Synthesis of Highly Monodisperse Citrate-Stabilized
Silver Nanoparticles of up to 200 nm: Kinetic Control and Catalytic
Properties
Neus G. Bastús
Florind Merkoçi
Jordi Piella
Victor Puntes
10.1021/cm500316k.s001
https://acs.figshare.com/articles/journal_contribution/Synthesis_of_Highly_Monodisperse_Citrate_Stabilized_Silver_Nanoparticles_of_up_to_200_nm_Kinetic_Control_and_Catalytic_Properties/2297572
Highly monodisperse sodium citrate-coated
spherical silver nanoparticles
(Ag NPs) with controlled sizes ranging from 10 to 200 nm have been
synthesized by following a kinetically controlled seeded-growth approach
via the reduction of silver nitrate by the combination of two chemical
reducing agents: sodium citrate and tannic acid. The use of traces
of tannic acid is fundamental in the synthesis of silver seeds, with
an unprecedented (nanometric resolution) narrow size distribution
that becomes even narrower, by size focusing, during the growth process.
The homogeneous growth of Ag seeds is kinetically controlled by adjusting
reaction parameters: concentrations of reducing agents, temperature,
silver precursor to seed ratio, and pH. This method produces long-term
stable aqueous colloidal dispersions of Ag NPs with narrow size distributions,
relatively high concentrations (up to 6 × 10<sup>12</sup> NPs/mL),
and, more important, readily accessible surfaces. This was proved
by studying the catalytic properties of as-synthesized Ag NPs using
the reduction of Rhodamine B (RhB) by sodium borohydride as a model
reaction system. As a result, we show the ability of citrate-stabilized
Ag NPs to act as very efficient catalysts for the degradation of RhB
while the coating with a polyvinylpyrrolidone (PVP) layer dramatically
decreased the reaction rate.
2014-05-13 00:00:00
sodium
PVP
200 nm
agent
concentration
RhB
kinetically
model reaction system
tannic acid
Ag NPs