Speaker
Description
X-ray absorption spectroscopy (XAS) is a powerful tool for characterisation of local structure and chemical state of selected elements in di fferent new functional materials and biological or environmental samples. The XAS spectroscopy is based on extremely bright synchrotron radiation X-rays sources, which allow precise characterisation of bulk, nanostructured or highly diluted samples. The rapid development of extremely bright synchrotron sources of X-ray and ultraviolet light in recent years has opened new possibilities for research of matter at the atomic or molecular level, indispensable in the development of new functional nanostructured materials with desired properties. The talk will present the possibilities offered by X-ray absorption spectroscopy with synchrotron light for ex-situ or operando characterization of various functional porous and other nanomaterials, before, after and during their operation [1,2,3,4]. New generation of synchrotron light sources also opened the possibility of combining X-ray absorption with high-resolution emission [5] an d inelastic scattering spectroscopy [6], and microscopy with sub-micron resolution [7]. Examples of operando XANES and EXAFS analysis to track changes in the valence states and local structures of selected elements in different energy storage materi als and in various (photo)catal ysts, during chemical reactions under controlled reaction conditions, will be presented, which provided insight into the dynamic functional properties and reaction mechanisms of these materials. Access to SR facilities of Petra III (beamlines P65, P64 and P01), ESRF (beamlines BM23, ID21, ID26) and Elettra (beamlines XAFS, XRF), for the presented research is kindly acknowledged.
[1] M. Zabilskiy; I. Ar čon; P. Djinovi ć; E. Tchernychova; A. Pintar, In ‐situ XAS study of catalytic N2O decomposition over CuO/CeO2 catalysts ChemCatChem, 2021, 13, 7, 1814-1823,
https://doi.org/10.1002/cctc.202001829
[2] D. Menga, J. L. Low, Y.-S. Li, I. Ar čon, B. Koyutürk, F. Wagner, F. Ruiz-Zepeda, M. Gaberšček, B. Paulus, T.-P. Fellinger, Resolving the Dilemma of Fe −N−C Catalysts by the Selective Synthesis of Tetrapyrrolic Active Sites via an Imprinting Strategy, J. Am. Chem. Soc. 2021, 143, 43,
https://doi.org/10.1021/jacs.1c04884
[3] T. Čizmar, U. Lavren čič štangar, M. Fanetti, I. Ar čon, Effects of different Cu loadings on photocatalytic activity of TiO2‐SiO2 prepared at low temperature oxidation of organic pollutants in water, ChemCatChem, 2018, 10, 2982–2993, DOI : 10.1002/cctc.201800249
[4] R. Dominko, A. Vižintin, G. Aquilanti, L. Stievano, H. M. Joseph, A. Reddy Munnagi, M. Fichtner, I. Arčon, Polysulfides formation in different electrolytes from the perspective of X-ray absorption spectroscopy. Journal of the Electrochemical Society, 2018, 165, 1, A5014-A5019.
doi: 10.1149/2.0151801jes .
[5] A. Robba, A. Vižintin, J. Bitenc, G. Mali, I.Ar čon, M. Kavčič, M. Žitnik, K. Bučar, G.Aquilanti, C. Martineau-Corcos, A. Randon-Vitanova, R. Dominko A Mechanistic Study of Magnesium Sulfur Batteries, Chem. Mater. 2017, 29, 21, 9555–9564, doi: 10.1021/acs.chemmater.7b03956
[6] A. Rajh, I. Ar čon, K. Bu čar, M. Žitnik, M. Petric, A. Vizintin, J. Bitenc, U. Košir, R. Dominko, H. Gretarsson, M. Sundermann, M. Kav čič, Characterization of Electrochemical Processes in Metal−Organic Batteries by X ‑ray Raman Spectroscopy, J. Phys. Chem. C, 2022, 126, 12, 5435–5442,
https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.1c10622
[7] P. Pongrac, I. Ar čon, H. Castillo-Michel, K. Vogel-Mikuš, Plants, 2020, 9, 1, 79,
https://doi.org/10.3390/plants9010079
