Influence of Synthesis Conditions of Nanosized Titanium Dioxide on the Structure and Phase Composition

In this work, nanosized titanium dioxide was synthesized and the effect of acidity of the medium on its structure and properties was studied. Photocatalysts were prepared by a sol–gel method from titanium tetrabutoxide, ethyl alcohol, and water in a ratio of 1 : 1 : 4 at different pH (3, 7, and 9). Powder modification was carried out by annealing in air at 150–750°C. The structure of the synthesized initial and modified annealed photocatalysts was studied by XRD analysis and the phase ratios were determined. An analysis of the experimental data showed that the acidity of the medium did not have a strong influence on the phase formation and phase ratio of the resulting photocatalysts. It was found that the annealing temperature had a greater effect on the structure and properties: the phase ratio, coherent scattering regions (CSR), and specific surface area were changed. The powders prepared in this work had high specific surface area and complicated phase composition, which made them promising for photocatalysis, in particular, in a hydrogen evolution reaction.