Heterometal Alkoxides as Precursors for the Preparation of Porous Fe– and Mn–TiO 2 Photocatalysts with High Efficiencies

Transition‐metal‐doped titanium glycolates (M–TG, with M=Fe, Mn), which are the first non‐stoichiometric heterometal alkoxides, have been synthesised through a solvothermal doping approach. X‐ray diffraction, UV/Vis diffuse reflectance and ESR spectroscopy revealed that the dopant ion (Fe 3+ or Mn 2+ ) is substituted for Ti 4+ in the TG lattice. Fe 3+ prolongs the crystallisation time of Fe–TG, whereas Mn 2+ has a smaller effect on the crystallisation time in comparison with Fe 3+ . The as‐synthesised M–TG materials were used directly as single‐source precursors for the preparation of metal‐doped titania (M–TiO 2 ) through a simple thermal treatment process. The as‐prepared M–TiO 2 materials maintain the rod‐like morphology of the precursors and possess a mesoporous structure with high crystallinity. It has been proved that the dopant ions are incorporated into the TiO 2 lattice at the Ti 4+ positions. The photocatalytic activities of the M–TiO 2 materials obtained were evaluated by testing the degradation of phenol under UV irradiation. From the photocatalytic results, it was concluded that high crystallinity, a large surface area and appropriate transition‐metal‐doping are all beneficial to the enhancement of the photocatalytic performance of the doped TiO 2 material. In addition, it was noted that in comparison with Mn–TiO 2 , Fe–TiO 2 shows higher photocatalytic activity due to the better inhibition effect of Fe 3+ on recombination of photogenerated electron–hole pairs. In contrast to the conventional nanosized TiO 2 photocatalyst, the micrometre‐sized M–TiO 2 particles we obtained can be easily separated and recovered after the photocatalytic reactions.