  The use of hot electrons generated from the decay of surface plasmons is a
new paradigm to increase the conversion yield in solar energy technologies.
Titanium nitride (TiN) is an emerging plasmonic ceramic that offers
compatibility with CMOS technology, corrosion resistance, as well as mechanical
strength and durability thus outperforming noble metals (i.e., Au, Ag) in terms
of cost, mechanical, chemical and thermal stability. Here, we show that
plasmonic TiN nanoparticles produce 25% higher photocurrent enhancement than Au
nanoparticles decorated on TiO2 nanowires for photoelectrochemical water
splitting. Our results highlight that TiN offers superior performance in hot
carrier generation due to enhanced absorption efficiency, increased electron
mean free path, and the ability to form an Ohmic junction with TiO2, thus
enabling an extremely efficient electron collection not achievable with
plasmonic Au nanoparticles. Our findings show that transition metal nitrides
enable practical plasmonic devices with enhanced performance for solar energy
conversion.
