TheFig enhancement of photocatalytic performance should be ascribedto the increase in the visible light absorption and the reductionin electron-hole pair recombination in TiO2with the F doping,
which has been confirmed from the absorption and EIS spectra. Inaddition, the oxygen vacancies can act as new active sites to reduceO2and form superoxide radicals and hydroxyl radicals, which isresponsible for photocatalytic degradation of organic pollutants