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Proceedings Paper

Surface plasmon spectroscopy study of electron exchange between single gold nanorods and metal oxide matrix during hydrogen gas sensing (Presentation Recording)
Author(s): Michela Cittadini; Sean Collins; Paul Mulvaney; Alessandro Martucci

Paper Abstract

The direct optical monitoring of electron exchange on single plasmonic nanoparticles, involved in chemical reactions with gas molecules, is one of the main challenges in the heterogeneous catalysis and gas sensing fields. Catalysts are substances that speed up reactions by providing an alternative pathway with lower activation energy than that required for the uncatalysed reaction. A lot of research, both fundamental and applied, has been carried out to investigate how catalysts work and to increase their efficiency. The present work shows how the use of Dark Field Microscopy (DFM) coupled with surface plasmon spectroscopy, enables the direct observation of the kinetics of H2 gas interaction with single gold nanorods (NR) coupled with Pt nanoparticles (NPs) and/or with metal oxide matrices. The plasmonic particles, gold NRs, act as optical probes, and enable the monitoring of the electron exchange through the measurement of their surface plasmon resonance (SPR) band shift. To improve the redox reaction kinetics, the Au NRs have been coupled with Pt NPs and embedded also into a TiO2 or ZnO low scattering matrix. The Au NRs, the Pt, TiO2 and ZnO NPs have been synthetized by colloid chemistry. Several samples made of bare Au NRs, or Au NRs coupled with only Pt NPs or with Pt and TiO2 NPs or with Pt and TiO2 have been deposited by spin coating on silica substrates. The longitudinal Au SPR band shift has been monitored by DFM looking at the variation of the scattering spectrum of a single Au NRs in the presence of H2. Time-resolved measurements have been also conducted at fixed wavelength in order to monitor the kinetics of the H2 reaction. With such measurements it was possible to elucidate the importance of the adsorbed oxygen and the TiO2 matrix on the H2 reaction with the Pt NPs.

Paper Details

Date Published: 5 October 2015
PDF: 1 pages
Proc. SPIE 9558, Nanostructured Thin Films VIII, 955806 (5 October 2015); doi: 10.1117/12.2186659
Show Author Affiliations
Michela Cittadini, Univ. degli Studi di Padova (Italy)
Sean Collins, The Univ. of Melbourne (Australia)
Paul Mulvaney, The Univ. of Melbourne (Australia)
Alessandro Martucci, Univ. degli Studi di Padova (Italy)


Published in SPIE Proceedings Vol. 9558:
Nanostructured Thin Films VIII
Akhlesh Lakhtakia; Tom G. Mackay; Motofumi Suzuki, Editor(s)

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