posted on 2021-12-12, 18:03authored byJoshua Piaskowski, Alisher Ibragimov, Fedja J. Wendisch, Gilles R. Bourret
A variety of multisegmented
nanorods (NRs) composed of dense Au
and porous Rh and Ru segments with lengths controlled down to ca.
10 nm are synthesized within porous anodic aluminum oxide membranes.
Despite the high Rh and Ru porosity (i.e., ∼40%), the porous
metal segments are able to efficiently couple with the longitudinal
localized surface plasmon resonance (LSPR) of Au NRs. Finite-difference
time-domain simulations show that the LSPR wavelength can be precisely
tuned by adjusting the Rh and Ru porosity. Additionally, light absorption
inside Rh and Ru segments and the surface electric field (E-field)
at Rh and Ru can be independently and selectively enhanced by varying
the position of the Rh and Ru segment within the Au NR. The ability
to selectively control and decouple the generation of high-energy,
surface hot electrons and low-energy, bulk hot electrons within photocatalytic
metals such as Rh and Ru makes these bimetallic structures great platforms
for fundamental studies in plasmonics and hot-electron science.