title: Enhanced photochemistry of ethyl chloride on Ag nanoparticles.
abstract: Enhanced photodecomposition of ethyl chloride (EC) adsorbed on SiO2/Si (100) supported silver nanoparticles (Ag NPs) under ultrahigh vacuum (UHV) conditions has been studied in order to assess the potential contribution of plasmonic effects. The cross section for photodecomposition of EC and overall photoyield were found to increase with increasing photon energy regardless of the plasmon resonant wavelength and with Ag coverage without any noticeable particle size effect. The influence of EC-Ag NPs separation distance on the rate of EC decomposition was studied in order to examine potential local electric field influence on the photodissociation process. Long (∼5 nm) photoactivity decay distance has been observed which excludes local surface plasmon dominance in the photodecomposition event. These findings suggest that the alignment of excited electron energy and adsorbate affinity levels is central for efficient photochemical reactions, whereas short-range electric field enhancement by plasmon excitation on top and at the immediate vicinity of silver nanoparticles does not have any measurable effect.
authors.affiliation: Institute of Chemistry, The Hebrew University of Jerusalem , Edmund J. Safra Campus-Givat Ram, Jerusalem 91904, Israel.
authors.forename: Gil
authors.initials: G
authors.lastname: Toker
authors.forename: Alexander
authors.initials: A
authors.lastname: Bespaly
authors.forename: Liat
authors.initials: L
authors.lastname: Zilberberg
authors.forename: Micha
authors.initials: M
authors.lastname: Asscher
mesh_terms: D005018:Ethyl Chloride / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D055668:Photochemical Processes; D020349:Surface Plasmon Resonance
chemical_list: D005018:Ethyl Chloride; D006046:Gold
keywords: Surface photochemistry; metal nanoparticles; photocatalysis; surface plasmon resonance