Plasmonic Electrochemistry (Surface Plasmom Effect)

Introduction

Photoelectrochemistry has been applied to photocatalysis [Chapter 309535, 310654] and redox reaction-based solar cells such as dye-sensitized solar cells [Chapter 309529, 327536].  In photoelectrochemistry, semiconductors such as TiO₂ or dye molecules such as Ru-complexes are used for light harvesting elements.  Those elements are often used as thick deposits so that incident photons are absorbed extensively.  An alternative approach to sufficient light absorption is the use of plasmonic metal nanoparticles.  Nanoparticles of noble metal such as Au, Ag, and Cu absorb and scatter light due to localized surface plasmon resonance (LSPR), which is collective oscillation of conduction electrons at the metal surface by coupling with an incident electromagnetic field.  LSPR is of interest for the following three aspects, (1) strong light absorption, which is roughly proportional to particle volume, (2) tunable optical properties,