CF4 plasma treatment is performed on commercial TiO2 to improve the photocatalytic efficiency. The CF4 plasma treatment is a facile and fast method for simultaneous introduction of carbon and fluorine atoms onto TiO2. Photodegradation of rhodamine B, methyl orange, and methylene blue is carried out under solar light irradiation to determine its CF4 plasma treatment effect. The dye removal of commercial TiO2 to rhodamine B, methyl orange, and methylene blue is 60.0, 18.9, and 49.2%, respectively, whereas TiO2 treated with CF4 plasma for 50 min is 93.5, 71.0, and 88.6% for rhodamine B, methyl orange, and methylene blue, respectively. In addition, the photodegradation rate constants of TiO2 treated with CF4 plasma for 50 min were 0.0135, 0.0083, and 0.0129min-1 for rhodamine B, methyl orange, and methylene blue, respectively, which are up to 7.5 times higher than that of untreated TiO2 (0.0049, 0.0011, and 0.0039min-1). This improvement is attributed to the increase in oxygen vacancies by the introduction of carbon atoms into TiO2 using CF4 plasma treatment. In addition, the F- ions physically adsorbed to the TiO2 surface promote the formation of hydroxyl free radicals, enabling effective decomposition of various dyes.