Gold and copper nanoparticles supported on cerium(IV) oxide-a photocatalyst mineralizing organic acids under red light irradiation

Abstract

Gold and copper nanoparticles supported on cerium(IV) oxide (CeO2) powder, which were prepared using a simple multistep photodeposition method, showed strong absorptions at around λ=620nm attributed to the surface plasmon resonance of Cu-Au nanoparticles and exhibited a higher level of activity than that of Au/CeO2 in the mineralization of organic acids (formic acid and acetic acid) in aqueous suspensions under light irradiation (λ=640nm) from a red light-emitting diode. The action spectrum in the mineralization of formic acid indicates that this mineralization involved a photoinduced step by the SPR of Cu-Au supported on CeO2. The apparent quantum efficiency reached 7.5% at λ=625nm and 5.2% even at λ=700nm. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.