F-doped TiO 2 (FT) powders were prepared by spray pyrolysis from an aqueous solution of H 2 TiF 6 . These FT powders demonstrated very high visible-light (Vis) photocatalytic activities for decompositions of both acetaldehyde and trichloroethylene, although their UV–Vis spectra indicated that F-doping had less effect on the optical absorption property of bulk TiO 2 . However, photoluminescence (PL) spectra revealed that two kinds of oxygen vacancies (F and F + centers) were formed by F-doping. The appearance of Vis photocatalytic activity for FT powders was ascribed to the creation of these oxygen vacancies.