Characterization of inhomogeneity at edges of graphene oxide films using tip‐enhanced Raman spectroscopy
Masanobu Yoshikawa, Masataka Murakami, Yasuhiko Fujita
Abstract
Abstract We developed a reflection‐type tip‐enhanced Raman spectroscopy system with a high spatial resolution to be able to apply for many kinds of opaque samples and obtained Raman images and Raman spectra at the edges of graphene oxide (GO) films using this system. We found that the relative intensity of the D band to the G band ( I D / I G ) increased 0.6 to 1.5 at the edges of the GO plane and the C‐H stretching mode at approximately 2920 cm −1 was strongly observed at the edges. These results suggest that the graphite network structures are broken down at the edges of the GO plane, resulting in the high I D / I G ratio, and the dangling bonds are mainly terminated by C‐H, C‐O, O‐H, and/or COO‐ groups.