Abstract
Nanometer-sized metal clusters are prime candidates for photoactivated catalysis, based on their unique tunable optical and electronic properties, combined with a large surface-to-volume ratio. Due to the very small optical cross sections of such nanoclusters, support-mediated plasmonic activation could potentially make activation more efficient. Our support is a semi-transparent gold film, optimized to work in a back-illumination geometry. It has a surface plasmon resonance excitable in the 510–540 nm wavelength range. Ptn clusters (size distribution peaked at n = 46 atoms) have been deposited onto this support and investigated for photoactivated catalytic performance in the oxidative decomposition of methylene blue. The Pt cluster catalytic activity under illumination exceeds that of the gold support by more than an order of magnitude per active surface area. To further investigate the underlying mechanism of plasmon-induced catalysis, the clusters have been imaged with optically-assisted scanning tunneling microscopy under illumination. The photoactivation of the Pt clusters via plasmonic excitation of the support and subsequential electronic excitation of the clusters can be imaged with nanometer resolution. The light-induced tunneling current on the clusters is enhanced relative to the gold film support.
Original language | English (US) |
---|---|
Pages (from-to) | 30570-30577 |
Number of pages | 8 |
Journal | PHYSICAL CHEMISTRY CHEMICAL PHYSICS |
Volume | 19 |
Issue number | 45 |
DOIs | |
State | Published - Nov 2 2017 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2022-06-03Acknowledgements: This work was supported by the Nanosystems Initiative Munich (NIM) (S. W. and U. H.) and the DFG projects HE3454/18-1 and -2, HE3454/23-1 (U. H. and F. F. S.), respectively ES349/1-1 and -2 (F. E. and F. L. K.). Research at Illinois was supported by grants from the National Science Foundation, NSF CHE and DMR (L. N., S. W., J. W. L. and M. G.). J. J. S. thanks the Royal Commission for the Exhibition 1851 (UK) for a Research Fellowship. Electron beam evaporation was performed at the Micro and Nanotechnology Laboratory, University of Illinois. The authors thank Marian D. Rtzer, Maximilian Krause and Aras Kartouzian for assistance with sample preparation and Dalaver H. Anjum from the 'Advanced Nanofabrication Imaging and Characterization' lab at King Abdullah University of Science and Technology (KAUST) for his help in acquiring the STEM micrographs.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry