X-RAY PHOTOELECTRON SPECTROSCOPY AND NEAR EDGE X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY STUDY OF SYNCHROTRON RADIATION EFFECTS ON FLUORINATED GRAPHITE INTERCALATED N2O4

15 Jul 2020, 17:50
20m
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Oral X-ray spectroscopy X-ray spectroscopy

Speaker

Galina Semushkina (Nikolaev Institute of Inorganic Chemistry)

Description

Fluorinated graphite (FG) attracts the attention of researchers due to a wide range of physicochemical properties, which is promising for its use as an element base of microelectronic devices (LED elements, gas sensors, etc.), and also as a cathode for lithium-ion batteries. More importantly, recent studies have shown that intercalated systems based on graphite and its derivatives can be used as a nanoreactor. In these devices, the layering of graphite and its screening effect allows you to purposefully change the reactivity of molecules and regulate the activity of functional groups on the surface. In addition, the subsequent thermal or photochemical treatment of fluoride graphite intercalated compound (FGIC), including irradiation with high-intensity light, can lead to a significant restructuring of the electronic structure of the system, which opens up new possibilities for using FG.
For the purpose of a detailed analysis of the mechanism of processes occurring on the surface of FGIC under the influence of thermal and photochemical effects, a comprehensive study of the electronic structure of intercalated N2O4 fluorinated graphite С2F0.8-0.9 before and after continuous in situ illumination with polychromatic photon beam of high intensity (zero-order light from the dipole beamline of BESSY II synchrotron radiation facility). X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS), and Fourier transform infrared spectroscopy (FTIR) are used for this.
Thus, the effect of synchrotron radiation on the atomic and electronic structure of FGIC C2F0.8-0.9 N2O4 has been studied. It was found that in the initial samples of N2O4 on the surface, the FG is in an equilibrium mixture with various nitrogen-containing functional groups NO2, NO, NO3, N2. Thermal and photochemical effects on FGIC lead to defluorination of the sample and the formation of defects, on the edge of which CF2 and CF3 bonds arise. In addition, the FG matrix recovery in progress with partial removal of the intercalate.
This work was supported by RFBR grant № 18-29-19073 мк.

Primary authors

Galina Semushkina (Nikolaev Institute of Inorganic Chemistry) Alexander Okotrub (Nikolaev Institute of Inorganic Chemistry) Lyubov Bulusheva (Nikolaev Institute of Inorganic Chemistry) Dr Igor Prosvirin Dmitry Pinakov (Nikolaev Institute of Inorganic Chemistry) Galina Chekhova (Nikolaev Institute of Inorganic Chemistry) Julia Fedoseeva (Nikolaev Institute of Inorganic Chemistry)

Presentation Materials