The improved method typically involves the following steps: 1. Oxidation: Graphite is oxidized using strong oxidizing agents like potassium permanganate (KMnO4) in the presence of sulfuric acid (H2SO4) and phosphoric acid (H3PO4). This step increases the interlayer spacing of graphite, making it easier to exfoliate into graphene oxide. 2. Exfoliation: The oxidized graphite is then exfoliated by sonication or mechanical stirring, resulting in the formation of graphene oxide sheets. 3. Purification: The resultant GO is purified by repeated washing and filtration to remove any residual acids and impurities.
