| Autor: |
Graf M; Institute for Materials Research, Helmholtz Center Geesthacht, D-21502 Geesthacht, Germany.; Leiden Institute of Chemistry, Leiden University, 2333 CD Leiden, The Netherlands., Vonbun-Feldbauer GB; Institute of Advanced Ceramics, Hamburg University of Technology, D-21703 Hamburg, Germany., Koper MTM; Leiden Institute of Chemistry, Leiden University, 2333 CD Leiden, The Netherlands. |
| Abstrakt: |
Plasmonic photocatalysis via hot charge carriers suffers from their short lifetime compared with the sluggish kinetics of most reactions. To increase lifetime, adsorbates on the surface of a plasmonic metal may create preferential states for electrons to be excited from. We demonstrate this effect with O adsorbates on a nanoporous gold electrode. Nanoporous gold is used to obtain a broadband optical response, to increase the obtained photocurrent, and to provide a SERS-active substrate. Only with adsorbates present, we observe significant photocurrents. Illumination also increases the adsorbate coverage above its dark potential-dependent equilibrium, as derived from a two-laser in situ SERS approach. Density functional theory calculations confirm the appearance of excitable states below the Fermi level. The photocurrent enhancement and broadband characteristics reveal the potential of the plasmonic approach to improve the efficiency of photoelectrochemical water splitting. |
