Thickness and photocatalytic activity relation in TiO $$₂$$ 2 :N films grown by atomic layer deposition with methylene-blue and E. coli bacteria

This study presents an analysis of the photocatalytic efficiency in $$\hbox {TiO}₂$$ :N thin films grown by atomic layer deposition related to the film thickness. The nitriding process was carried out with nitrogen plasma by molecular nitrogen decomposition after $$\hbox {TiO}₂$$ deposition. The study was performed using the time-dependent degradation of colour units for methylene-blue solutions and inactivation percentages for Escherichia coli bacteria, for potential applications in sewage purification. To determine the optoelectronic properties of the films, the optical, structural, surface and thickness characterizations were carried out by photoluminescence, Raman spectroscopy, atomic force microscopy and scanning electron microscopy, respectively.