posted on 2021-02-24, 15:03authored byQi Xiao, Calum Kinnear, Timothy U. Connell, Muhammad Kalim Kashif, Christopher D. Easton, Aaron Seeber, Laure Bourgeois, Gus. O. Bonin, Noel W. Duffy, Anthony S. R. Chesman, Daniel E. Gómez
Plasmonic
noble metal nanoparticles exhibit intense interactions
with light but are inherently chemically unreactive. Alloying plasmonic
gold with catalytic palladium forms a hybrid catalyst incorporating
each metal’s benefits. In this work we demonstrate a robust
method for preparing alloyed nanoparticles without the need for colloidal
synthesis or time-consuming lithography. This method results in uniform,
densely packed monolayers of alloyed AuPd nanoparticles suitable for
inclusion in electromagnetic perfect absorbers, which further strengthen
existing light-matter interactions. While these materials demonstrate
a strong photocathodic response not possible using monometallic Au
nanoparticles on a n-type spacer and exhibit higher
photon-to-energy efficiencies than Pd analogues, they are also capable
of a photoanodic response characterized by electron injection across
the Schottky junction with TiO2. The alloying of plasmonic
Au and catalytic Pd and subsequent incorporation in a highly absorbing
material represents a promising step toward efficient photoelectrocatalysts
for hydrogen production that operate under real-world conditions.