COMPARISON OF NITROGEN-DOPED PHOTOCATALYTIC SURFACES SYNTHESIZED BY PVD AND SOL-GEL METHODS

Abstract

The aim of this study was to produce photocatalytic TiO2–xNx coatings that can be active in visible light using different methods. Physical vapour deposition (PVD) and sol-gel methods were preferred for these coatings. Thin films were synthesized by dip coating on a glass substrate using the sol-gel method. In addition, thin glass film coatings were obtained by applying an arc for one minute to the glass films using the PVD method. Since the coating phase is important in terms of photoactivity, a phase analysis was performed using XRD. The obtained surfaces will be used in antibacterial applications. Therefore, the thickness of the coatings was determined with the X-Ray refraction method, and their optical band gap was measured. Based on these values, it was observed that nitrogen has a reducing effect on the optical band gap in titanium oxide-based coatings. The aim of nitrogen doping was to enhance photoactivity by adding an additional band between the valence band and conduction band of a photocatalytic surface. After these experiments using rhodamine-B and methylene blue solutions, specimens’ photocatalytic effects under fluorescent, sun and UV light were tested. It was determined that nitrogen’s decreasing effect on the optical band gap results in increased photoactivity with both PVD and sol-gel techniques. In addition, it was found that the coatings made with PVD exhibited a more controlled structure in a shorter time, while the production of sol-gel coatings was a much cheaper method, with low investment costs.