Figure 3: Mechanism of GOFe synthesis with the oxidant of K2FeO4.
From: An iron-based green approach to 1-h production of single-layer graphene oxide
The whole synthetic process (1 h) contains two main stages: intercalation–oxidation (IO) and oxidation–exfoliation (OE). The in situ generated FeO42− and atomic oxygen [O] act as oxidants and the O2 formed from residual [O] provides mild and durative gas exfoliation. In the IO stage, the concentrated sulphuric acid and oxidants intercalate into the layers of graphite to form intercalated graphite oxide (GIO). During the intercalation, the oxidants break the π–π conjugated structures of graphite, generating negatively charged functional groups, and increasing the interlayer spacing. In the following OE stage, the oxidants further oxidize the carbon basal planes of GIO, giving rise to more functional groups and enlarging the interlayer space. After recycling of sulphuric acid and washing with water, 100% slGO is achieved.
