1. Synthesis of morphology-controlled ZnO nanostructures and evaluation of their photocatalytic and gas-sensing propertiesShu Cui, Haixin Zhao, Chengyou Liu, Hai Yu, Nan Li, Xiaotian Li, 2025, original scientific article Keywords: zinc oxide, synthesis, photocatalysis, gas sensing, ethanol
Published in DiRROS: 02.10.2025; Views: 153; Downloads: 73
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2. Tuning the photocatalytic activity of nanocrystalline titania by phase composition control and nitrogen doping, using different sources of nitrogenNejc Rozman, Luka Škrlep, Miran Gaberšček, Andrijana Sever Škapin, 2014, original scientific article Abstract: Titania nanoparticles were synthesized by employing the hydrothermal method and using TiOSO4as a titanium source. By varying pH between 0.5 and 1.0 and adding isopropanol to the hydrothermal reaction mixture, different mixtures of anatase, rutile, and brookite were obtained. The samples were also doped with nitrogen at different N concentrations using, respectively, urea, ammonium nitrate, and tripropylamine as nitrogen sources. The samples were characterized by X-ray powder diffraction, field emission scanning electron microscopy, infrared spectroscopy, UV-Vis diffuse reflectance spectroscopy 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 polymorphs. 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.
Keywords: titanium dioxide, rutile, hydrothermal synthesis, photocatalysis, nitrogen doping
Published in DiRROS: 26.09.2025; Views: 257; Downloads: 100
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3. Component optimization of ▫$g-C_3N_4/TiO_2$▫ hetero-structure composite and its activity enhancement for photocatalytic degradation of rhodamine BZikang Cao, Yating Liu, Luqi Wang, Xu Gao, Sitian Chen, Sitian Cheng, Yan Yu, Li Li, 2025, original scientific article Keywords: hydrothermal synthesis, g-C3N4, TiO2, photocatalysis
Published in DiRROS: 21.02.2025; Views: 583; Downloads: 326
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4. Effect of ▫$TiO_2$▫ morphology on the properties and photocatalytic activity of ▫$g-C_3N_4/TiO_2$▫ nanocomposites under visible-light illuminationMatevž Roškarič, Gregor Žerjav, Janez Zavašnik, Matjaž Finšgar, Albin Pintar, 2025, original scientific article Keywords: visible-light photocatalysis, photocatalytic degradation, morphology, bisphenol A
Published in DiRROS: 12.02.2025; Views: 692; Downloads: 382
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5. Effect of Ce:Ti ratio and cerium salts on the properties of mesoporous Ti-Ce oxides and their photocatalytic activityPeter Nadrah, Mateja Knap, T. Vikram Sagar, Andrijana Sever Škapin, Urška Lavrenčič Štangar, 2025, original scientific article Abstract: To investigate the influence of different CeO2 precursors and Ce:Ti ratios, we have synthesised 8 mesoporous Ti-Ce oxides via the evaporation-induced self-assembly (EISA) method with Ce:Ti ratios between 0.2 and 20 mol%.The materials exhibited type IV isotherms and a specific surface area of 140–180 m2⋅g 1 with pore diameters in range of 3–20 nm. The crystalline phases of materials comprised predominantly anatase with a significant decrease in overall crystalline content with increasing Ce:Ti ratio. Materials with higher Ce:Ti ratio showed an increased light absorption in the visible region. Although crystalline CeO2 was not detected, the presence of Ce(IV) was confirmed by X-ray photoelectron spectroscopy. For the photocatalytic experiments, we compared these materials with the TiO2-CeO2 composites of our previously published syntheses to yield 16 samples synthesized via three synthesis approaches: (1) concurrent synthesis from titanium alkoxide and cerium salts in one pot, (2) synthesis of TiO2 in the presence of previously-synthesised CeO2 and (3) physical mixing of separately-synthesised TiO2 and CeO2. Samples produced by physically mixing the separately-synthesised TiO2 and CeO2 showed the best photocatalytic activity towards gaseous isopropanol degradation, while the samples with TiO2 synthesised in the presence of CeO2 showed the best photocatalytic stability.
Keywords: Ti-Ce oxides, evaporation-induced self-assembly, isopropanol oxidation, photocatalysis, mesoporous material
Published in DiRROS: 30.01.2025; Views: 650; Downloads: 472
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6. Fotokatalitski heterostrukturirani nanomateriali za izkoriščanje sončne energije : zaključno poročilo o rezultatih raziskovalnega projektaAndrijana Sever Škapin, Peter Nadrah, Miran Gaberšček, 2024, final research report Keywords: fotokataliza, heterostrukture, TiO2-CeO2, TiO2-Cu, sokatalizator, photocatalysis, heterostructures, co-catalyst
Published in DiRROS: 14.10.2024; Views: 906; Downloads: 0
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7. 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, original scientific article Abstract: 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.
Keywords: sol-gel processes, X-ray methods, chemical properties, TiO2, photocatalysis
Published in DiRROS: 14.08.2024; Views: 934; Downloads: 824
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8. Fenton-like photocatalyzed degradation of dibutyl phthalate with goethite and carboxylic acidsS. Hejdai, D. Buzek, Petr Klusoň, Oliver Bajt, 2023, original scientific article Abstract: Detailed investigation of photocatalyzed degradation of dibutyl phthalate (DBP), an endocrine disrupter, in the presence of α-FeOOH (goethite) and different carboxylic acids is the focus of this study. To get a better insight into the efficiency of the degradation, the influence of different parameters, such as concentration of total Fe and Fe(II), dissolved oxygen, DBP concentration, pH and salinity is investigated. The reaction mechanism consists of several interrelationship steps. The first step is the chemical reaction of carboxylic acid groups of the organic acids with hydroxyl groups of the α-FeOOH and a charge transfer upon illumination generating Fe(II). The second step is the release of Fe(II) into the solution followed by H2O2 oxidation to form highly photoactive hydroxyl complex of iron(III) and ˙OH. Simultaneously, the superoxide radical O2˙− and hydroperoxyl radical is formed in acidic solutions in presence of carboxylic acids as well. This mechanism explains the genesis of different reactive species oxidizing DBP. From the variety of the studied carboxylic acids (oxalic, citric, salicylic, pyruvic, maleic, and fumaric), oxalic acid is the best Fe-ligand for the photoreductive dissolution of goethite. Concentrations of the total amount of Fe and its dissociated forms Fe(II) as well as oxygen and hydroxyl radicals play a fundamental role in efficiency of DBP degradation. The photodegradation of DBP with goethite and the use of suitable carboxylic acids under optimized reaction conditions could be an efficient process for decontamination of polluted waters.
Keywords: photocatalysis, goethite, dibutyl phthalate, carboxylic acid, water treatment
Published in DiRROS: 31.07.2024; Views: 883; Downloads: 547
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9. Photocatalytic CO2 reduction over mesoporous TiO2 photocatalystsMartin Reli, Peter Nadrah, Miroslava Filip Edelmannová, Rudolf Ricka, Andrijana Sever Škapin, Urška Lavrenčič Štangar, Kamila Kočí, 2024, original scientific article Abstract: 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.
Keywords: CO2 reduction, TiO2, photocatalysis, mesoporous material, Sol-gel method
Published in DiRROS: 14.11.2023; Views: 1539; Downloads: 291
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10. Photocatalytic reduction of carbon dioxide to methanol : carbonaceous materials, kinetics, industrial feasibility, and future directionsGanji Parameswaram, Ramesh Kumar Chowdari, Blaž Likozar, 2023, review article Keywords: alcohols, catalysts, oxides, photocatalysis, two dimensional materials
Published in DiRROS: 23.06.2023; Views: 1592; Downloads: 709
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