1. Resolving a structural issue in cerium-nickel-based oxide : single compound or a two-phase system?Jelena Kojčinović, Dalibor Tatar, Stjepan Šarić, Cora Pravda Bartus, Andraž Mavrič, Iztok Arčon, Zvonko Jagličić, Maximilian Mellin, Marcus Einert, Angela Altomare, Rocco Caliandro, 2023, original scientific article Abstract: CeNiO3 has been reported in the literature in the last few years as a novel LnNiO3 compound with promising applications in different catalytic fields, but its structure has not been correctly reported so far. In this research, CeNiO3 (RB1), CeO2 and NiO have been synthesized in a nanocrystalline form using a modified citrate aqueous sol-gel route. A direct comparison between the equimolar physical mixture (n(CeO2) : n(NiO) = 1:1) and a compound RB1 was made. Their structural differences were investigated by laboratory powder X-ray diffraction (PXRD), selected area electron diffraction (SAED), transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy detector (EDS), and Raman spectroscopy. The surface of the compounds was analyzed by X-ray photoelectron spectroscopy (XPS), while the thermal behaviour was explored by thermogravimetric analysis (TGA). Their magnetic properties were also investigated with the aim of exploring the differences between these two compounds. There were clear differences between the physical mixture of CeO2 + NiO and RB1 presented by all of these employed methods. Synchrotron methods, such as atomic pair distribution function analysis (PDF), X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) were used to explore the structure of RB1 in more detail. Three different models for the structural solution of RB1 were proposed. One structural solution proposes that RB1 is a single-phase pyrochlore compound (Ce2Ni2O7) while the other two solutions suggest that RB1 is a two-phase system of either CeO2 + NiO or Ce1–xNixO2 and NiO. Keywords: cerium oxide, nickel oxide, crystallography Published in RUNG: 22.12.2023; Views: 2128; Downloads: 9 Full text (4,13 MB) This document has many files! More... |
2. Multicomponent Cu-Mn-Fe silica supported catalysts to stimulate photo-Fenton-like water treatment under sunlightAndraž Šuligoj, Ivalina Trendafilova, Ksenija Maver, Albin Pintar, Alenka Ristić, Goran Dražić, Wael H. M. Abdelraheem, Zvonko Jagličić, Iztok Arčon, Nataša Zabukovec Logar, Dionysios D. Dionysiou, Nataša Novak Tušar, original scientific article Keywords: Magnetic catalyst, Photocatalyst, Water treatment, Sunlight, Contaminants of emerging concern, Photo-Fenton-like systems, Cu, Mn, Fe, XANES, EXAFS Published in RUNG: 06.07.2023; Views: 2551; Downloads: 9 Full text (4,32 MB) |
3. Unraveling the arrangement of Al and Fe within the framework explains the magnetism of mixed-metal MIL-100(Al,Fe)Gregor Mali, Matjaž Mazaj, Iztok Arčon, Darko Hanžel, Denis Arčon, Zvonko Jagličić, 2019, original scientific article Abstract: Properties of mixed-metal MOFs depend on the distribution of different
metals within their frameworks. Determination of this distribution is often very
challenging. Using an example of aluminum- and iron-containing MIL-100, we
demonstrate that 27Al NMR spectroscopy, when combined with first-principles
calculations and magnetic, X-band electron paramagnetic resonance, Fe K-edge extended
X-ray absorption fine structure, and Mössbauer measurements, enables one to accurately
determine the arrangement of Al and Fe within the metal trimers, which are the basic
building units of MIL-100. In this particular material, the incorporation of Fe and Al on
the framework metal sites is random. Crucial for deciphering the arrangement is detecting
NMR signals, shifted because of the strong hyperfine interaction between the 27Al nuclei
and the unpaired electronic spins of Fe3+ ions, assigning the shifted signals aided by first-principles calculations of hyperfine
couplings, and quantitatively evaluating the NMR intensities and the measured effective magnetic moment. Keywords: Fe EXAFS, XANES, MIL100, MOF, magnetizem Published in RUNG: 26.03.2019; Views: 4057; Downloads: 0 This document has many files! More... |
4. The first example of a mixed valence ternary compound of silver with random distribution of Ag(I) and Ag(II) cationsIztok Arčon, Zvonko Jagličić, Wojciech Grochala, Zoran Mazej, Evgeny A. Goreshnik, Tomasz Michałowski, Jadwiga Szydłowska, 2015, original scientific article Keywords: srebrov fluorid, mešana valenca, srebro, XANES Published in RUNG: 16.06.2016; Views: 5044; Downloads: 160 Link to full text |