Publikace detail

TiO2 and Nitrogen Doped TiO2 Prepared by Different Methods; on the (Micro)structure and Photocatalytic Activity in CO2 Reduction and N2O Decomposition

Rok: 2018

Druh publikace: článek v odborném periodiku

Název zdroje: Journal of Nanoscience and Nanotechnology

Název nakladatele: American Scientific Publishers

Místo vydání: Valencia

Strana od-do: 688-698

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	TiO2 a dusíkem dopované TiO2 připravené odlišnými metodami; mikrostruktura a oftokatalytická aktivita v CO2 redukci a N2O rozkladu	nanostrukturovaný prášek TiO2 byl připraven sol-gel procesem a hydrotermální metodou v kombinaci s procesem stlačování horkou vodou a metanolem nebo kalcinací. V následujícím syntézním kroku byl nanostrukturní TiO2 modifikován dusíkem za použití komerční močoviny. Výsledný materiál byl charakterizován pomocí N2 fyzisorpce, XRD, XPS a DR UV-Vis spektroskopie. Všechny materiály obsahovaly zejména anatasovou fázi a pouze malé množství brookitu. Fotokatalytická aktivita získaných materiálů byla testována v CO2 redukci a rozkladu N2O.	TiO2; fotokatalýza; CO2; N2O
eng	TiO2 and Nitrogen Doped TiO2 Prepared by Different Methods; on the (Micro)structure and Photocatalytic Activity in CO2 Reduction and N2O Decomposition	TiO2 as nanostructured powders were prepared by (1) sol-gel process and (2) hydrothermal method in combination with (A) the processing by pressurized hot water and methanol or (B) calcination. The subsequent synthesis step was the modification of prepared nanostructured TiO2 with nitrogen using commercial urea. Textural, structural, surface and optical properties of prepared TiO2 and N/TiO2 were characterized by nitrogen physisorption, powder X-ray diffraction, X-ray photoelectron spectroscopy and DR UV-vis spectroscopy. It was revealed that TiO2 and N/TiO2 processed by pressurized fluids showed the highest surface areas. Furthermore, all prepared materials were the mixtures of major anatase phase and minor brookite phase, which was in nanocrystalline or amorphous (as nuclei) form depending on the applied preparation method. All the N/TiO2 materials exhibited enhanced crystallinity with a larger anatase crystallite-size than undoped parent TiO2. The photocatalytic activity of the prepared TiO2 and N/TiO2 was tested in the photocatalytic reduction of CO2 and the photocatalytic decomposition of N2O. The key parameters influencing the photocatalytic activity was the ratio of anatase-to-brookite and character of brookite. The optimum ratio of anataseto- brookite for the CO2 photocatalytic reduction was determined to be about 83 wt.% of anatase and 17 wt.% of brookite (amorphous-like) (TiO2-SG-C). The presence of nitrogen decreased a bit the photocatalytic activity of tested materials. On the other hand, TiO2-SG-C was the least active in the N2O photocatalytic decomposition. In the case of N2O photocatalytic decomposition, the modification of TiO2 crystallites surface by nitrogen increased the photocatalytic activity of all investigated materials. The maximum N2O conversion (about 63 % after 18 h of illumination) in inert gas was reached over all N/TiO2.	Titania; Pressurized Hot Fluid; Nitrogen Doped; Photocatalysis; Carbon Dioxide; Nitrous Oxide

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