In a deviation from the conventional Hummers method, a spontaneous expansion approach was introduced with expanded graphite as the precursors. The intercalating agent (H2SO4) was able to penetrate into the expanded graphite; this had further expanded the graphite and as a result, a foam-like intermediate was produced. The foam-like graphite was more easily oxidized in reaction with the oxidant (KMnO4) to form graphene oxide (GO).
Expanded graphite is a kind of adsorbent with good performance, especially it has loose porous structure, has a strong adsorption ability to organic compounds, 1g expanded graphite can absorb 80g oil, so expanded graphite has been designed as a variety of industrial oils and oils adsorbent.
The expanded graphite can easily adsorb oil, organic molecules and hydrophobic substances, and has irreplaceable effects in water environmental treatment. When it is used for oil removal on water surface in granular form, the dosage is 1 ~ lo% /rn according to the size of oil area on the water surface and different types of oil, and the adsorption time can vary from 15rain to several hours.