Separation method of graphene oxide different in sizes in graphene oxide preparation process

The invention provides a separation method of graphene oxide different in sizes in a graphene oxide preparation process, and relates to graphene oxide preparation. According to the separation method, graphene oxide prepared by using an oxidation reduction method is separated according to difference of dispersibility of the graphene oxide different in sizes in a solvent so as to obtain the following graphene oxide different in sizes: precipitates B-COSs1 which are graphene oxide products, the sizes of which are greater than 25 micrometers, precipitates GOSs2 which are graphene oxide products, the sizes of which are greater than 15 micrometers and are less than or equal to 25 micrometers, precipitates GOSs3 which are graphene oxide products, the sizes of which are greater than 5 micrometers and less than or equal to 15 micrometers, and precipitates F-COSs4 which are graphene oxide products, the sizes of which are less than or equal to 5 micrometers. The separation method can be used for overcoming the defects t