Effects of Ag 0 -modification and Fe 3+ -doping on the structural, optical and photocatalytic properties of TiO 2 .

Pure TiO 2 , Ag 0 -modified TiO 2 , Fe 3+ -doped TiO 2 , and Ag 0 -modified/Fe 3+ -doped TiO 2 photocatalysts were synthesized via sol-gel technology. The crystal structure, element composition and surface morphology of the obtained photocatalysts were characterized via XRD, XPS, SEM and TEM, respectively. The results indicate that Ag-TiO 2 samples show higher photocatalytic activity than pure TiO 2 . Unexpectedly, the photocatalytic activities of Fe-TiO 2 and 1% Ag/1% Fe-TiO 2 are lower than pure TiO 2 . To analyze the main factors affecting photocatalytic performance, the samples were further investigated by PL, DRS and BET. The results prove that the additions of Ag and Fe are advantageous for inhibiting the recombination of photoinduced pairs and improving the utilization of light. Fe-TiO 2 and 1% Ag/1% Fe-TiO 2 exhibit smaller specific surface areas than pure TiO 2 , which is the primary reason for their reduced photocatalytic performances.