The paper reviews the available technologies for producing photocatalytic active self-cleaning materials based on cement, including concretes and dry building mixtures. Used photocatalytic additives and their influence on the cement system are considered. The applied methods for assessing the photocatalytic activity of self-cleaning cement materials are presented. The compositions of concrete mixtures, their properties, areas and prospects of application are analyzed. The main problems of development, production and application of photocatalytic active self-cleaning materials based on cement are presented. The main directions to increase the self-cleaning ability of photocatalytic active materials based on cement are: optimization of the microstructure of the photocatalyst and the composite with its use in the direction of creating a developed surface of the photocatalyst - hierarchical microstructure; it intensifies the diffusion processes of photocatalytic reaction reagents and increases the contact area photocatalyst with a pollutant; it absorbs and accumulates ultraviolet radiation waves; optimization of the phase composition of titanium dioxide - search for the ratio of the anatase and rutile phases, at which the maximum photocatalytic activity is achieved; choosing of economically feasible method for periodical updating of the surface of concrete products carbonized during operation in order to restore self-cleaning ability.

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The paper considers the dependences of the properties of self-cleaning fine-grained concrete on the composition of the concrete mixture: the ratio of sand to white Portland cement, the content of plasticizer, the content of photocatalytic composite material. The photocatalytic composite material (PCM) is a diatomite-based anatase-silica material obtained by sol-gel deposition of nanoscale TiO2 of anatase modification on a silica carrier. The investigated properties of fine-grained concrete were: average density, compressive strength and self-cleaning ability, which was determined by evaluating the photocatalytic decomposition of an organic dye – Rhodamine B. It was shown that an increase in the content of PCM to increase the ability of the coating to self-cleaning leads to a loosening of the structure of fine-grained concrete, but this can be successfully offset by an increase in the content of plasticizer, which additionally improves the distribution of the photocatalytic agent in the cement-sand matrix. An increase in the proportion of sand and the content of plasticizer also contribute to an increase in the ability to self-cleaning. The pozzolan activity of the PCM provides an increase in the strength of concrete. The results of comparing the self-cleaning ability of fine-grained concrete of various compositions indicate a high photocatalytic activity of samples with PCM, which allows its application for creating self-cleaning coatings.

The paper presents the results of the determination of the effect of a photocatalytic composite material (PCM) with the composition SiO2‒TiO2 on the main properties of white Portland cement: heat release during hydration, phase composition and microstructural features of cement stone, pressure strength and self-cleaning ability. PCM was synthesized by a sol-gel method based on tetrabutoxytitanium and finely dispersed diatomite powder and 15% cement was added instead. The presence of PCM in the cement system provided the reduction of the induction period of cement hydration, consolidation of the microstructure of the cement stone with the products of the pozzolanic reaction, the ability to photocatalytic self-cleaning of the cement stone surface.

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