Silver Nanocubes Coated in Ceria: Core/Shell Size Effects on Light-Induced Charge Transfer

Devin B. O'Neill, Daniel Prezgot, Anatoli Ianoul, Cees Otto, Guido Mul, Annemarie Huijser*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Plasmonic sensitization of semiconductors is an attractive approach to increase light-induced photocatalytic performance; one method is to use plasmonic nanostructures in core@shell geometry. The occurrence and mechanism of synergetic effects in photocatalysis of such geometries are under intense debate and proposed to occur either through light-induced charge transfer (CT) or through thermal effects. This study focuses on the relation between the dimensions of Ag@CeO2 nanocubes, the wavelength-dependent efficiency, and the mechanism of light-induced direct CT. A 4-mercaptobenzoic acid (4-MBA) linker between core and shell acts as a Raman probe for CT. For all Ag@CeO2 nanocubes, CT increases with decreasing excitation wavelength, with notable increase at and below 514 nm. This is fully explainable by CT from silver to the 4-MBA LUMO, with the increase for excitation wavelengths that exceed the Ag/4-MBA LUMO gap of 2.28 eV (543 nm). A second general trend observed is an increase in CT yield with ceria shell thickness, which is assigned to relaxation of the excited electron further into the ceria conduction band, potentially producing defects.

Original languageEnglish
Pages (from-to)1905-1912
Number of pages8
JournalACS Applied Materials and Interfaces
Volume12
Issue number1
DOIs
Publication statusPublished - 8 Jan 2020

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Keywords

  • UT-Hybrid-D
  • FDTD
  • light-induced charge transfer
  • plasmonic
  • Raman spectroscopy
  • sensitized photocatalyst
  • silver nanocube
  • ceria

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