Chemical and electronic state analyses of oxidizing graphene

Abstract

In order to investigate the process of oxidizing graphene, the chemical and electronic states have been studied by X-ray absorption fine structure (XAFS) and photoelectron spectroscopy (PES) measurements. Single layer graphene oxide was formed on α-Al2O3(0001). After oxidation until 30 s, XAFS results showed a decrease of C π∗ intensity and an appearance of O π∗ intensity and PES results showed a similar electronic state. However, 45 s oxidation leaded to a different electronic state, and the O π∗ intensity decreased for 60 s oxidation. The oxidation is thought to firstly introduce the oxygen functional groups, then to modify the graphene.