Role of exposure time in graphite oxide synthesis

The role of exposure time after the addition of hydrogen peroxide in synthesis of graphite oxide was investigated. The synthesis of graphite oxide was carried out by the modified Hummers' method. Graphite oxide was investigated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. It has been shown that exposure of graphite oxide (GO) in reaction mixture during 24 h and 7 days after the addition of H₂O₂ leads to the increase of C:O ratio, indicating the partial reduction of graphite oxide. The decrease of heat released during GO reduction can indicate the decrease of amount of water intercalated between graphene layers as a result of long-term exposure of GO in reaction mixture.