Publisher DOI: 10.1021/acscatal.9b00384
Title: Surface-to-Volume Ratio Drives Photoelelectron Injection from Nanoscale Gold into Electrolyte
Language: English
Authors: Graf, Matthias 
Jalas, Dirk 
Weissmüller, Jörg 
Petrov, Alexander  
Eich, Manfred 
Issue Date: 5-Apr-2019
Source: ACS Catalysis 4 (9): 3366-3374 (2019-04-05)
Abstract (english): 
Hot charge carriers from plasmonic nanomaterials currently receive increased attention because of their promising potential in important applications such as solar water splitting. While a number of important contributions were made on plasmonic charge carrier generation and their transfer into the metal's surrounding in the last decades, the local origin of those carriers is still unclear. With our study employing a nanoscaled bicontinuous network of nanoporous gold, we take a comprehensive look at both subtopics in one approach and give unprecedented insights into the physical mechanisms controlling the broadband optical absorption and the generation and injection of hot electrons into an adjacent electrolyte where they enhance electrocatalytic hydrogen evolution. This absorption behavior is very different from the well-known localized surface plasmon resonance effects observed in metallic nanoparticles. For small ligament sizes, the plasmon decay in our network is strongly enhanced via surface collisions of electrons. These surface collisions are responsible for the energy transfer to the carriers and thus the creation of hot electrons from a broad spectrum of photon energies. As we reduce the gold ligament sizes below 30 nm, we demonstrate an occurring transition from absorption that is purely exciting 5d-electrons from deep below the Fermi level to an absorption which significantly excites "free" 6sp-electrons to be emitted. We differentiate these processes via assessing the internal quantum efficiency of the gold network photoelectrode as a function of the feature size providing a size-dependent understanding of the hot electron generation and injection processes in nanoscale plasmonic systems. We demonstrate that the surface effect, compared with the volume effect, becomes dominant and leads to significantly improved efficiencies. The most important fact to recognize is that in the surface photoeffect presented here, absorption and electron transfer are both part of the same quantum mechanical event. Copyright © 2019 American Chemical Society.
ISSN: 2155-5435
Journal: ACS catalysis 
Institute: Optische und Elektronische Materialien E-12 
Werkstoffphysik und -technologie M-22 
Document Type: Article
Project: SFB 986: Teilprojekt B2 - Feste und leichte Hybridwerkstoffe auf Basis nanoporöser Metalle 
SFB 986, Teilproject C1 - Strukturierte Emitter für effiziente und effektive Thermophotovoltaik 
Photocatalytic water splitting with nanoporous gold 
Optical properties of nanoporous gold 
More Funding information: DFG - SFB 986 “M3”, subprojects C1 and B2
Appears in Collections:Publications without fulltext

Show full item record

Page view(s)

Last Week
Last month
checked on Jun 3, 2023


Last Week
Last month
checked on Jun 30, 2022

Google ScholarTM


Add Files to Item

Note about this record

Cite this record


Items in TORE are protected by copyright, with all rights reserved, unless otherwise indicated.