Cleaning of surfaces from pollutants and microorganisms is one of the application spheres of photocatalysts which accelerate light-based chemical reactions. For this purpose, in particular, nanocrystalline powders of titanium dioxide – a white pigment often included in enamels, varnishes and paints – are used. However, crushed titanium dioxide has a disadvantage: this photocatalyst is sensitive only to ultraviolet light, making impossible its usage in room light.
The scientists of the Institute of Catalysis of the Siberian Branch of the RAS have found a solution to this problem: they created a composite photocatalyst based on nitrogen-doped titanium dioxide and bismuth tungstate – a compound of two shiny metals of silver and silver-gray color. “Nitrogen-doped titanium dioxide possesses excellent surface properties and absorbs light in the visible area. Another component, bismuth tungstate, allows us to significantly increase the oxidative degradation rate by creating a heterostructured composite and providing an efficient charge transfer,” the Institute of Catalysis of the Siberian Branch of the RAS quotes Dmitry Selischev, PhD in Chemical Sciences.
By synthesizing the new composite, the scientists have developed and patented an aerosol method of its application to fabric and solid surfaces. For this purpose, an aerosol composition is used which contains a photoactive component, a binding compound and a solvent. After application and drying of the mixture, a thin film photoactive coating is formed on a hard surface, the coating which is self-cleaning under the action of light. Scaling up this technology will allow the manufacturing of the household and industrial cleaning agents.
