Growth behaviour and plasmon resonance properties of photocatalytically deposited Cu nanoparticles

Abstract

Cu nanoparticles (NPs) were deposited on UV-irradiated TiO₂ in an aqueous solution containing Cu(CH₃COO)₂ and ethanol by a photocatalytic reaction. Cu NPs on TiO₂ exhibit an extinction (= absorption + scattering + reflection) peak due to localized surface plasmon resonance at around 600 nm initially. The density and size as well as the extinction of Cu NPs increase during the deposition, accompanied by a slight redshift of the peak. Eventually, TiO₂ is mostly covered with coalesced Cu NPs that exhibit a spectrum less characteristic of Cu NPs, but more characteristic of a Cu layer.