Hydrothermal and Mechanochemical Modification as a Tool for Preparing ZrO2 with Desired Physicochemical Characteristics and Improved Photocatalytic Properties

Hydrothermal treatment of precipitated ZrO₂ at 300 °C promotes the transformation of amorphous ZrO₂ into a pure monoclinic phase, as well as the formation of a uniform mesoporous structure, which has higher thermal stability. Soft dry post-milling of monoclinic ZrO₂ causes the introduction of defects into its structure without a noticeable change in the porosity and preservation of the phase composition. The presence of defects is confirmed directly by UV-Vis spectra and indirectly by the manifestation of photocatalytic activity of milled samples under visible irradiation.