Effect of Structural and Dimensional Characteristics of TiO2 and its Photocatalytic Activity in the Oxidation of Tetracycline

Samples of mesoporous TiO2 nanostructures with crystallite sizes of 8-10 nm, forming spheroidal particles of 60-170 nm with average mesopore diameter of 5.5-3.4 nm and specific surface area of 140-200 cm3/g, were obtained by the solvothermal sol–gel method with sulfuric acid mediums and subsequent calcination. With increase of the H2SO4 concentration the content of anatase in the reaction mixture and the size of its crystallites decrease, and the micro-mesoporous materials are transformed into mesoporous and nonporous. It was shown that the photocatalytic activity of these TiO2 materials during exposure to UV light depends largely on the anatase content and the specific surface area, whereas during exposure to visible light it also depends on the presence of acetate groups and titanyl sulfate.