Mechanically stable and photocatalytically active TiO2/SiO2 hybrid films on flexible organic substrates

Photocatalytic porous coatings (micro-, meso-and macroporous) are obtained by the dispersion of TiO2 nanoparticles in sol-gel hybrid matrices. The sol-gel silica matrix is used as a binder stabilizing the nanoparticle dispersion and as a protective layer for the organic substrates. Organic groups are introduced into the matrix to induce the film flexibility and a part of them is used to create the final microstructure allowing remarkable improvement of the photocatalytic properties. The film structure and UV stability are fully characterized. The photocatalytic activity is evaluated through a test with formic acid. Flexible efficient photoactive composites are obtained showing important capabilities for depollution (water and air) and self-cleaning applications.