N-doped TiO2 adsorbed platinum chloride (PtCl (x) /N-TiO2, x being an unidentified number) was found to show much higher photocatalytic activity than either N-TiO2 or PtCl (x) /TiO2 for the decomposition of acetic acid into CO2 and H2O under Visible-light irradiation, while neither PtCl (x) /SiO2, PtCl (x) /Al2O3 nor an aqueous solution of H2PtCl6 was active. An enhancement of the photo-activity on PtCl (x) /N-TiO2 has been proposed as a Z-scheme mechanism.