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Commercially available TiO 2 of anatase structure produced in the Chemical Factory Police S.A. was modified by doping Ag from AgNO 3 solution via photodeposition method. The obtained amount of deposited Ag on TiO 2 was in the range of 0.11 to 0.98 mass %. Deposition of Ag on TiO 2 resulted in the retarding of the recombination reaction and formation of the higher amount of OH radicals on the photocatalyst surface during irradiation with UV light. The photocatalytic activity of samples was tested for the decomposition of phenol and Reactive Black in the water solution under both, UV and artificial solar light radiation. Deposition of Ag on TiO 2 surface increased its photocatalytic activity towards the Reactive Black decomposition but not for phenol. High adsorption of Reactive Black on Ag modified TiO 2 photocatalysts, which was higher than on TiO 2 , could enhance the photocatalytic activity of these samples. The solution with 1% slurry of TiO 2 -Ag was sprayed on the surface of concrete. For concrete impregnated with TiO 2 -Ag slurry the both, fungicidal and self-cleaning effect for dyes were observed.

Photocatalysis belongs to one of the Advanced Oxidation Processes (AOP). These processes make possible the decomposition of organic compounds to carbon dioxide and water. The most useful photocatalyst is titanium dioxide which, to make it active, requires irradiation with suitable wavelengths. Pure titanium dioxide can be activated only by ultraviolet light irradiation (UV). For a long time, studies have been carried on modified titanium dioxide materials to obtain more effective photocatalysts with greater activity under UV light irradiation or to obtain photocatalysts which may be active also under visible light irradiation. One of the possible ways for modifying TiO

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Photocatalytic disinfection of Escherichia coli by carbon modified TiO 2 photocatalysts was tested under UV and visible light irradiation. Carbon modification of TiO 2 in a pressure reactor was conducted at 120 °C for 4 h. For modification purposes, five alcohols were used (methanol, ethanol, n-butanol, 2-butanol, and tert-butanol). The amount of carbon in photocatalysts was calculated with a termogravimetric analyser. It was found that photocatalysts with low content of carbon have better antibacterial ability under visible light irradiation and photocatalysts with higher content of carbon have better antibacterial ability under UV light irradiation.