Figure 3 : Raman and XPS spectra of the GNRs.

From: Nanotomy-based production of transferable and dispersible graphene nanostructures of controlled shape and size

Figure 3

(a,c,e) Raman spectra and (b,d,f) G-band scans of the w=15 nm (a,b), w=25 nm (c,d) and w=50 nm (e,f) GNRs show low ID/IG ratios. As expected, narrower ribbons exhibited higher ID/IG because of higher percentage of edges. The ID/IG ratios were 0.28 (a), 0.24 (b) and 0.22 (c) for 15 nm, 25 nm and 50 nm GNRs; and the I2D/IG ratios were 1.25 (a), 1.04 (b) and 1.21 (c), respectively. (g) FESEM image of large quantities of 50 nm, squared GQDs. (h) Typical XPS spectra for the C 1 s-binding energies of the GNRs showing the sp2 carbon peak at 284.5 eV with high-percentage carbon >98%. High-resolution XPS scans for S 2p-binding energies (see Supplementary Information and Supplementary Fig. S7) showed traces of sulphur (~0.92%). Inset shows the chemical structure of a probable edge-sulphonation-chemistry on the armchair (AA) and zigzag (ZZ) GNR edges24.