Self-assembly of graphene oxide nanosheets in t-butanol/water medium under gamma-ray radiation

The research on the properties of graphene oxide (GO) in various media has become one of the hottest topics since GO is now the main raw material for graphene-based advanced materials. In this work, the γ-ray radiation chemistry effect of GO nanosheets and their self-aggregation behavior in t-butanol/water medium were investigated. The results show that GO nanosheets are reduced and hydroxyalkylated simultaneously by the alcohol free radicals produced by the radiolysis of t-butanol/water solution under γ-ray radiation. The radiation-modified GO nanosheets will self-assemble into a self-standing graphene hydrogel when the pH of the solution is lower than 2. A hydroxyl-functionalized free-standing graphene aerogel is further obtained simply by freeze-drying. This work provides not only a general self-assembly mechanism of GO nanosheets in strong acidic alcohol/water media under high energy radiation, but also a facile and economical preparation method for hydroxyalkylated graphene-based aerogel.