posted on 2024-05-15, 23:46authored byNabi E. Traoré, Michelle Berthold, Lukas Hartmann, Patricia Schmul, Benjamin Apeleo Zubiri, Erdmann Spiecker, Wolfgang Peukert
In this work, we independently tune both the particle
size and
the chemical composition of bimetallic silver–gold alloy nanoparticles
(NPs) by carefully controlling the reaction pathway. NP synthesis
involves control of the supersaturation profile in time and space.
For the reaction-controlled case, this supersaturation profile is
determined by a network of reactions leading to the buildup of the
monomer concentration. Using a variety of characterization tools,
we show how the process conditions influence the coupled reactions
in the complex formation mechanism of Ag–Au alloy NPs. Applying
a simple mass balance allows for the independent control of size and
chemical composition of these NPs, yielding particles with constant
composition and varying size in the range of 20 to 40 nm. A series
of constant sizes and varying chemical compositions in the range of
10% to 100% molar gold content is also possible. Our new methodology
shows an example of how reaction networks can be tailored to achieve
targeted NP properties and paves the way for better control in the
synthesis of multicomponent NPs.