چكيده به لاتين
Nanostructured Titania coatings show high photocatalytic activity under UV radiation, but by extending the absorption threshold from UV to visible region, the photocatalytic efficiency of these coatings can be significantly improved. For this purpose, doped Titania coatings with high-photocatalytic activity under ultraviolet and visible radiation are prepared. In this study, pure titanium sol and soles containing different amounts of nitrogen, manganese and fluorine as dopant were prepared by sol gel metjod, using urea (CH4N2O), manganese nitrate (MnN2O6 * 4H2O) and ammonium fluoride (NH4F ) as precursors. after determining the optimum thickness, soles were applied on glass substrates (Soda lime) by dip coating method. The coated samples were dried at 100 ° C and calcined at 500 ° C. X-ray analysis and Grazing Incidence XRD analysis were used to identify the coatings phase composition. optical properties were investigated by DRS and the thickness and coatings microstructure were studied with scanning electron microscopy (FE-SEM). In order to study the photocatalytic properties of the coatings, their ability to decompose methylene blue and rhodamine B solution under ultraviolet and visible radiation was measured. The results showed that nanostructured titania coatings were308 nm in thickness on the glass substrate. nitrogen doping reduced the bandgap energy and shifted the absorption edge to the visible region, which resulted in better photocatalytic performance between the samples. Among the nitrogen-doped samples, the samples with molar ratio 1.5= N / Ti and = N / Ti 1 showed the best photocatalytic activity under visible light and UV irradiation repectively.In manganese doped coatings, titania bandgap energy reduction and formation of coatings with more uniform microstructures compared with pure titanium, improved the photocatalytic performance under UV and visible light irradiation. Among the doped samples with different manganese values, the sample with the lowest manganese content (= Mn / Ti 001/0%) had the best photocatalytic activity. In the fluorine doped sample, Titania band gap energy was not significantly reduced compared to pure titanium, but the formation of a coating with very uniform microstructure and smaller particle size improved the photocatalytic activity of these samples under uv irradiation and. The rate of methylene blue dissolution in the F-doped sample was 56% higher than pure titanium. in titania doped with nitrogen, fluorine and manganese, photocatalytic activity under both visible and UV radiation was considerably improved compared to pure titanium, which can be attributed to the simultaneous effect of dopants on microstructure And titania band structure. nitrogen and manganese dopants reduced titania band gap energy and increased the absorption and fluorine dopant improved the photocatalytic activity under visible light and UV radiation light by fine-tuning the structure and creating a homogeneous microstructure coating. Among doped samples with one dopant, the N-doped titania showes the best photocatalytic activity under visible light irradiation, and F-doped fluoride sample has the best UV-light performance, which can be attributed to band gap reduction and a homogeneous and fine-grained microstructure.
