Graphite fluorides: An XPS study of a new type of C-F bonding

On the so-called “semi-ionic” C–F bond character in fluorine–GIC

“…The C F atoms in C x F are connected to the network of the conjugated C C -C C double bonds, therefore the hyperconjugation involving C-F, C F -C C and C C -C C bonds is supposed to occur as has been reported for benzyl fluorides such as C 6 H 5 CH 2 F and C 6 H 5 CFMe 2 [22][23][24][25][26]. The electrons involved in the covalent C-F bonds in C x F are slightly delocalized by this hyperconjugation, resulting in the C-F bond order lower than those in (CF) n and (C 2 F) n as has been suggested by XPS and IR [5][6][7][8][9][10][11]. Consequently, r C-F in C x F (0.140 nm) is slightly elongated compared to those in (CF) n and (C 2 F) n (0.136 nm [15]) due to the decrease of the bond order.…”

“…C x F with a stage-1 structure possesses relatively high thermal and chemical stabilities in GICs [2][3][4], suggesting that the bonding between fluorine and carbon atoms in this compound is much stronger than the coulombic interaction between the intercalates and planar graphene sheets in general GICs. On the other hand, spectroscopic analyses such as X-ray photoelectron spectroscopy (XPS) and infrared (IR) absorption spectroscopy have indicated that the C-F bond order in C x F is slightly lower than those of covalent C-F bonds in (CF) n and (C 2 F) n [5][6][7][8][9][10][11]. The C1s and F1s XPS peaks ascribed to the carbon and fluorine atoms bound to each other in C x F appears at 287-288 and 686-687 eV [6,[9][10][11], respectively, the binding energies (E 0 B s) being lower than those found for (CF) n and (C 2 F) n (around 290 and 690 eV for C1s and F1s peaks [12], respectively).…”

“…On the other hand, spectroscopic analyses such as X-ray photoelectron spectroscopy (XPS) and infrared (IR) absorption spectroscopy have indicated that the C-F bond order in C x F is slightly lower than those of covalent C-F bonds in (CF) n and (C 2 F) n [5][6][7][8][9][10][11]. The C1s and F1s XPS peaks ascribed to the carbon and fluorine atoms bound to each other in C x F appears at 287-288 and 686-687 eV [6,[9][10][11], respectively, the binding energies (E 0 B s) being lower than those found for (CF) n and (C 2 F) n (around 290 and 690 eV for C1s and F1s peaks [12], respectively). The IR absorption band ascribed to the C-F stretching mode in C x F is observed at lower wave number of around 1100 cm À1 [5][6][7][8][9] than those found for (CF) n and (C 2 F) n (around 1220 cm À1 [12]).…”

The effect of carbon in slag on steel reoxidation and carbon analysis by x-ray photoelectron spectroscopy in the CaO-SiO2-Al2O3-MgO-MnO-Fe t O system

“…(graphite-284 eV), [12] and the remaining peak is thought to be carbide ions by the aforementioned literature survey. The three peaks in Figure 3 coincide with the reference peaks in Figure 4 and, therefore, are inferred to be carbonate ions, graphite, and carbide ions.…”

Preparation of Nitrogen and Sulfur dual-doped Mesoporous Carbon for Supercapacitor Electrodes with Long Cycle Stability

“…A further high-resolution view of the F1s spectra reveals two main F1speaks at the binding energies of ~687.5 eV and ~684.2 eV, respectively (the Figure not provided). The letter is related to the C-F covalent bond originating from an ionic-F bond [34,35], which is attributed to iron fluoride produced in the process of HF leaching. However, these characteristics disappear for (NSMC) LH2 (Fig.…”