Water treatment using photocatalysis has gained extensive attention in recent years.Photocatalysis is promising technology from green chemistry point of view. The mostwidely studied and used photocatalyst for decomposition of pollutants in water underultraviolet irradiation is TiO2 because it is not toxic, relatively cheap and highly activein various reactions.Within this thesis unmodified and modified TiO2 materials (powders and thin films)were prepared. Physico-chemical properties of photocatalytic materials werecharacterized with UV-visible spectroscopy, scanning electron microscopy (SEM),transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS),inductively coupled plasma optical emission spectroscopy (ICP-OES), ellipsometry,time-of-flight secondary ion mass spectrometry (ToF-SIMS), Raman spectroscopy,goniometry, diffuse reflectance measurements, thermogravimetric analysis (TGA) andnitrogen adsorption/desorption. Photocatalytic activity of prepared samples in aqueousenvironment was tested using model compounds such as phenol, formic acid andmetazachlor. Also purification of real pulp and paper wastewater effluent was studied.Concentration of chosen pollutants was measured with high pressure liquidchromatography (HPLC). Mineralization and oxidation of organic contaminants weremonitored with total organic carbon (TOC) and chemical oxygen demand (COD)analysis. Titanium dioxide powders prepared via sol-gel method and doped withdysprosium and praseodymium were photocatalytically active for decomposition ofmetazachlor. The highest degradation rate of metazachlor was observed when Pr-TiO2treated at 450ºC (8h) was used. The photocatalytic LED-based treatment of wastewatereffluent from plywood mill using commercially available TiO2 was demonstrated to bepromising post-treatment method (72% of COD and 60% of TOC was decreased after60 min of irradiation). The TiO2 coatings prepared by atomic layer deposition techniqueon aluminium foam were photocatalytically active for degradation of formic and phenol,however suppression of activity was observed. Photocatalytic activity of TiO2/SiO2films doped with gold bipyramid-like nanoparticles was about two times higher thanreference, which was not the case when gold nanospheres were used.
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