F, Ca co-doped TiO₂ was synthesized by a facile one-step hydrothermal method. After doping with F, electrons can be simultaneously excited from valence band to the F doping energy level. The smaller crystal size caused by doping with Ca can exhibit more powerful redox ability and the efficient separation of photogenerated hole–electron pairs. Therefore, F, Ca co-doped TiO₂ exhibited enhanced photocatalytic activity.