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A study was carried out to obtain effective photocatalytic coatings on a ceramic silicate carrier. The analysis of the characteristics of silicate materials, such as: ceramic carrier "Biopur"; porous glass carrier "Siporax"; glass-ceramic carrier (sitall) "Biopur forte" produced by the company "SERA", Germany, was made. According to X-ray phase analysis data, it was shown that the “Biopur” ceramic support is formed by magnesium aluminosilicates of the composition MgAl2Si3O10 and MgAl2Si4O12. The porous material “Siporax” is X-ray amorphous. The silicate material “Biopur forte” does not have a pronounced amorphous component in its structure and can be assigned to the class of sitall with a high SiO2 content and a low content of alkali and alkaline earth metal cations in the structure. A method for impregnating a ceramic support with a solution of a bismuth photo-catalyst precursor, a specially developed composition of a complex of bismuth with sorbitol, is considered. An effective concentration of a solution of a complex of bismuth with sorbitol in ethanol equal to 10% was found. By low-temperature pyrolysis at , photo-catalytically active coatings of strontium bismuthates were obtained on each of the considered types of ceramic supports. The highest photocatalytic activity was detected in the coating deposited on a ceramic carrier with a glass structure – “Biopur forte”. A study of the photocatalytic activity of coatings, based on strontium bismuthate, depending on the multiplicity of coating on a “Biopur forte” ceramic carrier, was made. The effective number of layers of the photocatalytic coating on a “Biopur forte” ceramic carrier is determined, which corresponds to the highest rate of decrease in the optical density of a model organic pollutant upon irradiation with visible light in the spectrum.

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This paper presents the results pertaining to studying the properties of the photocatalytically active composition of strontium bismuthate SrBi2.70O5.05, SrBi2.90O5.35, and SrBi3.25O5.88 and bismuth carbonate (BiO)2CO3 in molar ratios 1/0.67, 1/0.56, and 1/0.37, respectively. These compositions are obtained through pyrolytic synthesis from organic precursor complexes of strontium and bismuth with sorbitol. It has been established that the synthesised powder materials absorb the light of the visible range up to 500 nm owing to the presence of a narrow-gap semiconductor strontium bismuthate. The presence of a wide-band semiconductor (BiO)2CO3 ensures an effective separation of electron-hole pairs. The diffuse reflection spectra (DRS) of compositions differ from the analogous spectra of a mechanical mixture of these semiconductor phases with the same composition, which allows one to assume the heterostructural structure of the semiconductor system. The same heterostructure is confirmed by the results of mapping. Catalytic particles that are synthesised at a temperature of 500°C containing 27 mass% (BiO)2CO3 (corresponding to SrBi2.9O5.35/(BiO)2CO3 = 1/0.56) have the greatest activity with respect to the photodecomposition of methylene blue (MB). The possibility of controlling the optical properties and photocatalytic activity of the composition is depicted due to the joint formation of the strontium bismuthate phase and the bismuth carbonate phase.