Photocatalytic self-cleaning lime coatings

The article presents the results of assessing the self-cleaning properties of lime coatings. The use of zinc oxide immobilized on synthesized aluminosilicates as a photocatalyst is considered. The technology of synthesis and properties of aluminosilicates are described. The photocatalytic activity of zinc oxide is analyzed depending on the technology of obtaining the photocatalyst. It was found that the band gap width of the photocatalyst obtained by immobilizing zinc oxide on synthetic zeolite decreased from 3.37 eV to 2.7 eV. Comparison of the self-cleaning ability of lime coating samples, in the formulation of which the photocatalyst was introduced, is carried out using the methods specified in the regulatory documentation- according to the test method in accordance with GOST R 57255-2016, according to the method of the Italian standard UNI 11259. The results of tests according to the methods established in regulatory documents indicate the high photocatalytic activity of the lime coating. It has been established that the lime coating with the use of zinc oxide photocatalyst immobilized on synthetic zeolite exhibits high photocatalytic activity. In accordance with the requirements of the Italian standard UNI 11259, the photocatalytic activity of the surface after 4 hours is R=21.94-55.42%, and after 26 hours – 51.96 - 98.2% depending on the specific surface of zinc oxide.