X-ray absorption spectroscopy of graphite oxide

We have investigated the electronic structure of graphite oxide using X-ray absorption spectroscopy at the carbon and oxygen K-edges. The unoccupied π^* and σ^* states associated with sp² hybridization in graphite, are also apparent in the graphite oxide, which indicates that it has a graphitic structure even though it experiences oxidation and annealing. Additional electronic states of the graphite oxide which are not present in its precursor, graphite, are ascribed to the functional groups such as epoxide, carboxyl, and hydroxyl groups.