Pure TiO2, Ag0-modified TiO2, Fe3+-doped TiO2, and Ag0-modified/Fe3+-doped TiO2 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-TiO2 samples show higher photocatalytic activity than pure TiO2. Unexpectedly, the photocatalytic activities of Fe-TiO2 and 1% Ag/1% Fe-TiO2 are lower than pure TiO2. 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-TiO2 and 1% Ag/1% Fe-TiO2 exhibit smaller specific surface areas than pure TiO2, which is the primary reason for their reduced photocatalytic performances.
This journal is © The Royal Society of Chemistry.