Titania nanoparticles were synthesized by employing the hydrothermal method and using TiOSO 4 as a titanium source. By varying pH between 0.5 and 1.0 and adding isopropanol to the hydrothermal reaction mixture, different mixtures ofanata- se, rutile, and brookite were obtained. The samples were also doped with nitrogen at different N concentrations using, res- pectively, urea, ammonium nitrate, and tripropylamine as nitrogen sources. The samples were characterized by X-ray pow- der diffraction, field emission scanning electron microscopy, infrared spectroscopy, UV-Vis diffuse reflectance spectros- copy and according to their specific surface area. Additionally, their photocatalytic activity was measured in a gas-solid reactor system. The results show that low pH favours rutile formation, whereas a higher pH yields mixed phase titania poly- morphs. Isopropanol addition also favours rutile formation, and boosted the photocatalytic activity of the resulted particles. Contrary to most data in the literature, rutile turned out to be the more active phase in the present investigation. Nitrogen doping, on the other hand,did not contribute to higher photocatalytic activity, but was rather detrimental to it.
COBISS.SI-ID: 2065511
The underground environment that is equipped for tourist visit is challenged by ultrasonic noice derived from different electric devices and growth of lampenflora phototrophs around lamps. Mass tourism is responsible for changing of quality of cave air and transmission of microbes. In the paper are presented some parameters for monitoring of tourist caves and solutions to minimize human impact.
COBISS.SI-ID: 36519213