromide (CTAB). A strong relationship
was found between the seed dimensions and the yield of Au NR formation,
where 3.1 nm seeds displayed an optimal anisotropic grow behavior.
This effect could be related to the different abilities of CTAB micelles
to passivate gold seeds with distinct dimensions, as suggested by
molecular dynamic experiments. Compared with the 1–2 nm seeds
traditionally used in the Au NR synthesis, the enhanced ability of
3.1 nm seeds to evolve anisotropically facilitates the growth of high-quality
Au NRs with sub-10 nm lengths in an unprecedented manner. An optimal
concentration of silver was also critical for the efficient evolution
of 3.1 nm seeds into sub-10 nm Au NRs. Moreover, the synthesized small
Au NRs were used as anisotropic seeds to fabricate sub-10 nm diameter
Au NRs with tunable aspect ratios and core–shell electrocatalysts.
The insight gained on the role of seed size enabled us to develop
an advanced reproducible and scalable route for the synthesis of Au
NRs with sub-10 nm lengths.