Photocatalytic thin films containing TiO2:N nanopowders obtained by the layer-by-layer self-assembling method

► In this work were synthesized by high-energy ball milling TiO2-N and immobilized these powders on glass slides for layer-by-layer method using polyethylenimine. ► We studied the effect of the milling time on the characteristics of material. ► We concluded that the grain size of the samples decreases, UV-Vis spectroscopy showed shift in the onset of light absorption. ► The TiO2-N samples had higher photocatalytic activity than undoped, which was assigned to the effect of introducing N atoms and XPS results confirm it.