1 research outputs found
Plasmonic Au@Pd Nanorods with Boosted Refractive Index Susceptibility and SERS Efficiency: A Multifunctional Platform for Hydrogen Sensing and Monitoring of Catalytic Reactions
Palladium
nanoparticles (NPs) have received tremendous attention
over the years due to their high catalytic activity for various chemical
reactions. However, unlike other noble metal nanoparticles such as
Au and Ag NPs, they exhibit poor plasmonic properties with broad extinction
spectra and less scattering efficiency, and thus limiting their applications
in the field of plasmonics. Therefore, it has been challenging to
integrate tunable and strong plasmonic properties into catalytic Pd
nanoparticles. Here we show that plasmonic Au@Pd nanorods (NRs) with
relatively narrow and remarkably tunable optical responses in the
NIR region can be obtained by directional growth of Pd on penta-twinned
Au NR seeds. We found the presence of bromide ions facilitates the
stabilization of facets for the directional growth of Pd shell to
obtain Au@Pd nanorods (NR) with controlled length scales. Interestingly,
it turns out the Au NR supported Pd NRs exhibit much narrow extinction
compared to pure Pd NRs, which makes them suitable for plasmonic sensing
applications. Moreover, these nanostructures display, to the best
of our knowledge, one of the highest ensemble refractive index sensitivity
values reported to date (1067 nm per refractive index unit, RIU).
Additionally, we showed the application of such plasmonic Au@Pd NRs
for localized surface plasmon resonance (LSPR)-based sensing of hydrogen
both in solution as well as on substrate. Finally, we demonstrate
the integration of excellent plasmonic properties in catalytic palladium
enables the <i>in situ</i> monitoring of a reaction progress
by surface-enhanced Raman scattering. We postulate the proposed approach
to boost the plasmonic properties of Pd nanoparticles will ignite
the design of complex shaped plasmonic Pd NPs to be used in various
plasmonic applications such as sensing and <i>in situ</i> monitoring of various chemical reactions