Transition-Metal Decorated Aluminum Nanocrystals

Recently,
aluminum has been established as an earth-abundant alternative
to gold and silver for plasmonic applications. Particularly, aluminum
nanocrystals have shown to be promising plasmonic photocatalysts,
especially when coupled with catalytic metals or oxides into “antenna-reactor”
heterostructures. Here, a simple polyol synthesis is presented as
a flexible route to produce aluminum nanocrystals decorated with eight
varieties of size-tunable transition-metal nanoparticle islands, many
of which have precedence as heterogeneous catalysts. High-resolution
and three-dimensional structural analysis using scanning transmission
electron microscopy and electron tomography shows that abundant nanoparticle
island decoration in the catalytically relevant few-nanometer size
range can be achieved, with many islands spaced closely to their neighbors.
When coupled with the Al nanocrystal plasmonic antenna, these small
decorating islands will experience increased light absorption and
strong hot-spot generation. This combination makes transition-metal
decorated aluminum nanocrystals a promising material platform to develop
plasmonic photocatalysis, surface-enhanced spectroscopies, and quantum
plasmonics.