Ultrasonication effects on the visible-light photocatalytic activity of Au-modified TiO2 powder

After a rutile powder was modified with Au, visible-light photocatalytic activity of the powders before and after sonication treatment was evaluated using the decomposition of gaseous 2-propanol (IPA) to acetone. The modified powders possessed almost identical Au concentrations, and the difference of specific surface area before and after sonication was negligible. Au nanoparticles on the surface of rutile were grown and the wavelength of the peak attributable to localized surface plasmon resonance (LSPR) by Au was red-shifted 46 nm by sonication treatment. Photocatalytic activity measurements done by changing the wavelength range of illuminated light suggest that the wavelength of sensitivity for photocatalysis using LSPR under visible light is tunable by sonication.

► A TiO2 (rutile) powder was modified with Au.
► Au nanoparticles on the rutile surface were grown by sonication treatment.
► Peak wavelength attributable to LSPR by Au was red-shifted.
► Sensitive wavelength for photocatalysis using LSPR was tunable by sonication.