One-step synthesis of Fe–N–S-tri-doped TiO2 catalyst and its enhanced visible light photocatalytic activity

Abstract Fe–N–S-tridoped TiO 2 was synthesized through simple one step sol–gel reactions in the presence of ammonium ferrous sulfate. The resulting materials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectrum and surface photovoltage spectroscopy. Results revealed that Fe and S were incorporated into the lattice of TiO 2 by substituting for some Ti atoms and N for O atoms in the lattice of TiO 2 . Tri-doping with Fe, N and S could inhibit the phase transformation of TiO 2 from anatase to rutile, restrain the growth of crystallite sizes, extended the light absorption into the visible region and separate photoinduced charge carriers. The visible photocatalytic activity of Fe–N–S-tridoped TiO 2 was higher than that of N-TiO 2 and P25 TiO 2 . The enhanced photocatalytic activity was attributed to the small crystallite size, high crystallinity, the intense light absorption in visible region, narrow band gap and high separation efficiency of photoinduced charge carriers.