Preparation and visible-light photocatalytic activity of Au- and Cu-modified TiO2 powders

Abstract A rutile powder was modified with either Cu or Au, or both. Then, visible-light photocatalytic activity of the obtained powders was evaluated by the decomposition of gaseous 2-propanol (IPA) to acetone. The modified powders possessed almost identical Cu and Au concentrations, and the difference of specific surface area among the powders was within 10%. The order of acetone generation by photocatalytic decomposition of IPA was Cu–Au–TiO2 > Cu–TiO2 > Au–TiO2 > bare TiO2. The photocatalytic activity measurement by changing the wavelength range of illuminated light suggests that both the localized surface plasmon resonance from Au and the interfacial charge transfer by Cu contribute the entire photocatalytic decomposition activity of IPA on Cu–Au–TiO2 under visible light.