The invention provides a preparing method of oxidized
graphene. The preparing method comprises the following steps that at first, on the condition of pressurization of protective gas,
graphite, an intercalator and an
oxidizing agent are subjected to low-temperature reaction after being mixed, and a reaction mixture is obtained; then the reaction mixture obtained in the above step is separated, and then a
reaction product is obtained; finally, the
reaction product obtained in the above step is stripped in a dispersing agent, and oxidized
graphene dispersing liquid is obtained. By the adoption of the low-temperature condition, the defect rate is reduced obviously, under the effect of pressure, the intercalator is inserted between
graphene sheet
layers, the acting force between the
layers is reduced, and the distance between the
layers is increased; then the
oxidizing agent enters the portions between the graphene sheet layers, the oxidizing reaction is carried out, and thus oxidized graphene is formed; and due to the effect of the pressure, the intercalator and the
oxidizing agent enter the portions between the graphene sheet layers faster, the reaction is promoted to be more complete within a short time, one-step intercalation to graphene is achieved, and then graphene
powder with the low defect rate and high quality is obtained and prepared.