METHOD FOR PRODUCING A MIXED PHOTOCATALYST BASED ON TITANIUM OXIDE Russian patent published in 2021 - IPC B01J21/06 B01J37/03 C01G23/53 C02F1/30 

FIELD: chemical technology.

SUBSTANCE: invention relates to the field of chemical technology. This invention can be used for the treatment of industrial wastewater containing difficult-to-oxidize organic compounds. The method for producing a mixed photocatalyst based on titanium oxide includes three stages: the first stage is carried out according to the peroxide technique, and 0.05 M sodium silicate is added to a 0.1 M solution of titanium oxysulfate and hydrolyzed with sodium hydroxide with a concentration of 1.5 M to pH 3.2 ; the resulting gel-like precipitate is centrifuged at a speed of 3000 rpm and washed with distilled water until a negative reaction to counterions of the initial salts; then a 30% solution of hydrogen peroxide is added to the hydrogel and adjusted with distilled water and aqueous ammonia 3M to pH 7, obtaining a titanium peroxo complex and silicic acid; after which a 3 M solution of nitric acid is added dropwise to the mixture until a pH value of 2 is reached, then hydrothermal treatment is carried out in an autoclave at a self-regulating pressure of 3 MPa and a temperature of 180°C for 24 hours, the resulting precipitate is separated by centrifugation at a speed of 3000 rpm, washed with distilled water and dried in an oven at 60°C for 24 hours; the second stage includes obtaining a silicic acid sol, while a sodium silicate solution with a concentration of 0.28 g/l is passed through a burette with a KU-2-8 cation exchanger, photocatalytically active titanium oxide is introduced into the obtained silicic acid sol, obtained in the first stage, the particles are redistributed under the influence of ultrasound with a frequency of 60 Hz for 90 minutes; the third stage is the granulation of the photocatalyst by the method of dropwise introduction into the immersion oil for 24 hours, after which the resulting granules are washed from the oil and dried in an oven at a temperature of 100°C to constant weight.

EFFECT: obtaining a highly efficient granular mixed photocatalyst based on TiO₂/SiO₂ in a silica gel matrix with a granule size of 0.1+ cm and a photocatalytically active particle size of 15-20 nm.

1 cl, 1 ex