Preparation of Expandable Graphite by Ozone Oxidation Method

In order to reduce environmental pollution and recycle the intercalating solution, a new way to prepare expandable graphite (graphite intercalation compound, GIC) by ozone oxidation was proposed. The influences of the intercalating solution, reaction time, ozone flow and concentration of sulfuric acid on exfoliated volume (EV) were discussed in detail. The EV of H2SO4-GIC is much bigger than that of HClO4-GIC or fuming HNO3-GIC. The optimum condition with the maximum EV of 285 ml/g at 950°C may be that reaction time, ozone flow, sulfuric acid concentration are 3.5 hours, 80 ml/min and 98 wt.%, respectively. X-ray diffraction (XRD) patterns were used to analyze the structure and confirmed that GIC had indeed been prepared successfully. Scanning electron microscope (SEM) images showed the morphologies of GIC and exfoliated graphite (EG).