1. Tailoring the crystalline and amorphous phase ratios of TiO2 through the use of organic additives during hydrothermal synthesisNejc Rozman, Andrijana Sever Škapin, David Maria Tobaldi, Goran Dražić, Peter Nadrah, 2024, izvirni znanstveni članek Povzetek: The photocatalytic properties of TiO2 are primarily determined by its crystallinity and crystalline phase ratios. To improve the photocatalytic properties of TiO2, greater control over the formation of crystalline and amorphous phases during synthesis is therefore required. In this study, we demonstrate how the addition of minute amounts of three organic compounds (isopropanol, acetone and acetic acid) during hydrothermal treatment affects the amorphous and crystalline phase ratios: the addition of isopropanol or acetone accelerates the phase transition from anatase and brookite to rutile, whereas the addition of acetic acid inhibits the transformation of anatase to rutile, increasing the content of amorphous phase compared to samples where no organic compound was added. We show that the combination of the organic compound added, along with the duration of the hydrothermal treatment, can be used to tailor the phase composition of TiO2, so as to obtain either: i) TiO2 with a high content of both rutile and amorphous phase, ii) TiO2 with a high rutile content and iii) TiO2 with different ratios of all four phases, when the duration of synthesis is short (2–4 h). The materials synthesized exhibited high photocatalytic activity (in most cases higher than P25), which is attributed to the beneficial phase composition and high specific surface area.
Ključne besede: sol-gel processes, X-ray methods, chemical properties, TiO2, photocatalysis
Objavljeno v DiRROS: 14.08.2024; Ogledov: 188; Prenosov: 227
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2. Photocatalytic CO2 reduction over mesoporous TiO2 photocatalystsMartin Reli, Peter Nadrah, Miroslava Filip Edelmannová, Rudolf Ricka, Andrijana Sever Škapin, Urška Lavrenčič Štangar, Kamila Kočí, 2024, izvirni znanstveni članek Povzetek: In this study, we investigated different synthesis methods (template-free and template-based) using copolymers of poly(ethylene oxide) and poly(propylene oxide) to enhance the CO2 reduction activity of mesoporous TiO2. Our main goal was to identify key factors affecting photocatalyst efficiency and selectivity. We compared the newly synthesized TiO2 photocatalysts with the commercial photocatalyst P25. Among the materials studied, TiO2-P123 in its pure anatase form demonstrated the highest photoreduction efficiency and CO2 selectivity. In contrast, TiO2-EG, TiO2-F127, and P25, which contained both rutile and anatase phases, exhibited decreased photoactivity due to the formation of a type II heterojunction between the phases and higher oxygen adsorption on rutile's surface. Additionally, we observed that the choice of chemicals for photocatalyst preparation significantly influenced the specific surface area. TiO2-P123, the most active photocatalyst, had the highest specific surface area, providing more reactive sites for improved light absorption efficiency and prolonged electron-hole pair lifetimes, resulting in enhanced photocatalytic activity. We also calculated apparent quantum yields to support our findings.
Ključne besede: CO2 reduction, TiO2, photocatalysis, mesoporous material, Sol-gel method
Objavljeno v DiRROS: 14.11.2023; Ogledov: 655; Prenosov: 88
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3. In-depth rheological characterization of tungsten sol-gel inks for inkjet printingUrša Opara Krašovec, Tjaša Vidmar, Marta Klanjšek Gunde, Romana Cerc Korošec, Lidija Slemenik Perše, 2022, izvirni znanstveni članek Ključne besede: rheology, inkjet printing, tungsten oxide, sol-gel
Objavljeno v DiRROS: 11.02.2022; Ogledov: 1076; Prenosov: 710
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4. Prirastne in anatomske značilnosti rdečega bora (Pinus sylvestris L.), izpostavljenega solem za posipanje cestiščTom Levanič, Primož Oven, 2002, izvirni znanstveni članek Ključne besede: prirastoslovje, sol, vpliv na drevo, rast drevesa, kambijeva cona, rdeči bor, Pinus sylvestris, anatomija lesa, Slovenija
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4775; Prenosov: 2076
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