Electrochemical reduction of carbon dioxide (CO2) typically suffers from low selectivity and poor reaction rates that necessitate high overpotentials, which impede its possible application for CO2\ capture, sequestration, or carbon-based fuel production. New strategies to address these issues include the utilization of photoexcited charge carriers to overcome activation barriers for reactions that produce desirable products. This study demonstrates surface-plasmon-enhanced photoelectrochemical reduction of CO2\ and nitrate (NO3-) on silver nanostructured electrodes. The observed photocurrent likely originates from a resonant charge transfer between the photogenerated plasmonic hot electrons and the lowest unoccupied molecular orbital (MO) acceptor energy levels of adsorbed CO2, NO3-, or their reductive intermediates. The observed differences in the resonant effects at the Ag electrode with respect to electrode potential and photon energy for CO2\ versus NO3-\ reduction suggest that plasmonic hot-carriers interact selectively with specific MO acceptor energy levels of adsorbed surface species such as CO2, NO3-, or their reductive intermediates. This unique plasmon-assisted charge generation and transfer mechanism can be used to increase yield, efficiency, and selectivity of various photoelectrochemical processes.
}, year = {2018}, booktitle = {Advanced Energy Materials}, journal = {Advanced Energy Materials}, series = {Advanced Energy Materials}, volume = {8}, pages = {1800363}, month = {08/2018}, doi = {10.1002/aenm.201800363}, language = {eng}, }