Figure 5
From: Graphene nanowalls formation investigated by Electron Energy Loss Spectroscopy
(a) STEM-HAADF image of PECVD grown GNWs on Cu from the beginning of interface toward the growth direction (left to right). The embedded graph shows the normalized contribution of \({sp}^{2}\)(π*) and \({sp}^{3}\)(σ*) and the \({{\text{I}}sp}^{2}/{{\text{I}}sp}^{3}\) ratio in the dedicated areas (A–E) along the growth direction, suggesting a change in carbon hybridization/graphitization. Areas A, B, C, D, and E are marked as the bases of the \({sp}^{2}/{sp}^{3}\) contribution of carbon. (b) Corresponding carbon K-edge core-loss EELS spectra of areas A–E. (c) EELS mapping of GNWs on Cu, along with dynamic EELS mapping of Cu (L2&L3), π*, and σ*, reveals significant features. Strong π* EELS signals from both the interface (dotted square) and the side edge (arrow) of GNWs confirm the dominant graphitic hybridization.
