Preparation of Graphene Oxide by Ultrasound-Assisted Hummers Method

Graphene Oxide with layer spacing of ～1 nm was prepared by the ultrasound-assisted Hummers method.Firstly,the ultrasonic vibration was applied in the low temperature and mid temperature stages to improve the intercalation efficiency and oxidation degree of Graphite.Secondly,at the beginning of the high temperature stage,the mixed liquid containing residual sulfuric acid was added dropwise into the ice water,then the mixture was heated to the set temperature to avoid the inserting molecule such as sulfuric acid emerging from graphite since the local temperature was too high.Thirdly,Graphite Oxide was obtained after the low-speed centrifugation.Graphite oxide preparation by the title method was convenient and quick.The layer spacing of graphite oxide was effectively expanded and increased with the ultrasonic power.