1 research outputs found
Size- and Shape-Controlled Synthesis and Properties of Magnetic–Plasmonic Core–Shell Nanoparticles
Magnetic–plasmonic core–shell
nanomaterials offer
a wide range of applications across science, engineering, and biomedical
disciplines. However, the ability to synthesize and understand magnetic–plasmonic
core–shell nanoparticles with tunable sizes and shapes remains
very limited. This work reports experimental and computational studies
on the synthesis and properties of iron oxide–gold core–shell
nanoparticles of three different shapes (sphere, popcorn, and star)
with controllable sizes (70 to 250 nm). The nanoparticles were synthesized
via a seed-mediated growth method in which newly formed gold atoms
were added onto gold-seeded iron oxide octahedrons to form a gold
shell. The evolution of the shell into different shapes was found
to occur after the coalescence of gold seeds, which was achieved by
controlling the amount of additive (silver nitrate) and reducing agent
(ascorbic acid) in the growth solution. First-principles calculation,
together with experimental results, elucidated the intimate roles
of thermodynamic and kinetic parameters in the shape-controlled synthesis.
Both discrete dipole approximation calculation and experimental results
showed that the nanopopcorns and nanostars exhibited red-shifted plasmon
resonance compared with the nanospheres, with the nanostars giving
multispectral feature. This research has made a great step further
in manipulating and understanding magnetic–plasmonic hybrid
nanostructures and will make an important impact in many different
fields