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Optical Excitation of a Nanoparticle Cu/p-NiO Photocathode Improves Reaction Selectivity for CO2 Reduction in Aqueous Electrolytes
journal contribution
posted on 2020-03-10, 16:04 authored by Joseph
S. DuChene, Giulia Tagliabue, Alex J. Welch, Xueqian Li, Wen-Hui Cheng, Harry A. AtwaterWe report the light-induced
modification of catalytic selectivity
for photoelectrochemical CO2 reduction in aqueous media
using copper (Cu) nanoparticles dispersed onto p-type nickel oxide
(p-NiO) photocathodes. Optical excitation of Cu nanoparticles generates
hot electrons available for driving CO2 reduction on the
Cu surface, while charge separation is accomplished by hot-hole injection
from the Cu nanoparticles into the underlying p-NiO support. Photoelectrochemical
studies demonstrate that optical excitation of plasmonic Cu/p-NiO
photocathodes imparts increased selectivity for CO2 reduction
over hydrogen evolution in aqueous electrolytes. Specifically, we
observed that plasmon-driven CO2 reduction increased the
production of carbon monoxide and formate, while simultaneously reducing
the evolution of hydrogen. Our results demonstrate an optical route
toward steering the selectivity of artificial photosynthetic systems
with plasmon-driven photocathodes for photoelectrochemical CO2 reduction in aqueous media.