Synthesis of fibrous TiO2 from layered protonic tetratitanate by a hydrothermal soft chemical process

Fibrous TiO2 (anatase) was prepared by a hydrothermal soft chemical process using H2Ti4O9·0.25H2O as a template precursor. The influence of reaction time, temperature and precursor concentration on the phase formation, morphology and crystal-axis orientation were studied. The results have shown that fibrous anatase can be obtained at 220 °C for 24 h with the precursor concentrations in the range of 0.025–0.100 M, and that particles had diameters of 0.2–1 μm and lengths of 2–20 μm. The fibrous TiO2 anatase prepared by this method showed a high orientation along a-axis direction. X-ray diffractometer (XRD) and SEM analyses have indicated that in situ transformation mechanism dominated the entire hydrothermal process but dissolution–recrystallization also occurred on the surface of the particles.