engleski

N/TiO2 nanocomposites: nitrogen effect on the material properties

TiO2 heterogeneous photocatalysis is actively studied as an alternative technology for the degradation and/or removal of organic micropollutants (OMPs) present in water [1-2]. However, photoactivation of TiO2 occurs only under UV light and the photogenerated charges that start oxidation processes recombine quite fast, affecting the photocatalytic activity [3]. Therefore, this study focuses on the synthesis of nitrogen-doped TiO2 for enhancing its photocatalytic activity under visible light, using the non-conventional microwave- assisted method, and evaluating the amount of nitrogen on the photocatalytic activity under different sources of radiation for the degradation of a model pollutant – antibiotic drug ciprofloxacin in aqueous solution. Nitrogen-doped TiO2 (N/TiO2) photocatalyst was synthesized by the microwave-assisted method, using urea as a nitrogen source. To evaluate the effect of nitrogen in the photocatalytic and morphological properties, N/TiO2 were prepared varying the amount of urea. The obtained materials were characterized by XRD, FTIR, Raman spectroscopy and N2 adsorption isotherms. The only crystalline phase present in the N/TiO2 materials was anatase. The incorporation of urea as a nitrogen source does not affect the crystallinity either the crystal phase of TiO2. Although the urea incorporation reduces the specific surface area, the obtained materials have three times bigger surface area than commercial catalyst Degussa P25. N/TiO2 materials show photoactivity under UV, Solar light simulator and visible light, while commercial photocatalyst Degussa P25 TiO2 shows activity only under UV light and Solar light simulator. Increasing the amount of urea increases the photocatalytic activity of the materials under the different radiation sources for the degradation of ciprofloxacin. However, beyond a specific concentration, there is no further improvement of the materials' photoactivity.

N/TiO2 nanocomposites, photocatalysis, UV radiation, solar radiation

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