Influence of Mechanochemical and Sonochemical Methods of Preparation of TiO.sub.2/ZrO.sub.2 Composites on Photocatalytic Performance in Prometrine Decomposition

Nanosized TiO.sub.2/ZrO.sub.2=1:1 composites have been obtained by mechanochemical, ultrasonic, and coprecipitation methods. It is shown that mechanochemical and ultrasonic treatments of a TiO.sub.2 and ZrO.sub.2 mixture lead to size reduction of oxide particles, changes in X-ray diffraction spectra, the formation of a mesoporous structure of TiO.sub.2/ZrO.sub.2 samples, and an increase in their photocatalytic activity in the reaction of Gesagard (prometryn) herbicide destruction in an aqueous medium when compared to a mechanical TiO.sub.2 and ZrO.sub.2 mixture. It is found that the sample obtained by coprecipitation is X-ray amorphous with a well-developed surface, however, it is significantly inferior to samples obtained by alternative methods in terms of photoactivity.