In this paper, we describe the chemical engineering aspects of the preparation of highly active and stable photocatalytic textiles and show several examples of the application of these materials for the efficient degradation of harmful volatile organic compounds (VOCs) and adverse macromolecules, namely, deoxyribonucleic acid (DNA) contaminants. The photoactive textiles were obtained by the impregnation method. Titanium(IV) oxysulfate and titanium(IV) isopropoxide were used as the precursors of TiO2 and were hydrolyzed under different conditions. The effect of the preparation conditions on the photocatalytic activity of the materials was investigated. The addition of nanocrystalline TiO2 to the impregnating compound during the synthesis substantially increased the photocatalytic activity of the materials. As a result, we proposed a technique for the modification of cotton fabric using titanium(IV) isopropoxide and nanocrystalline TiO2, which allowed the production of textiles with high stability toward washing and with photocatalytic activity similar to the activity of powdered TiO2 photocatalysts. The complete oxidation of VOCs with the formation of carbon oxides and water as the final oxidation products was detected on the surface of synthesized textiles under UV light. In the case of an S-containing pollutant, deactivation of the material was observed during long-term oxidation, but as an advantage over powdered photocatalysts, the textile material could be easily reactivated by simple washing. Additionally, in this paper, we show using the polymerase chain reaction (PCR) technique the ability of photoactive textiles to decompose human genomic DNA contaminants under UV light.