Characterization of Conformation and Locations of C–F Bonds in Graphene Derivative by Polarized ATR-FTIR

Abstract

It is still a challenge to explore the orientation and location of chemical groups in the two-dimensional derivative of graphene. In this study, polarized attenuated total reflectance Fourier transform infrared spectroscopy (polarized ATR-FTIR) was employed to investigate the orientation and location of C-F groups in the corresponding graphene derivative sheets, which facilitates building a relationship between the bonding nature and fine structure. There were two types of C-F bonding, (C-F)I and (C-F)II, in fluorinated graphene sheets. It was found that (C-F)II bonds were linked at the coplanar carbon atoms in the weakly fluorinated region (CxF, x ≥ 2), whereas the (C-F)I bonds cluster at the strongly deformed carbon framework with a F/C ratio of about 1. The thermostability of (C-F)II is lower than that of (C-F)I bonds. This is because the coplanar structure of the weakly fluorinated region tends to transform to the planar aromatic ring with the breaking of the C-F bond as compared with the strong fluorinated nonplanar region.

Determination of amino groups on functionalized graphene oxide for polyurethane nanomaterials: XPS quantitation vs. functional speciation

“…Whereas physicists are still fascinated with the semiconducting properties, 1 room temperature quantum effects 2,3 and other unique phenomena of graphene and other low-dimensional carbon structures, chemists have found the chemistry of graphene somewhat poor 4 and turned back to related laminar materials bearing various (mainly oxygen-containing) functional groups, many of which were introduced years before Geim and Novoselov's discoverysee, e.g., Hummers and Offeman's 'graphitic oxide'. 5 The new generation of graphene derivatives include hydrogenated graphene (graphane), uorinated graphene (uorographene) 6 and graphene introduced with acetylenic chains (graphyne and graphdiyne), 7 as well as sulfonated graphene 8 or N-containing reduced graphene oxide (GO). 9 Introduction of the above-mentioned functional groups to the structure of GO improves not only the dispersibility and solubility of this material but also its reaction with other organic molecules, polymers and biological systems.…”

Tunable Synthesis of Predominant Semi-Ionic and Covalent Fluorine Bonding States on a Graphene Surface

“…The C-F peaks appeared between 1000 and 1150 cm −1 . The vibration mode at 1080 cm −1 corresponded to C-F semi-ionic bonding [33][34][35]. FG(F) and FG(HU) showed higher peak intensities at 1080 cm −1 , implying that there are predominant semi-ionic bonds in FG(F) and FG(HU) compared with FG(P).…”

One-Step Direct Fixation of Atmospheric CO2 by Si-H Surface in Solution

“…The FTIR spectrum shows two strong peaks at 1,220 and 1,150 cm À1 (Figure 2D), the characteristic ones for C-F bonds (Wang et al, 2016;Li et al, 2016). FTIR spectra of products with different reaction times (D) FTIR of the product; inset is the enlarged view with wavenumber ranging from 1,100 to 1,300 cm À1 , the peaks at 1,220 and 1,150 cm À1 corresponding to the characteristic peaks for C-F bonds.…”

“…At first, there is only silicon powder and only two strong Si-O peaks at 1,050 and 1,090 cm À1 . After the addition of HF solution and exposure of the silicon to CO 2 atmosphere, these two Si-O peaks disappear gradually and various new peaks appear; the peaks at 1,145 and 1,218 cm À1 belong to C-F bonds (Wang et al, 2016;Li et al, 2016); those at 1,030, 1,042 and 1,084 cm À1 are attributed to Si-O-C bonds (Schwartz et al, 2006;Jung and Park, 2011); and peaks at 920, 975, and 1,200 cm À1 are assigned to C-H bonds. With the increase of time, the intensity of C-F vibration becomes stronger (Figure 3B), indicating increase in the F-POM product.…”