Patent ID: 8753540

Claim:
A method for preparing a graphene sheet, the method comprising the steps of: Oxidizing a graphitic structure having a turbostratic structure to produce an oxidized graphitic structure, wherein the oxidation step is carried out by immersing the graphitic structure in hydrogen peroxide, not using one of the group consisting of sulfuric acid, potassium permanganate, carboxylic acid, and formic acid; Ultrasonic treating the oxidized graphitic structure immersed in hydrogen peroxide to produce an ultrasonic treated oxidized graphitic structure immersed in hydrogen peroxide; Subjecting the ultrasonic treated oxidized graphitic structure immersed in hydrogen peroxide to microwave irradiation to produce a few-layer graphene; and Sonicating the few-layered graphene to produce graphene sheets; Wherein the concentration of hydrogen peroxide used in the oxidation step is 30-40%.